Multidimensional characterization of heterogeneity in pesticide co-exposure patterns.

OBJECTIVES: This study analyzed clinical data from 1641 pesticide-exposed patients screened for a total of 159 pesticide compounds admitted to Shandong First Medical University Affiliated Provincial Hospital from 1 January 2023 to 31 December 2024, aiming to elucidate the multidimensional heterogeneity of pesticide co-exposure patterns. METHODS: Clinical information and biological samples were collected from all participants. Pesticide detection was performed using Agilent 7890B-7250 Q-TOF/MS and AB SCIEX Triple Quad 4500MD mass spectrometry systems. Seasonal, gender-specific, and age-group variations in pesticide exposure were assessed, and a co-occurrence network was constructed to evaluate concurrent exposure patterns and concentration distributions. RESULTS: Herbicides exhibited the highest exposure prevalence within their respective tested sub-cohorts. Specifically, glyphosate showed a targeted detection frequency of 49.32% (144/292) among the screened individuals. Concentration peaks for glyphosate and paraquat occurred between July and September, with median levels reaching 3.42 and 3.15 log10 μg/L, respectively. Pesticide exposure displayed a bimodal age distribution, with a secondary peak among individuals aged 15-20 years and a primary peak in those aged 55-60 years. In the 40-55 age group, male exposure prevalence was significantly higher than female (male-to-female ratio: 2.8:1). Network analysis identified 38 significant co-occurrence patterns (r > 0.5, P < 0.0016), with the most prominent involving glyphosate, imidacloprid, and metolachlor. Log-transformed pesticide concentrations revealed marked differences in variability across chemical classes. Herbicides (e.g., glyphosate, paraquat) and certain broad-spectrum insecticides (e.g., chlorfenapyr) showed highly right-skewed concentration distributions, whereas tebuconazole and cinosulfuron exhibited relatively concentrated profiles. Thiamethoxam demonstrated substantially greater concentration variability compared to other compounds, indicating pronounced heterogeneity in its application patterns. Collectively, these findings highlight complex heterogeneity in pesticide exposure across temporal, demographic, and chemical dimensions. CONCLUSION: This study reveals distinct multidimensional heterogeneity in pesticide exposure, providing critical evidence for developing targeted intervention strategies. Tailored protective measures based on seasonal trends, gender-age subgroups, and prevalent co-exposure patterns may more effectively mitigate pesticide-related risks among agricultural populations.