METALS. Lead, Pb. Unique properties - used since antiquity Mostly anthropogenic sources (Greenland snow pack data, 1954) Banned as paint additive Europe 1921 USA 1978 Sources: smelters, refineries, power plants, incinerators, manufacturing and recycling operations. Exposure to Pb.
(Greenland snow pack data, 1954)
Annual US air emissions:
In blood - 25 days
Half life In soft tissue - 40 days
In bone - 25 years !
(phosphate and acetate forms)
CNS effects from blood level =10ug/dl (1ug/ml) - CDC
OSHA air 200ug/m3
EPA max 0.01mg/l, (goal 5ug/l)
Critical daily dose 300mgHg Health effects
No drinking water safety levelNickel - Ni