We report the association of levels of urinary arsenic (As) compounds (arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ), dimethylarsinic acid (DMA V ), and arsenobetaine (AB)) with genetic polymorphisms of candidate genes, glutathione S-transferase omega 1 (GSTO1) and 2 (GSTO2), mu 1 (GSTM1), and theta 1 (GSTT1), arsenic (+3 oxidation state) methyltransferase (AS3MT), methylenetetrahydrofolate reductase (MTHFR), and DNA repair gene XPD in 100 subjects from Ha Nam Province in the Red River Delta, Vietnam. No significant relationship between As levels and genetic polymorphisms of GSTT1 and MTHFR was observed. GSTM1 null was found to be associated with increased percentage of urinary DMA V. High concentrations of As V in urine were observed in individuals with Asn142Asp genotype of GSTO2. Subjects with gene polymorphisms of Glu155del in GSTO1 and Met287Thr in AS3MT had higher ratios of urinary MMA V /(As III + As V ) indicating higher capacity for primary As methylation. We found that intronic polymorphisms of G12390C wild-type homozygosity and G35991A variant-type homozygosity in AS3MT were associated with lower DMA V / MMA V and DMA V percentages in urine, respectively. Percentages of As III in the urine of subjects with Lys751Gln genotype in XPD were higher than those with wild type. From our findings, it can be concluded that genetic polymorphisms in GSTM1, GSTO1, GSTO2, AS3MT, and XPD may be responsible for As metabolism and toxicity in Vietnamese.
Artisanal small-scale gold mining (ASGM) is the largest single source of mercury (Hg) emissions globally. In this study, Hg contamination was investigated in rice, vegetables, soil, drinking water and groundwater near ASGM sites in Mandailing Natal District, North Sumatra, Indonesia to assess the human health risk of Hg to the residents. The mean Hg concentrations in the rice and vegetables were 50±33 μg/kg dw (n=20) and 2,100±2,500 μg/kg dw (n=12), respectively, and that in the paddy soil and farm soil were 5,600±12,000 μg/kg dw (n=20) and 19,000±33,000 μg/kg dw (n=12), respectively. Hg concentrations in the food, soil and drinking water samples decreased significantly with increasing distance from the amalgam burning facility to the sampling site, suggesting that the burning facility is a major source of Hg in this area. All drinking water samples were below the WHO safe value of Hg, whereas 96% of the vegetable and 82% of rice samples exceeded the safe value from the Indonesian National Standard or the FAO/WHO. The non-cancer risk calculated from the hazard quotients for the rice and vegetables exceeded 1 for children and adults. This paper provides information on Hg contamination in food and the environment in an understudied area, employing health risk assessment to evaluate long-term impacts on human health and offering insights for government decision-making regarding food quality.
On April 16, 2016, a series of earthquakes with a maximum magnitude of 7.0 struck Kumamoto Prefecture, Japan, and about 1,300,000 metric tons of land-derived debris (building materials, household appliances, furniture, and wood) required disposal. Because public lands were used as emergency debris storage sites, environmental contamination by organic micropollutants from the debris has been a public concern. To identify chemicals of concern in the soil, our research group used a novel scheme in the combination of comprehensive target analysis (CTA) with an automated identification and quantification system (AIQS) that made use of gas chromatography–mass spectrometry (GC-MS). CTA-AIQS identified a total of 120 organic micropollutants in the soil samples from the debris storage sites. The predominant chemical groups in debris soils were PAHs, plasticizers, and pesticides. Higher concentrations of pesticides (insecticides and fungicides) were detected in soil under waste wood because those chemicals were used as wood preservation and termiticides. Estimated hazard quotients of the detected chemicals via soil ingestion by children (a high-risk group) suggested that the health risk was probably negligible. It was concluded that CTA-AIQS would be a useful tool for emergencies such as natural disasters.
Arsenic concentrations in hair and urine, and urinary levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, were examined for inhabitants of the Mekong Basin in Kratie Province, Cambodia. Also, the arsenic levels of tube-well water were determined. Total arsenic concentrations in tube-well water ranged from <1 to 886 μg L−1, and 44.8% of these exceeded the WHO drinking water guideline of 10 μg L−1. Elevated levels of arsenic were observed in the human hair and urine, and also a significant positive correlation was observed between the concentrations in hair and urine. These results suggest that the inhabitants are chronically exposed to arsenic through drinking the tube-well water. Levels of urinary 8-OHdG were higher for the subjects with higher arsenic levels in hair and urine, suggesting that induction of oxidative DNA damage was caused by chronic exposure to arsenic in tube-well water for the inhabitants in Kratie Province. To our knowledge, this is the first report on the oxidative DNA damage caused by chronic exposure to arsenic in groundwater for the inhabitants in Cambodia.
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