Exposure to leaded gasoline lowered the IQ of about 50 {a78e43caf781a4748142ac77894e52b42fd2247cba0219deedaee5032d61bfc9} the inhabitants of the United States, a new research estimates. The peer-reviewed study, printed Monday in the journal Proceedings of the National Academy of Sciences, focuses on persons born ahead of 1996 — the year the U.S. banned fuel made up of lead. Total,