Non-Chemical Stressors and Cumulative Risk Assessment: An Overview of Current Initiatives and Potential Air Pollutant Interactions

Abstract

Regulatory agencies are under increased pressure to consider broader public health concerns that extend to multiple pollutant exposures, multiple exposure pathways, and vulnerable populations. Specifically, cumulative risk assessment initiatives have stressed the importance of considering both chemical and non-chemical stressors, such as socioeconomic status (SES) and related psychosocial stress, in evaluating health risks. The integration of non-chemical stressors into a cumulative risk assessment framework has been largely driven by evidence of health disparities across different segments of society that may also bear a disproportionate risk from chemical exposures. This review will discuss current efforts to advance the field of cumulative risk assessment, highlighting some of the major challenges, discussed within the construct of the traditional risk assessment paradigm. Additionally, we present a summary of studies of potential interactions between social stressors and air pollutants on health as an example of current research that supports the incorporation of non-chemical stressors into risk assessment. The results from these studies, while suggestive of possible interactions, are mixed and hindered by inconsistent application of social stress indicators. Overall, while there have been significant advances, further developments across all of the risk assessment stages (i.e., hazard identification, exposure assessment, dose-response, and risk characterization) are necessary to provide a scientific basis for regulatory actions and effective community interventions, particularly when considering non-chemical stressors. A better understanding of the biological underpinnings of social stress on disease and implications for chemical-based dose-response relationships is needed. Furthermore, when considering non-chemical stressors, an appropriate metric, or series of metrics, for risk characterization is also needed. Cumulative risk assessment research will benefit from coordination of information from several different scientific disciplines, including, for example, toxicology, epidemiology, nutrition, neurotoxicology, and the social sciences.

Chemical and non-chemical stressors affecting childhood obesity: a systematic scoping review

“…[31][32][33] Non-chemical stressors are factors found in the built, natural, and social environments such as noise, temperature, humidity, stress from the built environment, social factors, and lack of health care. 24,26,33 Using PubMed and Google Scholar, we identified relevant literature articles using several search strings ( Figure 1-Step 1). More information on the search strings (including specific stressor terms) can be found in the Supplementary Information.…”

“…[17][18][19][20][21][22][23] In addition to physical activity and caloric intake, other non-chemical stressors that may influence weight include personal habits (e.g., smoking); psychosocial stress (e.g., parental divorce, domestic violence, exercising poor judgement, depression); access to health care; and/or aspects of the built and natural environments. [24][25][26][27] There is also increasing evidence that obesogens (i.e., chemical stressors) may influence obesity by affecting metabolic activities in the body. Finally, genetic predisposition plays a large role, accounting for 440% of the population variation in body mass index (BMI), suggesting that genes factor into how the body captures, stores, and uses energy from food consumption.…”

Cumulative Health Risk Assessment: Finding New Ideas and Escaping from the Old Ones

“…However, there have been comparatively few CRAs that attempt to incorporate nonchemical stressors, such as psychosocial factors (e.g ., discrimination, poverty), physical agents (e.g ., heat, noise) or biological stressors (e.g ., pathogens) into the formal analysis process (Callahan and Sexton 2007;NRC 2009;Sexton 2012). Efforts are currently underway to develop methods for integrating analysis of psychological, social and economic factors-such as low income, deficient education, unemployment, inadequate housing, high-crime neighborhoods, substandard diet, and lack of access to health care-into CRAs (deFur et al 2007;Menzie et al 2007;Ryan et al 2007;NJDEP 2009;CalEPA 2010;NEJAC 2010;Lewis et al 2011;Zartarian et al 2011;Linder and Sexton 2011;Sexton and Linder 2011;Alexeeff et al 2012). The objective of this Perspective is to describe the inherent challenges of putting CRA principles into practice, with particular emphasis on effects-based approaches.…”

The Role of Non-Chemical Stressors in Mediating Socioeconomic Susceptibility to Environmental Chemicals

“…Recent reviews and case studies have called for greater attention to, and improved methods for, the integration of nonchemical stressors into CRA [72][73][74]. Interest has been driven by environmental justice concerns of heightened chemical exposures among lower-SEP populations [75,76], and the EPA authority to protect susceptible populations and improve population health [77].…”