HEALTH RISK ASSESSMENT OF CARBONYL COMPOUNDS AND BTEX AMONG HIGHLY EXPOSURE WORKERS IN THE INNER CITY OF BANGKOK

Abstract

BTEX and CCs (carbonyl compounds) were detected for the ambient air and personal exposure of five workers who worked in Pathumwan district, Bangkok, Thailand, a traffic intensive urban area in both summer and rainy seasons of the year 2012 to 2014. Health risk assessments of the outdoor workers at roadside area (street vendors, motorcycle taxi drivers and security guards), the outdoor workers at road intersection (traffic policeman), and the indoor workers were estimated. The results showed that the mean ambient air BTEX levels of street vendors, motorcycle taxi drivers, security guards, traffic policemen and indoor workers were 213.95±200.17, 172.42±188.26, 118.34±92.23, 2563.19±921.06 and 439.33±176.39 µg/m3, whereas, those of formaldehyde were 10.65±4.77, 14.19±10.72, 8.25±3.30, 17.44±8.20, 26.48±14.18 µg/m3, and 5.81±5.54, 5.70±3.21, 2.49±1.54, 43.13±35.06, 8.73±4.91µg/m3 for acetaldehyde. For personal exposure sample, traffic policemen were contained the highest concentrations of BTEX (1,990.59±942.30 µg/m3) and acetaldehyde (11.06±11.00 µg/m3), however, the indoor workers showed the greatest value of formaldehyde (23.31±12.41 µg/m3). For the health risk assessment, traffic policemen had the greatest total cancer-risk level of benzene, ethylbenzene, formaldehyde and acetaldehyde (2.64E-04 to 4.21E-04) followed by security guards (1.44E-05 to 3.72E-05), street vendors (8.77 E-06 to 2.52E-05), motorcycle taxi drivers (5.00E-06 to 2.13E-05), and indoor workers (8.49E-06 to 1.58E-05), respectively. For total non-cancer risk, the values of all workers were in an acceptable level. The scenario of risk reduction was expressed that the use of mask during the working time was the best way that can be decreased these toxic pollutants, however, total cancer risk level still greater than an acceptable value for security guards and traffic policemen. In view of risk perception and risk communication, knowledge (K) and attitude (A) questionnaires were conducted, and it was found that most workers were more understand and concerned on their health effect and tended to changed their practice to protect themselves from BTEX and CCs. For statistical analysis, the correlations between knowledge of air pollution of street vendors were affected on their attitude on air pollution. For health risk assessment part, the relationships between knowledge and attitude were found for motorcycle taxi drivers and traffic policemen. The associations between all parts of knowledge (air pollution, health risk assessment and practice) and attitude on practice were found for motorcycle taxi drivers, security guards and traffic policemen.