20 Environmental Stress and Health Gary W Evans Cmtell University Although environmental conditions play a prominent role in health and psychological processes, antecedent factors in these processes have largely been neglected within health psychology Instead, the focus has been on various markers of health, with considerable attention to stress-related mechanisms, interceding between the environment and health Another focus within health psychology that has directed attention away from environmental factors has been coping resources, with the examination of either social support, personality, or coping strategies that potentially alter the impact of environmental demands on health But what characteristics of the environment itself are likely to impinge on health and psychological processes? When this question has been addressed within health psychology, environment has been operationalized primarily in social terms Family and work social climates, as well as sociocultural and economic conditions, predominate in the few environmental studies in health psychology This chapter intends to draw greater attention to the potential role of the physical environment in health and psychological processes Why might the physical environment be important to health psychology? For one reason, the physical environment clearly impacts health Adverse physical conditions can cause toxicological reactions, challenge homeostatic balance, produce physical trauma, or function as vectors bearing pathogens Physical factors can also be a source of environmental demands that pressure coping resources A second reason the physical environment is worthy of scrutiny within health psychology is because the environment can be modified and thus becomes a potential intervention target to improve health and well-being Third, environmental conditions are objective and thus can be measured more readily in reliable and valid ways For example, researchers can systematically monitor density or noise levels in precise, accurate ways that can then be examined as possible causal factors in health Fourth, physical environmental conditions tend to be stable Increasingly, research suggests that chronic environmental demands are most likely to have negative impacts on health (Lepore, 1995) Finally, the concept of psychological stress that is central to several formulations of health, behavior, and disease (see chap 17, this volume) has been utilized to broaden understanding of how physical features of the environment can influence human health and wellbeing There are at least three major ways in which the physical environment might operate as a psychological stressor, straining human adaptive capacities First, this can occur when a stressor directly loads, or pressures, the system Both crowding and noise, for example, create a surfeit of stimulation that can directly overload the system, causing discomfort, negative affect, and under some circumstances, the marshaling of adaptive resources Both negative affect and adaptive responses to challenge or threat in turn directly affect neuroendocrine and cardiovascular functioning Physical stressors can also interact with psychosocial conditions to exacerbate negative affect and/or psychophysiologic mobilization For example, noise plus high workload demands leads to more serious health outcomes than workload levels alone Noise and crowding frequently covary with other psychosocial risk factors (e.g., poverty, inadequate working conditions), and thus have the potential to contribute to multiple risk situations A second manner in which the physical environment can contribute to stress is by damaging or ameliorating coping resources themselves People rarely respond to suboptimal physical or psychosocial conditions passively; instead, they -365invoke various coping strategies to reestablish some modicum of balance between environmental demands and personal resources Evidence is presented herein, for example, that crowding interferes with the development and maintenance of socially supportive relationships in the residential environment Both chronic noise and chronic crowding appear to contribute to learned helplessness, adversely affecting self-efficacy and related motivational processes The third way in which physical conditions can operate as stressors is to elicit coping strategies that in turn lead to poor health Studies of noise, for example, reveal that increases in substance abuse occur under noisy working conditions Another aspect of research on psychological stress and health relevant to this chapter on environmental stressors are the concepts of vulnerability and resilience (Cohen, Kessler, & Gordon, 1995; Rutter, 1983) Just as certain personal or situational characteristics can render individuals more or less vulnerable to social stressors, there is evidence of vulnerable subgroups among the population who appear more adversely affected by noise and by crowding, respectively Thus throughout both direct, man effects and associations between environmental stressors and health, as well as occasions with vulnerable subgroups, are noted The field of environmental stress (Cohen, Evans, Stokols, & Krantz, 1986; Evans, 1982; Evans & Cohen, 1987) is sufficiently developed such that exhaustive coverage is impossible A small amount of environmental stress research has examined climatic conditions as potential psychological stressors influencing human stress responses (Bell & Greene, 1982; Evans, 1994) Research on housing conditions as a possible stressor have also been undertaken (Framan, 1984) The focus of this chapter is on the two most studied environmental stressors, crowding and noise Health outcomes include physical health and psychological health Moreover, the chapter examines underlying psychosocial psychophysiological processes that may help explain the linkages between noise and crowding and major physical and psychological health outcomes Psychophysiological mechanisms, immune function, social resources, coping strategies, and motivational processes are examined CROWDING The element of crowding that relates most strongly to physical and psychological health is people per room Traffic congestion may also prove to be a potent stressor Area measures of crowding, such as people per acre, generally have little or no relation to health Although some studies of crowding separate group size effects from density effects, the vast majority of studies have confounded these two factors, manipulating or measuring density as it covaries with group size Therefore, some of the effects attributed to crowding may be clue to group size rather than the amount of space per person At the same time, when attempts have been made to distinguish between these related concepts, density and group size, the impacts of density typically persist Physical Health Early interest in crowding in the public health field emanated from concerns about the spread of disease among crowded populations (Cox, Paulus, McCain, & Karlovac, 1982) There is a large literature on this topic Physical health has been operationalized in this literature as rates of illness based on archival data, visits to infirmary, physical development among children, and self-reports of somatic symptoms Archival evidence for positive associations between crowding and ill health come from studies in prisons (McCain, Cox, & Paulus, 1976; Paulus, 1988), refugee camps (Amow, Hierholzer, Higbee, & Harris, 1977), and schools (Essen, Fogelman, & Head, 1978; Koopman, 1978) The Arnow et al (1977) study is noteworthy because they demonstrated over time between Vietnamese refugee camp population fluctuations with changes in a highly contagious disease (acute conjunctivitis) There is also evidence that crowded residential conditions are linked to disease both among children (Booth & Johnson, 1975; Jacobson, Chester, & Fraser, 1977) and among adults (Levy & Herzog, 1978; McGlashen, 1977; Menton & Meyers, 1977; Sims, Downham, McQuillin, & Gardner, 1976; Wyndham, Gonin, & Reid, 1978; Yarnell, 1979) Yodfat, Fidel, Cohen, and Eliakim (1979) found that linkages among residential crowding and asthma were due to number of children rather than density per se Booth (1976) found that male adults, but not women, had greater levels of disease in crowded homes Traffic congestion levels among commuters is also associated with illness-related absenteeism from work (Novaco, Stokols, & Milanesi, 1990) Several studies of residential crowding find little or no correlates with disease (Brett & Benjamin, 1957; Collette & Webb, 1974; Mackintosh, 1934; McKinlay & Truelove, 1947; Quinn, Lowry, & Zwaag, 1978), and Winsborough (1965) uncovered an inverse relation between area density and tuberculosis Schmitt and colleagues also found no relation between residential density and disease rates, but found small, positive correlations with area density (people per acre) measures (SGhrnitt, 1966; Schmic, Zane, & Nishi, 1978) Similar trends have been uncovered by Levy and Herzog (1974) Kellett (1984) made the important point that certain diseases should be expected a priori to correlate with crowding more so than others Kellett examined morality patters for specific diseases in London for a S-year period As in prior work, persons per room rather than people per acre appeared more useful in predicting mortality Second, diseases wherein a major stress component is believed to be operative (e.g., hypertension, myogardial infarction, vascular disorders, asthma) were related to household crowding whereas many other diseases (e.g., various forms of cancer) were not Fradman and colleagues challenged many of these studies of crowding and disease, noting that poor or nonexisting controls for other variables such as socioeconomic status are common in the crowding and epidemiological literature They found in a well-controlled residential crowding was not a significant predictor of distiase (Freedman, Heshka, & Levy, 1975) However, the prison -366- studies and a few of the residential studies (e.g., Menton & Meyers, 1977) have good controls for SES Furthermore, there are trends in the data indicating that when individual levels of exposure to density and individual indices of health are compared rather than aggregated population statistics, such as used by Freedman and colleagues, stronger results occur Nonetheless, Freedman and colleagues' cautious perspective on crowding and disease is well taken Overall findings are suggestive but not rigorously or consistently supportive of a crowding-disease link It would be useful to include, in the same individual-based study, disease rates for disorders that ought to vary with stress exposure plus inclusion of immunological measures A handful of studies in institutional contexts have examined crowding and infirmary visits These studies converge on positive associations between levels of crowding and infirmary visits among shipboard military personnel (Dean, Pugh, & Gunderson, 1975, 1978), college campus residents (Baron, Mandel, Adams, & Griffen, 1976; Stokols, Ohlig, & Resnik, 1978), and prisoners (Paulus, 1988) The prison effects were most noticeable among inmates forced to live under dormitory- like conditions rather than in single cells Trends also indicated that the associations in prisons were somewhat stronger for men than women and for African American in comparison to Anglo prisoners (Paulus, 1988) Wener and Keys (1988) found that increases in density (doubling up cell mates) markedly elevated (nearly 50%) sick call rates among prison inmates A few studies have examined physical development among crowded children, uncovering evidence of negative associations between household density and physical stature (Booth, 1976; Essen et al., 1978; Goduka, Poole, & Aotaki- Phenice, 1992) Crowded children, particularly boys, are shorter Shapiro (1974) also found that boys, but not girls, motoric development appeared to be inhibited in crowded homes Moreover, this effect was amplified among children of less educated mothers More recently, Widmayer and colleagues (1990) found delayed psychomotor development among infants as a function of household density, controlling for socioeconomic status (SES) Self-reported levels of physical illness are positively associated with crowding in prisons (Cox, Paulus, & McCain, 1984; McCain et al., 1976), among college dormitory women but not men (Karlin, Epstein, & Aiello, 1978), and among crowded home settings (Gove & Hughes, 1983)-although Booth (1976) found this association among men, but not women, in crowded homes Giel and Ormel (1977) and Baldassare (1979) failed to replicate the association between home crowding levels and self-reported illness The validity of all the self-report data on illness and crowding is suspect given retrospective self-report indices On the other hand, Cox et al (1984) found a dose-response function between number of inmates per cell and selfreported illness levels among male prisoners Of additional interest, Gove and Hughes (1983) provided some evidence that heightened illness levels associated with crowded residences are related to lack of sleep and lower resistance when exposed to other sick family members (all self-reported) There is evidence that some of the association between crowded living conditions and self-reported health symptoms is mediated by loss of perceived control over the living environment Ruback and associates found that both female and male prisoners' reports of ill health in association with crowding were also negatively related to perceived control (Ruback & Carr, 1984; Ruback, Carr, & Hopper, 1986) Another way in which environmental stressors like crowding can impinge on health is through injuries Rhesus monkeys when crowded, for example, show a 5-fold increase in incidents of injuries (Boyce, O'Neill-Wagner, Price, Haines, & Suomi, 1998) Psychophpysiologieal Several studies have examined the relation between crowding and blood pressure in people Laboratory studies with random assignment to density levels have found small but significant elevations among crowded versus uncrowded participants (Epstein, Lehrer, Csz Woolfolk, 1978; Evans, 1979) Field studies of prisoners (D'Atri, 1975; Paulus, McCain, & Cox, 1978) and automobile commuters (Novaco, D Stokols, Campbell, & J Stokols, 1979; Schaeffer, Street, Singer, & Baum, 1988; Stokols et al., 1978) have also revealed correlational evidence for elevated blood pressure under more crowded or congested living or commuting conditions The commuting studies have found that the effects are stronger for car poolers rather than solo drivers, for Type B rather than Type A drivers, among external versus internal locus of control drivers, and among drivers with less residential choice One field study found no relations between chronic residential crowding and blood pressure or neuroendocrine indices among adults (Booth, 1976), although small, statistically significant elevations in serum cholesterol were noted among crowded men No such correlation was noted among women Booth's sample did not vary much in density, which may have weakened his findings Evans, Lepore, Shej wal, and Palsane (1998) found elevated blood pressure among crowded boys, but not girls, among working- class families in India Another cardiovascular function, blood pressure reactivity, has been related to chronic crowding in adults Residents of more crowded neighborhoods had higher reactivity (increase from baseline in blood pressure levels) and took longer to return to resting baseline levels (Fleming, Baum, Davidson, Rectanus, & McArdle, 1987) Both heightened reactivity and protracted recovery to baseline are potentially important precursors to the development of coronary heart disease Neuroendocrine markers of stress, typically urinary catecholamines and cortisol, have been noted in several studies of crowded commuters (Lundberg, 1976; Singer, Lundberg & Frankenhaeuser, 1978) and among bus drivers operating under more congested driving conditions (Evans & Carrere, 1991) Pedestrian exposure to more crowded urban areas elevates neuroendocrine activity, at least for males (Heshka & Pylypuk, 1975), and residence in neighborhoods perceived as more crowded because of commercial establishments and more people on the street is associated with increased urinary catecholamine levels (Fleming, Baum, & Weiss, 1987) Dormitory -367crowding, however, had no apparent effects on neuroendocrine activity among college students (Karlin et al., 1978) A small sample size may have rendered low power These authors did find, however, that uncrowded residents' neuroendocrine indices dropped over the course of the semester, whereas crowded residents' neuroendocrine levels increased over the same time period Schaeffer, Baum, Paulus, and Gaes (1988) found that prisoners housed in more open, unpartitioned dormitories felt more crowded and experienced elevated chronic catecholamine levels in comparison to prisoners living in smaller groups The critical role of control has been implicated in some of these psychophysiological crowding studies Lundberg (1976) and his colleagues found that passengers with greater choice over seating were less negatively impacted by congested commuting Evans and Carrere (1991) found that the neuroendocrine effects of traffic congestion on bus drivers were largely mediated by perceived control on the job On the other hand, perceived control did not mediate the positive relation between prison crowding and neuroendocrine elevations (Schaeffer, Baum, Paulus, A few laboratory studies have also utilized skin conductance as an index of psychophysiologic stress, generally finding elevations among more crowded participants (Aiello, Epstein, & Kalin, 1975; Aiello, Nicosia, & Thompson, 1979; Bergman, 1971; Nicosia, Hyman, Karlin, Epstein, & Aiello, 1979) Studies of crowding and skin conductance are evenly split on gender differences, with some studies finding more pronounced effects among males than females and other studies finding no sex differences There is also evidence that skin conductance may be more strongly affected by crowding when physical touching occurs McCallum, Walden, and Schopler (1979) found that acute crowding elevated palmar sweat but only when experimental subjects were motivated to maintain high levels of group performance When performance was permitted to deteriorate under crowding, no physiological elevations were noted Finally, in a field study, Cox, Paulus, McCain, and Schkade (1979) found a significant positive correlation between the palmar sweat index and crowding among prison inmates Although indirect, some findings by Hutt and Vaizey (1966) may shed some light on psychophysiological mechanisms associated with crowding and psychophysiologic responses Chronically overaroused children responded to high density laboratory conditions by extreme social and physical withdrawal; whereas chronically underaroused children and children without arousal disturbance reacted in the opposite direction, becoming more engaged and aggressive with other children Many animal studies have examined endocrine activity among crowded species both under laboratory and field conditions (see Evans, 1978, for a review) Generally, this research indicates support for a population regulation feedback mechanism whereby crowded animals' fertility declines This occurs more markedly among subordinate rather than dominant animals and appears to be mediated by adrenal cortical activity Attempts to link crowding with population regulation among human beings have proven futile Immune Function Animal but not human work has examined immunological processes as a function of crowding, generally finding evidence of compromised immune functioning among more crowded animals (Christian, 1963; E A Edwards & Dean, 1977; Thiessen & Rodgers, 1961) These effects appear to be stronger among subordinate rather than dominant animals and among animals without a history of crowded living conditions (Cassel, 1971) Cassel(1974) pointed out, however, that compromised immune function alone cannot account for changes in morbidity among crowded animals because both infectious and noninfectious diseases are elevated among crowded animals Psychological Health Ever since 1962 when Calhoun published his famous Scientific American study of pathology among overpopulated rats, researchers and policymakers alike have wondered about the potential role of crowded living conditions on mental health The chapter first reviews research on linkages between density and psychological distress and then turns its attention to recent work examining possible underlying mechanisms for this linkage Many studies have uncovered positive relations between residential density and self-reported psychological distress (Edwards, Fuller, Sermsri, & Vorakitphokatorn, 1990; Evans, Palsane, Lepore, & Martin, 1989; Gabe & Williams, 1987; Gove & Hughes, 1983; Hassen, 1977; Jain, 1987; Lakey, 1989; Marsella, Escudero, & Gordon, 1970) Mitchell (1971) found greater worrying among crowded families but only if they were also poor Crowding in Mitchell's study was unrelated, however, to more serious indices of psychiatric illness Lepore, Evans, and Schneider (1991) found evidence that residential crowding causes psychological distress in a prospective, longitudinal study of crowding and mental health Controlling for educational levels and income, they found that crowded residents did not differ from uncrowded residents in psychological distress symptoms during initial occupancy (I- = 12), but after months and months the associations became significant (r = 21; r = 27) This is the only prospective study of crowding and health Webb and Collette (1975) found an association between residential density and use of prescription hypnotics Booth (1976), Baldassare (1979), and Giel and Ormel (1977) failed to find a positive association between residential crowding and psychological distress These studies had little variance in density Moreover, Baldassare relied on mental health indices of questionable sensitivity (one dichotomous item in one case, and three dichotomous items in a second case) Two studies of neighborhood crowding levels have also found linkages to psychological distress (Collette & Webb, 1974; Fleming, Baum, $I Weiss, 1987) Studies utilizing archival indices such as psychiatric admissions or suicide rates generally find very weak or insignificant associations between crowding and pathology when measured in the aggregate (Freedman et al., 1975; Gove & -368Hughes, 1980; Schmitt, 1966; Schmitt et al., 1978) In some studies negative associations between density and psychiatric admissions have been uncovered, probably created by the association of living alone and mental disorder (Galle, Gove, & McPherson, 1972; Levy & Herzog, 1974/1978) One exception to these generally negative trends in archival indices of mental health and crowding is notable Several prison studies have found clear, strong associations between the total population size of prison populations and indices of psychiatric illness (Paulus, 1988) Quite a number of studies have examined psychological symptoms among children living in crowded homes Plant (1937) described several case studies noting a pattern of low self-sufficiency and little idealism among children from crowded homes He attributed these patterns to mental strain associated from always having to get along with others and to exposure to adults under close quarters that made it difficult to look up to or idealize grownups Crowded children have increased levels of various symptoms of psychological distress (Booth, 1976; Gasparini, 1973; Murray, 1974; Saegert, 1982; Wachs, 1987) Parents in more crowded homes report relief when their children are outside (Gove & Hughes, 1983), have more difficulty supervising their children (Mitchell, 197 l), and are generally less responsive and involved with their children (Bradley & Caldwell, 1984; Evans, Maxwell, & Hart, 1999; Wachs & Camli, 1991) in comparison to uncrowded parents of comparable social class These trends appear to be exacerbated in the presence of other risk factors, particularly poverty (Baldassare, 1981; Bradley et al., 1994) Psychosocial Resources Some of the relation between high residential density and psychological distress in children may be linked to family interactions, which have been found to be more contentious under crowded living conditions (Booth, 1976; Gasparini, 1973; Saegert, 1982) There may also be greater incidence of physical punishment and open expression of anger between parents and children in crowded homes (Booth & Edwards, 1976; Light, 1973), although Gove and Hughes' (1983) study did not support this finding Another factor that may help explain the link between high residential crowding and symptoms of psychological distress in children is withdrawal Aiello, Thompson, and Baum (1985) reviewed several field and laboratory studies documenting increased social withdrawal under crowded conditions among young children Similar trends exist in the adult literature, indicating that crowded adults interact with housemates less (Baum & Valins, 1977, 1979; Proshansky, Ittelson, & Rivlin, 1970); are less friendly with their neighbors (McCarthy & Saegert, 1978), and have impaired social support with those they live with (Evans et al., 1989; Lakey, 1989; Lepore et al., 1991) Baldassare (1979) did not replicate linkages between residential crowding and neighboring People under crowded conditions also tend to be less affiliative in their behaviors toward others (R L Munroe & R H Munroe, 1972) and view others in more negative or suspicious terms (Bickman et al., 1973; Griffit & Veitch, 1971; McCarthy & Saegert, 1978) There is also evidence that crowded working conditions lead to greater social withdrawal from coworkers (Oldham & Fried, 1987) Finally, as already noted, parents in crowded homes are less responsive to their children (Bradley & Caldwell, 1984; Wachs Bt Camli, 1991) Furthermore, this relative unresponsiveness partially accounts for less complex parent to child verbalizations to infants and toddlers (Evans, et al., 1999) Evidence that social withdrawal and impaired social relationships are a primary mechanism accounting for the relation between crowding and psychological distress has been documented in some detail by two research programs Baum and colleagues found that more crowded dorm residents report more unwanted social interaction in their dorms These same crowded residents also evidence greater behavioral indices of withdrawal outside of the dorm They sit farther away from other research participants and withdraw more in group interaction games (Baum & Valins, 1977, 1979) Residential exposure to high levels of street traffic is also associated with less neighboring (Appleyard & Lintell, 1972; Halpern, 1995) Evans and Lepore showed direct evidence for a similar pattern They found both crosssectionally (Evans et al., 1989) and in a prospective, longitudinal design (Lepore et al., 1991) that the negative effects of residential crowding on psychological distress (with controls for social class) are mediated by social support Similar patterns also appear to occur among children in crowded residences (Evans, et al., 1998) Evans and Lepore (1993a) also found that crowded relative to uncrowded residents were less likely to offer support to a confederate under stress in an uncrowded laboratory setting Of additional interest, crowded residents in comparison to uncrowded residents were also less responsive to offers of social support during a stressful situation (see Fig 20.1 ) Ignored meant that the subject did not look at or made no verbal acknowledgment of the confederate; acknowledgment meant some brief comment or a head nod was given in response to offers of support; and accepted meant the subject was very responsive FIG 20.1 -369to the confederate's offers of support, elaborating or embellishing on their offers of support Motivation Many theorists have postulated that a prime reason why crowding can have negative impacts on psychological health is because of reduced behavioral options and greater difficulty in regulating social interaction (Altman, 1975; Baron 8z Rodin, 1978; Schmidt & Keating, 1979) An important psychological consequence of prolonged exposure to an aversive, uncontrollable stressor, such as crowding, may be learned helplessness Persons chronically exposed to crowding report feeling a greater sense of powerlessness over their living environments than their less crowded counterparts (Baum & Valins, 1977, 1979; Baron et al., 1976; Carr, Hopper & Ruback, 1986; Saegert, 1978) Sherrod (1976), Aiello, DeRisi, Epstein, and Karlin (1977), Evans (1979), Nicosia et al (1979), and Doofey (1978) all found negative aftereffects immediately following laboratory exposure to crowded conditions Sherrod, Evans, and Nicosia and colleagues each utilized the Glass and Singer (1972) aftereffects paradigm that measures persistence on challenging puzzles Giving up sooner in the face of challenge in an achievement context may be indicative of greater helplessness (Cohen, 1980; Glass & Singer, 1972) Dooley (1978) incorporated proofreading performance as her aftereffects measure Saegert, Mackintosh, and West (1975) reported that crowded train stations produced negative aftereffects in women only Nicosia's data also indicated more severe aftereffects of crowding among women Parallel trends to the laboratory work have been noted in studies of more chronic, crowded living conditions, finding less persistence on difficult puzzles among persons living in more crowde.d neighborhoods (Fleming, Baum, & Weiss, 1987) Moreover, perception of control over social interactions largely accounted for the main effect of neighborhood crowding on the helplessness indicator Residents of crowded dorms feel less control over social interaction than their uncrowded counterparts (Baum & Valins, 1977, 1979) exhibit behavioral strategies in a group' prisoners' dilemma game consistent with helplessness (Baum, Aiello, & Calesnick, 1978; Baum, Gatchel, Aiello, & Thompson, 1981) Interestingly, the development of helplessness strategies in the game over the course of the initial semester under crowded conditions was mirrored by residents growing external attributions for problems in the dormitory over this same time period (Baum et al., 1981) Uncrowded residents generally felt self-efficacy over problems in their dormitory over the course of the semester and these internal attributions remained stable over time Crowded dormitory residents are also less likely to seek clarification when given ambiguous instructions about an impending laboratory procedure than were uncrowded dormitory residents Traffic congestion also is related to motivational deficits Greater traffic congestion levels have been related to decreased task motivation on challenging puzzles and proofreading (Novaco et al., 1979; Schaeffer et al., 1988; D Stokols, et al., 1978) The most direct evidence for helplessness induced by crowding comes from a pair of studies on residential crowding and children by Rodin (1976) Matched on socioeconomic indicators, elementary-aged schoolchildren living in more crowded public housing were less likely to control the administration of outcomes in an operant conditioning paradigm in comparison to their less crowded counterparts In a second study, helplessness was induced in adolescents by a classic helplessness paradigm, pretreatment with an insoluble versus a soluble puzzle Helplessness was monitored on a second challenging but solvable puzzle The main effect of pretreatment solvability (the helplessness induction) was significantly moderated by residential crowding with heightened vulnerability to the induction of helplessness among the more crowded children In their study of children in India, Evans, et al., (1998) replicated Rodin's effects (but for girls only) Saegert (1982), however, did not replicate these findings examining a sample of children from public housing projects in New York City Summary Residential crowding has little impact on physical morbidity among the general population Residential crowding may be linked, however, to ill health among vulnerable subgroups of the populations, particularly young children and extremely crowded, captive populations (e.g., prisons, refugee camps) Evidence linking high density exposure either under controlled conditions or in the field to elevated cardiovascular functioning is quite strong Neuroendocrine functioning also appears elevated, although less data are available The potential clinical implications of these two data patterns has not been explored in the crowding literature Psychological distress is increased by residential crowding Individual but not aggregate level analyses continue to uncover a positive association between crowded living conditions and poorer psychological health Several studies have excellent controls for sociodemographic factors and one is a prospective, longitudinal analysis Psychological distress associated with residential crowding may be caused by a typical coping strategy for dealing with chronic high density living conditions-social of this social withdrawal may be a breakdown in socially supportive relationships There is not strong evidence, however, that human crowding is associated with more extreme forms of psychopathology characterized in some animal studies as a behavioral sink There is also evidence that crowding may lead to the development of motivational deficits, particularly among children in achievement-related contexts There is indirect evidence suggesting that these motivational deficits are related to learned helplessness from diminished perceived control over the environment NOISE Noise, which is defined as unwanted sound, is typically measured in decibels Decibels is a logarithmic scale with a -370change in 10 decibels perceived as approximately twice as loud There is considerably more research on noise and health in comparison to research on crowding and health The bulk of the noise and health research has occurred in industrial settings More recently, studies of noise and health have also focused on people living in airport impact zones or near to road traffic noise Prolonged exposure to high levels of noise is clearly linked to hearing damage (Kryter, 1994) Because the thrust of this chapter is on environmental stress, the noise- related hearing damage literature is not discussed Physical Health Studies have examined exposure to either occupational noise or community noise and disease Outside of cardiovascular problems, there appears to be little relation between noise exposure and physical disease In industrial settings, noise has been associated with increased risk for myocardial infarction (Ising, Babisch, & Giinther, 1999), reductions in cardiorespiratory efficiency (Semczuk & Gorny, 197 l), difficulties in peripheral circulation and cardiac problems generally (Jansen, 1961), electrocardiogram abnormalities suggestive of coronary heart disease (Cuesdan general sickness- related absenteeism (Cohen, 1973), and self-reported fatigue (Carlestam, Karlsson & Levi, 1973; Melamed & Bruhis, 1996) Several industrial studies have found no associations between occupational noise exposure and rates of coronary heart disease (Lees, Romeril, & Wetherall, 1980) or rates of total illness (Lees et al., 1980) Community airport noise studies have shown that higher levels of noise exposure are associated with greater contact with physicians for coronaryrelated problems (Knipschild, 1977a) and, for women only, use of drugs to treat hypertension (Knipschild & Oudshoorn, 1977; Koszarny, Maziarka, & Szata, 1981) These studies also show an association with greater physician contact in general (Knipschild, 1977b), rates of colds (Ising et al., 1990), as well as total health symptoms (Pulles & Stewart, 1990), and higher levels of coronary heart disease symptoms among women but not men (Koszarny et al., 1981) Graeven (1974) and Hiramatsu, Tamamoto, Taira, Ito, and Nakasone (1993), however, found no differences in self-reported health symptoms between persons living in airport impact zones versus citizens in quiet neighborhoods Turning to road traffic noise, Cameron, Robertson, and Zaks (1972) found little relation between community noise levels (self-reported) and illness rates Babisch, Elwood, Ising, and Kruppa (1993) found slight elevated risk (1.2 odds ratio) in noisier traffic areas in three different sites for men residing in areas above 65 dBA Leq However, when comparing across different noise levels varying from > 50 dBA Leq to 70, they uncovered no linear relation Another area of physical health worthy of note in the noise literature is birth defects and other abnormalities during pregnancy Not surprisingly, findings in this area are highly controversial and not at all definitive Jones and Tauscher (1978) found higher rates of birth defects in high airport noise impact zones relative to quieter areas, but Edmonds, Layde, and Erickson (1979) could not replicate the findings Several rodent studies have found abnormal fetal development following noise exposure (Welch, 1973) There is evidence that women working under very noisy conditions, particularly if subjected to additional stressors like shiftwork, have more pregnancy complications such as vaginal bleeding and pregnancy- induced hypertension (Nurminen & Kurppa, 1989) Babies born in areas with high noise impact have lower birth weights (Ando & Hattori, 1977; Knipschild et al (1981) with controls for socioeconomic status Ando (1987) also found an increase in low birth weight babies following the opening of a new airport Schell (1981) also noted that female infants, but not males, had significantly shorter gestation periods in high airport noise impact zones Moreover, Ando and Hattori (1977) showed diminished levels of human placental lactogen levels in mothers living in high noise airport impact zones Finally, Schell and Ando (1991) found a dose- response function relating airport noise levels and 3-year-olds' physical stature (but not weight) in a large epidemiological study The data on possible linkages between noise and early development are sobering to consider in light of environmental surveys of neonatal, intensive care units that are often populated by premature babies Levels of noise match or exceed recommended standards for ambient traffic exposure and health (Lawson, Daum, & Turkewitz, 1977) Psychophysiogical Although previous reviews of noise indicate that cardiovascular responses (typically blood pressure or pulse) to noise under acute exposures rapidly habituate (Glass & Singer, 1972; Kryter, 1994), more careful scrutiny of this literature indicates important exceptions Persons who are noise sensitive not easily habituate (Conrad, 1973; Stansfeld & Shine, 1993), nor individuals who are hypertensive (von Eiff, Friedrich, & Neus, 1982) Shortterm habituation is blocked when people perform demanding cognitive tasks under noise (Carter & Beh, 1989; Conrad, 1973; Mosskov & Ettema, 1977) Evans et al (1996) also showed that noise significantly increases blood pressure over a 20-minute period without habituation, if it follows exposure to a psychological stressor (i.e., giving a speech, taking a final examination) Other psychophysiological indices examined under acute noise have included electrodermal activity, ECG, EEG, and neuroendocrine activity Results parallel the cardiovascular data, indicating rapid habituation (Finkle & Poppen, 1948; Fruhstorfer & Hensel, 1980) Recent findings suggest, however, that when short-term exposure to loud noise is accompanied by demanding tasks, habituation may be blocked (Frankenhaeuser & Lundberg, 1977; Ising, Rebentisch, Poustka, & Curio, 1990; Lundberg & Frankenhaeuser, 1978) Work by Tafalla and Evans (1997) indicated a central role of effort in the performance/physiological activation tradeoff Performance can be maintained, at least under many circumstances (e.g., short-term tasks that not demand large amounts of attention or memory), by additional cognitive effort Such maintenance of performance, however, appears to exact a cost of greater psychophysiological -371activation It is noteworthy that McCallum et al (1979) found a very similar pattern for performance under crowded laboratory conditions There is also evidence indicating that habituation is interfered with by calling attention to the potential negative impacts of noise on the person (Vera, Vila, & Godoy, 1992) This latter finding might explain why noise sensitive persons apparently not readily habituate to repeated exposures of acute noise in the laboratory Perhaps they are more threatened or concerned about potential harmful effects of the noise Field research on noise and psychophysiologic outcomes has occurred primarily in industrial settings The occupational noise and psychophysiologic literature is too large to review exhaustively herein Several reviews of this literature (Kryter, 1994; Thompson, 1981, 1993; Welch; 1979) have characterized the findings similarly Unfortunately, nonexperimental designs have frequently been employed in the occupational noise and health literature with poor or nonexisting controls, and many studies have relied on poor estimates of noise exposure Furthermore, blood pressure is often poorly measured Many of the industrial studies have relied on one or two measures of blood pressure taken during a physical at work by medical personnel Moreover, annual medical examinations or other medical screenings may seriously bias estimates since some workers become excluded Thompson concluded from her two reviews that workers with adequate hearing protection are unlikely to show much effect of noise on the cardiovascular system Kryter (1994) reflected greater concern but also remained skeptical, noting the paucity of well-designed research studies; Welch (1979) sounded a considerably greater sense of alarm about cardiovascular health risks from chronic, occupational exposure to noise Interestingly, Welch's review is based primarily on Eastern European literature that includes worksites with generally very high levels of occupational noise exposure, often coupled with a paucity of hearing protection programs The bulk of the literature in the other major reviews is based on North American and Western European studies where occupational noise levels tend to be lower and hearing protection programs more common Difficulties in exposure estimation in industrial studies of noise and cardiovascular functioning are illustrated by one of the most thorough investigations (Talbott et al., 1985) Although these investigators found no significant differences in blood pressure readings that were carefully administered to men from noisy and from quiet manufacturing plants, they also uncovered a clear, consistent positive link between elevated diastolic blood pressure and severe hearing loss in the noisy plant Moreover, looking at the subset of men who had worked for at least 15 years in the two respective manufacturing plants, occupational noise exposure did significantly relate to both systolic and diastolic blood pressure (Talbott et al., 1990) See Lercher (1996) for an in-depth discussion of noise exposure estimation and health outcomes It is also conceivable that subsets of workers may be particularly vulnerable to the chronic effects of noise exposure on their cardiovascular systems For example, Tarter and Robins (1990) found that male, African American automobile plant workers suffered increased blood pressure, whereas their Anglo counterparts, who were exposed to comparable levels of high noise at work, did not show this relation Tarter and Robins speculated that perhaps racial differences in propensity for hypertension might explain these findings Given the fact that individual differences in noise sensitivity interfere with habituation to acute noise exposure as reviewed earlier, it might be hypothesized that noise sensitivity creates vulnerable subgroups within occupationally noise-exposed groups This idea has not been tested, although mixed support of such a pattern has been uncovered in community studies of aircraft noise (Neus, Ruddel, & Schulte, 1983; Stansfeld, 1993) A few longitudinal studies of noise and cardiovascular functioning in industrial settings have been conducted By comparing the same worker in quiet and noisy periods, some of the weaknesses most endemic to crosssectional studies (e.g., selection bias) are reduced The U.S Raytheon (1975) study, for example, found a significant reduction in medical problems after the implementation of a hearing conservation program in the plant No changes in similar health indices occurred over the same time period among workers in quiet plant areas Moreover, the greater the level of compliance observed (e.g., wearing hearing protection), the greater the apparent health benefit Hypertension and cardiovascular disease were included in the overall health records monitored but could not be singled out because of insufficient sample size Antonova (1971) compared miners before and after their workshifts in either noisy or quiet areas of the mine Noise significantly elevated mean arterial pressure with no changes in the quiet group pre and post work Systolic blood pressure was significantly elevated among brewery workers when they did not wear ear plugs in comparison to days in which they did (Ising & Melchert, 1980) Cortisol fluctuations were also shown to be dependent on the use of earplugs in a similar design (Melamed & Bruhis, 1996) Another more rigorous approach to studying industrial noise exposure and psychophysiological responses is to simulate occupational noise exposure under experimental conditions with random assigment to noise conditions Three-hour exposure to jet turbines significantly elevated blood pressure over resting levels among workers in a jet assembly plant (Ortiz, Arguelles, Crespin, Sposari, & Villafane, 1974) Mosskov and Ettema (1977) and Rovekamp (1983) found elevations in blood pressure in 2- to 3-hour noise exposures but at much lower intensities of noise than employed by Ortiz and colleagues Cartwright and Thompson (1975) found no effects, however, of a l-hour exposure to loud noise, but Carter and Beh (1989) were able to significantly elevate cardiovascular parameters from hour of exposure, as long as participants simultaneously worked at a difficult task This latter finding, along with other experimental findings reviewed earlier on the multiplicative effects of noise and task demands on cardiovascular and neuroendocrine functioning, is interesting to consider in light of a small number of occupational noise studies that have also incorporated additional measures of working conditions A Russian industrial study reviewed by Welch (1979) found elevated cardiovascular functioning in a noisy manufacturing plant among workers -372with higher levels of workload demands Workers with low workloads did not reveal any cardiovascular correlates of occupational noise exposure Parallel results were recently uncovered in a longitudinal study (Melamed, BonehKristal, & Froom, 1999) Cottington, Matthews, Talbott, and Kuller (1983) also reported a significant interaction of job stress and noise on diastolic blood pressure Job stress was associated with higher blood pressure in a noisy manufacturing plant but not a quiet one with good controls for SES and cardiovascular risk Similarly, Lercher, Hortnagl, and Kofler (1993) found that annoyance with noise at work had a small positive association with diastolic blood pressure This relation was significantly amplified, however, among workers who also reported job dissatisfaction and low levels of social support on the job Occupational exposure to noise levels may also interact with shift work Ottmann, Rutenfranz, Neidhart, and Boucsein (1987) and Cesana et al (1982) both found elevated catecholamine levels related to noise levels at work but only among workers on rotating shifts Nonshift workers in noisy work areas did not reveal these associations Lercher et al (1993) also found higher levels of blood pressure among workers annoyed by noise who also engaged in shiftwork relative to nonshiftwork employees There has been a small number of industrial studies or simulation studies with prolonged noise exposure that have examined neuroendocrine and other biochemical markers of stress rather than cardiovascular functioning Mixed results have been uncovered with no relation between noise exposure and cholesterol (Brown, Thompson, & Folk, 1975), cortisol (Brandenberger, Follenius, & Tremolieres, 1977; Cavatorta et al., 1987; Slob, Wink, & Radder, 1973), and with one or more catecholamines (Carlestam et al., 1973; J Osguthorpe, Mills, & N Osguthorpe, 1983; Paulocci, 1975; Slob et al., 1973) Other studies have uncovered significant, although typically small, associations between noise levels on the job or from simulated exposures and various psychophysiologic indicators, such as reduced urine volume and 17-ketosteroid levels (Gibbons, Lewis, & Lord, 1975), elevated fatty acids (Ortiz et al., 1974; Proniewska et al., 1972), higher levels of cholesterol (Cantrell, 1974; Ortiz et al., 1974; Rai, Singh, Upadkyay, Patil, & Nayer, 198 l), increased epinephrine levels (Cavatorta et al., 1987; Ortiz et al., 1974; Slobet al., 1973), elevated cortisol (Cantrell, 1974; J Osguthorpe et al., 1983; Rai et al., 1981), and increased levels of ACTH and oxytocin (Fruhstorfer & Hensel, 1980) Although there are more published positive findings, it is important to keep in mind that most of these noise and biochemical studies find small changes, and null results are more difficult to get published On the other hand, there is also a large animal literature generally consistent with significant biochemical outcomes from acute noise exposure under controlled conditions (B Welch & A Welch, 1970) Increasingly, researchers have turned their attention to community studies of noise and psychophysiologic parameters, particularly blood pressure Traffic noise levels appear to have no relation to blood pressure in community samples (Elwood, Ising, & Babisch, 1993; Lercher & Kofler, 1993; Knipschild & Salle, 1979) or show a small positive associa tion (von Eiff, Friedrich, & Neus, 1982; Neus, Ruddel, Schulte, & von Eiff, 1983, Wu, Chiang, Huang, & Chang, 1993) Regecova and Kellcrova (1995) found that traffic noise both at home and at school was associated with elevated blood pressure among 3- to 7-year-olds were multiplicative effects as well of school and home noise The Neus study is noteworthy because it is longitudinal The Wu study bears mention as well since they found that traffic noise elevated young children's blood pressure as a function of hearing status Congenitally deaf children were unaffected by road noise, whereas their able-hearing counterparts suffered small elevations Herbold, Hense, and Keil (1974) noted a small positive relation between traffic noise levels and hypertension prevalence among adults and Babisch, Fromme, Beyer, and Ising (1996) found elevated overnight neuroendocrine stress hormones Simulated exposure to traffic noise under controlled conditions elevates both cardiovascular and neuroendocrine activity as a function of sound intensity (Ising, Dienel, & Markert, 1980; Osada, Ogawa, Hirokawa, & Haruta, 1973) Ising's study is particularly interesting because, as in several of the acute noise exposure studies noted earlier, he found that exposure to simulated traffic noise while working had significant effects on both cardiovascular and neuroendocrine levels, especially when mental loads were higher In one of the more rigorous tests of ambient noise exposure and cardiovascular health, Peterson, J S Augenstein, Tanis, and D G Augenstein (1981) were able to produce sustained, elevated arterial blood pressure in monkeys exposed for long periods of time to simulated recordings of aircraft and traffic noise played at typical ambient levels (Leq = 78) Their work also showed that these monkeys sustained no hearing damage Studies of airport noise, which is typically louder and less predictable than road traffic noise, generally find stronger associations between noise exposure and elevated cardiovascular functioning in comparison to the road traffic noise studies Most studies have focused on children rather than adults, which might also explain the generally more consistent, positive results than those uncovered in the road traffic noise literature Knipschild (1977a) found a dose-response relation between community airport noise exposure and hypertension among adult residents in Amsterdam Two studies of simulated, military aircraft flights at low altitude have shown significant increases in blood pressure among elderly residents (Michalak, Ising & Rebentisch, 1990) and in catecholamines among middleaged adults (Maschke, Breinl, Grimm, & Ising, 1992) Several studies have found significant relations between exposure to aircraft noise and elevated blood pressure in children (Cohen, Evans, Krantz, & Stokols, 1980; Cohen et al., 1986; Evans, Hygge & Bullinger, 1995; Ising et al., 1990; Karagodina, Soldatkina, Vinokur, & Klimukhin, 1969; Karsdorf & Klappach, 1968; Schmeck & Poustka, 1993) Several of these studies have very thorough statistical controls for socioeconomic status One study has found no relation between airport noise levels and blood pressure (Cohen, Evans, Krantz, Stokols, & Kelly, 1981), but these data were explained by selective attrition (persons in noisy areas with -373the highest levels of blood pressure left the area) Troche, Chumlea, ambient noise exposure in suburban communities with no nearby airports or major highways This study is flawed because of unreliable blood pressure measurement procedures and use of self-reports for noise exposure estimation Evans and colleagues (1995) also investigated reactivity to a noise source, as well as chronic neuroendocrine activity levels as a function of community airport noise exposure As shown in Table 20.1, they found evidence of elevated catecholamine activity, but no shifts in cortisol among elementary schoolchildren living in the flight path of a major international airport Of further interest, children chronically exposed to noise appeared less reactive to an acute noise source while reading Ising and his colleagues found parallel trends for epinephrine, but not norepinephrine, and also found elevated cortisol in two sets of studies with adults that simulated exposure to night-time aircraft operations (Maschke, Ising, & Arndt, 1995) Of additional interest, in one study they generated a dose-response function between elevated overnight hormonal levels and sound intensity levels Finally, Evans, Bullinger, and Hygge (1998) replicated their cross-sectional aircraft noise and young children's health findings in a prospective, longitudinal study of children living in the vicinity of the new, Munich international airport Immune Function A large number of animal studies have utilized noise as a stressor to investigate altered immune function The results, like those of the few human studies are quite mixed (Bly, Goodard, & McLean, 1993) Sieber et al (1992), for example, found that uncontrollable but not controllable noise significantly decreased natural killer cells among healthy male subjects; Weisse et al (1990) found the opposite pattern with controllable noise causing lymphocyte resistance to mitogens to drop Coping Behaviors An alternative pathway by which noise and other environmental stressors may impact physical health is the exacerbation of substance abuse Cigarette smoking and alcohol consumption both increase under stress (Cohen et al., 1986) In the presence of loud noise, nicotine ingestion reduces muscle tension (Hutchinson & Emley, 1973) and accelerates habituation (Friedman, Horvath, & Meares, 1974) In a particularly interesting study, Cherek (1985) demonstrated a dose-response function between cigarette smoking (objective, experimental measures) and controlled exposures to varying noise levels (60–90 dBA) Psychological Health Several different types of studies have examined chronic noise exposure and mental health The first set of studies explored possible relations between psychiatric admissions and aircraft noise exposure with decidedly mixed results Several studies have found positive correlations between admission rates and high noise exposure (Abey-Wickrama, A'Brook, Gattioni, & Herridge, 1969; Herridge & Chin, 1972; Jenkins, Tarnopolsky, & Hand, 1981; Meecham & Smith, 1977) Nonsignificant relations have been found by Gattoni and Tarnopolsky (1973), and Jenkins, Tarnopolsky, Hand, and Barker (1979) found an inverse relation between noise levels and psychiatric admissions in the same region (Heathrow, to the West of London) utilized by Abey-Wickrama and by Jenkins et al (1981) Kryter (1990), in a further analysis of some of Jenkins' data, discovered large ethnic differences that might have explained Jenkins' puzzling findings Many of these studies have poor controls for social class and all are cross-sectional Self-reports of psychological distress were unrelated to road traffic noise levels in two cross-sectional studies (Tarnopolsky & Morton-Williams, 1980; Tarnopolsky, Watkins, & Hand, 1980) and in a prospective, longitudinal study (Stansfeld, 1993) The absence of support for a link between road traffic noise exposure and psychological health could be due, in part, to noise measurement Halpem (1995) found that peak noise levels predicted several indices of psychological health, controlling for socioeconomic status of residents Mean levels of traffic noise had no mental health correlates Physician treatment for psychological problems, as well as use of hypnotic drugs, was associated with aircraft noise around Amsterdam (Knipschild, 1977b) Koszarny et al (1981) demonstrated a similar relation, but only among women Knipschild and Oudshoorn (1977) also found a clear relation among prescription rates for tranquilizers and aircraft noise over a 7-year period Moreover, these authors found longitudinal trends in use of hypnotic pharmaceuticals that tracked changes in noise levels in airport impact zones At the same time, they noted lower and consistently similar utilization rates among quiet neighborhoods of comparable socioeconomic composition Grandjean, Graf, Lauber, Meier, and Muller (1976) found a dose-response function linking airport noise exposure to self-reported use of sleeping pills and tranquilizers Watkins, Ttamopolsky, and Jenkins (1981), however, could not replicate the linkages between drug usage and aircraft noise exposure One study has also uncovered a coarse dose-response function between occupational noise exposure and psychological symptoms among blue-collar workers (Mc- Donald, 1989) Interestingly, in light of earlier work on crowding, social support and psychological health, MC Donald also noted that impaired interpersonal relationships at work appeared to play a role in the mental health-noise links -374- Motivation Interestingly, the initial study of helplessness and human beings utilized inescapable noise as the induction stimulus Hiroto (1974) demonstrated that short-term exposure to inescapable noise induces helplessness Adults were exposed to noise or quiet during an initial phase of an experiment Half of the noise subjects could avoid the noise by learning an avoidance response For the other half of the noise subjects, the noise was inescapable The groups were then tested in a similar situation where noise could easily be avoided by a simple manual response A second series of experiments replicated Hiroto's findings and also demonstrated that the helplessness induced by inescapable noise generalized to persistence on subsequent task performance (Hiroto & Seligman, 1975) Subjects exposed to inescapable noise exhibited significantly greater helplessness in the second testing phase, regardless of the similarity of the helplessness induction and testing phase (Hiroto & Seligman, 1975) Furthermore, the helplessness effects of inescapable noise were greater for external locus of control individuals (Hiroto, 1974) Krantz, Glkass, and Snyder (1974) found similar results in two studies of inescapable versus escapable noise One final detail of Hiroto and Seligman's work worthy of note is that the learned helplessness effects of inescapable noise were quite similar to the induction of helplessness produced by exposing subjects to insoluble concept formation problems A large number of studies, initiated by Glass and Singer's pioneering work on perceived control and stress (1972) have examined performance aftereffects, immediately following exposure to uncontrollable noise The basic paradigm includes exposing participants to noise while working on a cognitive task for a period of about 30 minutes The participant then leaves the room and is asked to another, apparently unrelated task where noise is no longer present (see Cohen, 1980, for an overview of this paradigm) Uncontrollable noise causes deficits in task persistence on puzzles (Gardner, 1978; Glass & Singer, 1972; Glass, Singer, and Friedman, 1969; Percival & Loeb, 1980; Sherrod, Hage, Halpern, & Moore, 1977; Wohlwill, Nasar, DeJoy, & Foruzani, 1976) Work by Glass and Singer (1972) also showed that the controllability, and to a lesser extent the predictability, of the noise is a critical component of these aftereffects In a test of the external validity of the initial Glass and Singer findings, Moran and Loeb (1977) utilized taperecorded aircraft noise and found, unexpectedly, that such noise did not appear to induce aftereffects in the laboratory Percival and Loeb (1980) reasoned that perhaps airport noise, because of its temporal qualities, is rather predictable Thus, they replicated the original Moran and Loeb finding utilizing the same stimuli, but of particular interest, found that when the aircraft noise bursts were sudden rather than the typical slow onset pattern of an approaching aircraft, negative aftereffects could be reliably produced Rotton, Olszewski, Charleton, and Soler (1978) also showed that meaningful speech rather than noise could induce the same negative aftereffect Evans et al (1996) indicated that these negative aftereffects are amplified if exposure to uncontrollable noise occurs among subjects already under psychological stress Finally, Glass and Singer (1972) found that uncontrollable noise interferes with subsequent proofreading accuracy A small number of studies has also examined possible relations between chronic noise exposure and susceptibility to helplessness Evans et al (1995) adapted the Glass and Singer aftereffects puzzle for young children They found that children living in high airport noise zones were less likely to persist at solving line tracing puzzles than their quiet community counterparts Cohen and colleagues (Cohen et al., 1980, 1981) found that aircraft noise-exposed children were significantly less likely to solve a difficult, challenging puzzle than quiet comparison groups Of particular interest, noise-impacted children were also more likely to simply give up on the puzzle before the allotted minutes had passed Fifteen percent of children from noisy schools failed the puzzle by giving up in comparison to only 2% of children from quiet schools It is worth noting that the puzzles were designed and pretested to be fun and engaging to elementary-aged schoolchildren These effects were replicated by Cohen and colleagues and similar trends were also found for home noise levels (Cohen et al., 1986) Both the Evans and Cohen studies had well-matched SES comparison groups Moth-Sibony (1984) found very similar results in kindergarten children exposed to higher levels of aircraft noise in Paris Wachs (1987) also showed that infants exposed to more noise at home manifest less masteryoriented play as indexed by a standardized observation instrument Of additional interest, teachers in noisy schools frequently report more difficulties motivating students than teachers from quiet schools (see Evans & Lepore, 1973b, for a review) Finally, Cohen et al (1986) uncovered a relation between children's willingness to relinquish choice and chronic noise exposure Children from noisy schools relative to quiet schools were significantly more likely to allow an experimenter to choose a reward at the conclusion of their experiments rather than make their own choice Summary Both industrial and community studies find no clear, consistent pattern of data on noise and morbidity Similarly, data on acute noise exposure and altered immune functions are mixed Although not plentiful, there is a confluence of findings suggestive of noise impacts on in utero development that warrant followup Several studies point to noise as a factor in elevated smoking Acute noise produces short-lived elevations in cardiovascular and neuroendocrine functioning Recent research suggests, however, that individuals sensitive to noise as well as situations with high workload demands can diminish and perhaps even block such habituation A plethora of methodologically weak, occupational noise and health studies reveal decidedly mixed findings on noise and blood pressure Some longitudinal studies indicate small, positive associations between occupational noise exposure and blood pressure elevations Road traffic noise appears to have no significant impact on blood pressure of community residents, but persons living in the proximity of airports, particularly children, are at risk -375for elevated blood pressure The clinical significance of these elevations is unknown at this time Data on noise and psychological health are unclear The preponderance of poorly designed studies links community noise levels to rates of psychiatric illness There are better studies indicating some link between community noise exposure and utilization of pharmaceutical hypnotics Both laboratory and field studies reveal that noise, particularly uncontrollable noise, can contribute to diminished motivation related to learned helplessness Children chronically exposed to noise may be particularly susceptible to this phenomenon DISCUSSION Application of the construct of psychological stress to examine the role of the physical environment in human health has proven useful in the case of crowding and noise The primary contributions to date have been the identification of stress- related outcome measures likely to be related to environmental stressors and the preliminary development of a conceptual model for thinking about how and under what conditions noise, crowding, and other environmental stressors might adversely impact human wellbeing Conceptual Issues A central deficiency has been an inattention to the role of underlying psychophysiological processes or social resources in the environmental stressor-disease link In searching for answers to the question, why does crowding or noise cause disease?, there are very little data that has tested mechanisms like elevated cardiovascular functioning or diminished selfefficacy What the data generally show, as depicted in Fig 20.2, is a broad set of outcome measures independently assessed More studies are needed that simultaneously investigate physical or psychological health outcomes and one or more underlying processes in the same sample of individuals For example, Evans and Lepore (Evans et al., 1989; Evans & Lepore, 1993a; Lepore et al., 1991) showed evidence for the model shown in Fig 20.3 -namely, that high residential density causes deterioration in social support resources, which in turn accounts for the linkage between density and psychological ill health There are an unbelievably large number of studies of noise and cardiovascular functioning (principally blood pressure) that have not also looked at some disease endpoint Similarly, no studies have examined crowding, immune function, and physical morbidity Several psychophysiologic mechanisms are prime candidates for more indepth scrutiny as intervening processes that could link environmental conditions to ill health Alterations in neuroendocrine functioning affect cardiovascular activity, primarily via adrenomedullary action as well as alter immune functioning via adrenocortical pathways (Baum & Grunberg, 1995) Cardiovascular reactivity is another process warranting analysis Two viable, competing hypotheses exist Sustained, chronic exposure to uncontrollable, environmental stressors like crowding or noise may deplete the organism's ability to respond adequately to challenge with cardiovascular mobilization (Dienstbier, 1989) Alternatively, heightened sensitivity and vigilance from chronic stressor exposure might exacerbate reactivity (Krantz & Manuck, 1984) Learned helplessness and other motivational processes related to chronic environmental stressor exposure have not been adequately developed It seems clear that one of the potentially most injurious aspects of chronic environmental stressors is their intractability Several aspects of motivation and chronic environmental stress warrant additional research The role of attributional processes, which is well documented in the helplessness literature, has not been applied to environmental stress research It is clear that attributional processes are salient to environmental stressors like noise and crowding Noise annoyance is strongly affected by 'attributions about the origins of noise stimuli, as well as their perceived health impacts (Koelega, 1987) Feelings of arousal induced by personal space invasions (Worchel & Teddlie, 1976), expectancies (Schmidt & Keating, 1979), or informational cues (Langer & Saegert, 1977; Paulus & Matthews, 1980) can all be attributed to crowding or other environmental conditions with varying consequences The potential interplay among environmental stressors and uncontrollability, helplessness, and negative health outcomes (such as depression) is an area ripe for further study Motivation or effort to maintain task performance or productivity under suboptimal conditions may be a salient factor, as well, in determining the long-term health consequences of chronic exposure to adverse environmental conditions Several noise studies both in the laboratory and the field, as well as one crowding study indicate that task performance can be sustained under adverse conditions but at a “cost” of psychophysiological activation The longterm health consequences of people expending additional effort to their job when the environment is not optimal is an important and unresearched topic Studies of underlying psychosocial processes, such as social support or control, also raise provocative conceptual issues about environment, stress, and coping Social support and control have each traditionally been conceptualized as exogenous factors that moderate stressor-outcome relations As can be seen herein, however, chronic exposure to crowding or to noise directly effects social support and control processes, respectively These psychosocial processes mediate rather than moderate the impacts of these chronic environmental demands Other chronic stressors may have similar effects on coping resources In considering hypothetical mechanisms, it is also prudent to carefully scrutinize the traditional practice of statistically controlling risk factors in environmental epidemiology For example, several noise and coronary heart disease investigations control for smoking levels However, what if noise exposure increases smoking as a coping device, as suggested by some studies already reviewed? By statistically partialling out a “risk” factor, a psychologically relevant process that may underlie the noise-health link has been eliminated At a more abstract level, the construct validity implications of statistical controls or the practice of random assignment -376FIG 20.2 FIG 20.3 in experimental studies of stress and health should be carefully considered By removing environmental stressors from their natural context (i.e., poverty, other suboptimal environmental factors) for the purposes of study, ecological validity of the stressor-health relation may be distorted Perhaps crowding and poverty together or noise and certain job requirements together, respectively, lead to pathology By isolating one independent variable either through statistical or experimental design means for purposes of causal modeling, the actual incidence of adverse outcomes from suboptimal environmental conditions may be dramatically underestimated (Lepore & Evans, 1996) It might also be valuable to conceptualize the physical environment not only as a source of stress but also as a source of coping resources (Becker, 1990) Research on coping, like stress, tends to overly focus on intrapsychic mechanisms, missing the potential role of the social and physical environment to promote or interfere with health For example, research on crowding suggests that floorplan layouts that incorporate greater intervening, hierarchically arranged -377spaces, buffer the negative effects of residential crowding on psychological distress (Evans, Lepore, & Schroeder, 1996) Similarly, children in crowded homes who have a place where they can spend some time by themselves appear to suffer fewer negative outcomes (Wachs & Gruen, 1982) Although children exposed to multiple risk factors are more likely to suffer adverse physical and mental health outcomes, some children are more resilient than others (Rutter, 1987) Bradley and colleagues (1994) found that low residential density was a significant, independent, protective factor among poor, low birth weight babies tested and years later on a wide array of physical and psychological health measures Methodological Issues In addition to some of the conceptual issues associated with statistically controlling for risk factors, statistical approaches that partial out variables in order to “control” for possible confounding effects are also fraught with analytic problems Statistical models that partial or covary out variables are based on the assumption of no interaction between the independent variable and the potential control variable on the outcome Controlling for social class, for example, presupposes that noise or crowding not interact with social class to affect health or well-being The same statistical problem may occur with controls for certain risk factors, such as family history of coronary heart disease, hypertension status, or age, to name some common examples Utilization of analysis of covariance or its regression equivalents assumes that the slopes of the respective regression lines between the outcome variable and the independent variable and the covariate (partial b) are parallel (i.e., no statistical interaction) Researchers should not employ covariance or analogous regression Iprocedures to control for risk factors or contextual factors, such as socioeconomic status, without first assessing this basic statistical assumption Another analytic issue concerns effect size considerations When the correlation coefficient between noise exposure and blood pressure, for example, is squared, not a lot of variance is explained But this is also true if the same is done for cigarette smoking and lung cancer It is also true that the variance explained in mental health by crowding is on the same order of magnitude as the variance explained by income (Evans et al., 1998; Gove & Hughes, 1983) Critics of the apparently small role of the physical environment in health need to grapple with this issue more in comparative, rather than in absolute, terms There is critical need for prospective, longitudinal designs in the field There is only one crowding study incorporating such a design (Lepore et al., 1991) and just a handful of industrial studies of noise and health that incorporate a longitudinal component Self-selection into noisy or crowded environments, as well as possible spuriousness, loom as major threats to internal validity in most of the field studies reviewed herein Too many cross-sectional field studies exist Furthermore, not enough integrated research programs have examined the same environmental stressor and health in the lab and in the field The value of integrating lab and field work is illustrated by Cohen and colleagues' work on aircraft noise and children where laboratory-based concepts and measures were brought to bear on the study of chronic, community noise exposure (Cohen et al., 1986) Caution is needed in generalizing from aggregate level, epidemiological studies to individual health responses to the physical environment Several examples of this ecological fallacy were previously reviewed, particularly in crowding field studies, where people per room as indexed by census tract did not yield the same pattern of results as when individual health measures were assessed Parallel trends were noted in the noise and health literature (Lercher, 1996) One reason aggregate-level comparisons can be misleading is related to exposure estimation Large degrees of variance in exposure are truncated into a single estimate of exposure when aggregate level data are examined Furthermore, the actual environment as experienced is even further removed from the exposure metric in comparison to individual residential or work environment assessments The problems of exposure estimation and adequate representation of physical stressors in studies are common in the environmental stress literature Many studies have only gross estimates of actual exposure to the physical stressor Crowding and noise are typically estimated indirectly and not account for individual movement throughout the day across settings One indication of the importance of this issue is found in the noise literature where several studies on industrial noise show that duration of exposure is a critical variable Similarly, utilization of hearing protection affects noises and health findings in industrial settings Residential room location can also impact noise exposure (Lercher, 1996) An interesting example of the importance of exposure estimation comes from a recent study by Maxwell (1996) of crowding in preschoolchildren Children in more crowded day-care centers had greater behavioral and emotional problems only if they also lived in crowded homes Moreover, the range of environmental variables in many studies is often truncated and/or the distribution of environmental exposures is badly skewed Both of these problems strain the general linear model that forms the underlying statistical basis employed in'most studies of the physical environment, stress, and health For example, many studies of crowding have hardly any people in homes with more than 1.5 persons per room Most laboratory studies expose people to quiet or noise and several community noise studies transform continuous data into a noise/quiet dichotomy Badly skewed data, as well as use of dichotomous categories, reduce statistical power Furthermore, there is some indication of threshold effects for noise and crowding health effects Recall for example some recent evidence that traffic noise above 65 dBA Leq appears necessary before cardiovascular risk elevates This nonlinearity also adversely affects statistical power Studies of traffic congestion and health outcomes indicate that log transformations (Halpern, 1995), or use of indices such as percentage of time at high congestion levels (Evans & Carrere, 1991), predict outcomes significantly better than mean levels of exposure This nonlinearity can also appear at the opposite end of the environmental exposure spectrum Living alone is associated -378with psychological impairment as well as low social support (Gabe & Williams, 1987; Galle et al., 1972) Crowding studies that calculate persons per room as the density' metric that include people living alone distory the “stirna” of association between crowding and health outcomes Outcome measures are also wanting Several studies of psychological health employed one item or scales of unknown psychometric standardized, sensitive indicators Immune function would be a particularly valuable adjunct to environmental morbidity studies Several studies of blood pressure incorporated one or two readings, often taken in a medical setting Such data are unreliable and of questionable validity Health psychology has demonstrated that individual, biological, and personological characteristics are central to understanding health and disease A smaller body of work within health psychology has also examined the potential role of sociocultural factors in human health Hopefully, this chapter has directed attention to the potential direct, indirect, and interactive roles the physical environment can play in health and human behavior ACKNOWLEDGMENTS Preparation of this chapter was partially supported by grants from the National Institutes of Health (1 ROl I-IL4732501) the National Science Foundation (BNS-8920483) and the U.S Department of Agriculture (HatchNo 327407) I am grateful to Jana Cooperman and Tamir Ebbin for bibliographic assistance I thank Steve Lepore, Paul Paulus, and Shirley Thompson for critical feedback on earlier drafts  ... impossible A small amount of environmental stress research has examined climatic conditions as potential psychological stressors influencing human stress responses (Bell & Greene, 1982; Evans,... representation of physical stressors in studies are common in the environmental stress literature Many studies have only gross estimates of actual exposure to the physical stressor Crowding and noise... noisy working conditions Another aspect of research on psychological stress and health relevant to this chapter on environmental stressors are the concepts of vulnerability and resilience (Cohen,