Association of pesticide exposure and risk of breast cancer mortality in Mississippi

Abstract

Breast cancer is the most common form of cancer among women in the United States. Established risk factors include advancing age, early menarche, late menopause, positive first relative, late age of first birth and socioeconomic status. Mississippi has a combination of risk factors making it suitable for studying the pathways of breast cancer etiology. The purpose of this study was to analyze pesticide exposure and the risk of breast cancer mortality. Data for this study consisted of secondary analyses of the Mississippi age-adjusted breast cancer mortality aggregated by period (1970-1994). The total number of acres planted during 1997-2000 for each Statistical Economic Area (SEA) and by type of crop was used as proxy measure for pesticide exposure. Analyses by SEA revealed potential evidence for an association between pesticide exposure and risk of breast cancer mortality in three areas: Greenville, Corinth and Yazoo. The total number of acres planted was positively and significantly associated with female breast cancer mortality rate, and these associations differed by race and type of crop. The strongest correlation was between breast cancer mortality rate for white women and rice crops planted in Yazoo (rho = 0.674, p < 0.030). Moderate correlations were found between African-American breast cancer mortality rates and total acres planted in Corinth (rho = 0.667, p < 0.049), catfish crops in Greenville (rho = 0.648, p < 0.031), and although not statistically significant (p < 0.066) also with total planted acres in Greenville (rho = 0.573). In conclusion, there are moderate statistically significant associations between number of acres of crops planted and the mortality rate from breast cancer in Mississippi. The association varies by state economic area, race and type of crop planted.