Charcoal workers in Bahia: Occupational hazards and urinary biomarkers of exposure to wood smoke.

摘要

Brazil has the largest production of charcoal in the world, which is used mostly in the iron and steel industries. This process depends heavily on human labor and empirical knowledge, resulting in less efficient charcoal production. The working conditions are precarious, and workers are exposed to wood smoke as well as to charcoal dust, which contain some irritant and genotoxic compounds. However, the health conditions of workers in this industrial activity are hardly ever targeted, and studies on chemical exposure in this occupation and the possible genetic damages are not available in the literature. Therefore, we conducted an industry-based cross-sectional study in the northeastern area of Bahia State, Brazil, to assess occupational hazards in charcoal industries, as well as biomarkers of exposure to wood smoke. Of 11 charcoal plants in the area, 8 companies were visited and 169 male adults that worked either in the wood cutting activity or in charcoal kilns were contacted. In addition to social demographic data, respiratory symptoms were collected using a standard questionnaire. Urinary mutagenicity, DNA damage detected by single cell gel electrophoresis in nasal epithelia, and 2-naphthol and 1-pyrenol in urine were quantified and related to levels of exposure to wood smoke. Some possible confounders or effect modifiers of the exposure-outcome relationships, such as smoking, polymorphism of glutathione S-transferase, alcohol and coffee intake, age, and nutritional habits were also assessed. In conclusion, we have demonstrated the applicability of three urinary biomarkers for monitoring exposure to wood smoke among charcoal workers. For this population, with a low smoking rate, all three biomarkers were convenient and informative. Urinary 2-naphthol was the most sensitive indicator of wood smoke exposure and was associated with the other variables. This is also the first report of the magnitude of internal exposure to wood smoke among charcoal workers. Because charcoal production is still an important activity in many developing countries, this cross-sectional study serves as a base for future research on the health effects of wood smoke exposure on charcoal workers.