Industrial lead poisoning in China over the past 33 years.

This paper is a review of the 48 articles in scientific journals and special reports of investigations emanating from the author's department involving 2504 subjects. During the past 33 years, as a result of the establishment of health and antiepidemic stations throughout the country, the enactment of hygienic standards, and the setting up of the reporting system for industrial poisoning and occupational diseases, the air lead level has been reduced from 10 mg/m3 in the years soon after liberation (1949) to below 0.03 mg/m3 at present. Severe plumbism has disappeared. Some mild cases, however, could still be found among workers in lead smelters and electric battery plants. Great advances have been made in techniques for early diagnosis of lead poisoning. Blood lead, urine lead, aminolevulinic dehydrase, free erythrocyte protoporphyrin, and zinc protoporphyrin (ZnPP) have been used as criteria for lead exposure. For the purpose of preventive monitoring, ZnPP as a screening index is the first choice. Behavioral function and sensory and motor nerve conduction velocity measurements of median nerve might also be used for the investigation of lead exposure. The maximum allowable concentration of 0.03 mg/m3 for air lead level in the workshop, in agreement with the results of a nationwide lead industry investigation, has been proven safe. There is also the need to monitor the air lead level and blood lead level in the general population and children living adjacent to a lead industry.