Department of Occupational Health and Safety, Faculty of Public Health, Mahidol University, 420/1 Rajvidhi Road, Bangkok 10400, Thailand.
Center of Excellence on Environmental Health and Toxicology, EHT, Bangkok 10400, Thailand.
Int J Environ Res Public Health. 2019 Jul 29;16(15):2704. doi: 10.3390/ijerph16152704.
Pesticides can act as endocrine disruptors by different mechanisms including inhibition of iodine absorption, increases in thyroid hormone clearance, decreased cellular uptake of thyroid hormones, or changes in expression of thyroid hormone regulated genes. This study examined how exposure to pesticides impacts thyroid hormone levels, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), free T3 (FT3), and free T4 (FT4) by comparing conventional ( = 195) and organic farmers ( = 222), and by evaluating which types of pesticides might be associated with changes in thyroid hormone levels. Questionnaires were used to collect information about farmer characteristics, self-reported stress, agricultural activities, and history of pesticide use. Conventional farmers were asked to report the type and quantity of pesticides used each day. The TSH, FT3, T3, and T4 levels of conventional farmers were 1.6, 1.2, 1.3, and 1.1 times higher than those of organic farmers, respectively, after adjusting for covariates. Several specific herbicides had a significant relationship between the amount applied and an increase in thyroid hormone levels, after covariate adjustment. They included: paraquat (TSH, FT3 and T3); acetochlor (FT4); atrazine (TSH, FT3 and T3); glyphosate (T4); diuron (TSH) and the "other" herbicides including alachlor, propanil, and butachlor (FT4 and T3). The most commonly used herbicide among conventional farmers was glyphosate, followed by paraquat, 2,4-dichlorophenoxyacetic acid (2,4-D). These findings suggest that exposure to pesticides could impact the development of metabolic diseases and other health outcomes by altering the endocrine system (the thyroid hormone levels) through the hypothalamic-pituitary-thyroid (HPT) axis. This work is a part of a longitudinal study which will evaluate the sub-chronic effects of repeated exposure to different types of pesticides on thyroid hormone levels.
农药可以通过不同的机制充当内分泌干扰物，包括抑制碘吸收、增加甲状腺激素清除率、减少甲状腺激素的细胞摄取，或改变甲状腺激素调节基因的表达。本研究通过比较传统农民（=195）和有机农民（=222），评估了暴露于农药如何影响甲状腺激素水平、促甲状腺激素（TSH）、三碘甲状腺原氨酸（T3）、甲状腺素（T4）、游离 T3（FT3）和游离 T4（FT4），并评估了哪些类型的农药可能与甲状腺激素水平的变化有关。调查问卷用于收集有关农民特征、自我报告的压力、农业活动和农药使用史的信息。传统农民被要求报告每天使用的农药类型和数量。调整协变量后，传统农民的 TSH、FT3、T3 和 T4 水平分别比有机农民高 1.6、1.2、1.3 和 1.1 倍。几种特定的除草剂与甲状腺激素水平的增加之间存在显著的关系，这些除草剂包括：百草枯（TSH、FT3 和 T3）、乙草胺（FT4）、莠去津（TSH、FT3 和 T3）、草甘膦（T4）、敌草隆（TSH）以及其他除草剂包括甲草胺、异丙甲草胺和丁草胺（FT4 和 T3）。传统农民中最常用的除草剂是草甘膦，其次是百草枯和 2,4-二氯苯氧基乙酸（2,4-D）。这些发现表明，暴露于农药可能通过下丘脑-垂体-甲状腺（HPT）轴改变内分泌系统（甲状腺激素水平），从而影响代谢性疾病和其他健康结果的发展。这项工作是一项纵向研究的一部分，该研究将评估反复暴露于不同类型的农药对甲状腺激素水平的亚慢性影响。
