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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.

Substances added to food are considerable for survival and are the oldest technologies used in preservation, sweetening and coloring. This work was conducted to evaluate the toxicity of the food additives sunset yellow (SY) and brilliant blue (BB) on Allium cepa root meristematic cells. Control and treatment groups were created from germinated roots. Group 1 (control group) did not receive chemicals. Group 2 (SY or BB-treatment group), received increasing doses of SY (25, 50, 100 and 500 ppm) and BB (100, 200, 400 and 500 ppm) with time periods of 24, 48 and 72 h. After different treatment periods, the roots were obtained from all groups and EC 50 concentrations, cell death, chromosome aberrations, mitotic index were observed by a light microscopy. Changing antioxidant capacity of roots was determined by FRAP and TEAC assay. Also, DNA damage was measured by comet assay and RAPD-PCR technique. Approximately 50 and 200 ppm were accepted as EC 50 value for SY and BB, respectively. Chromosome aberration values were obtained with increasing concentrations and longer treatment times such as chromosome bridge, C-mitosis, micronucleus, chromosome mis-segregation in both groups. Increasing exposure doses of SY and BB caused decreasing mitotic index values at 72 h. FRAP and TEAC assay showed that antioxidant capacity of roots was decreased by increasing concentrations of SY and BB. The tail DNA% and tail length significantly increased for all exposure times when compared to the control group. 50 and 200 ppm of SY and BB caused a genotoxic effect on genetic material at 72 h according to RAPD-PCR. Increasing the doses of SY and BB resulted in increased toxicity to all studied parameters of A. cepa. In conclusion, the SY and BB tested in this study have cytotoxic and mutagenic potential. Furthermore, SY is more harmful than BB for use in the A. cepa root meristematic cells.

The genotoxicity of copper oxychloride was investigated in human lymphocytes using chromosome aberration (CA) and micronucleus (MN) tests and the randomly amplified polymorphic DNA-polymerase chain reaction technique. The lymphocytes were treated with 3, 6, and 12 µg/mL of copper oxychloride for 24 and 48 h. Copper oxychloride increased CA and abnormal cells in a dose-dependent manner. The frequency of MN and micronucleated binuclear cells also increased at all concentrations and treatment periods. However, copper oxychloride cytotoxicity, observed through lower mitotic and nuclear division index, was significantly lower only at the higher concentrations (6 and 12 µg/mL). Copper oxychloride increased the polymorphic bands and decreased genomic template stability. In conclusion, in this study it was confirmed that copper oxychloride has genotoxic potential for human lymphocytes in vitro. Additionally, caution is advised for its use as a fungicide, because it may increase the risk of exposure through the food chain., Competing Interests: The authors report no declaration of interest.