Prenatal organophosphorus pesticide (OPP) exposure has been associated with child attention-deficit/hyperactivity disorder (ADHD) in agricultural communities and those that are exposed to residentially applied insecticides. To examine this association in populations that are exposed primarily through diet, we estimate the associations between prenatal OPP exposure and preschool ADHD in the Norwegian Mother, Father and Child Cohort Study (MoBa), and describe modification by paraoxonase 1 (PON1) gene variants. We used participants from the MoBa Preschool ADHD Sub-study (n = 259 cases) and a random sample of MoBa sub-cohort participants (n = 547) with birth years from 2004 to 2008. Prenatal urinary dialkylphosphate (DAP) metabolites (total diethylphosphate [∑DEP] and total dimethylphosphate [∑DMP]) were measured by an ultra-performance liquid chromatography-time-of-flight system and summed by molar concentration. Maternal DNA was genotyped for coding variants of PON1 (Q192R and L55M). We used a multivariable logistic regression to calculate the odds ratios (OR) and 95% confidence intervals, adjusted for maternal education, parity, income dependency, age, marital status, ADHD-like symptoms, pesticide use, produce consumption, and season. We found no associations between DAP metabolite concentrations and preschool ADHD. The adjusted ORs for exposure quartiles 2–4 relative to 1 were slightly inverse. No monotonic trends were observed, and the estimates lacked precision, likely due to the small sample size and variation in the population. We found no evidence of modification by PON1 SNP variation or child sex. Maternal urinary DAP concentrations were not associated with preschool ADHD.

Prenatal organophosphorus pesticides (OPs) are ubiquitous and have been linked to adverse neurodevelopmental outcomes. However, few studies have examined prenatal OPs in relation to diagnosed attention-deficit/hyperactivity disorder (ADHD), with only two studies exploring this relationship in a population primarily exposed through diet. In this study, we used a nested case-control study to evaluate prenatal OP exposure and ADHD diagnosis in the Norwegian Mother, Father, and Child Cohort Study (MoBa). For births that occurred between 2003 and 2008, ADHD diagnoses were obtained from linkage of MoBa participants with the Norwegian Patient Registry (N = 297), and a reference population was randomly selected from the eligible population (N = 552). Maternal urine samples were collected at 17 weeks’ gestation and molar sums of diethyl phosphates (ΣDEP) and dimethyl phosphates metabolites (ΣDMP) were calculated. Multivariable adjusted logistic regression models were used to estimate the association between prenatal OP metabolite exposure and child ADHD diagnosis. Additionally, multiplicative effect measure modification (EMM) by child sex was assessed. In most cases, mothers in the second and third tertiles of ΣDMP and ΣDEP exposure had slightly lower odds of having a child with ADHD, although confidence intervals were wide and included the null. EMM by child sex was not observed for either ΣDMP or ΣDEP. In summary, we did not find evidence that OPs at 17 weeks’ gestation increased the odds of ADHD in this nested case-control study of ADHD in MoBa, a population primarily experiencing dietary exposure.

Background: Drinking water can be an important source of exposure to nitrate and disinfection by-products, including trihalomethanes (THMs) and haloacetic acids (HAAs). N-nitroso compounds formed endogenously after nitrate ingestion are animal carcinogens, and THM and HAA exposures increase the risk of some cancers. Our objectives were to evaluate associations of drinking water nitrate and disinfection byproducts with total and aggressive (distant stage, poorly differentiated grade, fatal, or Gleason score ≥7) prostate cancer in the Agricultural Health Study cohort. Methods: Male participants who were cancer free and used private wells or public water supplies (PWS) for drinking water at enrollment (1993-1997, n = 40 403) were followed through 2021 (mean = 21.9 years). Average nitrate-nitrogen (nitrate-N) concentrations were estimated for private well users based on state-specific geologic and meteorologic factors. We used monitoring data to compute average nitrate-N, THMs, and HAAs for PWS users. We estimated hazard ratios (HRs, 95% CIs) per doubling and categories of exposure for total (n = 3625) and aggressive (n = 2200) prostate cancer using Cox proportional hazards regression. Results: Median (interquartile range) average water nitrate-N was 1.49 (0.76-3.01) mg L−1; 6% >10 mg L−1 (PWS maximum contaminant level). Compared to nitrate-N ≤ 1 mg L−1, exposures >10 mg L−1 were significantly positively associated with total (1.16, 1.01-1.35; P = .10 for trend) and aggressive disease (1.22, 1.02-1.47; P = .03 for trend). We observed weak associations between higher nitrate-N (Q4 vs Q1) and total (1.05, 0.95-1.16) and aggressive (1.13, 0.99-1.27) disease. We did not observe associations with total THMs or HAAs. Conclusions: These findings suggest that drinking water nitrate-N exposure, at average levels > 10 mg L−1, is a risk factor for prostate cancer, particularly aggressive disease.

Between 1917 and 2007, Alcoa operated an aluminum smelting plant in Badin, North Carolina, resulting in hazardous occupational and environmental exposures in West Badin, a predominantly Black community. We partnered with the Concerned Citizens of West Badin Community to document the experiences of prior employees and their families. We used a community-engaged survey approach to summarize residents’ workplace and community-level experiences. Fourteen interviews were coded for recurring themes. Potroom work was the most frequently reported job. Occupational exposures included asbestos, extreme heat, and dust inhalation. Additional workplace stressors included take-home exposures and racism. Most participants expressed concerns about environmental exposures as well. Health conditions most frequently reported included cancer, heart disease, and lung disease. Badin residents experience cumulative impacts of occupational and environmental hazards resulting from Alcoa's operations. This survey served as a tool for documenting their experiences, identifying ongoing environmental concerns, supporting community organizing, and highlighting the resilience of the West Badin community.