국내 조선소 주변해역의 해양오염 현황 - 2. 2010년 하계 대형조선소 주변 해수의 중금속오염 평가
국내 대형 조선소 주변해역의 중금속오염 현황을 밝히기 위하여 2010년 여름에 4개의 대형 조선소 주변 11개의 채수정점과 4개의 대조 정점에서 해수 시료를 채취하여 6종의 금속(Cu, Zn, Fe, Cd, Pb, Hg)을 분석하였다. 조선소별 주변해역 수중의 금속을 분석한 결과, (1) 구리(Cu)의 평균 농도는 0.817 ~ 1.638 ㎍/L로 해역환경기준(사람의 건강보호기준 20 ㎍/L, 해양생태계 보호 단기기준 3 ㎍/L)보다 낮았지만, 대조정점에 비하여 1.64 ~ 2.75배의 높은 값을 나타냈다. (2) 아연(Zn)의 평균 농도는 0.228 !~ 0.567 ㎍/L로 해역환경기준(사람의 건강보호기준 100 ㎍/L, 해양생태계 보호 단기기준 34 ㎍/L)보다 낮았지만, 대조정점에 비하여 1.62 ~ 5.91배의 높은 값을 나타냈다. (3) 철(Fe)의 평균 농도는 3.332 ~ 7.410 ㎍/L로 대조정점에 비하여 1.30 ~ 6.75배의 높은 값을 나타냈다. (4) 카드뮴(Cd)의 평균 농도는 0.013 ~ 0.028 ㎍/L로 해역환경기준(사람의 건강보호기준 10 ㎍/L, 해양생태계 보호 단기기준 19 ㎍/L)보다 낮았지만, 대조정점에 비해 1.18 ~ 2.33배의 높은 값을 나타냈다. (5) 납(Pb)의 평균 농도는 0.007 ~ 0.126 ㎍/L로 해역환경기준(사람의 건강보호기준 50 ㎍/L, 해양생태계 보호 단기기준 7.6 ㎍/L)보다 낮았다. (6) 수은(Hg)의 평균 농도는 0.002 ~ 0.004 ㎍/L로 해역환경기준(사람의 건강보호기준 0.5 ㎍/L, 해양생태계 보호 단기기준 1.8 ㎍/L)보다 낮았다. 비록 모든 중금속의 수중 농도가 해역환경기준보다 낮다고 할지라도, 선박 건조작업에 사용되는 구리, 아연, 철과 같은 중금속의 농도가 대조해역에 비해 조선소 주변해역에서 높다는 것은 조선소의 영향에 기인하는 것을 암시한다. 따라서 조선소로부터 각종 오염물질이 해양에 유입되지 않도록 통제하고 해양오염을 방지하는 국가적 차원의 해양환경관리가 필요하다.
In order to elucidate the current state of marine pollution of heavy metals around major shipyards in Korea, seawater samples were collected at eleven sampling stations and four control stations around 4 major shipyards located in the southeastern coast of Korea in summer 2010, and 6 kinds of metals such as copper(Cu), zinc(Zn), iron(Fe), cadmium(Cd), lead(Pb) and mercury(Hg) in seawater samples were analyzed. The analyses of heavy metals in seawater showed that the mean Cu concentrations in seawater around 4 major shipyards were in the range of 0.817 ~ 1.638 ㎍/L which were lower than Korean environmental standards of 20 ㎍/L for the protection of human health(PHH) and of 3 ㎍/L for short-term protection of marine ecosystem(SPME) but higher than Cu concentration at control station by a factor of up to 2.75. The mean Zn concentrations were in the range of 0.22 ~ 8 0.567 ㎍/L which were lower than Korean environmental standards of 100 ㎍/L for PHH and 34 ㎍/L for SPME but higher than Zn concentration at control station by a factor of up to 5.91. The mean Fe concentrations were in the range of 3.332 ~ 7.410 ㎍/L which were higher than Fe concentration at control station by a factor of up to 6.75. The mean Cd concentrations were in the range of 0.013 ~ 0.028 ㎍/L which were lower than Korean environmental standards of 10 ㎍/L for PHH and 19 ㎍/L for SPME but higher than Cd concentration at control station by a factor of up to 2.33. The mean Pb concentrations were in the range of 0.007 ~ 0.126 ㎍/L which were lower than Korean environmental standards of 50 ㎍/L for PHH and 7.6 ㎍/L for SPME. The mean Hg concentrations were in the range of 0.002 ~ 0.004 ㎍/L which were lower than Korean environmental standards of 0.5 ㎍/L for PHH and 1.8 ㎍/L for SPME. Although the concentrations of metals such as Cu, Zn and Fe which were used in shipbuilding works were lower than Korean environmental standards for PHH and SPME, the fact that the concentrations of Cu, Zn and Fe at sampling stations around major shipyards were higher than those at control stations implies that the works in shipyards had some effects on marine water quality around shipyards. Therefore, marine environment management such as the prevention and control of the discharge of various pollutants from shipyards is required on national level.