[Plastic industry and exposure to carcinogenic chemical agents: an Italian Multicentric Study in Lombardy]. / Stampaggio della plastica ed agenti chimici cancerogeni: l'esperienza dello studio PPTP-Plastica.

The potential carcinogenic risk at the workplaces is a primary interest of occupational health, but some questions are also controversially discussed. Particularly, in the plastic forming industry a great attention was directed to the hot processing and their possible exposure to monomers, some of which were classified as carcinogen by the International Agency for Research on Cancer (IARC) and/or the European Union (EU). In Lombardy, a study on occupational exposure to chemical carcinogens in the plastic forming industry was planned during last years. The aim was to recognize and promote preventive technical and medical solutions, basing on efficacy. By an investigation at workplace supported with standardized questionnaires, the presence of chemical carcinogens was registered in 59% of a representative sample of firms; but an effective possibility of exposure was found only for 34% of cases. The evaluation of exposure to monomers by air monitoring (acrylonitrile, 1,3-butadiene, styrene, formaldehyde), involving a representative sample of factory with ABS and formaldehydic resins processing, showed low level exposure, because the common hygienic prevention measures were applied; some particular occupation shoved greater exposure to formaldehyde.

[Lombardy regional project: prevention of occupational tumors]. / Progetto regione lombardia: prevenzione dei tumori professionali.

In Lombardy, the regional project "Prevention of occupational cancers" is ongoing. The main objectives of this project are to identify work environments in which there might be a possible exposure to carcinogenic substances and to elaborate preventive measures. A casual sample of 250 working settings representing the different economic activities has been selected and evaluated. The 10% of the examined workplaces showed a possible exposure to chemical carcinogens. The most common carcinogens were trichloroethylene, preparation of plastics materials containing acrylonitrile-butadiene-stirene, formaldehyde, wood dust, hexavalent chromium, silica and polycyclic aromatic hydrocarbons. Galvanic industries, Bitumen production and placing companies and Plastics processing plants will be studied for environmental and biological monitoring and for the development of preventive measures.

Behaviour of indicators of exposure and effect after cessation of occupational exposure to lead.

The behaviour of blood lead (PbB) and of some indicators of effect (erythrocyte protoporphyrin IX (EP), delta-aminolaevulinic acid dehydratase activity of erythrocytes (ALAD), and urinary delta-aminolaevulinic acid (ALAU)) were studied in subjects who had ceased working with inorganic lead for at least one year. Relations between these indices and chelatable lead (PbU-EDTA (lead in urine after injection of CaNa2 EDTA 1 g intravenously)), a test that is used to evaluate the lead deposits in the body, were also analysed. As a comparison, a group of subjects currently exposed was studied. In the workers with past exposure the PbB values were significantly lower, at the same PbU-EDTA levels, than those found in subjects at work. The relation between EP and PbU-EDTA shows that, corresponding levels of chelatable lead, the values of the erythrocyte metabolite are identical in the two groups. Considering the EP-PbB relation, however, at the same PbB levels the protoporphyrin values appear distinctly more altered in the subjects with past exposure. Similar results were obtained from a study of the relations between ALAD and PbU-EDTA and between ALAD and PbB. The relation between ALAU and PbU-EDTA, however, shows that, at the same PbU-EDTA levels the urinary metabolic in past-exposed subjects is distinctly lower than in subjects at work, while the relation between ALAU and PbB shows that, for similar blood lead values, the ALAU levels are identical. On the basis of the results obtained it is concluded that in subjects with past exposure, EP and ALAD can be used in establishing the persistence and extent of an "active deposit" of lead in the organism, while PbB is of very limited use.