Mortality from breast cancer and use of pesticides in the western mesoregion of Santa Catarina – Brazil

Abstract

Chronic exposure to endocrine-disrupting pesticides may be related to breast cancer emergence in agricultural regions. This study aimed to investigate whether the consumption of pesticides is correlated with breast cancer mortality rates in the female population of western Santa Catarina. A retrospective ecological study was carried out. The number of deaths from breast cancer and agricultural production per planted area in the western mesoregion were obtained from public databases. The average of the standardized mortality coefficients was calculated in the periods: 2005 to 2009, 2010 to 2014, and 2015 to 2019. Raw data on pesticide consumption were grouped from 2000 to 2004, considering that the biological effects of chronic exposure occur late. Thus, previous exposure was considered in this study, in which consumption of pesticides occurred five, ten, and 15 years before death. For statistical analysis, thematic cartography and the Quantum GIS technique were used. The overlay method was applied to perform the spatial correlation. Considering 15 years of exposure, the sum of municipalities with an above-average rate of mortality from breast cancer occurred in 93 of the 118 municipalities in western Santa Catarina, which have an above-average history of pesticide consumption (R2=0.69). In 79% of cases, mortality occurred at a frequency above the average in municipalities whose pesticide consumption also exceeded the regional average. A proportional correlation between breast cancer mortality rates and the use of endocrine-disrupting pesticides was found.