Chemical and non-chemical stressors in a postpartum cohort through wristband and self report data: Links between increased chemical burden, economic, and racial stress.

Multiple external stressors are known to have adverse impacts on health and development. Certain groups are more vulnerable and/or more likely to be exposed toenvironmental, psychological, and social stressors simultaneously. Yet, few studies have examined combined exposure to environmental toxicants and psychosocial stress. Here, we integrated environmental chemical exposure data collected using silicone wristbands and self-report social stressor data within the Brain and Early Experience (BEE) perinatal cohort to understand co-exposure to environmental chemicals and social stress. Silicone wristbands were worn for one week by mothers throughout central North Carolina who were 6 months postpartum (n = 97). Exposure to 110 environmental chemicals across eight chemical classes was quantified on silicone wristbands using gas chromatography mass spectrometry. Social stress was evaluated using eight established self-report questionnaires (e.g., Brief Symptom Inventory, Perceived Stress Scale), quantifying experiences such as race-related stress, economic strain, and relationship conflict. Hair cortisol levels were measured as an additional metric of stress. The chemical exposure landscape and associations among chemical exposure, demographic characteristics, and social stress were characterized through individual variable analyses, cluster and data reduction, and compiled scoring approaches to comprehensively evaluate chemical and social stress burdens. We found that chemicals contain co-occurring patterns largely based on chemical class, with phthalates representing the chemical class with highest exposure and polychlorinated biphenyls the lowest. Chemicals showed differential exposure across racial groups, with diethyl phthalate, triphenyl phosphate, and tris(3,5-dimethyl phenyl) phosphate at higher levels in Black participants compared with White participants. Integrating social stressor profiling with chemical exposure data identified one particularly vulnerable subset of participants in which high chemical exposure burden coincided with high experiences of racism and economic stress. These findings demonstrate co-occurring chemical and social stress, warranting further investigation to better understand how these combined stressors may contribute to disparities in maternal and child health.