Btex in an occupational environment

Abstract

The BTEX group (benzene, toluene, ethyl benzene and xylene) are known for their potential toxic, mutagenic and carcinogenic effects, especially in an indoor occupational environment, where these substances dissipate with greater difficulty. Thus, the present work evaluated the concentrations, mutagenicity and cytotoxicity of the BTEX group in the indoor air of workshops involving painting and varnishing. Samples were collected using air pumps from the outside of the open environment workshops and from the inside of each of the three workshops. The chemical analyses were carried out using gas chromatograph with mass spectrometry. The mutagenic and cytotoxicity potentials were determined using the Salmonella/microsome and WST/LDH assays, respectively. The concentrations of each constituent of the BTEX group were below the limits established by the National Institute for Occupational Safety and Health and toluene presented the highest value. Moreover, these compounds did not induce mutagenic activity in the TA98 and TA100 Salmonella typhimurium strains either in the presence or in the absence of metabolization, and no cytotoxic effects were observed in the A549 human lung cells. These results may be related to the low BTEX values found in the occupational environment, as can be seen in some other studies. Nevertheless, at low concentrations, these compounds may cause toxicity by a pathway not investigated in this study or may have interacted with other non-monitored air constituents, reducing their toxicity. The present study sought to obtain more information and clarifications regarding occupational exposure to BTEX, contributing to the risk assessment of the workers exposed to these substances.

Assessment of the mutagenicity of two common indoor air pollutants, formaldehyde and toluene

“…The findings indicated that both the original toluene and its intermediates (312–2500 µg per plate of toluene) exhibited no mutagenic activity against strains TA98 and TA100 in the presence or absence of the S9 mixture 51 . In addition, Martins et al 52 used Salmonella/microsome to evaluate the mutagenic and cytotoxic potentials of the BTEX group collected from painting and varnishing workshops and indicated that low concentrations of BETX below the limits established by the National Institute for Occupational Safety and Health did not show mutagenicity in S. typhimurium TA98 and TA100 strains, either with or without S9. Furthermore, SKC‐activated charcoal tubes were used to collect benzene, toluene, and xylenes, and the mutagenicity of the extracts of the samples was studied by Singla et al 22 These researchers found that the extracts were mutagenic in both TA98 and TA100 without metabolic activation 22 .…”