Relation of Breast Cancer and Malathion Aerial Spraying in Arica, Chile

Abstract

SUMMARY:Breast cancer mortality has been increasing in Arica Chile where it has surpassed the national rates 11 times between 1990 and 2010. The city of Arica was sprayed with the organophosphrous pesticide malathion in order to control the Mediterranean fly 33 years ago. Moreover we have demonstrated that a malathion treatment induces the formation of breast carcinomas in Sprague Dowley female rats. The objective of this work was to find a relationship between malathion aerial spraying and the increased mortality rate due to breast cancer that has been observed in Arica in recent years. We extracted city data bases with all breast cancer cases diagnosed from 1995 to 2005 from the Dr. Juan Noe Crevani Hospital of Arica city and Ernesto Torres Hospital of Iquique. The number of patients was 100 in Arica and 58 in Iquique, nearby city that has never been sprayed with malathion which had a similar population than Arica in those years. The statistical analysis of the characteristics of the sample related to breast cancer risk showed that there is no significant difference between women from Arica and from Iquique. Nevertheless the patients with more times of exposure to malathion were 5.7-times more likely to be diagnosed with breast cancer (OR= 5.7; p<0.02). In addition, metastases were found in 30.5% of the malathion-exposed group and only in 16% in the group never exposed (p<0.05). This study suggests that the increase in the mortality rate due to breast cancer occurring in Arica has a significant correlation with the exposure to malathion sprayed over the city more than 30 years ago.

Carcinogenicidade e mutagenicidade do malathion e seus dois análogos: uma revisão sistemática

“…The other half of them obtained positive associations at statistically significant levels for thyroid cancer 78 , ovarian cancer in menopausal women 78 , prostate cancer 80,88 and its aggressive type 83 , breast cancer 81 , NHL 94,98 and between body mass index and cancer colonization among men who used malathion 89 .…”

“…In Chile, about 33 years after the first malathion spraying on the city of Arica, Cabello et al 81 conducted a case-control study with women living in the city and women from Iquique, a control city where spraying had never occurred. The authors observed that those with the most extended exposure to malathion were 5.7 times more likely to be diagnosed with breast cancer, besides 30.5% of the cases of metastases found in the exposed group, compared to 16% in the never exposed group (p < 0.05).…”

Plaguicidas organofosforados y cáncer en Latinoamérica: Evidencia para una discusión bioética

“…En otro estudio, Calaf et al (2009) evaluaron los efectos de pesticidas OP paratión y malatión ante la presencia de E2 en la transformación maligna e inestabilidad genómica e informaron que estos pesticidas, por separado o en combinación con E2 inducen transformación maligna en células mamarias, evidenciado por un incremento significativo en la expresión de las proteínas p53 y c-Ha-ras, cruciales para el proceso del cáncer. Cabello et al (2013) evaluaron la relación entre las 24 aspersiones con malatión realizadas sobre la ciudad de Arica en 1983 y el aumento en la tasa de mortalidad por cáncer de mama observada en dicha ciudad en los últimos años. Los autores encontraron que las mujeres con mayor tiempo de exposición a malatión fueron 5.7 veces más propensas a ser diagnosticadas con cáncer mamario (OR = 5.7, p < 0.02), evidenciándose además metástasis en un 30.5% del grupo expuesto y un 16% del grupo no expuesto.…”

Risk factors of breast cancer and knowledge about the disease: an integrative revision of Latin American studies

“…In a Chilean study on the relationship between BC and malathion aerial spraying, Cabello et al extracted additional data on BC patients from medical records 47 . Three studies used databases instead of interviews (Chart 1) 35,36,50 .…”