Nasterlack Michael
Occupational Medicine and Health Protection Department, BASF AG, Ludwigshafen, Germany.
Int J Hyg Environ Health. 2007 Oct;210(5):645-57. doi: 10.1016/j.ijheh.2007.03.001. Epub 2007 Apr 16.
Epidemiological studies have reported associations between childhood cancer and either parental or child exposure to pesticides. Reviews have been published in 1997, 1998 and 2006 where the evidence was found suggestive but not conclusive. The present review is an extended update of the latter one.
The PubMed database was searched to identify published studies on this topic issued between 1998 and 2006.
Thirty-six new studies have been identified for this review. Some cohort studies and the majority of the case-control studies suggest an increased risk for the cancer types studied, associated with exposure to pesticides in at least one of a large variety of exposure categories. However, the evidence is conflicting with regard to cancer types as well as to causative factors across studies. The major shortcomings concern exposure assessment, where, e. g., "farming" is treated equal to "exposure to pesticides", disregarding other possible exposures, e.g., to biological or infectious agents, and hitherto unidentified lifestyle factors. Also, many exposure categories used, mainly in case-control studies, lack chemical or toxicological plausibility. In most studies exposures were categorized as "ever vs. never", with little regard of exposure intensity or duration.
The available literature does not allow firm conclusions with regard to pesticides and any type of childhood cancer. But even if the reported associations were true, exposure to pesticides could not explain the vast majority of childhood cancer cases. Investing in the acquisition and critical review of exposure information appears to be the crucial step for causal assessment in future research. However, focusing on the presence of pesticides, and not asking the question why they were used, might mask relevant associations to other causative agents.
流行病学研究报告了儿童癌症与父母或儿童接触杀虫剂之间的关联。1997年、1998年和2006年已发表相关综述，其中发现证据具有提示性但不具有决定性。本综述是对后者的扩展更新。
检索PubMed数据库，以识别1998年至2006年期间发表的关于该主题的研究。
本次综述确定了36项新研究。一些队列研究和大多数病例对照研究表明，在所研究的癌症类型中，至少在多种接触类别中的一种中接触杀虫剂会增加风险。然而，关于癌症类型以及不同研究中的致病因素，证据存在冲突。主要缺点在于接触评估，例如，“务农”被等同于“接触杀虫剂”，而忽略了其他可能的接触，如接触生物或传染因子以及迄今尚未明确的生活方式因素。此外，许多主要在病例对照研究中使用的接触类别缺乏化学或毒理学合理性。在大多数研究中，接触被分类为“曾经接触与从未接触”，而很少考虑接触强度或持续时间。
现有文献无法就杀虫剂与任何类型的儿童癌症得出确凿结论。但即使所报告的关联是真实的，接触杀虫剂也无法解释绝大多数儿童癌症病例。投资获取和批判性审查接触信息似乎是未来研究因果评估的关键步骤。然而，关注杀虫剂的存在，而不探究其使用原因，可能会掩盖与其他致病因素的相关关联。
