A study involving Iowa women who live on farms finds exposure to some common farm chemicals may bring a greater risk for developing thyroid disease. Dr. Whitney Goldner, a researcher at the University of Nebraska Medical Center, says they studied more than 16,000 women who are married to farmers who were licensed to apply pesticides in Iowa and North Carolina.

Dr. Goldner, an assistant professor at the N-U Department of Internal Medicine, says, “There is increasing evidence that environmental exposure to pesticides should be considered a potential risk factor for thyroid disease.” She says 12.5% of the women who were exposed to the pesticides developed thyroid disease, compared to 1-to-8% in the general population.

Goldner says this shows there is an association between one of the fungicides and hyperthyroidism. She says, “They may have a bigger role than we’ve given them credit for and we need to explore this further.” Goldner says it’s important that those women who may have been exposed to pesticides are aware of the potential risks, the signs and symptoms of a thyroid problem.

She says, “Certain insecticides, herbicides and fungicides have been previously reported to be endocrine disrupters, which can interfere with the endocrine hormone system.”

Hypothyroidism, which is an underactive thyroid, may include symptoms of weight gain, fatigue, hair and skin changes and sensitivity to cold temperatures.

Hyperthyroidism is an overactive thyroid and can be associated with weight loss, higher heart rate, eye and skin changes and heat sensitivity.

The study was published in the American Journal of Epidemiology.