국내 혼획 고래류의 섭취기준 마련을위한 무기질 및 중금속 함량 평가

Abstract

In Korea, the many marine mammals have been being caught by entanglement in fishing gear including the narrow-ridged finless porpoise Neophocaena asiaeorientalis, common dolphin Delphinus delphis, common minke whale Balaenoptera acutorostrata, and pacific white-sided dolphin Lagenorhynchus obliquidens. This study aims to establish criteria for ensuring the safe consumption of cetaceans and reducing bycatch of marine mammals in capture fisheries. The study focused on analyzing the levels of minerals and heavy metals in various categories of cetaceans, common minke whale (CMW), common dolphin (CD), pacific white-sided dolphin (PWD). Based on the analysis results, their nutritional intake and health risk assessment based guidance value by Joint FAO/WHO Expert Committee on Food Additives evaluated. Human exposure was calculated for a total person average for all surveyors in the National Health and Nutrition Examination Survey and an ingestion person average for only the ingestion person. The linearity, limit of detection (LOD), and limit of quantification (LOQ) of minerals and heavy metal standards were determined. All linearity results showed a positive R2 value of 0.999 or higher. The automatic mercury analyzer showed that the recovery rates of mercury and methylmercury from DORM-4 were effective. In order to compare pre-treatment methods, a standard reference material (SRM) was utilized for both graphite block and microwave digestion. The results indicated that the use of the graphite block method did not yield effective recovery rates for sulfur, selenium, and zinc, but using a microwave for pre-treatment led to all mineral recovery rates falling within the effective range in SRM. The mineral and heavy metal contents of cetaceans were analyzed by categorizing them based on their species and body parts. It was shown that there was a significant variation in mineral content between the meat and organs when they were compared. The contents of sodium, calcium, iron, copper, manganese, and selenium were high in the organs, but other minerals in them were similar to the meat. For example, sodium levels ranged from 656.18 to 3,426.61 mg/kg, calcium levels varied from 66.43 to 616.07 mg/kg, iron levels varied from 21.35 to 943.71 mg/kg, copper levels ranged from 0.45 to 15.19 mg/kg, manganese levels ranged from 155.52 to 4,558.18 μg/kg, selenium levels ranged from 382.35 to 19,152.65 μg/kg, and molybdenum levels varied from 4.73 to 532.90 μg/kg in organs of cetaceans, the meat of cetaceans had low levels of them, ranging from 533.40 to 1,379.69 mg/kg (sodium), 56.41 to 129.11 mg/kg (calcium), 5.68 to 180.52 mg/kg (iron), 0.52 to 2.33 mg/kg (copper), 66.16 to 964.54 μg/kg (manganese), 299.73 to 5,771.84 μg/kg (selenium), and 4.77 to 20.82 μg/kg (molybdenum). The minerals in the liver and kidney were found to be at high concentrations, while the other body parts had similar levels of minerals. In terms of heavy metals, there was no notable difference in the levels of mercury and methylmercury between meat and organs. However, organs had higher concentrations of lead and cadmium, ranging from 12.00 to 91.66 μg/kg (lead) and 16.32 to 50,414.05 μg/kg (cadmium). The liver and kidney had significantly higher levels of these heavy metals. When comparing mineral contents based on cetacean species, CDs had high levels of major minerals such as sodium, magnesium, phosphorus, potassium, and zinc, ranging from 961.79-3,426.61 mg/kg for sodium, 104.97-436.74 mg/kg for magnesium, and 719.89-3,321.8 mg/kg for phosphorus. Potassium levels were found to be between 1,095.66-5,450.34 mg/kg, and zinc levels were between 14.11-74.44 mg/kg. PWDs had high levels of trace minerals, particularly molybdenum and selenium, ranging from 5.26-532.90 μg/kg for molybdenum and 775.00-19,152.65 μg/kg for selenium. There was no difference in mercury and lead content of heavy metals between the cetacean species. Methylmercury was predominantly detected in cetacean muscle and cadmium was present in high levels throughout their bodies, including their organs and meat. Although all cetaceans tested did not exceed the standard value for lead and methylmercury, all parts of their bodies exceeded the cadmium standard. Furthermore, the mercury standard was exceeded in the intestines of all cetaceans, and most parts of their bodies contained similar to Korea’s maximum levels of 500 μg/kg. Mineral intakes were evaluated using the dietary intake (DI) and maximum intake (MI) methods. RNI and PTWI values for heavy metals were calculated based on these methods. After analyzing the DI, it was determined that both RNI and PTWI were quite low, indicating that the intake of minerals and heavy metals is safe. According to the MI, the RNI for calcium, copper, and manganese was lower than that of the main food sources, while the RNI for iron in the liver and selenium in the organs exceeded the upper limit RNI. Regarding PTWI, lead was less than 100% in meat and organs, but most cadmium, mercury, and methylmercury in organs exceeded 100%. Some meat regions also exceeded 100% for these substances, and mercury in VM exceeded 100% in all regions. Based on the data collected, the ADIs for CMW were 858.81 g/day (DM), 75.91 g/day (VM), 1,310.56 g/day (blubber), 275.58 g/day (liver), 83.33 g/day (lung), 65.82 g/day (intestine), 46.93 g/day (kidney), and 65.18 g/day (heart). Additionally, the ADIs for CD were 241.79 g/day (DM), 89.33 g/day (VM), 99.00 g/day (blubber), 2.74 g/day (liver), 50.33 g/day (lung), 53.82 g/day (intestine), 1.10 g/day (kidney), and 84.54 g/day (heart). Finally, the ADIs for PWD were 726.99 g/day (DM), 48.78 g/day (VM), 165.77 g/day (blubber), 11.30 g/day (liver), 119.79 g/day (lung), 58.87 g/day (intestine), 6.30 g/day (kidney), and 78.13 g/day (heart). The heavy metal results of meat of cetacean species bycatch in Korean coastal waters met all Korean maximum levels. However, lead and cadmium of internal organs exceed Korean standards as the maximum detection concentration standard, and continuous monitoring in the future is considered necessary. The human body exposure calculated using the congestion intake and heavy metal detection concentrations was less than the JECFA human safety standard, and the risk of heavy metals due to meat cetacean species bycatch in Korean coastal waters intake was acceptable. The results of this survey will be used as basic data for heavy metal pollution in cetacean species bycatch in Korean coastal waters. It can also be used as policy data for the safe seafood supply.