It is here presented the project sustained by the Ministry of Public Instruction, University and Research "Environmental and Occupational Exposure to Inorganic Lead: assessment of human health effects due to current doses and preventive measures" ruled out between 2001 and 2003. The aim of the study was to investigate about the toxic effects related to current occupational exposures to inorganic lead (particularly those effects concerning blood pressure, carcinogenic risk, nervous and immunological systems), to identify hypersusceptibility conditions, particularly the ALAD genetic polymorphism and to evaluate the role of traditional biomarker and the possibility of introducing new ones. In the present article the procedures followed during the project lasting and the contribution of each Unit are described. The results of the research, presented in detail in the current issue, do confirm the inadequacy of the biological exposure index nowadays ruled by Lex 25/2002.