Indoor level of BTEX and health risk assessment at science laboratories in a university

Abstract

The levels of volatile organic compounds (VOCs) such as Benzene, Toluene, Ethylbenzene, and Xylene isomers (BTEX) are important parameters for an indoor air quality assessment. Exposure to BTEX in science laboratories in a university can potentially cause health risks to workers. Active sampling was carried out using Tenax® GR sorbent tubes and analyzed with thermal desorption gas chromatography-mass spectrometry (TD-GCMS) to measure the BTEX levels at selected indoor areas. The average concentration of individual BTEX at the laboratories complex were as follows: Benzene (1.76 ± 0.44 μg/m3), Toluene (8.15 ± 2.99 μg/m3), Ethylbenzene (3.75 ± 0.69 μg/m3), m, p-Xylene (6.07 ± 1.19 μg/m3) and o-Xylene (4.84 ± 0.43 μg/m3). The distribution of the BTEX components varied depending on the floor level, laboratory activities, laboratory size, and interior furniture. Non-cancer risk estimates based on hazard quotient value for BTEX were < 1, indicating unlikely non-cancer risk. Lifetime cancer risk estimates for Benzene were in the range of 1.16 × 10-6 – 2.54 × 10-6 indicating possible cancer risk at the sampled indoor locations. Therefore, science laboratories can potentially pose a health risk to workers from long-term exposure to BTEX.