서울시 지하철 역사 내부 설비 공사에 따른 석면의 발생 실태

Abstract

[한글]

본 연구는 환기, 소방, 전기설비 등 내부 설비 공사가 이루어지고 있는 서울시 지하철의 10개 역사를 대상으로 설치작업과 철거작업으로 구분하여 석면의 발생원을 파악하고, 또한 공사가 진행되고 있는 지하역사내의 작업내용별, 시간대별, 시료채취 방법별 석면의 노출실태를 파악하기 위하여 실시하였으며, 고형시료 및 공기중 시료에 대한 TEM-EDX 분석결과는 다음과 같다.

첫째, 지하철역사의 석면 발생원 파악을 위하여 고형시료를 분석한 결과 총시료 44개중 29개에서 석면이 검출되었고(65.9%) 검출된 석면의 종류는 백석면(chrysotile)이 93.1%, 투각섬석(tremolite)이 6.9%이었으며, 주요 발생원은 덕트 이음부의 가스켓, 퇴적분진,

천장 도포물질, 천장재, 불티 방지포 등이었다.

둘째, 공기중 석면농도는 기하평균 0.0038 f/cc, 범위는 0∼0.0520 f/cc, 기하표준편차는 2.0882이었고 농도가 가장 높은 역사는 기하평균 0.0128 f/cc로 가장 낮은 역사 0.0028 f/cc보다 4.6배 정도 높았으나 산업안전보건법에서 규정하고 있는 노출기준, 2 f/cc를

초과하는 곳은 없었다. 또한 공기중 시료에서 검출된 석면은 대부분이 백석면이었으나, 가-2 역사에서는 투각섬석과 양기석(actinolite)이 검출되었는데 고형시료 분석결과 투각섬석이 검출된 역사와 동일한 역사이었다. 공기중에서 발생되는 석면의 노출실태를 보면 철거작업 기하평균이 0.0056 f/cc로 설치작업 0.0031 f/cc보다 1.8배 높았다. 작업 시간대별 석면농도는 설치작업의 주간 기하평균이 0.0032 f/cc, 야간이 0.0029 f/cc이었으며, 철거작업 주간이 0.0092 f/cc, 야간이 0.0040 f/cc로 나타나 전체적으로 주간작업이 야간보다 높았고, 시료채취 방법에 따른 농도는 개인시료 기하평균이 0.0065 f/cc, 지역시료 0.0035 f/cc로 개인시료가 지역시료 보다 높았다.

셋째, 내부 설비 공사시 발생된 석면농도와 지하생활공간 공기질 관리 측면에서 권고하는 기준과의 비교결과 공기중 시료의 4.3%가 권고기준인 0.01 f/cc를 초과하고 있었으며 최고농도는 0.0178 f/cc로써 권고기준의 1.78배 수준으로 내부 설비 공사가 지하생활공간

을 오염시키는 주된 원인으로 예측할 수 있다.//이상의 결과를 종합하여 보면 지하역사 내부 설비 공사시에는 직접 작업을 수행하는 근로자의 건강보호를 위하여 분진 차단막 설치, 물분무(습식작업), 진공청소 등 석면발생 억제조치와 표준작업수칙 준수, 개인보호구 착용의 철저한 실천이 필요한 것으로 사료된다.

[영문]

The objective of this study was to identify sources of the air-borne asbestos at the renovation works of ventilation system, fire extinguisher and electric facility being currently executed at ten subway stations in Seoul, assess the asbestos exposure by types of works, working time and sampling methods. The results of this study were as follows

First, the results of an analysis of bulk samples to identify sources of air-borne asbestos at the subway stations showed that asbestos was detected in 29 out of 44 samples (65.9%), the kinds of the asbestos detected pointed chrysotile by 93.1% and tremolite by 6.9%, and main sources of the air-borne asbestos were the gaskets at duct seams, accumulated dust, materials sprayed on the ceiling, anti-spark shielding materials, etc.

Second, as for the concentrations of asbestos in the air, the geometric mean pointed out 0.0038 f/cc (range 0∼0.0520 f/cc), the geometric standard deviation 2.0882. The geometric mean at the station of the highest concentration indicated 0.0128 f/cc, 4.6 times as high as that of the lowest concentration, 0.0028 f/cc.

But there was no station that exceeded the permissible exposure limit, 2 f/cc, as stipulated by the Occupational Safety and Health Act announced by the Korea Ministry of Labor. Furthermore, the asbestos detected from air samples consisted for the most part of chrysotile but tremolite and actinolite were detected at

station 가-2 which was found as a result of Bulk Sample analysis to be the same station where tremolite was detected.

Regarding the asbestos generated in the air, the geometric mean in dismantlement work was 0.0056 f/cc, 1.8 times as high as that of installation work, 0.0031 f/cc. For the concentrations of asbestos by working time, the geometric mean in daytime installation work pointed out 0.0032 f/cc, that of nighttime was 0.0029 f/cc, while that in daytime dismantlement work was 0.0092 f/cc and that of nighttime was 0.0040 f/cc, which reveals that the concentrations of air-borne asbestos in daytime was higher than that in nighttime in general. The concentrations by sampling methods represented a geometric mean of 0.0065 f/cc in personal air samples, while 0.0035 f/cc in area samples. Here the geometric mean in the former was higher than that in the latter.

Third, a comparison between the concentrations of asbestos generated from interior renovation works and 0.01 f/cc, the air quality standard of asbestos by Underground Living Space Air Quality Act announced by Korea Ministry of Environment revealed

that 4.3% of the air samples exceeded the standard. the highest concentrations was 0.0178 f/cc, 1.78 times as high as that of the standard. It follows from this that renovation works are the main causes that contaminate underground living space.

For the purpose of preventing the health risk of interior renovation workers at subway stations, it is needed to take proper interventions such as the installation of dust cutoff veils, water spray, vacuum cleaning, standard working procedure for preventing asbestos generation, and personal protective equipments.