RISK ANALYSIS OF VOLATILE ORGANIC COMPOUNDS THROUGH DAILY LIFE CYCLE IN THE INDUSTRIAL CITY IN KOREA

摘要

This study analyzed the risk of exposure to volatile organic compounds (VOCs) through a study of activity patterns in the Korean industrial city, Ulsan. The daily life cycle patterns (LCPs) of 331 people in Ulsan were surveyed and the average LCPs in Ulsan were obtained by statistical analysis. Nine to twelve personal air samples of VOC exposure at the breathing zones were ccllected at each LCP. This included hours for sleeping, cooking and eating, going to and from work, working, participating in field or outdoor activities, reading, watching TV, and shopping. The components and concentrations of the collected VOCs were identified by a Gas Chromatography-Mass Detector (GC-MS). The overall reproducibility of all GC analytical procedures of the simultaneously collected duplicate sample pairs represented a mean of percent differences ranging from about 9 to 13%. For the general population of Ulsan, the carcinogenic and non-carcinogenic risk of exposure to the VOCs during the LCPs was evaluated. The carcinogenic risk was analyzed using both the chronic daily exposure or lifetime average daily exposure (CDI) and the cancer potency factor. The non-carcinogenic risk was analyzed using both the CDI and the chronic reference dose. The major chemical forms of the identified VOCs were oxidized forms (43%), aliphatic alkanes (29%) and aromatics (15%). Even though the highest total exposure strength per unit time of each activity was observed during shopping, the highest total amount of exposure to VOCs was identified as the exposure during work. The total carcinogenic risk of exposure to the carcinogenic VOCs through daily life cycle in Ulsan was 2.0 x 10~(-4) which is substantially exceeding the permissible carcinogenic risk level, 10~(-5) ～1()~(-6). The carcinogenic risk during most of the life cycle activities, except for reading, mainly performed indoors, was higher than that of the activities performed outdoors. The carcinogenic risk by benzene exposure was about 56% (time weighted average) of the total carcinogenic risk by the exposure to the carcinogenic VOCs. During cooking and eating, shopping and out door activities, however, the carcinogenic risk by the exposure to chlorinated compounds like chloroform exceeded the exposure to benzene. The overall hazard index (non-carcinogenic risk) by a chronic exposure to carcinogenic and non-carcinogenic VOCs through daily life cycle in Ulsan was evaluated as 3.91 x 10(-1) , which is much less than 1.0 considered as a hazard level to human health, and thus it seems likely not to produce a severe health hazard.