Health risk assessment of workers exposure to BTEX from incense smoke at worship places in Bangkok

Abstract

This study aimed to determine BTEX (benzene, toluene, ethylbenzene, and xylene) concentration, to evaluate the potential health risk and estimate wokers health risk for the workers at worship places. The sampling was performed on weekend (Sunday) and non peak (Wednesday) days in April (dry season), July (wet season) and December (cold season) 2012 at Tao Maha Bhrama (TMB) shrine and Kanlayanamit Woramahawiharn (KW) temple. Each sampling was performed for 8 working hours using an activated charcoal filled glass tube connected to a personal air pump with an air flow rate of 100 ml/min. At both places, the sampling equipments were set at four different sampling points covering a worship area at 1.50 m height above the ground. The BTEX samples were extracted and analyzed by gas chromatography with flame ionization detector. The highest 8-h average BTEX concentration was found at the point close to incense stick pot at the TMB with the value of benzene (107.14 µg/m3) and o-xylene (16.59 µg/m3). At the KW temple, the ambient sample near the entrance was found to have the highest average concentration of benzene, toluene, and m,p- xylene at 36.23, 46.67 and 8.48 µg/m3, respectively. At the TMB, the 8-h average concentration of toluene, ethylbenzene, m,p-xylene, and o-xylene on the non-peak days were 1.32-, 1.96-, 1.76-, and 1.15-fold higher, respectively, than those on the peak days. Similarly all of the 8-h average concentration of benzene, toluene, and m,p-xylene on the non-peak days at the KW temple were 1.15-, 1.84-, and 1.37-fold higher than those on the peak days. At TMB, toluene was found the highest concentration as 105.77 µg/m3 follow by benzene (57.28 µg/m3). For KW temple, toluene was also found the highest concentration as 39.12 µg/m3 but lower than the highest exposed of toluene at TMB (2.70-fold). For benzene, the janitor at TMB had the highest lifetime cancer risk (3.07x10⁻⁶-103x10⁻⁶) of all workers from both places which 4.41 and 1.7-fold higher than guard and Thai folk dancer, respectively. The highest lifetime cancer risk at KW temple was found for the incense seller (0.85 x10⁻⁶-5.71 x10⁻⁶) which 4.32- and 1.65-fold higher than janitor and lottery seller. The total chronic daily intake and 95% confidental interval of lifetime cancer risk of the worker at TMB was 2.25-and 2.21- fold higher than that of KW temple. The probability of the workers exposed to benzene and ethylbenzene at the risk (95% CI of LCR) higher than acceptable criteria of 10⁻⁶ was found at 100 % (3.79x10⁻⁶-3.45 x 10⁻⁴) and 83.82 % (2.91x10⁻⁷-1.87x10⁻⁵), for TMB, and 100% (1.72x10⁻⁶-8.99x10⁻⁵) and 42% (3.29x10⁻⁷⁻⁵.71x10⁻⁶), for KW temple. For non-carcinogenic substances, all the 95% CIs of the HQs of the workers was no more than 1 and indicated that no increased health risk concern above generally acceptable levels.