Although some epidemiological studies have identified the associations between exposure to organophosphate pesticides (Ops) and respiratory diseases, diabetes mellitus (DM), and cardiovascular diseases (CVDs), controversial results still exist. In this review and meta-analysis, we aimed to investigate the overall pooled effect estimates and the possible mechanisms of the relationship between OP exposure and adverse health outcomes. In this study, Web of Science, PubMed, Embase, OVID, and the Cochrane Library were systematically searched until September 2022. Nineteen observational studies that focused on the general population or occupational populations examined the associations between OP exposure and respiratory diseases, DM, and CVD were included. Based on the overall pooled results, a significantly positive association was observed between OP exposure and respiratory diseases (OR: 1.12, 95% CI: 1.06–1.19). A significant link was also observed between various individual species of OP exposure and respiratory diseases, with an OR value of 1.11 (95% CI: 1.05–1.18). In particular, there was a significant association of OPs with wheezing and asthma, with OR values of 1.19 (95% CI: 1.08–1.31) and 1.13 (95% CI: 1.05–1.22), respectively. In addition, a significant association was also observed between OP exposure and DM (OR: 1.18, 95% CI: 1.07–1.29). However, no significant association was observed between OP exposure and CVD (OR: 1.00, 95% CI: 0.94–1.05). Exposure to OPs was associated with a significantly increased risk of respiratory diseases and DM, but there was no evidence of a significant association between OP exposure and CVD. Considering the moderate strength of the results, further evidence is needed to confirm these associations.

Background: Previous studies have explored the association between ambient ozone (O₃) exposure and gestational diabetes mellitus (GDM). However, little is known about the association of O₃ with different GDM clinical classifications—diet-controlled GDM (GDMA1) and insulin-treated GDM (GDMA2), and whether temperature modifies the associations. Methods: We conducted a retrospective cohort study including 11,491 pregnant women between 2017 and 2023 in Tianjin, China. O₃ exposure levels for each participant were assessed using the Tracking Air Pollution in China dataset. Logistic regression models were employed to analyze the associations of trimester-specific O₃ exposure with GDMA1 and GDMA2. Distributed lag nonlinear model (DLNM) was used to identify potential critical gestational weeks of O₃ exposure. Ambient temperature was categorized using the 10th and 90th percentiles to evaluate the effect modification of extreme temperatures on these associations. Results: No statistically significant association was observed in the fully adjusted trimester-specific models. In the weekly-specific DLNM analyses, we observed 5–12 weeks before pregnancy and 26–28 gestational weeks as sensitive windows where O₃ exposure was weakly associated with elevated GDMA1 risk, and 11–25 gestational weeks for GDMA2. Each 10 μg/m³ increase in O₃ during pregnancy was associated with small increases in the odds of GDMA1 (28 weeks: OR = 1.019, 95% CI: 1.002, 1.035) and GDMA2 (25 weeks: OR = 1.018, 95% CI: 1.002, 1.035). High temperatures appeared to strengthen the observed association between preconception O₃ exposure and GDMA1. Additionally, O₃ exposure during pregnancy may increase the risk of GDMA1 among women aged <35 years, preconception obesity, gestational hypertension, and family history of diabetes. Conclusions: This study suggests possible weak weekly-specific associations between O₃ exposure and GDM classifications and indicates that ambient high temperature may modify the O₃-GDM association. These findings should be interpreted cautiously and require confirmation in future studies.