Keywords: agriculture, environmental exposure, hyperthyroidism, hypothyroidism, pesticides, thyroid gland. Identifying modifiable risk factors for thyroid disease is important, given that an estimated 5%–9% of adults have subclinical thyroid disease and 0.8%–7.5% have clinical thyroid disease (1 – 3).ssociation between pesticide use and thyroid disease. There were 16,529 spouses who had thyroid data, pesticide use data, and all covariate data; 2.2% were classified as hyperthyroid, 6.7% as hypothyroid, 3.4% as having other thyroid disease, and 87.6% as having no thyroid disease.