Background

A number of epidemiologic studies with a variety of exposure assessment approaches have implicated pesticides as risk factors for childhood cancers. Here we explore the association of pesticide exposure in pregnancy and early childhood with childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) utilizing land use and pesticide use data in a sophisticated GIS tool.

Methods

We identified cancer cases less than 6 years of age from the California Cancer Registry and cancer-free controls from birth certificates. Analyses were restricted to those living in rural areas and born 1998–2011, resulting in 162 cases of childhood leukemia and 9,805 controls. Possible carcinogens were selected from the Environmental Protection Agency's classifications and pesticide use was collected from the California Department of Pesticide Regulation's (CDPR) Pesticide Use Reporting (PUR) system and linked to land-use surveys. Exposures for subjects were assessed using a 4000m buffer around the geocoded residential addresses at birth. Unconditional logistic and hierarchical regression models were used to assess individual pesticide and pesticide class associations.

Results

We observed elevated risks for ALL with exposure to any carcinogenic pesticide (adjusted Odds Ratio (aOR): 2.83, 95% CI: 1.67–4.82), diuron (Single-pesticide model, adjusted (OR): 2.38, 95% CI: 1.57–3.60), phosmet (OR: 2.10, 95% CI: 1.46–3.02), kresoxim-methyl (OR: 1.77, 95% CI: 1.14–2.75), and propanil (OR: 2.58, 95% CI: 1.44–4.63). Analyses based on chemical classes showed elevated risks for the group of 2,6-dinitroanilines (OR: 2.50, 95% CI: 1.56–3.99), anilides (OR: 2.16, 95% CI: 1.38–3.36), and ureas (OR: 2.18, 95% CI: 1.42–3.34).

Conclusion

Our findings suggest that in rural areas of California exposure to certain pesticides or pesticide classes during pregnancy due to residential proximity to agricultural applications may increase the risk of childhood ALL and AML. Future studies into the mechanisms of carcinogenicity of these pesticides may be beneficial.

中文翻译：

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产前农药暴露和儿童白血病 - 加利福尼亚州全州病例对照研究。

背景

许多采用各种暴露评估方法的流行病学研究表明，农药是儿童癌症的危险因素。在这里，我们利用复杂的 GIS 工具中的土地利用和农药使用数据，探讨了怀孕和幼儿期农药暴露与儿童急性淋巴细胞白血病 (ALL) 和急性髓性白血病 (AML) 的关联。

方法

我们从加利福尼亚癌症登记处确定了 6 岁以下的癌症病例，并从出生证明中确定了无癌症对照。分析仅限于生活在农村地区和 1998-2011 年出生的人，导致 162 例儿童白血病和 9,805 例对照。可能的致癌物是从环境保护局的分类中选出的，农药使用是从加州农药管理部 (CDPR) 的农药使用报告 (PUR) 系统中收集的，并与土地使用调查相关联。在出生时使用地理编码的住宅地址周围的 4000m 缓冲区评估受试者的暴露情况。无条件逻辑和层次回归模型用于评估单个农药和农药类别的关联。

结果

我们观察到暴露于任何致癌农药的 ALL 风险升高（调整后的优势比 (aOR)：2.83，95% CI：1.67–4.82）、敌草隆（单一农药模型，调整后（OR）：2.38，95% CI：1.57 –3.60)、亚胺磷 (OR: 2.10, 95% CI: 1.46–3.02), kresoxim-methyl (OR: 1.77, 95% CI: 1.14–2.75), and propanil (OR: 2.58, 95% CI: 1.44–4. ）。基于化学类别的分析显示，2,6-二硝基苯胺（OR：2.50，95% CI：1.56-3.99）、苯胺（OR：2.16，95% CI：1.38-3.36）和尿素（OR）组的风险升高: 2.18, 95% CI: 1.42–3.34)。

结论

我们的研究结果表明，在加利福尼亚的农村地区，由于住宅靠近农业应用，怀孕期间接触某些杀虫剂或杀虫剂类别可能会增加儿童患 ALL 和 AML 的风险。未来对这些农药致癌机制的研究可能是有益的。