title: Letter: Chronic low-level lead exposure and mental retardation.
mesh_terms: D002648:Child; D004781:Environmental Exposure; D006801:Humans; D008607:Intellectual Disability / Q000139:chemically induced*; D007854:Lead / Q000032:analysis; D007855:Lead Poisoning / Q000150:complications*; D014867:Water / Q000032:analysis; D014877:Water Pollution, Chemical
chemical_list: D014867:Water; D007854:Lead