Experience in controlling lead poisoning in the People's Republic of China.

This paper summarizes the work done to control lead poisoning in the People's Republic of China. The work can be divided into the following four phases: (i) health surveillance of lead workers, (ii) health standard setting, (iii) research for early detection indicators, and (iv) improvement of the work conditions and health surveillance of "undeserved" groups. In 1949 prevention started with the initiation of the health surveillance of lead workers. Since then health surveillance has been used to supplement environmental monitoring in the early detection of lead poisoning, and the prevalence of lead poisoning has decreased. This activity has also helped to identify the needs for improvement in technological control. The next step has been the promulgation of health standards. The current standard for lead gives the maximum allowable concentration in air as 0.03 mg/m3 for lead fume and 0.05 mg/m3 for lead dust. Research on indicators for the early detection of lead has improved the quality of prevention. It has recently led to the addition of zinc protoporphyrin to the list of indicators in use. Finally the work conditions and surveillance of workers that had earlier been considered "underserved," particularly workers in agriculture and small industries in rural areas, are being improved.