DNA damage in oral epithelial cells of individuals chronically exposed to indoor radon (222Rn) in a hydrothermal area

• Published in: Environmental geochemistry and health 2018-10, Vol.40 (5), p.1713-1724
• Main Authors: Linhares, Diana Paula Silva, Garcia, Patrícia Ventura, Silva, Catarina, Barroso, Joana, Kazachkova, Nadya, Pereira, Rui, Lima, Manuela, Camarinho, Ricardo, Ferreira, Teresa, dos Santos Rodrigues, Armindo
• Format: Article
• Language: English
• Subjects: Adult; Aged; Air Pollutants, Radioactive - analysis; Air Pollutants, Radioactive - toxicity; Air Pollution, Indoor - analysis; Area; Azores; Banding; Cancer; Carcinogenesis; Carcinogens; Chronic exposure; Cross-Sectional Studies; Damage assessment; Damage detection; Degassing; Deoxyribonucleic acid; Detectors; DNA; DNA Damage; Earth and Environmental Science; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring - methods; Epithelial cells; Epithelial Cells - cytology; Epithelial Cells - metabolism; Epithelial Cells - radiation effects; Exposure; Female; Gases; Geochemistry; Hazardous areas; Human populations; Humans; Hydrothermal systems; Indoor air pollution; Indoor environments; Lung cancer; Lungs; Male; Micronucleus Tests; Middle Aged; Mouth Mucosa - cytology; Mouth Mucosa - metabolism; Mouth Mucosa - radiation effects; Mutation; Nucleotide sequence; Original Paper; PCR; Polymerase chain reaction; Population studies; Portugal; Primers; Public Health; Radon; Radon - analysis; Radon - toxicity; Radon isotopes; Radon levels; Random amplified polymorphic DNA; Random Amplified Polymorphic DNA Technique; Risk analysis; Risk factors; Soil; Soil Science & Conservation; Stream degassing; Terrestrial Pollution; Volcanic activity; Volcanic Eruptions; Volcanic gases; Volcanoes
• ISSN: 0269-4042; 1573-2983
• DOI: 10.1007/s10653-016-9893-2

Hydrothermal areas are potentially hazardous to humans as volcanic gases such as radon ( 222 Rn) are continuously released from soil diffuse degassing. Exposure to radon is estimated to be the second leading cause of lung cancer, but little is known about radon health-associated risks in hydrothermal regions. This cross-sectional study was designed to evaluate the DNA damage in the buccal epithelial cells of individuals chronically exposed to indoor radon in a volcanic area (Furnas volcano, Azores, Portugal) with a hydrothermal system. Buccal epithelial cells were collected from 33 individuals inhabiting the hydrothermal area (Ribeira Quente village) and from 49 individuals inhabiting a non-hydrothermal area (Ponta Delgada city). Indoor radon was measured with Ramon 2.2 detectors. Chromosome damage was measured by micronucleus cytome assay, and RAPD-PCR was used as a complementary tool to evaluate DNA damage, using three 10-mer primers (D11, F1 and F12). Indoor radon concentration correlated positively with the frequency of micronucleated cells ( r s  = 0.325, p  = 0.003). Exposure to radon is a risk factor for the occurrence micronucleated cells in the inhabitants of the hydrothermal area (RR = 1.71; 95% CI, 1.2–2.4; p  = 0.003). One RAPD-PCR primer (F12) produced differences in the banding pattern, a fact that can indicate its potential for detecting radon-induced specific genomic alterations. The observed association between chronic exposure to indoor radon and the occurrence of chromosome damage in human oral epithelial cells evidences the usefulness of biological surveillance to assess mutations involved in pre-carcinogenesis in hydrothermal areas, reinforcing the need for further studies with human populations living in these areas.