An evaluation of recent blood lead levels in Port Pirie, South Australia

The Port Pirie Lead Program commenced in 1984. The abatement program involves identification of children with elevated blood lead levels, house decontamination, soil treatment, development of heavily vegetated buffer zones around the smelter, family education and support and community education. Since 1984 the smelter has also implemented substantial new emission controls and environmental improvements. Blood lead and air monitoring programs as well as investigations of emission sources, ongoing household contamination and infant exposure mechanisms are in place. Although capillary blood lead monitoring has shown a significant decrease in the mean blood lead levels of the children, 61% of children aged 1-4 years still exceed 10 microg/dl, with 28% at or above 15 microg/dl. Re-entrainment of lead from the contaminated areas within the city is only a small contributor to air-borne lead levels compared with that from the smelter and its environs. The smelter has undertaken extensive work to reduce windborne fugitive emissions. While attempts to demonstrate reductions in air lead have been hampered by large annual variations in wind speed and direction, air lead studies have confirmed that only small losses are now arising from the stockpile area of the smelter site. Evidence suggests that worker hygiene improvements, relocation of children to lower exposure suburbs, community education, house decontamination, specific measures for individual children with elevated blood lead, and avoidance of tank rainwater have all been partially successful. A substantial investigation program has refocused intervention efforts towards reducing exposure from indoor environments during the first year of life and contributed to improved identification and ranking of ongoing smelter emission sources.