Browse

Characteristics of Disinfection By-Products Production and Associated Health Risk Assessment in Tap water and Indoor Swimming Pool Water in Seoul, Korea : 서울시 수돗물과 실내 수영장물의 소독부산물 발생특성과 건강 위해성 평가

Cited 0 time in Web of Science Cited 0 time in Scopus
Authors

Lee, Jin

Advisor
조경덕
Major
보건학과
Issue Date
2012-02
Publisher
서울대학교 대학원
Abstract
The tap water in Seoul, the capital of Korea, is supplied by six municipal water treatment plants all using chlorination as a disinfection method. Chlorine can react with naturally present organic matters to produce a variety of disinfection by-products (DBPs) including trihalomethanes (THMs) [chloroform, bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform], haloacetic acids (HAAs) [monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), bromochloroacetic acid (BCAA), bromodichloroacetic acid (BDCAA), dibromochloroacetic acid (DBCAA), monobromoacetic acid (MBAA), dibromoacetic acid (DBAA), and tribromoacetic acid (TBAA)], haloacetonitriles (HANs) [dichloroacetonitrile (DCAN), trichloroacetonitrile (TCAN), bromochloroacetonitrile (BCAN), and dibromoacetonitrile (DBAN)], and chloral hydrate (CH). Some DBPs can cause adverse public health effects. Disinfection in swimming pools is critical to protect the public against pathogenic micro-organisms. Indoor swimming pool water in Seoul are treated with three different disinfection methods such as chlorine, ozone/chlorine, and a technique that uses electrochemically generated mixed oxidants (EGMOs). Thus, the main objectives of this study were (1) to investigate the seasonal and spatial variations in the concentrations of THMs and HAAs in the tap waters passing through the water distribution systems in six water treatment plants in Seoul, Korea (study 1), (2) to measure the concentrations of THMs, HAAs, HANs and CH in eighty-six indoor swimming pools in Seoul, Korea, treated with different disinfection methods, including chlorine, ozone/chlorine, and EGMOs, and assess the correlation between the concentrations of DBPs and water quality parameters based on the disinfection method used (study 2), (3) to conduct the health risk assessment from the exposure to THMs in tap water and indoor swimming pool water (study 3).
For study 1, the concentration ranges for total THMs (TTHMs; chloroform, BDCM, DBCM, and bromoform) and HAA5 (MCAA, MBAA, DBAA, DCAA, and TCAA) in tap water samples were 3.9~53.5 μg/L and < LOD~49.5 μg/L, respectively. Among the DBPs, chloroform, BDCM, DCAA, and TCAA were detected at the highest frequencies. The concentrations of THMs and HAAs at all sampling locations complied with the standards for drinking water quality. Seasonal and spatial variations in concentrations of THMs and HAAs in the six water distribution systems were significant (P < 0.001). The highest THMs and HAAs concentrations were detected in summer, while the lowest in winter. THMs increased in the extremities of the distribution systems, whereas HAAs decreased.

For study 2, the geometric mean (geometric standard deviation) concentrations of total DBPs in swimming pool waters were 183.1 (2.5) μg/L, 32.6 (2.1) μg/L, and 139.9 (2.4) μg/L in pools disinfected with chlorine, ozone/chlorine, and EGMO, respectively. Chlorinated DBP (chloroform, DCAA, TCAA, DCAN, and CH) concentrations were most abundant species in the pools that were treated with chlorine, whereas in the EGMO-treated samples, the brominated DBP (BDCM, DBCM, bromoform, BCAN, and DBAN) concentrations were highest and more variable. THAAs concentrations were highest, followed by TTHMs, CH, and THANs in all swimming pools regardless of disinfection method. Total organic carbon (TOC) in pool waters was the dominant factor governing the amounts of DBPs in pool water in all disinfection methods.
For study 3, lifetime health risks associated with various exposure routes (oral ingestion, dermal contact, and inhalation) by THMs in tap water and indoor swimming pool water were estimated. While lifetime non-cancer risks for residents and swimmers exposure to THMs were negligible, lifetime cancer risks were higher than 10-6, which is the acceptable risk level defined by the US EPA. The 95th percentiles of lifetime cancer risks for both male and female residents were 1.93×10-4 and 2.07×10-4, respectively. For both male and female swimmers, the lifetime cancer risks at the 95th percentile were 4.12×10-4 and 4.88×10-4, respectively. The major exposure routes for residents and swimmers were found to be inhalation during showering and swimming.
DBPs concentrations in tap water in Seoul complied with drinking water standard. However, lifetime cancer risk of exposure to DBPs in tap water was significantly increased when inhalation exposure during showering was included. The findings demonstrated a need to consider all exposure routes into the regulation of DBPs concentrations in drinking water. DBPs concentrations in indoor swimming pool water were higher than those found in tap water. The lifetime cancer risk was even higher when exposure during swimming was included. Cancer risk of DBPs was significantly affected by showering and swimming. Therefore, regulators and researchers should pay more attention to ventilation in showering facilities and chemical water quality for swimming pool water.
수돗물과 수영장물의 소독은 수인성 질병의 발생을 최소화하기 위하여 매우 중요하다. 염소는 뛰어난 살균력과 잔류성, 그리고 경제성 때문에 현재에도 가장 탁월한 소독제로 사용되고 있다. 그러나 염소는 물속의 유기물과 반응하여 트리할로메탄 (THMs), 할로아세틱엑시드 (HAAs), 할로아세토나이트릴 (HANs), 그리고 클로라하이드레이트 (CH)와 같은 다양한 소독부산물 (DBPs)을 생성한다. 몇몇의 소독부산물은 건강에 악영향을 주는 물질로 알려져 있다.
대한민국의 수도인 서울의 수돗물은 6개 정수센터에서 염소 소독하여 생산하고 있으며, 서울에 소재하는 86개 실내 수영장은 염소소독, 오존과 염소 병합소독, 그리고 전기화학적으로 생성된 혼합 산화제 (EGMO)로 소독하고 있다. 따라서 본 연구는 서울시 수돗물과 실내 수영장물의 소독부산물의 농도를 조사하고 소독부산물의 잠재적인 건강 위해성을 평가하였다.
서울시 수돗물의 TTHMs와 HAA5의 농도범위는 3.9~53.5 μg/L와 < LOD~49.5 μg/L 이었고, 소독부산물 중에서 chloroform, BDCM, DCAA, 그리고 TCAA가 가장 많이 검출된 물질이었다. 모든 수돗물 시료에서 THMs과 HAAs의 농도는 먹는 물 수질기준에 적합하였다. 6개 정수센터 급수시스템에서 THMs과 HAAs의 계절 및 공간적 농도변화는 상당하였다 (P < 0.001). THMs와 HAAs의 농도는 여름에 가장 높은 반면에 겨울철에 가장 낮았다. THMs의 농도는 급수시스템 말단으로 갈수록 증가한 반면 HAAs의 농도는 감소하였다.
수영장물의 총 소독부산물의 기하평균 (기하표준편차) 농도는 염소소독 183.1 (2.5) μg/L, 오존/염소소독 32.6 (2.1) μg/L, 그리고 EGMO소독 139.9 (2.4) μg/L 이었다. 염소소독한 수영장물에서 염소계 소독부산물 (chloroform, DCAA, TCAA, DCAN, and CH)의 농도가 가장 높은 반면, EGMO소독한 수영장물에서는 브롬계 소독부산물 (BDCM, DBCM, bromoform, BCAN, and DBAN)의 농도가 가장 높았다. 모든 수영장물에서 THAAs의 농도가 가장 높았고, 다음은 TTHMs, CH, 그리고 THANs 순이었다. 총유기탄소 (TOC)는 수영장물의 총 소독부산물 양을 규제하는 중요한 인자이었다.
수돗물과 실내 수영장물의 THMs의 노출경로 (경구섭취, 피부접촉, 그리고 호흡)에 따른 건강 위해성 평가를 실시하였다. 서울시 성인남녀의 수돗물과 수영장물의 THMs에 의한 평생 비발암 위해도는 무시할 수 있었지만, 평생 발암 위해도는 미국 환경청 (US EPA)에서 권고한 허용 발암 위해도 (10-6)를 초과하였다. 성인남녀 거주자의 평생 발암 위해도의 95th 백분위수 (percentile)는 1.93×10-4 와 2.07×10-4 이었고, 성인남녀 수영자의 평생 발암 위해도의 95th 백분위수는 4.12×10-4 와 4.88×10-4 이었다. THMs의 주요 노출 경로는 호흡에 의한 것으로 나타났다.
본 연구의 결과에 따르면 서울시 수돗물의 소독부산물 농도는 먹는물 수질기준에 적합하였다. 그러나 샤워하는 동안 호흡 경로를 통한 소독부산물의 평생 발암 위해도는 상당히 증가하였다. 따라서 먹는물 수질기준에서 소독부산물은 모든 노출경로를 고려하여 기준을 설정할 필요가 있다. 실내 수영장의 소독부산물의 농도는 수돗물보다 높았으며, 수영으로 인한 평생 발암 위해도는 한층 더 높았다. 소독부산물의 평생 발암 위해도는 샤워와 수영에 의해 상당히 영향을 받았다. 따라서 정책 결정자와 연구자들은 샤워시설의 환기와 수영장물의 수질화학에 더 많은 관심을 기울여야 할 것이다.
Language
eng
URI
https://hdl.handle.net/10371/156349

http://dcollection.snu.ac.kr:80/jsp/common/DcLoOrgPer.jsp?sItemId=000000000139
Files in This Item:
There are no files associated with this item.
Appears in Collections:
Graduate School of Public Health (보건대학원)Dept. of Public Health (보건학과)Theses (Ph.D. / Sc.D._보건학과)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse