Summary

The aim of this study is to provide information on the occupational exposure of Québec workers to lead, and covers an eight-year period (2001 – 2008). Lead in the air is a substance regularly analyzed by the IRSST laboratories, and blood lead is the most common toxicological analysis. The study provides information on the number of establishments involved in health programs for which analyses were requested and involving lead, their classification in Québec's economic activities (CAEQ) and in which economic activity sectors (SAEs) they work, as well as their geographical location by administrative region. For many two-digit CAEQ codes, at least 40% of the results exceed twice the new standard of 0.05 mg/m³. This is the case mainly for the CAEQ codes for Residential Developers and Builders, Wholesale Metal and Metal Products, Wholesale Waste and Recovery Materials businesses, Automobile Dealerships, Protection Services, Mines, Industrial Chemicals Industries, and Other Non-Metallic Mineral Product Industries. In total, there are 20 two-digit CAEQ codes where at least one-third of the results exceed the current standard.

The four-digit CAEQ codes for which the highest concentrations of lead in the air were measured during this period were Large Industrial Structures (93% of the results above twice the standard), Other Wholesale Waste and Recovery Materials (74%), Painting and Decorating Work (71%), Wholesale Scrap Metal (61%), Paint and Body Shops (58%), Wholesale Combination Metal and Metal Products, Gold Mines, Other Wire Products Industries, Plastic and Synthetic Resin Industries, and Local Police Forces, with all these latter sectors having 56% of the results above twice the standard.

For the period of the study, some 16,817 blood lead results are available and cover 6717 different workers from 500 establishments, 159 CAEQ codes and 28 SAEs. By retaining only the maximum blood lead levels for each worker, the results show that 27 workers exceeded a concentration of 2.42 µmol/L (500 µg/L) during the 2001-2004 period, with some workers exceeding this value for several years. This number decreased to 15 workers for the 2005-2008 period. It is very interesting to note that the number of workers with at least one high blood lead level has decreased regularly over time, suggesting better control of worker exposure.

The results presented allow the conclusion that the workers with the highest blood lead levels are found in the SAEs of Trade, Other Commercial and Personal Services, and Primary Metals Industries. More specifically, they are found in the CAEQ codes for the Battery Industry, Smelting and Refining of Non-Ferrous Metal Industries, Other Smelting and Non-Ferrous Metal Industries, Other Motor Vehicle Repair Shops, Other Rolled, Cast and Extruded Non-Ferrous Metal Products Industries, and Wholesale Scrap Metal Businesses. The results indicate that the existing preventive efforts must be pursued in many companies.