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1 Korean Journal of Environmental Agriculture Korean J Environ Agric (2013) Online ISSN: Vol. 32, No. 4, pp Print ISSN: Research Article Open Access 국내폐금속광산지역에서의토양, 지하수, 쌀의중금속노출에따른인체위해성평가 나은식, 이용재, 고광용, 정덕영, 이규승 * 충남대학교생물환경화학과 Risk Assessment for Heavy Metals in Soil, Ground Water, Rice Grain nearby Abandoned Areas Eun-Shik Na, Yong-Jae Lee, Kwang-Yong Ko, Doug-Young Chung and Kyu-Seung Lee * (Department of Bio Environmental Chemistry, Chungnam National University, Daejeon Korea) Received: 12 March 2013 / Revised: 16 May 2013 / Accepted: 1 July 2013 c 2013 The Korean Society of Environmental Agriculture This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract BACKGROUND: The objectives of this study are to investigate the contamination levels of heavy metals in soil, ground water, and agricultural product near the abandoned Boeun and Sanggok mine areas in Korea and to assess the health risk for these local residents exposed to the toxic heavy metals based on analytical data. METHODS AND RESULTS: By the results of human health risk assessment for local residents around Boeun and Sanggok, human exposure to cadmium, copper, arsenic from soil and to lead, cadmium, and arsenic from rice grain were higher in Sanggok, but human exposure to zinc and arsenic from ground water was higher in Boeun. By the results of hazard index (HI) evaluation for arsenic, cadmium, copper, lead, and zinc, HI values in both areas were higher than 1.0. This result indicated that the toxicity hazard through the continuous exposure to lead, cadmium, arsenic from rice, ground water, and soil would be likely to occur to the residents in the areas. Cancer risk assessment * 교신저자 (Corresponding author), Phone: ; Fax: ; kslee@cnu.ac.kr for arsenic, risks from the rice were exposed to one to two out of 10,000 people in Boeun and one of 1,000 people in Sanggok. These results showed that the cancer risks of arsenic in both areas were 10~100 times greater than the acceptable cancer risk range of US EPA ( ~ ). CONCLUSION(S): Therefore, if these two local residents consume continuously with arsenic contaminated soil, ground water, and rice, the adverse health effects (carcinogenic potential) would be more increased. Key words: Average daily dose, Ground water, Heavy metals, Health risk assessment, Rice grain, Soil 서론 우리나라의광업활동은해방이전에광산개발에주력하여오다가그후의혼란기에광업활동이거의미미한상태였고, 1960년대부터광산개발이활발히이루어졌다. 그러나 1980년대후반부터사회구조의변화, 에너지소비패턴의변화, 3D 노동의회피, 저렴한가격의광산물수입, 부가가치의하락등으로광업활동은위축되기시작하여경영합리화가되지못한광산들은휴 폐광하게되었고휴 폐광당시철저한광산보안조치또는환경보호조치가미흡하여, 관리자없이방치되었 245

2 246 NA et al. 다. 그결과폐갱도, 광미사나폐석등의광산폐기물과채광및선광제련등의시설물들이그대로방치되어있어집중가우나강풍에의해하부로분산되어광산하부의농경지와수계에서지속적으로환경오염이발생하고있다 (Thornton, 1983; Kelly, 1988; Alloway, 1990; Park, 1994; Lee et al., 2005). 이에따라, 광산활동에의해야기된환경오염에대한많은연구가수행되어왔으며, 선진국에서는광산, 산업및공업활동에의해야기된환경오염이인체에미치는부정적인영향을정량적으로평가하기위한기법의개발과연구가 1980년대부터이루어졌다 (Park et al., 2003). 미국에서는 1980년에환경오염물질방출에관련한피해를방지하기위한 Superfund법을제정하면서유해물질에대한장 단기대책을수립하게되었고, 이와동시에공중보건을보전하기위하여유독성물질에대한인체위해성평가가연구되기시작하였다 (EPA, 1991a; EPA, 1991b). 우리나라의경우 1990년대중반부터오염지역에대한위해성평가에대한중요성을인식하고, 위해성평가에포함되어있는세부적인변수에대한연구를시작하였다. 이후광산활동으로인해오염된토양, 지하수및농작물내독성원소들이주변지역주민의건강에미치는악영향을직접적으로평가하기위한기법의개발과연구가이루어졌다 (Gu et al., 2001; Lee et al., 2010). 본연구지역인보은광산은충북보은군회남면의보은탄전일대에위치하는석탄광의하나로, 현재폐광상태이며폐광석이산사면에그대로방치되어있어자연미관을해칠뿐아니라, 석탄폐석내에서관찰되는황화광물의산화로용출되어나온철이수산화철을형성하며침전되어하상은이들침전물들로인하여적갈색을띠거나부분적으로백화현상을보이기도한다. 상곡광산은충북단양군적성면상원곡리에위치한연 아연및금 은을채광한광산으로대규모의갱도가개설되어있으며, 선광장및광미를폐기한것으로보이는계단식야적장에곳곳에서침출수가유출되어소규모의하천을이루고있는데, 이소하천에는적화및백화현상이뚜렷해회백색및적갈색의침전물들이많이관찰된다. 두광산모두주오염원은광산폐기물인광미로서, 이들광미가바람에의해비산되거나강우에의한침출수들이광미댐하부에위치한농경지를오염시키고, 오염된농경지에서재배되는농작물또한중금속에의해오염된다. 따라서이들지역주변에거주하는주민들이농업활동을하는동안중금속에의한위해성이노출되어체계적이고종합적인인체위해성평가가시급한실정이다. 본연구에서는폐광산인보은, 상곡광산지역주변의토양, 농작물및지하수시료중중금속에대한오염수준을조사하였고, 이들에대한화학분석자료를바탕으로독성중금속들이이들지역주민의건강에미치는위해영향을정량화하는인체위해성평가실시하며, 지역주민의중금속노출에따른인체위해성을정량적으로산출하여이들폐광산별위해도수준을비교ㆍ평가하고자한다. 재료및방법 시료채취충북보은군회남면보은광산일대와충북단양군적성면상원곡리상곡광산일대를대상으로 2002년부터 2004년까지토양, 농작물 ( 쌀 ), 지하수를채취하였다. 보은광산과상곡광산모두폐광시설물과광미가방치되어있고그하류로수계와농경지가잘발달되어광미적치장으로부터유출된침출수가혼합된물을관개수및식수로사용하고있어폐석이방치되어있는계곡의단일수계를따라총연장약 1 km의거리에서 m 간격으로 6개의지하수및마을주민이음용하고있는가정용식수를채취하였고, 수계를따라영향을받을것으로예상되는주변논토양을채취하였다. 각각의토양시료들은대표성을높이기위하여심도 0 15 cm의상부토양을대상으로 15 20개의부분시료를하나의완전시료로취하였다. 또한논토양에서재배되는벼시료를 개의부분시료를합하여 1 개의완전한시료로서채취하였다. 시료전처리및분석 토양시료는공기중에서자연건조하여 10 mesh (<2 mm) 로체질하여토양오염공정시험법 (1999) 에의하여불산, 질산및과염소산을 5:4:2의비율로혼합한강산으로분해하였다. 농작물시료 ( 벼 ) 는 3회이상증류수로세척한후자연바람을이용하여풍건시켰으며, 건조한식물시료는식물용분쇄기를이용하여미분쇄하여분말시료를제작하였다. 미분쇄한식물시료는 ternary solution (HNO 3:HClO 4:H 2SO 4 = 10:4:1) 으로분해하였다. 수질시료는펌프를이용하여동일압력하에서 cellulose nitrate membrane filter (0.45 μm, 동호엘앤시 , 한국 ) 에통과시켜부유물질을제거한후, 양이온분석용과음이온분석용으로나누어보관하였으며, 양이온분석용시료는시간의경과에따라시료용기벽면에양이온 ( 중금속 ) 이흡착되는것을방지하기위해질산을가해 ph 2 이하로조정하였다. 시료채취이후분석까지모든운반및보관은아이스박스를이용하여저온상태 (<4 ) 를유지하였다. 채취된시료는전처리과정을수행한이후, ICP-MS (Perkin-Elmer, ELAN6000) 를이용하여비소, 카드뮴, 납, 구리및아연등을분석하였다. 위해성평가방법위해성평가방법은유해성확인 (Hazard identification), 노출평가 (Exposure assessment), 용량- 반응평가 (Dose-response assessment) 및위해도결정 (Risk characterization) 으로이루어졌으며, 위해성평가를하기위해서노출경로에따른일일평균노출량 (Average daily dose, ADD), 발암위해도 (Cancer risk) 및비발암위해도 (Hazard index, HI) 등은아래식을이용하여산출하였다. 이중발암위해도와비발암위해도를결정하기위해서는발암잠재력 (Slop factor, SF) 과참고섭취량 (Reference dose, RfD) 수치가필요한데 IRIS(Integrated Risk Information System) 데이터베이스의자료를인용하

3 Risk Assessment for Heavy Metals in Soil, Ground Water, Rice Grain nearby Abandoned Areas 247 Table 1. Reference dose(rfd) and slope factors(sf) of Zn, Pb, Cd, Cu and As obtained from US-EPA IRIS database Element RfD (mg/kg/day) SF (per mg/kg/day) As (1993) 1.5 (2002) Cd (water) / (food) (1994) - Cu (2001) - Pb (2002) - Zn (2005) - 였다 (Table 1). 일일평균노출량 (mg/kg/day) : C = 토양, 농작물, 지하수중금속함량 (mg/kg) IR = 토양, 농작물, 지하수의섭취량 (kg/day) ED = 노출기간 (years) EF = 노출빈도 (days/year) AT = 평균수명 (years) BW = 평균몸무게 (kg) 발암위해도의정량화 : Cancer risk = ADD SF (slope factor) ADD = 일일평균노출량 (mg/kg/day) SF = 발암잠재력 (per mg/kg/day) 비발암위해도의정량화 HQ(Hazard Quotient) = ADD / RfD HI(Hazard Indices) = HQs (sum of hazard quotients) RfD = 참고섭취량 HI = 비발암위해도지수 결과및고찰 토양, 지하수쌀의중금속오염수준폐광산지역의토양에대한중금속의오염수준을 Table 2 에나타내었다. 논토양내중금속원소들의평균함량을우리나라의일반논토양의중금속의평균함량과비교해보면, 보은광산의경우아연 42배, 카드뮴 10배, 구리와비소는 8배가량부하되어나타났고, 상곡광산의경우아연 89배, 납 1.2배, 카드뮴 2배, 구리 10배, 비소는 9배가량부하되어있음을알수있었다. Lee 등 (1997) 이보고한보은서부지역흑색셰일분포지역중논토양의중금속원소분석결과도이와비슷하거나다소높게나타났지만우리나라토양환경보전법 (2001) 의토양오염우려기준과비교해볼때 1/2~1/30의함량을보여안전한수준으로나타났다. 또한이들폐광산주변농작물및식수로사용되는지하수에대한중금속의오염수준을 Table 3, 4에제시되어있다. Kabata-pendias 등 (1984) 은일반적으로오염되지않은식물의배경값의범위를건조무게기준으로하여, 카드뮴 0.05 ~ 0.2 mg/kg, 구리 5 ~ 30 mg/kg, 납 5 ~ 10 mg/kg, 아연 27 ~ 150 mg/kg 및비소 1 ~ 17 mg/kg 으로제시하였으며, 독성을보일정도로오염된함량범위 (excessive or toxic value) 를건조무게기준으로카드뮴 5 ~ 30 mg/kg, 구리 20 ~ 100 mg/kg, 납 30 ~ 300 mg/kg, 아연 100 ~ 400 mg/kg 및비소 5 ~ 20 mg/kg으로제시하였다. 우리나라의경우 Jung(1995) 이제시한오염되지않은지역에서재배되는식물의중금속함량범위를카드뮴 0.1 ~ 2.0 mg/kg, Table 2. Concentrations of heavy metals in paddy soils from the abandoned metal mine areas mg/kg d.w Maximum Boeun Minimum Average ± SD ± ± ± ± ± 3.5 Maximum Sanggok Minimum Average ± SD ± ± ± ± ± 3.0 Paddy soil average 1) ) kim et al (2008)

4 248 NA et al. Table 3. Concentrations of heavy metals in rice grains from the abandoned metal mine areas Boeun Sanggok mg/kg d.w Maximum Minimum N.D. a) N.D. a) Average ± SD ± ± ± ± ± 0.03 Maximum Minimum N.D. a) Average ± SD ± ± ± ± ± 0.06 a) N.D. = Not Detected Table 4. Concentrations of heavy metals in groundwater used for drinking water from abandoned metal mine areas Boeun Sanggok mg/l Maximum Minimum 0.01 N.D. a) N.D. a)a) N.D. a) N.D. a) Average ± SD ± ± ± ± ± Maximum N.D. a) Minimum N.D. a) N.D. a) N.D. a) N.D. a) N.D. a) Average ± SD ± ± ± ± ± U.S drinkingwater Standard b) Permissible levels of drinking water b) a) N.D. = Not Detected b) Korea ministry of Environment (2011) 구리 10 mg/kg, 납 0.1 ~ 0.5 mg/kg, 아연 10 ~ 100 mg/kg으로제시하였는데, 연구지역인두광산과비교해보았을때카드뮴을제외한나머지원소들은자연함유량이하로나타났다. 그리고마을주민들이식수로이용하는지하수의중금속평균함량을환경부 (2011) 에서제시한함량과비교해보았을때, 보은광산의경우카드뮴, 상곡광산의경우납이기준보다다소높게나타났다. 노출평가노출평가는오염원으로부터파악된독성중금속들의노출경로에의해인간이섭취하게되는독성중금속들의섭취량을정량적으로산출하는것으로 (DEFRA and EA 2002), 인체노출량인 ADD를산출함으로써구할수있다. 본연구지역주민들이오염원으로부터독성중금속들에노출되는경로는토양노출경로 (soil pathway), 지하수 ( 식수 ) 노출경로 (groundwater pathway), 농작물 ( 쌀 ) 노출경로 (rice grain pathway) 3가지로파악할수있다. 폐광산지역의위해성평가에서대상이되는수용체는농업에종사하는농민들로서이들에대한평균몸무게, 평균수명, 일일섭취량등의인체노출인자를투입하여 인체노출량을산정해야하므로이들인자에대한자료를 Table 5 에제시하였다. 오염된토양에노출되는경로는농업활동을하는동안에토양과직접적으로접촉함으로써더러운손이나호흡을통해발생한다. 토양노출빈도는한국농부들의연평균농사기간이약 7개월 (210 days) 로하였으며토양섭취비는미국 EPA에서제시한 50 mg/day 수치를이용하였다. 오염된지하수에노출되는경로는지하수를직접식수로사용함으로써인체로흡수되어발생한다. ADD 식에투입되는지하수 ( 식수 ) 섭취비는환경부의조사자료에의하면 2.0 L/day 이며, 지하수내독성중금속들의화학분석결과 (Table 4) 를이용하였다. 오염된토양에서재배된농작물 ( 쌀 ) 에노출되는경로는이들오염된농작물을직접섭취함으로써인체로흡수되어발생한다. 이번노출평가에서는농작물에대한섭취흡수계수를 100% 로가정하였다. 2007년도환경부자료에의하면한국농부의쌀섭취량은 321 g/day 이며, 쌀내독성중금속들의화학분석결과 (Table 3) 도이용하였다. 폐광산인보은, 상곡광산지역에서의토양, 지하수, 농작물

5 Risk Assessment for Heavy Metals in Soil, Ground Water, Rice Grain nearby Abandoned Areas 249 Table 5. Exposure factors for an average korean farmer Factor/ Parameter Exposure Duration Exposure Frequency Averaging Time Symbol Units Residential/ Agricultural Source ED years 25 ME a), 2007 EF day/year 350 ME a), 2007 Carcinogens ATc year 73.5 KNSO b), 2001 Non-carcinogens ATnc year 30 US EPA, 1997 Body Weight BW kg 62.8 ME a), 2007 Ingestion Rate Soil IRs kg/day US EPA, 2009 Rice (Farmer) IRr kg/day ME a), 2007 Drinking water IRw L/day 2.0 ME a), 2007 a) Ministry of Environment b) Korea National Statistical Office Table 6. Results of ADD for An, Pb, Cd, Cu and As with different exposure pathway Pathway Soil Groundwater Rice grain Sum mg/kg/day Boeun Sanggok Boeun Sanggok Boeun Sanggok Boeun Sanggok ( 쌀 ) 의노출경로에따른중금속들의일일평균노출량산출결과를 Table 6에제시하였다. 용량-반응평가 ( 독성평가 ) 노출평가를통해산출한중금속의인체노출량을이용하여발암위해도와비발암 ( 독성 ) 위해도를결정하기위해서는용량 - 반응평가를통해산출된중금속의발암잠재력 (SF) 과참고섭취량 (RfD) 수치가필요하다. 앞서언급한대로이들수치들은미국 EPA의 IRIS 데이터베이스의자료를인용하여 Table 1 에제시하였다. 단, SF의값은발암물질인비소에대해서만산정되어있으므로비소의발암위해도만을결정할수있었다. 위해도결정폐광산지역들에대한비소, 카드뮴, 구리, 납및아연의비발암위해도를결정하기위해서필요한 HQ 및 HI 지수를 Table 7, 8에제시하였다. 납, 카드뮴및비소등의 HI 지수가두광산모두 1 이상으로나타났다. 따라서이지역에거주하는주민들의경우지속적인농작물 ( 쌀 ), 지하수, 토양의섭취를통한납, 카드뮴, 비소에의해비발암위해가발생할가능성이크다는것을알수있었다. 앞서언급한것같이 SF의값이비소에대해서만산정되어있어본연구에서는각각의노출경로에따른비소의발암위해도만을평가하였다 (Table 9). 그결과농작물 ( 쌀 ) 의섭취를통한비소의발암위해도는보은광산의경우만명중의수명으로나타났으며, 상곡광산의경우천명중의 1.2명으로나타났다. US EPA에서제시한위해성에근거한허용발암위해도는 로보은, 상곡광산지역모두토양, 지하수및농작물 ( 쌀 ) 의섭취를통해비소의발암위해도가허용발암위해도를초과하고있다. 따라서이들지역주민들이

6 250 NA et al. Table 7. Hazard quotients (HQ) of As, Cd, Cu, Pb and Zn in these study areas Pathway Soil Groundwater Rice grain Sum Boeun Sanggok Boeun Sanggok Boeun Sanggok Boeun Sanggok Table 8. Hazard indices (HI) of As, Cd, Cu, Pb and Zn in these study areas Boeun Sanggok Table 9. Cancer risk of As in these study areas Soil pathway Groundwater pathway Rice grain pathway Boeun Sanggok Sum 비소에의해오염된토양, 지하수, 그리고농작물 ( 쌀 ) 을지속적으로장기간섭취하게된다면비소가건강에미치는위해영향은크다고판단된다. 결론 폐광산인보은, 상곡광산지역주변토양, 농작물및지하수시료중중금속에대한오염수준을조사하였고, 이들에대한화학분석자료를바탕으로독성중금속들이이들지역주민의건강에미치는위해영향을정량화하는인체위해성평가실시하였다. 중금속원소들의인체노출평가결과, 토양섭취에의한카드뮴, 구리, 비소의인체노출량은상곡광산에서높게나타났으며, 지하수섭취에의한아연, 비소의인체노출량은보은광산에서높게나타났다. 농작물 ( 쌀 ) 섭취에의한납, 카드뮴, 비소의인체노출량은상곡광산에서다소높게나타났다. 비소, 카드뮴, 구리, 납및아연의비발암위해도 (HI) 평가결과납, 카드뮴및비소의 HI 지수가두광산모두 1 이상으로나타났다. 이들지역에거주하는주민들의경우지속적인농작물 ( 쌀 ), 지하수, 토양의섭취를통한납, 카드뮴, 비소에의해독성위해도가발생할가능성이크다는것을알수있었다. 비소에대한발암위해도평가결과, 농작물 ( 쌀 ) 의섭취를통한비소의발암위해도가보은광산의경우만명중의수명으로나타났으며, 상곡광산의경우천명중의 1명으로나타 났다. US EPA에서제시한위해성에근거한허용발암위해도는 로보은, 상곡광산지역모두토양, 지하수및농작물 ( 쌀 ) 의섭취를통해비소의발암위해도가허용발암위해도를초과하고있다. 따라서이들지역주민들이비소에의해오염된토양, 지하수, 그리고농작물 ( 쌀 ) 을지속적으로장기간섭취하게된다면비소가건강에미치는위해영향은크다고판단된다. References Alloway, B.J., Heavy Metals in Soil, p. 368, Blackie and Son Ltd. Bowen, H.J., Environmental chemistry of the elements. Academic Press, Lodon. Gu, J.M., Kim, K.S., Dong, J.I., Park, Y.H., Bae, W.G., Yang, J.W., Yeom, I.T. Yoon, S.P., Lee, J.Y., Lee, J.S., Jang, Y.Y., Jung, J.C., Choi, S.I., Hwang, K.Y., Hwang, J.S., Soil Environmental Engineering. pp , Hyangmunsa, Korea. Integrated Risk Information System (IRIS, Kanata-Pendias, A., Pendias, H., Trace elements in

7 Risk Assessment for Heavy Metals in Soil, Ground Water, Rice Grain nearby Abandoned Areas 251 soils and plants. p. 315, CRC Press, Inc. Kelly, M., Mininig and the freshwater environment. London: Elsevier science Publishers Lee, J.S., Chon, H.T., Kim, K.W., Human risk assessment of As, Cd, Pb, Cu and Zn in the ababdined metal mine site, Environ Geochem Health. 27, Lee, J.S., Chon, H.T., Kim, K.W., Dispersion and Migration of potentially Toxic elements in the Rock-Soil-Plant System from the Boeun area underlain by Black Shales, Korea, Eco. Environ. Geol. 30(6), Lee, J.S., Kim, Y.N., Kim, K.H., Suitability Assessment for Agriculture of Soils Adjacent to Abandoned Mining Area Using Different Human Risk Assessment Models, Korea J. Soil Sci. Fert. 43(5), Park, Y.H., Management of Wastes from Inactive or Abandoned s, p. 588, Korea Environment Institute. Park, Y.H., Kim, M.J., Jung, S.W., Lee, Y.H., Kim, M.J., Jo, J.E., A Study for Standards of Soil Contamination and Restoration by land-use. Korea Institute of Policy Evaluations. Thornton, I., Applied Environmental Geochemistry, p. 501, Academic Press. London. US EPA., Risk Assessment Guidance for Superfund, Vol. 1, Part A, EPA/540/I-89/002 US EPA., Risk Assessment Guidance for Superfund, Vol. 1, Part B, EPA/540/R-92/003. US EPA, Guideline for the Health Risk Assessment old Chemical mixture, 51 Fedral Regoster US EPA., 1999a. Risk assessment guidance for superfund(rags). Volumn Ⅰ : Human health evaluation manial(hhem), part B, development of risk-based preliminary remediation goals. US EPA., 1999b. Risk assessment guidance for superfund(rags). Volumn Ⅰ : Human health evaluation manial(hhem), supplemental guidance, Standrad Default Exposure Factors, Interim Guidance.

35(5)-04.fm

35(5)-04.fm y, 38«, 5y, 535-545, 2005 Econ. Environ. Geol., 38(5), 535-545, 2005 m, w w sƒ *Á zk w y lœw Risk Assessment of Arsenic by Human Exposure of Contaminated Soil, Groundwater and Rice Grain Jin-Soo Lee* and