Residential proximity to agricultural pesticide use and incidence of breast cancer in California, 1988-1997.

California is the largest agricultural state in the United States and home to some of the world’s highest breast cancer rates. The objective of our study was to evaluate whether California breast cancer rates were elevated in areas with recent high agricultural pesticide use. We identified population-based invasive breast cancer cases from the California Cancer Registry for 1988–1997. We used California’s pesticide use reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential. Using 1990 and 2000 U.S. Census data, we derived age- and race-specific population counts for the time period of interest. We used a geographic information system to aggregate cases, population counts, and pesticide use data for all block groups in the state. To evaluate whether breast cancer rates were related to recent agricultural pesticide use, we computed rate ratios and 95% confidence intervals using Poisson regression models, adjusting for age, race/ethnicity, and neighborhood socioeconomic status and urbanization. This ecologic (aggregative) analysis included 176,302 invasive breast cancer cases and 70,968,598 person-years of observation. The rate ratios did not significantly differ from 1 for any of the selected pesticide categories or individual agents. The results from this study provide no evidence that California women living in areas of recent, high agricultural pesticide use experience higher rates of breast cancer.

加利福尼亚是美国最大的农业州，也是世界上乳腺癌发病率最高的地区之一。我们研究的目的是评估在近期大量使用农用杀虫剂的地区，加利福尼亚的乳腺癌发病率是否升高。我们从1988 - 1997年的加利福尼亚癌症登记处确定了以人群为基础的浸润性乳腺癌病例。我们利用加利福尼亚的杀虫剂使用报告数据，根据使用量、致癌可能性和暴露可能性来选择用于分析的杀虫剂。利用1990年和2000年美国人口普查数据，我们得出了相关时间段内按年龄和种族划分的人口数量。我们使用地理信息系统汇总了该州所有街区群组的病例、人口数量和杀虫剂使用数据。为了评估乳腺癌发病率是否与近期农用杀虫剂的使用有关，我们使用泊松回归模型计算了比率和95%置信区间，并对年龄、种族/民族、社区社会经济地位和城市化程度进行了调整。这项生态学（综合）分析包括176302例浸润性乳腺癌病例和70968598人年的观察。对于任何选定的杀虫剂类别或单个药剂，比率与1相比均无显著差异。这项研究的结果没有提供证据表明生活在近期大量使用农用杀虫剂地区的加利福尼亚女性乳腺癌发病率更高。