A systematic review of the physical and chemical characteristics of pollutants from biomass burning and combustion of fossil fuels and health effects in Brazil

The aim of this study was to carry out a review of scientific literature published in Brazil between 2000 and 2009 on the characteristics of air pollutants from different emission sources, especially particulate matter (PM) and its effects on respiratory health. Using electronic databases, a systematic literature review was performed of all research related to air pollutant emissions. Publications were analyzed to identify the physical and chemical characteristics of pollutants from different emission sources and their related effects on the respiratory system. The PM2.5 is composed predominantly of organic compounds with 20% of inorganic elements. Higher concentrations of metals were detected in metropolitan areas than in biomass burning regions. The relative risk of hospital admissions due to respiratory diseases in children was higher than in the elderly population. The results of studies of health effects of air pollution are specific to the region where the emissions occurred and should not be used to depict the situation in other areas with different emission sources

Malignant Mesothelioma: Mechanism of Carcinogenesis

International audienceAlmost 60 years ago, malignant mesothelioma (MM) was acknowledged as a specific cancer related to the inhalation of asbestos fibers (1). Its strong association with asbestos exposure triggered the development of researches. They consisted in epidemiological studies to know the risk factors that explain MM occurrence in the population, and of experimental studies to understand MM biological development as a neoplastic disease. Since that time, MM remains a rare and highly aggressive cancer that prompts researches to better manage patients with MM and to offer efficient therapies. To achieve this goal, a solid knowledge of the mechanisms of mesothelial carcinogenesis is needed and deserves basic researches to progress. So far, our knowledge is based on pathophysiological and toxicological researches, and from biological and molecular studies using MM tissue tumor samples and cell lines from humans and experimental animals. Most experimental studies have been based on the cellular and/or animal responses to asbestos fibers, and in genetically modified mice, demonstrating the genotoxic effect of asbestos and relationship with MM induction. The development of large-scale analyses allowing global integration of the molecular networks involved in mesothelial cell transformation should increase our understanding of mesothelial carcinogenesis. In human, MM tumors appeared as heterogeneous entities, based on morphological patterns and molecular specificities including gene mutations. The recent development of high throughput methods allowed classification of MM according to their histological type, genomic and epigenomic characteristics and deregulated pathways. The aim of the present review is to propose a potential mechanism of mesothelial carcinogenesis by integrating data, underlying the mechanisms that may be shared with other types of fibres that may pose current health issue