October 11, 1988 New York Times headline–Science Watch; Less Lead in Rivers. “A decline in lead contamination in major American rivers has been found at two-thirds of 300 sites studied from 1974 to 1985, scientists at the United States Geological Survey have reported.
The report chiefly attributed the decline to a 75 percent drop in use of leaded gasoline in that period. The most rapid drop in lead content was recorded from 1979 to 1980, when use of leaded gasoline took its sharpest drop.
Preliminary analyses of more recent data indicate that the decline in lead contamination is continuing.”