Genotoxic effects in occupational exposure to formaldehyde: A study in anatomy and pathology laboratories and formaldehyde-resins production

ABSTRACT – Background: According to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Presently, the International Agency for Research on Cancer classifies formaldehyde as carcinogenic to humans (Group 1), based on sufficient evidence in humans and in experimental animals. Manyfold in vitro studies clearly indicated that formaldehyde can induce genotoxic effects in proliferating cultured mammalian cells. Furthermore, some in vivo studies have found changes in epithelial cells and in peripheral blood lymphocytes related to formaldehyde exposure. Methods: A study was carried out in Portugal, using 80 workers occupationally exposed to formaldehyde vapours: 30 workers from formaldehyde and formaldehyde-based resins production factory and 50 from 10 pathology and anatomy laboratories. A control group of 85 non-exposed subjects was considered. Exposure assessment was performed by applying simultaneously two techniques of air monitoring: NIOSH Method 2541 and Photo Ionization Detection equipment with simultaneously video recording. Evaluation of genotoxic effects was performed by application of micronucleus test in exfoliated epithelial cells from buccal mucosa and peripheral blood lymphocytes. Results: Time-weighted average concentrations not exceeded the reference value (0.75 ppm) in the two occupational settings studied. Ceiling concentrations, on the other hand, were higher than reference value (0.3 ppm) in both. The frequency of micronucleus in peripheral blood lymphocytes and in epithelial cells was significantly higher in both exposed groups than in the control group (p < 0.001). Moreover, the frequency of micronucleus in peripheral blood lymphocytes was significantly higher in the laboratories group than in the factory workers (p < 0.05). A moderate positive correlation was found between duration of occupational exposure to formaldehyde (years of exposure) and micronucleus frequency in peripheral blood lymphocytes (r = 0.401; p < 0.001) and in epithelial cells (r = 0.209; p < 0.01). Conclusions: The population studied is exposed to high peak concentrations of formaldehyde with a long-term exposure. These two aspects, cumulatively, can be the cause of the observed genotoxic endpoint effects. The association of these cytogenetic effects with formaldehyde exposure gives important information to risk assessment process and may also be used to assess health risks for exposed worker

Desenvolvimento de Competências Musicais no 2.º Ciclo do Ensino Básico: Práticas Pedagógicas

A disciplina de Educação Musical está presente no currículo do ensino básico nacional há quarenta e cinco anos, no entanto a informação sobre as práticas musicais nessas aulas é escassa. A presente tese tem por objecto de estudo as práticas dos professores de Educação Musical no 2.º ciclo do ensino básico e pretende perceber o que efectivamente se ensina nessas aulas. Participaram 411 alunos e 15 professores, ao longo de duas fases do estudo: uma fase exploratória, constituída por entrevistas qualitativas a uma pequena amostra (4 professores e 10 alunos) e uma segunda fase, dividida em duas etapas de recolha e análise de dados – questionário a alunos e professores (construído com base nos resultados do estudo exploratório), seguido de entrevistas focalizadas aos professores (participaram, nesta fase, 401 alunos e 11 professores de 9 escolas do 2º ciclo do ensino básico). Trata-se de um estudo misto (qualitativo e quantitativo). O questionário teve como objectivo averiguar as percepções dos alunos e dos professores relativamente às práticas pedagógicas desenvolvidas na aula de Educação Musical. Seguiram-se as entrevistas focalizadas aos professores, que tiveram o intuito de os confrontar com as suas respostas e com as dos seus alunos e ampliar a compreensão das mesmas. Os resultados mostraram que os professores realizam maioritariamente actividades no âmbito das áreas de interpretação, teoria e audição musical. Por outro lado, concretizam poucas experiências de aprendizagem e, ainda menos, actividades de composição musical. Constata-se que as contingências circundantes influenciam as práticas lectivas na disciplina de Educação Musical. A profissionalidade docente é uma construção indissociável das práticas dos professores. Discutem-se os resultados e suas implicações para intervenções pedagógicas no âmbito da Educação Musical, numa lógica de reflexão/investigação/acção sobre a prática.