ABSTRACT
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.
ABSTRACT
AIM: This study aimed to identify the surviving bacteria in commercial raw pet food and to analyze the factors associated with their contamination. MATERIALS AND METHODS: A total of 17 samples from 12 brands available in Thailand were randomly selected for analysis. Fifteen samples were frozen products and two were freeze-dried. The total bacterial counts (TBCs) of Clostridium perfringens, Campylobacter spp., Staphylococcus aureus, Escherichia coli, Salmonella spp., Listeria spp., and Listeria monocytogenes were measured. Association between the bacterial profile and feed ingredients, as well as with product types, was analyzed by Chi-squared and Fisher's exact tests. RESULTS: Campylobacter was not found in any product, whereas Salmonella spp. and Listeria spp. showed the highest prevalence with respect to the standard's limits. The TBC was significantly related to the type of the products (frozen or freeze-dried), and S. aureus and L. monocytogenes were significantly related to a chicken-based diet. CONCLUSION: Pet food contamination can occur during the manufacturing process, storage, or even preparation. The freezing and drying processes may reduce, but not eradicate, the bacterial contamination in raw pet food. These results emphasize the need for quality control in the manufacturing process and show the importance of personal hygiene for the pet owner to reduce health risks.
