Sureeporn Lorussachan. Cancer risk of 1,3-butadiene exposure to various receptors living near heavy traffic area in Bangkok, Thailand. Master's Degree(Technology of Environmental Management). Mahidol University. Mahidol University Library and Knowledge Center. : Mahidol University, 2018.
Cancer risk of 1,3-butadiene exposure to various receptors living near heavy traffic area in Bangkok, Thailand
Abstract:
This study aims to estimate cancer risk of 1,3 - Butadiene exposure to receptors living or having activities in or near heavy traffic areas in Bangkok. Ambient air samples were actively collected at Ko Phaya Thai next to the Victory Monument area on an hourly basis for 15 consecutive hours on Sunday (weekend) and Monday (weekday) from 22 January to 20 February 2017. The number of vehicles was simultaneously monitored for investigation of its relationship with atmospheric 1,3-butadiene concentration. In addition, separated air samples were continuously collected for 24 hours at the same time, for estimation of cancer risks. The collected samples were analyzed by GC-MS. The hourly concentrations of 1,3 - butadiene were in ranges of 0.17 - 3.33 μg/m3 on weekends and 0.11 - 2.01 μg/m3 on weekdays. The vehicles were classified into 7 types, the passenger cars and Taxi cars were the biggest portions on weekends, motorcycles and passenger cars were the most numbered on weekdays. During daytime both on weekends and weekdays, the variations of 1,3-butadiene and number of vehicles tended to have a relationship whereas during nighttime they seemed to have weak relationship. This implied that there were other sources besides traffic. On weekdays the concentrations of average hourly 1,3-butadiene in the night-time were greater than that of the day time. This finding confirms previous arguments that rapid destruction of 1,3-butadiene during the daytime was stimulated by photoinitiated reaction. Estimated cancer risk using inhalation unit risk of 3 x 10-5 per μg m-3 and was found that adult people who have been working near this roadside for 8 to 12 hour per day during Monday to Friday and Monday to Saturday for 54 years will experience the lifetime cancer risk of 6.4 - 9.7 and 6.8 - 10.4 times higher than the USEPA benchmark of one in a million. Adult vendors working for 3 - 12 hours per day for 5 weekdays for 54 years will have lifetime cancer risk of 2.4x10-6 - 9.7x10-6. Bus passengers aged 3-21 years who spend 1 to 2 hours per day waiting for a bus will get lifetime cancer risks of 0.73x10-6 to 1.4x10-6, and for residents, lifetime risks was 0.58x10-6 - 1.2x10-6. The results show that the model was under estimated as compared to actual measurement.