DNA methylation in context: Racial inequities in social adversity and vulnerability to the health impact of air pollution

点击翻译按钮获取中文摘要

Black-White inequities in healthy aging are well-known with Black adults experiencing greater risk of developing and earlier onset of chronic conditions such as cardiovascular disease (CVD), hypertension, and diabetes compared to White adults. Neighborhood context has emerged as a potentially powerful determinant of racial inequities in aging-related health conditions, including cognitive decline, and may be a key intervention site. Neighborhoods include both social and environmental exposures important for healthy aging. Evidence indicates stark racial inequities in exposure to segregated, under-resourced but over-surveilled and polluted neighborhoods. Pollution and aspects of social adversity are often correlated and may operate cumulatively to result in racial health inequities. Importantly, however, these chemical (i.e. pollution) and non-chemical (i.e., social adversity) stressors may act synergistically, whereby exposure to social adversity can heighten vulnerability to the deleterious health impact of even low levels of pollution. Yet, the environmental and social science literatures – even the environmental and social epidemiology literatures – are largely separate. There is a pressing need to integrate the study of these exposures given their likely cumulative and synergistic effects on racial health inequities in order to direct effective interventions and policies. In addition to the gaps in our knowledge about the combined impact of chemical and non-chemical stressors on racial inequities in healthy aging, there is a need to focus on outcomes that may serve as biological pathways to numerous diseases. Research on either pollution or social adversity has tended to focus on specific health outcomes. Focus on a single disease may underestimate the overall health impact of these racially unequal exposures. It is critical to clarify the shared biological mechanisms that underlie numerous chronic diseases to understand the full impact of pollution and social adversity on racial health inequities. A growing literature points to the importance of epigenetic factors, particularly DNA methylation, linking socioenvironmental context to health. Indeed, it may be that epigenetic processes are an important mechanism through which inequities in both air pollution and social adversity are embodied. Our objective is to identify underlying DNA methylation mechanisms linking neighborhood segregation and ambient and industrial air pollution and social adversity to measures of healthy aging. Clarifying the role of neighborhood in racial health inequities is critical, as neighborhoods are amenable to intervention. Identifying the role of DNA methylation patterns reflecting racial segregation, including chemical and non-chemical stressors, can point to specific disease etiologies and causal mechanisms effective interventions to eliminate racial inequities in healthy aging.