Molomo Regina Ntsubise, Veludo Adriana Fernandes, Viglietti Paola, Wey Hannah, Petitpierre Anouk, Lindh Christian, Röösli Martin, Dalvie Mohamed Aqiel, Fuhrimann Samuel
Swiss Tropical and Public Health Institute (Swiss TPH), 4123 Allschwil, Switzerland; University of Basel, 4002 Basel, Switzerland.
Centre for Environmental and Occupational Health Research, School of Public Health, University of Cape Town 7925 Cape Town, South Africa.
Environ Int. 2025 Aug;202:109651. doi: 10.1016/j.envint.2025.109651. Epub 2025 Jun 28.
Understanding pesticide exposure variability over time among children is crucial towards understanding potential acute and long-term health effects of pesticides but data is lacking.
We assessed spatiotemporal and seasonal variability of urinary biomarkers in children at five time points across two years within three agriculturally intensive areas of the Western Cape, South Africa (Grabouw, Piketberg and the Hex River Valley).
A total of 201 children (aged 9-15 years) provided a total of 1005 spot urine samples and completed pesticide exposure-related questionnaires at five time points between 2017 and 2019. Nineteen urinary pesticide biomarkers including organophosphates, pyrethroids, dithiocarbamate and triazoles were analyzed using liquid chromatography tandem mass spectrometry and adjusted for specific gravity. Intraclass correlation coefficients (ICCs) evaluated temporal agreements between repeated urine samples. Linear mixed-effects models assessed the effects of farm residency, study area and pesticide spraying period on urinary pesticides levels. Risks of daily intake of pesticides were estimated using reverse dosimetry.
Ten out of fourteen detected biomarkers had a detection frequency above 75%. Levels of 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy) (ICC = 0.60) and 3, 5, 6-trichloropyridinol (TCPy; ICC = 0.49) showed moderate and fair temporal agreement between the five sampling points. Children in Grabouw had on average higher biomarker levels compared to the other two areas. Pesticides' specific spraying periods were associated with an increased TCPy (+32%), IMPy (+79%) and ethylene thiourea (ETU) (+81%) levels compared to non-spraying periods. The estimated daily intakes (EDIs) for most biomarkers were within the acceptable daily intakes (ADIs). However, EDIs exceeded the ADIs in 23.0% of children for TCPy, 8.9% for IMPy, and 0.5% for both 3,5-dichlorophenyl-2-chloroacetic acid (DCCA) and 4-hydroxy-pyrimethanil (OHP).
High temporal variability and regional exposure contrasts highlight the need for repeated urinary biomarker measurements across locations to accurately assess pesticide exposure for epidemiological studies in rural children. Observed exposure levels exceeding safety thresholds for organophosphates, pyrethroids and triazoles warrant further investigation.
了解儿童随时间变化的农药暴露变异性对于理解农药潜在的急性和长期健康影响至关重要，但目前缺乏相关数据。
我们评估了南非西开普省三个农业密集区（格拉布、皮克伯格和赫克斯河谷）内两年间五个时间点儿童尿液生物标志物的时空和季节变异性。
共有201名9至15岁的儿童提供了总计1005份随机尿样，并在2017年至2019年的五个时间点完成了与农药暴露相关的问卷调查。使用液相色谱串联质谱法分析了19种尿液农药生物标志物，包括有机磷、拟除虫菊酯、二硫代氨基甲酸盐和三唑类，并对比重进行了校正。组内相关系数（ICC）评估了重复尿样之间的时间一致性。线性混合效应模型评估了农场居住情况、研究区域和农药喷洒时期对尿液农药水平的影响。使用反向剂量法估计农药的每日摄入量风险。
在检测出的14种生物标志物中，有10种的检测频率高于75%。2-异丙基-4-甲基-6-羟基嘧啶（IMPy）（ICC = 0.60）和3,5,6-三氯吡啶醇（TCPy；ICC = 0.49）在五个采样点之间显示出中等和一般的时间一致性。与其他两个地区相比，格拉布的儿童生物标志物平均水平更高。与非喷洒时期相比，农药的特定喷洒时期与TCPy（+32%）、IMPy（+79%）和乙撑硫脲（ETU）（+81%）水平升高有关。大多数生物标志物的估计每日摄入量（EDI）在可接受的每日摄入量（ADI）范围内。然而，23.0%的儿童TCPy的EDI超过了ADI，8.9%的儿童IMPy的EDI超过了ADI，3,5-二氯苯基-2-氯乙酸（DCCA）和4-羟基嘧霉胺（OHP）的EDI超过ADI的儿童比例均为0.5%。
高时间变异性和区域暴露差异凸显了在不同地点重复测量尿液生物标志物以准确评估农村儿童流行病学研究中农药暴露的必要性。观察到的有机磷、拟除虫菊酯和三唑类的暴露水平超过安全阈值，值得进一步调查。
