The standards for heavy metal levels in crustaceans are 0.5 mg/kg and 1.0 mg/kg or lower for lead and cadmium, respectively. Further, the contamination levels of arsenic, mercury, methyl mercury, and tin are being continuously investigated, considering their current exposure levels. Shrimps are potentially exposed to heavy metals because they inhabit areas with abundant organic matter, such as sandy or muddy shores, places with a lot of seaweed, and estuaries. This study measured the monetary value of reducing consumer anxiety and increasing consumer confidence if the government prohibits the sale of shrimp species that exceed the threshold for specific heavy metals and of the top shrimp species for which no threshold for heavy metals is specified. We derived consumer willingness-topay (WTP). Combining the estimated WTP with the number of households in the country, the total value of benefits was estimated to be 363.9 billion won. The results of this study will provide an important empirical finding, showing to what extent specific policies regarding heavy metals in seafood can alleviate consumer anxiety and provide psychological reassurance.
도시생활폐기물소각재(MSWI ash)을 매립하게 되면 장기적으로 중금속이 침출된다. 급속탄산화를 통하여 MSWI ash 내의 중금속을 탄산염 형태로 고정하여, 중장기적으로 침출을 방지할 수 있다. 본 연구에서는 급속 탄산화 방법을 통하여 소각재인 fly ash의 중금속 저감 및 이산화탄소 저감에 대해 수행하였다. NH4OH, NH4SCN, 및Ca(OH)2를 이용하여 test 하였으며, 소각재의 중금속을 탄산화 전, 후를 비교하여 중금속이 침출량을 비교 하였다. 추가적으로 이산화탄소가 fly ash에 포집된 이산화탄소 저감량을 나타내면서 이산화탄소 흡수제의 재사용 가능성을 확인하였다. 흡수제를 재생하는 과정에서 나온 CO32-이온에 의해 탄산화 된 금속염들의 성분 분석을 위해, XRD (X-ray diffraction analyzer(Ultima Ⅳ))를 사용하였다. 그리고 FE-SEM(Field emission scanning electron microscope, JEOL-7800)으로 filtering후 건조시킨 샘플과 fly ash의 표면구조를 촬영하고 비교하였다.
The effects of aloe on the MDA(malondialdehyde) and the blood biochemical components of heavy metal poisoning in SD rat were examined and the following results were obtained. In rat liver homogenate intoxicated with CdCl_2, lipidperoxide was increased each 2.37times(24h), 3.31times(72h) but lipidperoxide in aloe administration groups was lower each 47%, 64% than in heavy metal group. In rat kidney homogenate intoxicated with CdCl_2, lipidperoxide was increased 1.85times(24h), 1.33times(72h) but lipidperoxide in aloe administration groups was almost the same as that of normal group. Lipidperoxide of kidney homogenate was slightly decreased as time passed. Also heavy metal poisoning rats showed high levels(1.38-2.50times) of serum AST, ALT and BUN. However, the administration of aloe significantly inhibited the reduction of them. These results suggest that Cd-induced hepatic and renal injury, via increase lipidperoxide and release of AST, ALT and BUN. Aloe may be used to inhibit or prevent the hepatic and renal toxicity which results from the heavy metal.