Multigenerational exposures to polluting industries and developmental disabilities

Animal models suggest that environmental exposures can impact future generations of offspring. Yet, there are limited human epidemiological studies of multigenerational environmental exposures, and even fewer such studies of maternal and paternal exposures. Leveraging a unique data resource in Utah (USA), we examine if offspring (F2, n = 6380) are at increased risk of intellectual disability (ID) if the mother or father (F1) were exposed to polluting industrial facilities while their own mothers (F0) were pregnant. We obtained historical data on polluting industry locations and calculated facility densities within 3 km and 5 km of each child's (F2) grandmothers' (F0) residential addresses at time of their mothers' and fathers' (F1) births as well as their mother's address at the time of their birth. We weighted those counts by pairing industry codes with national Risk-Screening Environmental Indicators health risk scores. One standard deviation (SD) increase in the density of facilities near the pregnant maternal grandmother was associated with 1.12 (1.03-1.22) and 1.09 (1.003-1.19) times greater odds of ID at 3 km and 5 km, respectively. Weighing these facility densities by risk, odds ratios associated with SD increases were 1.12 (1.04-1.20, 3 km) and 1.08 (1.003-1.17, 5 km). Associations with facility densities near the pregnant paternal grandmother were positive but weak. Associations with risk-weighted facility density near the pregnant paternal grandmother were stronger at 5 km (1.12, 1.02-1.22) than at 3 km. Results indicated that ancestral exposures, particularly when the maternal grandmother (F0) was pregnant with the mother (F1), may increase risks of developmental disabilities in the next generation (F2).