title: Letter: Chronic low-level lead exposure and mental retardation.
mesh_terms: D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000139:chemically induced*; D007854:Lead / Q000009:adverse effects*; D007855:Lead Poisoning / Q000150:complications; D014877:Water Pollution, Chemical; D014881:Water Supply
chemical_list: D007854:Lead