Critical biological pathways for chronic psychosocial stress and research opportunities to advance the consideration of stress in chemical risk assessment

Abstract

Emerging evidence suggests that psychosocial stress and toxicants may interact to modify health risks. Stress-toxicant interactions could be important in chemical risk assessment, but these interactions are poorly understood and additional research is necessary to advance their application. Environmental health research can increase knowledge of these interactions by exploring hypotheses on allostatic load, which measures the cumulative impacts of stress across multiple physiological pathways, using knowledge about physiological pathways for stress-related health effects, and evidence of common target pathways for both stress and toxicants. In this article, critical physiological pathways for stress-related health effects are discussed, with specific attention to allostatic load and stress-toxicant interactions, concluding with research suggestions for potential applications of such research in chemical risk assessment.

FIGURE 1

Inverse relationship between SES and mortality ratio in Whitehall Study.^,, Note. SES = socioeconomic status. The standardized mortality ratio is the ratio of actual deaths to expected deaths. Note that there is an almost linear gradient with occupational status in the British Civil Service in which all persons have jobs and access to health care. The gradient indicates that there are aspects of income and education related to stress and lifestyle that are related to health and mortality.

FIGURE 2

The central role of the brain.^,

FIGURE 3

The nonlinearity of the mediators of stress and adaptation. Note. CNS = central nervous system; DHEA = dehydroepiandrosterone.