"A growing number of chemicals is linked with brain disorders in millions of children, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments. In 2006, we . . . identified five industrial chemicals as developmental neurotoxicants: lead, methylmercury, PCBs, arsenic, toluene, and six additional neurotoxicants — manganese, fluoride, chlorpyrifos, dichlorodiphenyltrichloroethane, tetrachloroethylene, and the polybrominated diphenyl ethers."