O gás radônio e a radiação natural em terrenos metagraníticos e pegmatíticos: O caso do município de Lages Pintadas (Rio Grande do Norte, Brasil).

Abstract

The Indoor Radon is an important risk factor for environmental contracting lung cancer. The city of Lages Pintadas (Brazil) has a high incidence of cancer in relation to neighbouring municipalities. Geologically the region is formed by metagranitic and pegmatitic rocks. This paper presents the results of 210 passive Radon detectors, distributed in the urban municipality of residences of cited city. Measurements occurred during two periods of 4 months in dry season (December-March). The room has no roof, with ceramic tiles, cement floor and/or ceramic. The Indoor Radon for two periods ranging between 15 to 2893 Bq/m3 (MED: 288; AM: 566; GM: 291; SD: 625). For the first measurement, the level varied between 11 to 4055 Bq/m3 (Med: 228; AM: 803; GM: 298; SD: 993), but for the second measurement, there are greater dispersion of data due to the occurrence of rain out-of-season , ranging 7 to 3792 Bq/m3 (Med: 320; AM: 750; GM: 284; SD: 800), but for the second sentence there has been greater dispersion of data due to the occurrence of rain out-of-season with 7 range on 3792 Bq/m3 (Med: 320; AM: 750; GM: 284; SD: 920). Therefore, all the dwellings studied exceeded the level of action 100 Bq/m3 for indoor Radon (WHO, ZEEB II & SHANNOUN III, 2009). Gamma radiation of dwellings varied between 16-109 nGy/h (MG: 78; DP: 17) were considered normal. The high values of “Indoor Radon” is due that the city of Lages Painted developed upon several outcrops of pegmatite bodies, which are naturally enriched and uranium.