Organochlorine pesticides (OC’s) are a form of pesticides used for mosquito control that have been banned in some countries but many countries still use these pesticides. These pesticides are dangerous to a human because they appear similar to the body's natural thyroid hormones t3 and t4, making them endocrine disruptors. Previous studies have shown they can also affect the immune system by causing an autoimmune thyroid, which is a condition due to the body's immune system attacking the thyroid gland, and is prevalent among two percent of the world population. This study is aimed to look at why the OC’s cause an autoimmune thyroid. It’s known that these OC’s are treated like antigens in the body, in which the immune system fights off to get rid of and create lymphocytes (memory cells). The hypothesis is that since OC's appear similar to t3 and t4, someone exposed to OC's will have lymphocytes against the OC’s that will recognize t3 and t4 as OC's, and produce antibodies that will attack the cells that make the t3 and t4, therefore causing an autoimmune thyroid. For the proposed experiment, people living in an area contaminated with OC pesticides will be given antinuclear antibody tests, tests that are able to determine if the lymphocytes against the OC have been producing antibodies that attack the body's thyroid gland, causing an autoimmune disorder. It is expected that these tests will be mostly positive due to previous studies using these tests while looking at other autoimmune disorders.