International Journal of Hygiene and Environmental Health
Childhood social position and associations between environmental exposures and health outcomes
Introduction
Social position is a determinant of health, with gradients for multiple health outcomes (Beckett et al., 1996; Mackenbach et al., 1997; Marmot, 2001; O’Neill et al., 2003). Low social position has also been found to be positively associated with numerous hazardous environmental exposures, including environmental risk factors concerning respiratory and allergic diseases like exposure to ambient and indoor air pollutants and allergens (Bolte et al., 2006; Bolte, 2006; Chaix et al., 2006; du Prel et al., 2005; Evans and Kantrowitz, 2002; Gunier et al., 2003; Lannerö et al., 2002).
Recent studies have focused on examining the associations between socioeconomic status (SES) and environmental health, hypothesising that groups of lower SES carry a disproportionate burden of environmentally related diseases (Bolte and Mielck, 2004; Evans and Kantrowitz, 2002; O’Neill et al., 2003). Studies examining the effect of air pollution on health have found higher effect sizes in low SES groups (Jerrett et al., 2004; Ponce et al., 2005; Pope, III et al., 2002). Several explanations might account for these differences: (1) higher and multiple hazardous exposures among socially disadvantaged groups cause an amplification of negative health effects and (2) biologic interaction between hazardous exposures and individual as well as contextual characteristics and behaviours lead to an increase in vulnerability (Bolte et al., 2005).
In contrast to the generally higher susceptibility of low SES groups, a lower prevalence of allergic diseases has been reported for socially disadvantaged children, even though the prevalence of environmental risk factors for allergic diseases is higher (Chaix et al., 2006; du Prel et al., 2006; Emanuel, 1988; Lannerö et al., 2002). However, severe asthma has been shown to be more prevalent in low SES groups (Heinrich et al., 1998). This raises questions regarding the validity of the results, often based on self-report, which show a positive association between high socioeconomic position and prevalence of respiratory or allergic disease in children in Germany (Heinrich et al., 1998). One possible explanation for this discrepancy may be reporting bias (Kuehni et al., 2006; Mackenbach et al., 1996). It has been hypothesised that a low parental social position is associated with a higher threshold for defining illness and that therefore self-reported morbidity might underestimate the true burden of disease in socially disadvantaged children (Mackenbach et al., 1996). Other investigators, however, did not find socioeconomic differences in responses to commonly used self-reported measures of chronic illness or found more over-reporting among lower socioeconomic groups (Heliövaara et al., 1993; Lindholm et al., 2002; Macintyre et al., 2005).
The distribution of environmental exposures and health outcomes across different social groups has been little examined in Germany. There is also a lack of knowledge concerning the effect of social position on environment–health associations. To partly fill this gap, we made use of data from a study originally designed to assess internal exposures and health effects in children living in small areas adjacent to intensive industrial activity (Krause et al., 2004; Sugiri et al., 2006).
The aim of this study was (1) to examine the associations between the different indicators of social position and environmental exposures as well as broad categories of health outcomes in children, and (2) to investigate how social position can influence environment–health relationships in an observational study.
Section snippets
Methods
We analysed data from a cross-sectional survey on 968 preschool children that was conducted in three highly industrialised districts in the Ruhr Area (Duisburg-Nord, Duisburg-Süd, Dortmund) and in one rural community (reference area: Borken) in North Rhine-Westphalia in 2000. Details of this study have been reported elsewhere (Krause et al., 2004; Wilhelm et al., 2007). It was approved by the local ethics committee. In short, children belonging to school districts within the study region were
Definition of social position
We constructed indicators of individual level social position from the database, comprising vertical as well as horizontal concepts. The child's nationality was defined non-German, if both parents were of non-German nationality. In addition to psychosocial challenges of migration, this group has potential social and political handicaps, connected with a non-German nationality.
To assess the broader concept of migration, influencing lifestyle and contextual factors without necessarily having the
Exposure assessment
Air pollutant concentrations around industrial sources display high spatial and temporal variations, depending on varying emissions, temperature, precipitation, wind strength and direction. Temporal variations were estimated from series of measurements performed since 1970. Highly resolved series of measurements on a spatial basis were performed during the study period and spatial interpolation techniques using Kriging methods applied to estimate the annual total suspended particulate matter
Outcome assessment
We defined four different categories of adverse health outcomes based on clinical or laboratory examinations and questionnaire responses. We chose broad categories to assess the general vulnerability of the children, in contrast to specific exposure–disease relationships, which were already reported elsewhere (Krause et al., 2004).
To assess allergic sensitisation (AS), patch tests (24 allergens, TRUE Test, Pharmacia, Hillerod, Dänemark), skin prick tests (inhalative allergens including pollen,
Statistical analysis
We examined the distribution of environmental exposures (TSP, ETS and ULC) according to social position with descriptive bivariate analysis. ETS and ULC were analysed as binary variables, TSP was analysed on a continuous scale and as binary variable (cutpoint >45 μg/m3) to increase sample size, because in one study region TSP concentrations were modelled only in two concentrations (⩽45 and >45 μg/m3). We calculated the crude odds ratio with 95% confidence interval (CI) for the association of
Funding
This study was funded within the “Action Program Environment and Health North Rhine-Westphalia” of the Ministry of the Environment and Conservation, Agriculture and Consumer Protection of the State of North Rhine-Westphalia in Düsseldorf, Germany and coordinated by the North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection, Germany.
Results
Three observations were excluded from the analysis due to missing information on sex, leaving 965 subjects. Table 1 displays the characteristics of the study population according to social position and area of residence. Nationality, immigration background, education, professional training, unemployment and relative poverty were distributed unequally across the four study regions, with the highest prevalence of disadvantageous social characteristics in Duisburg-Nord. With the exception of sex,
Discussion
We found strong associations between different indicators of social position and environmental exposures as well as health outcomes in this cross-sectional analysis of preschool children. Next to parental educational attainment, the most commonly used variable to describe SES, nationality, immigration background, unemployment and relative poverty were important indicators differentiating environmental exposures and health outcomes. Allergic and respiratory disease outcomes based on self-report
Acknowledgements
Our special thanks go to Mrs. Idel, Mr. Hadnagy and Mrs. Berendt, for the analysis of the immune parameters.
References (44)
- et al.
Reliability and validity of interview data on chronic diseases. The Mini-Finland Health Survey
J. Clin. Epidemiol.
(1993) - et al.
Socioeconomic inequalities in morbidity and mortality in western Europe. The EU Working Group on Socioeconomic Inequalities in Health
Lancet
(1997) - et al.
International Study of asthma and allergies in childhood (ISAAC): rationale and methods
Eur. Respir. J.
(1995) - et al.
Asthma among Puerto Rican Hispanics: a multi-ethnic comparison study of risk factors
Am. J. Respir. Crit. Care Med.
(1996) Umweltgerechtigkeit [Environmental justice]
Umweltmed. Forsch. Prax.
(2006)- et al.
Umweltgerechtigkeit. Die soziale Verteilung von Umweltbelastungen
(2004) - et al.
Socioeconomic factors in EU-funded studies of children's environmental health
Eur. J. Epidemiol.
(2005) - Bolte, G., Wildner, M., Fromme, H., 2006. Impact of socioeconomic position and housing environment on children′s health...
- et al.
Potential self-selection bias in a nested case-control study on indoor environmental factors and their association with asthma and allergic symptoms among pre-school children
Scand. J. Public Health
(2006) - et al.
Children's exposure to nitrogen dioxide in Sweden: investigating environmental injustice in an egalitarian country
J. Epidemiol. Community Health
(2006)
An estimate of the prevalence of asthma and wheezing among inner-city children
Pediatrics
Socioeconomic status and lung function among primary school children in Canada
Am. J. Respir. Crit. Care Med.
Changes in social inequality with respect to health-related living conditions of 6-year-old children in East Germany after re-unification
Preschool children's health and its association with parental education and individual living conditions in East and West Germany
BMC Public Health
Hay fever, a post industrial revolution epidemic: a history of its growth during the 19th century
Clin. Allergy
Socioeconomic status and health: the potential role of environmental risk exposure
Annu. Rev. Public Health
Traffic density in California: socioeconomic and ethnic differences among potentially exposed children
J. Expo. Anal. Environ. Epidemiol.
Armut in der Bundesrepublik Deutschland-Probleme der Messung und die Reichweite empirischer Untersuchungen
Childhood asthma and poverty: differential impacts and utilization of health services
Pediatrics
Agreement between questionnaire data and medical records. The evidence for accuracy of recall
Am. J. Epidemiol.
Soziale Ungleichheit und umweltbedingte Erkrankungen in Deutschland: Empirische Ergebnisse und Handlungsansätze
Cited by (19)
Children and youth's biopsychosocial wellbeing in the context of energy resource activities
2017, Environmental ResearchCitation Excerpt :Each study represents a comparable scenario; namely, exposure to toxic emissions in early life is linked to significant economic penalties in later life. In general, the literature suggests that families with a lower socioeconomic status experience more severe effects from air pollution (Bolte et al., 2009; Hoffmann et al., 2009), where economic impacts are operationalised through socioeconomic indicators such as educational attainment, poverty, unemployment, and earnings (Bell and Ebisu, 2012). As such, these interdependencies are underpinned with normative assumptions: equivalency–population-level measures are representative of the complex composition of the modern family; and linearity–the relationship between socioeconomic status and health outcomes is (often) portrayed as causal and unidirectional, rather than dynamically bi-directional or cyclic (Gee and Payne-Sturges, 2004).
The cumulative effect of nuisances from road transportation in residential sectors on the Island of Montreal - Identification of the most exposed groups and areas
2016, Transportation Research Part D: Transport and EnvironmentCitation Excerpt :Indeed, areas located less than 200 m from the center of a highway generally show high concentrations of air pollutant and road traffic noise levels, creating substantial impacts on the health and well-being of the people living there (Brugge et al., 2007; Rioux et al., 2010; Zhu et al., 2002b). Exposure to high concentrations of road transportation-related air pollutants, such as nitrogen dioxide (NO2), can lead to increases in respiratory difficulties and asthma (Jerrett et al., 2008; McConnell et al., 2006), impaired lung development in children (Gauderman et al., 2007) and heart problems (Hoffmann et al., 2009; Kan et al., 2008; Van Hee et al., 2009). As for road traffic noise, prolonged exposure can lead to sleep problems (Bluhm et al., 2004; Öhrström and Skånberg, 2004), high blood pressure (Bluhm et al., 2007), development of cardiovascular disease (Babisch, 2008), increased cognitive difficulties in children (Evans et al., 2001), issues with diabetes (Sorensen et al., 2012), and hearing loss (Moudon, 2009; Seto et al., 2007; van Kempen et al., 2002).
Asthma, respiratory symptoms and lung function in children living near a petrochemical site
2014, Environmental ResearchCitation Excerpt :The different impact between the two industrial sites could be explained by the higher amount of refinery emissions in the North Industrial Complex. The influence of socioeconomic factors on exposure and susceptibility of children to environmental factors has been widely recognized (Hoffmann et al., 2009; Bolte et al., 2010; Hafkamp-de Groen et al., 2012; Bell and Ebisu, 2012; Moore et al., 2012). Industrial neighborhoods are generally less desirable for residential purposes, except for the less educated and/or the economically disadvantaged.
Relative effects of educational level and occupational social class on body concentrations of persistent organic pollutants in a representative sample of the general population of Catalonia, Spain
2013, Environment InternationalCitation Excerpt :In spite of the involvement in health disorders of both environmental pollutants and social factors, there are wide gaps in knowledge of the influence of socioeconomic position on human contamination by POPs and other pollutants (Bergman et al., 2013; Borrell et al., 2004a; Davey Smith et al., 1998; Martikainen et al., 2007; Morrens et al., 2012; NRC, National Research Council and Committee on Human Biomonitoring for Environmental Toxicants, 2006; Porta et al., 2008b, 2012a; Subramanyam et al., 2013; Thayer and Kuzawa, 2011). Some evidence from studies based on non-representative samples indicates that such contamination does not affect all social and educational groups homogeneously; rather, some compounds seem to contaminate more intensely the more disadvantaged groups, generating a potentially unfair and perhaps avoidable gradient of inequalities in health (Brown, 1995; Freire et al., 2011; Hoffmann et al., 2009; Porta et al., 2008a). Even so, it has seldom been assessed to what extent structural differences among social groups in age and body weight explain their differences in POP contamination.
Social distribution of internal exposure to environmental pollution in Flemish adolescents
2012, International Journal of Hygiene and Environmental HealthCitation Excerpt :SES is however a multifaceted concept that cannot be captured with a single indicator (Braveman et al., 2005; Galobardes et al., 2006). Moreover, it has been shown that the type of SES indicator can determine the possible health outcomes and environmental exposures in children and adolescents (Hanson and Chen, 2007; Hoffmann et al., 2009). We selected parental education however not on an ‘ad hoc’ basis.
Association Between Socioeconomic Status and Prevalence of Hypersensitivity Diseases and Autism: A Nationwide Study of Children
2023, Maternal and Child Health Journal