Use of methanol and workers' risk of exposure at a biodiesel plant/Uso do metanol e risco de exposicao dos trabalhadores de uma usina de biodiesel

Background: Methanol is used as raw material for biodiesel production and might cause especially visual and neurological disorders. Occupational exposure mainly occurs through vapor inhalation. However, the available data on the effects of human chronic exposure to methanol are limited. Aims: To describe situations and activities involving risk of exposure to methanol in a biodiesel plant and the possible presence of symptoms of contamination in workers. Methods: Data collection was performed by means of direct observation, interviews, document analysis and application of a questionnaire. Results: The production process included eight different situation os methanol exposure. Among the 42 participants in the study, 27 worked under conditions of direct methanol exposure and reported headache (71.42%) and tingling (42.00%) among other symptoms. The most important complaints related to the neurotoxic effects of methanol were irritation (40.50%), anxiety (35.70%) and headache (64.30%). Similarly, workers in administrative areas exhibited the same symptoms of contamination by the chemical. Conclusions: Workers performing various different activities were exposed to methanol; analysis of the symptoms associated with exposure to the solvent showed that most of them exhibited symptoms compatible with methanol contamination. Keywords | methanol; biofuels; energy sources; occupational risks; toxicity. Contexto: O metanol e usado como materia-prima na fabricacao de biodiesel e pode causar, em especial, danos oftalmologicos e neurologicos. A exposicao ocupacional acontece principalmente pela inalacao de vapores. No entanto, os dados relacionados aos efeitos da exposicao cronica ao metanol em humanos sao limitados. Objetivos: Mostrar situacoes e atividades com risco de exposicao ao metanol em uma planta de biodiesel e a presenca de possiveis sintomas de contaminacao nos trabalhadores. Metodos: Questionario, entrevistas, observacao direta e analise documental possibilitaram a coleta dos dados. Resultados: O processo produtivo apresentou oito situacoes de exposicao ao metanol. Entre os 42 sujeitos da pesquisa, 27 trabalhavam diretamente expostos e relataram ter dor de cabeca (71,42%), formigamento (42,00%), entre outros sintomas. As mais importantes queixas relacionadas com os efeitos neurotoxicos foram irritacao (40,50%), ansiedade (35,70%) e dor de cabeca (64,30%). Funcionarios das areas administrativas tambem apresentavam sintomatologia identica a de contaminacao pelo