Towards a Brazilian radon map: consortium radon Brazil.

Recently, the idea of generating radon map of Brazil has emerged. First attempts of coordinating radon surveys--carried out by different groups across the country--and initial discussions on how to proceed on a larger scale were made at the First Brazilian Radon Seminary, Natal, September 2012. Conventionally, it is believed that indoor radon is no major problem in Brazil, because the overall benign climate usually allows high ventilation rates. Nevertheless, scattered measurements have shown that moderately high indoor radon concentrations (up to a few hundred Bq m⁻³) do occur regionally. Brazilian geology is very diverse and there are regions where an elevated geogenic radon potential exists or is expected to exist. Therefore, a Brazilian Radon Survey is expected to be a challenge, although it appears an important issue, given the rising concern of the public about the quality of its environment.

Feasibility study for a long-term follow-up in a historical cohort of Brazilian coal miners.

The first Brazilian historical mortality cohort study on miners was conducted. The cohort consisted of 3224 workers in the underground coal mining industry in southern Brazil. This industry has been operating since 1942 without compliance with any regulatory standards, since there were no relevant national regulations. Over almost 60 years, about 5000 workers were exposed to high levels of radiation. However, later radiation exposure was significantly reduced, particularly that due to radon exposure. Recent radon concentration measurements indicated an average annual exposure to radon progeny of 2.1 WLM, ranging from 0.2 to 7.2 WLM. As radon exposure in the past was unknown, it can be suggested that mine workers have not been working safely as regards the health hazard related to radon and radon progeny exposure. The cohort inclusion criteria are as follows: (a) all male employees who had worked for at least one year at the coal mine; (b) workers with complete workplace information (underground and surface); (c) employment hiring between 1945 and 1997 and (d) the worker must have been alive on 1 January 1979. Through multiple strategies of search it was possible to follow up the members of the cohort with a success rate of 92%. This paper presents the characteristics of the study population and provides information about the feasibility of conducting a retrospective mortality study in Brazil, taking into account the methodological and logistical difficulties of conducting such a study in a developing country.

High radon exposure in a Brazilian underground coal mine.

The main source of radiation exposure in most underground mining operations is radon and radon decay products. The situation of radon exposure in underground mining in Brazil is still unknown, since there has been no national regulation regarding this exposure. A preliminary radiological survey in nonuranium mines in Brazil indicated that an underground coal mine in the south of Brazil had high radon concentration and needed to be better evaluated. This paper intends to present an assessment of radon and radon decay product exposure in the underground environment of this coal mining industry and to estimate the annual exposure to the workers. As a product of this assessment, it was found that average radon concentrations at all sampling campaign and excavation sites were above the action level range for workplaces of 500-1500 Bq m(-3) recommended by the International Commission on Radiological Protection--ICRP 65. The average effective dose estimated for the workers was almost 30 times higher than the world average dose for coal miners.

Distribuição temporal e espacial dos casos de leucemia na cidade Goiânia após o acidente radiológico com Cs-137.

Apresentação que expõe os resultados da pesquisa que avaliou a variação temporal e a distribuição espacial de leucemia em Goiânia, após o acidente com o Césio 137. O estudo compreende o período de 1988 a 2002 e analisou a população por sexo e faixa etária, apontando os grupos que potencialmente tiveram mais contato com o acidente e que ainda hoje pedem reparações na justiça pelos danos. Inclui dados sobre a incidência de leucemia em diferentes períodos na região, a incidência de câncer na região e em outras regiões do Brasil, o mapa das áreas mais afetas pelo acidente, a distribuição dos 183 casos de leucemia em Goiânia de 1997-2002 e a distribuição da população na região. Expõe as conclusões e as limitações do estudo.