According to an article recently published in the American Journal of Epidemiology, use of some residential pesticides may increase the risk of breast cancer. However, further studies evaluating this association are warranted before definite conclusions are made.
Breast cancer is diagnosed in over 200,000 women annually in the United States alone. Due to its prevalence, researchers have focused on evaluating environmental factors with potential links to the risk of breast cancer. Variables such as diet, exercise, age of menarche (first menstrual period), age at childbirth, and breastfeeding have demonstrated a relationship to the development of breast cancer. Researchers continue to evaluate other environmental factors that may influence this risk.
Researchers from New York and North Carolina recently conducted a study to evaluate the use of residential pesticides and a potential link to breast cancer. This study included 1,508 women with newly diagnosed breast cancer and 1,556 women without breast cancer. Study participants, who lived in Long Island, New York, were evaluated between 1996 and 1997. Residential pesticide use, as well as other risk factors, was assessed through in-person questionnaires administered by an interviewer.
- The use of pesticides was associated with an approximate 40% increased risk in developing breast cancer.
- Lawn and garden pesticide use was associated with an increased risk of breast cancer; however, larger doses over longer periods of time were not associated with increased risks compared to smaller overall doses.
- There was no significant association found between the use of nuisance-pest pesticides, insect repellants, or agents used on pets to control lice, fleas, or ticks.
The researchers concluded that use of residential pesticides may increase the risk of breast cancer; however, there was no apparent association between increased doses and increased risk of developing the disease. The authors state, “This study is the first known to suggest that self-reported use of residential pesticides may increase breast cancer risk. Further investigation in other populations is necessary to confirm these findings.”
Reference: Teitelbaum S, Gammon M, Britton J, et al. Reported residential pesticide use and breast cancer risk on Long Island, New York. American Journal of Epidemiology. 2007; 165: 643-651.