Lawsuits claiming that the widely used bug killer chlorpyrifos caused brain damage in children were filed Monday in California. Past research has shown that the pesticide harms the brains of fetuses and children, the Associated Press reported.

Chlorpyrifos is approved for use on more than 80 crops but was banned for household use in 2001. The U.S. Environmental Protection Agency is considering whether to ban the pesticide or declare it safe. California banned the pesticide last year and the spraying of it this year. Some other states have moved to ban it, the AP reported. California records show that from 1974 through 2017, 61 million pounds of the pesticide were applied in Fresno, Kings, Madera, and Tulare counties, where the lawsuits were filed, according to Stuart Calwell, lead attorney in the lawsuits.

The plaintiffs are parents suing on behalf of children with severe brain damage that the lawsuits claim was caused by exposure to chlorpyrifos while they were in the womb or very young. At least 100,000 homes may need to dispose of most of their belongings because they are contaminated with the pesticide, lawyers said.

Nearby spraying is not the only source of contamination: Parents, relatives, or others in frequent contact with children worked in the fields or packing plants and were exposed to the chemical that they passed on to children. Calwell said he filed related lawsuits last fall on behalf of farmworkers who his firm said "spent years marinating in the pesticide."

The latest lawsuits seek potential class-action damages from Dow Chemical and its successor company Corteva Inc., which stopped making the pesticide last year. Neither company responded to requests for comment, the AP reported.