The notion that dental amalgam is a potential source of mercury exposure remains a controversial issue. However, there are few epidemiological analyses that have addressed whether this occurs in children. We aimed in our current study to identify the relationship between dental amalgam filling surfaces and the blood mercury levels in a cohort of 711 South Korean children aged between 8-9 years. Oral examinations were conducted to detect the number of amalgam filling surfaces on the teeth of these individuals. Blood samples were also taken from these children to assess the levels of mercury accumulation in the body. The amalgam filling surfaces were classified into four groups based on their number: 0 (n = 368), 1-5 (n = 219), 6-10 (n = 89), and 11+ (n = 35). The blood mercury levels in the children with more than 10 amalgam surfaces was 0.47 μg/L higher on average than those with no amalgam surfaces after adjusting for the frequency of fish or seafood consumption, age, and gender (P < 0.05). We found from our data that a higher number of dental amalgam fillings correlated with a higher blood mercury level in Korean children. Further studies are needed to investigate whether these elevated mercury levels exert neurotoxic or nephrotoxic effects.
In this work, the present concentration levels of total gaseous mercury (TGM) are compared among three East Asian countries, Korea, China, and Japan. Comparison of Hg distribution patterns was made by selecting representative figures for each type of land use among those three countries. The results of the analysis indicate that Hg concentrations within a country can fall into a wide range due probably to the diversity of source processes. It is seen that the urban areas of China and Japan generally exhibit large spatial variability with notably high Hg levels (above 10 ng m-3), compared to their Korean counterparts. Although the presence of high Hg levels in Chinese locations can be accounted for by the major man-made source processes (e.g., the use of coal), the causes of unexpectedly high Hg data in Japanese sites appear to be rather complicated. The Hg concentration levels in relatively remote locations however show much reduced values, above 3 ng m-3, which is still higher than the typical background concentrations of 1 to 2 ng m-3 in Europe or America. Considering that the presence of unusually high Hg levels in urban areas of Asia is the consequence of man-made activities, the prevalence of excessively high Hg values in certain regions of the Asian continent needs further research to accurately assess the fundamental picture of Hg geochemistry in the East Asia.
1980년대 말 시점과 1990년대 말 시점을 비교구간으로 설정하여 서울 한남동지역에 대한 대기중 수은의 농도분포변화양상을 비교해 보았다. 긴 시간 동안 발생원과 소멸원이 지닌 관계의 변화와 같은 영향에 의해, 양 기간대의 농도분포는 절대적 및 상대적 관점에서 모두 뚜렷한 차이를 보여 주었다. 80년대말 시점의 농도가 14.4±9.56 ngm-3인데 반해, 90년대 말 시점에는 이보다 1/3 가까이 감소한 5.34±3.92ngm-3를 유지하였다. 두 기간대에 관측된 농도 및 주변환경변수를 여러 가지 주기별로 수은의 농도분포양상을 비교해 보았다. 24시간 주기 또는 계절별로도 양기간대의 농도분포는 뚜렷한 차이를 보여 주었다. 과거 시점에는 낮 시간대에 고농도가 발생하는 현상이 빈번한데 반해, 현 시점에서는 이러한 양상을 확인하기가 어려웠다. 또한 계절적으로 겨울철에 고농도가 집중되는 현상은 과거나 현재나 유사하지만, 과거의 경우 겨울철 고농도가 여타 계절에 비해 확연했던데 반해, 최근의 분석결과는 계절간 차이가 상당 수준 줄어 들었다는 것을 보여 주었다. 이들 자료를 이용하여, 여러 가지 통계분석을 실시한 결과, 양 기간대에 현저하게 차이가 나는 농도분포는 주로 각 기간대별로 수은의 농도를 조절하는 주생성원의 성격이 현저하게 다른 데 따른 가능성이 강할 것으로 사료된다.