title: Mutagenic potential assessment associated with human exposure to natural radioactivity.
abstract: Lucrécia city, known to harbor a high cancer rate, is located in a semiarid region characterized by the presence of mineral reservoirs, facing a high exposure to metal and natural radioactivity. The present study aimed to assess the environmental scenario at a semiarid region located in Northeastern Brazil. Metal concentration, alpha and beta radiation, and cyanobacteria content in tap water along with indoor radon and gamma emitters (U, K and Th) concentrations were measured. In addition, mutagenic and nuclear instability effects were assessed using buccal micronucleus cytome assay. The study included five samplings corresponding to a period between 2007 and 2009. Drinking water from Lucrécia city presented levels of Mn, Ni and Cr along with cyanobacteria in concentrations one to four times higher than regulatory guidelines considered. Furthermore, high levels of all the tested radionuclides were found. A high percentage of the houses included in this study presented indoor radon concentrations over 100 Bq m-3. The mean annual effective dose from Lucrécia houses was six times higher than observed in a control region. The levels of exposure in most of the Lucrécia houses were classified as middle to high. A significant mutagenic effect, represented as an increase of micronuclei (MN) frequency and nuclear abnormalities as nuclear buds (NB), binucleated cells (BN), and pyknotic cells (PYC) were found. The results obtained highlight the role of high background radioactivity on the observed mutagenic effect and could help to explain the exacerbated cancer rate reported in this locality.
authors.affiliation: Graduate Program in Health Sciences, Center for Health Sciences, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Alexandre Endres
authors.initials: AE
authors.lastname: Marcon
authors.affiliation: Graduate Program in Development and Environment, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Julio Alejandro
authors.initials: JA
authors.lastname: Navoni
authors.affiliation: Graduate Program in Biochemistry, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Marcos Felipe
authors.initials: MF
authors.lastname: de Oliveira Galvão
authors.affiliation: Graduate Program in Development and Environment, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Anuska Conde Fagundes Soares
authors.initials: ACFS
authors.lastname: Garcia
authors.affiliation: Graduate Program in Development and Environment, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil; Graduate Program in Biochemistry, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil; Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Viviane Souza
authors.initials: VS
authors.lastname: do Amaral
authors.affiliation: Geology Department, Center for Exact and Earth Sciences, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Reinaldo Antônio
authors.initials: RA
authors.lastname: Petta
authors.affiliation: Geology Department, Center for Exact and Earth Sciences, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Thomas Ferreira da Costa
authors.initials: TFDC
authors.lastname: Campos
authors.affiliation: Department of Microbiology and Parasitology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Panosso
authors.affiliation: Centro Nacional de Energia Nuclear, Poços de Caldas, MG, Brazil.
authors.forename: Antônio Luiz
authors.initials: AL
authors.lastname: Quinelato
authors.affiliation: Graduate Program in Health Sciences, Center for Health Sciences, Federal University of Rio Grande do Norte, Natal, RN, Brazil; Graduate Program in Development and Environment, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil; Graduate Program in Biochemistry, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil; Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil. Electronic address: sbatistu@cb.ufrn.br.
authors.forename: Sílvia Regina Batistuzzo
authors.initials: SRB
authors.lastname: de Medeiros
mesh_terms: D000293:Adolescent; D000328:Adult; D000396:Air Pollutants, Radioactive / Q000032:analysis / Q000633:toxicity; D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000032:analysis; D001938:Brazil; D060766:Drinking Water / Q000032:analysis / Q000382:microbiology; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals / Q000032:analysis / Q000633:toxicity; D015162:Micronucleus Tests; D008875:Middle Aged; D009061:Mouth Mucosa / Q000187:drug effects; D009153:Mutagens / Q000032:analysis / Q000633:toxicity; D011851:Radioactivity; D011868:Radioisotopes / Q000032:analysis / Q000633:toxicity; D011886:Radon / Q000032:analysis; D014873:Water Pollutants / Q000032:analysis / Q000633:toxicity; D055815:Young Adult
chemical_list: D000396:Air Pollutants, Radioactive; D060766:Drinking Water; D008670:Metals; D009153:Mutagens; D011868:Radioisotopes; D014873:Water Pollutants; D011886:Radon
keywords: Cyanobacteria; Environmental radioactivity; Exfoliated buccal micronucleus cytome assay; Metals; Mutagenicity; Radon