Potential Health Effects of Heavy Metals and Carcinogenic Health Risk Estimation of Pb and Cd Contaminated Eggs from a Closed Gold Mine Area in Northern Thailand.

Gold-mining activities have been demonstrated to result in significant environmental pollution by Hg, Pb, and Mn, causing serious concerns regarding the potential threat to the public health of neighboring populations around the world. The present study focused on heavy-metal contamination in the eggs, blood, feed, soil, and drinking water on chicken farms, duck farms, and free-grazing duck farms located in areas < 25 km and > 25 km away from a gold mine in northern Thailand. In an area < 25 km away, Hg, Pb, and Mn concentrations in the eggs of free-grazing ducks were significantly higher than > 25 km away (p < 0.05). In blood, Hg concentration in free-grazing ducks was also significantly higher than those in an area > 25 km away (p < 0.05). Furthermore, the Pb concentration in the blood of farm ducks was significantly higher than in an area > 25 km away (p < 0.05). The concentration of Cd in drinking water on chicken farms was significantly higher for farms located within 25 km of the gold mine (p < 0.05). Furthermore, a high correlation was shown between the Pb (r2 = 0.84) and Cd (r2 = 0.42) found between drinking water and blood in free-grazing ducks in the area < 25 km away. Therefore, health risk from heavy-metal contamination was inevitably avoided in free-grazing activity near the gold mine. The incremental lifetime cancer risk (ILCR) in the population of both Pb and Cd exceeded the cancer limit (10−4) for all age groups in both areas, which was particularly high in the area < 25 km for chicken-egg consumption, especially among people aged 13−18 and 18−35 years old. Based on these findings, long-term surveillance regarding human and animal health risk must be strictly operated through food chains and an appropriate control plan for poultry businesses roaming around the gold mine.

Carcinogenic Risk of Pb, Cd, Ni, and Cr and Critical Ecological Risk of Cd and Cu in Soil and Groundwater around the Municipal Solid Waste Open Dump in Central Thailand.

Several consequences of health effects from municipal solid waste caused by carcinogenic and noncarcinogenic metals have been recognized. The water quality index (WQI) in the groundwater around this landfill is 2945.58, which is unacceptable for consumption. The contaminated groundwater mainly appears within a 1 km radius around the landfill. The metal pollution levels in the soil in descending order were Cu > Cd > Zn=Cr > Pb > Ni. The pollution degree (ER) of Cd was 2898.88, and the potential ecological risk index (RI) was 2945.58, indicating that the risk level was very high. Surprisingly, the hazard index (HI) of Pb (2.05) and Fe (1.59) in children was higher than 1. This indicated that the chronic risk and cancer risk caused by Pb and Fe for children were at a medium level. Carcinogenic risk by oral (CR oral) consumption of Ni, Cd, and Cr in children was 1.4E - 04, 2.5E - 04, and 1.8E - 04, respectively, while the lifetime carcinogenic risk (LCR) of Ni, Cd, and Cr in children was 1.5E - 04, 2.8E - 04, and 2.0E - 04, respectively. In adults, CR oral of Ni and Cr were 1.6E - 03 and 3.0E - 04, respectively, while LCR of Ni and Cr were 1.6E - 03 and 3.4E - 04, respectively, which exceeded the carcinogenic risks limits. Our study indicated a lifetime carcinogenic risk to humans. Environmental surveillance should focus on reducing health risks such as continuous monitoring of the groundwater, soil, and leachate treatment process.

Health significant alarms of toxic carcinogenic risk consumption of blood meal metals contamination in poultry at a gold mining neighborhood, northern Thailand.

The proposes of this study were to compare THg (total mercury), Pb(Lead), Cd(Cadmium), and Mn (Manganese) contamination in poultry blood between polluted areas (≤ 25 km) and unpolluted areas (> 25 km) adjacent to the largest gold mining in northern Thailand. The THg level in the free-grazing duck in polluted areas was significantly higher than unpolluted area. Both THg and Pb levels in free-grazing duck were also highest in polluted areas. In contrast, the level of (Mn) in chicken blood was the highest in polluted areas. Cadmium in farmed duck from polluted areas was significantly higher than unpolluted areas. The target hazard quotient (THQ) and hazard index (HI) of Hg, Pb, Cd, and Mn in all age groups in both areas did not exceed 1, meaning there is no possibility of the non-carcinogenic toxicity. Whereas, the incremental lifetime cancer risk (ILCR) of both Pb and Cd exceeded 1 × 10-4 in all age groups and these were particularly higher in the polluted area and considered to yield significant health effects of increasing the cancer risk. The ILCR in descending order for Pb and Cd was 13-18 years old = 18-35 years old > 6-13 years old = 35-65 years old > 3-6 years old > 65 up years old, respectively. The results revealed that the human cancer risk related to consuming poultry blood contaminated with both Pb and Cd in all age groups must be of concern, especially 13-18 and 18-35 years, it must be recommended to avoid raising animals in contaminated areas, especially free-grazing duck.

Pb, Cd, and Cu Play a Major Role in Health Risk from Contamination in Duck Meat and Offal for Food Production in Thailand.

Zinc, Pb, Cd, Mn, Fe, Cr, and Cu levels in duck meat from large-scale farms have been found to be significantly higher than those from free-grazing duck farms. Zinc, Co, Mn, Cr, and Cu contamination levels in duck liver from large-scale farms were significantly higher than those from free-grazing farms; only Cd in duck liver from free-grazing farms was higher than in liver samples from large-scale farms at P < 0.05. Lead, Cd, Fe, and Cr levels in duck intestine samples from free-grazing farms were higher than large-scale farms at P < 0.001. Moreover, the average concentrations of Pb in duck meat and liver samples from large-scale farms and Cd levels in duck liver samples from free-grazing farm also exceeded the FAO/WHO and Codex Alimentarius limits by 100% (55/55), 100% (54/54), and 67.6% (23/34), respectively. PCA analysis showed a strong positive relationship between the eight metals in meat, liver, and intestine was > 0.69, > 0.69, and > 0.72, in order. The relationship of the liver combined with the intestine was > 0.65. This study indicated that consumers may incur health risks from long-term consumption of duck due to high Pb and Cd concentrations from both types of farms, particularly from large-scale duck farms.