“…The rapid phasedown was accompanied by a nearly 90% reduction of children's blood Pb (Pirkle et al, 1994). By 1986, (5-6) Â 10 6 t of Pb had been used in the USA as a petrol additive, and about 75% of this Pb was released into the atmosphere (Chaney and Mielke, 1986;Mielke and Reagan, 1998). Thus, in the USA, an estimated 4-5 million tons of Pb was deposited into the environment, especially in urbanized areas, by vehicle traffic using petrol containing Pb additives (Mielke, 1994).…”