Controlling Painters' Exposure to Volatile Organic Solvents in the Automotive Sector of Southern Colombia

Assessment of occupational health risk due to inhalation of chemical compounds in an aircraft maintenance, repair, and overhaul company

This study was conducted in an aircraft maintenance, repair, and overhaul (MRO) company in 2021 to identify the extent of occupational exposures and quantitative assessment of the health risk due to inhalation of chemical compounds. According to the inspection of different parts of this company, heavy metals including Co, Cd, Ni, Pb, Cr(VI), and Mn and organic compounds including benzene, toluene, ethylbenzene, xylene (BTEX), and methyl ethyl ketone (MEK) were selected for health risk assessment. In total, the air in the inhalation area of active workers was sampled in 51 workstations. Measurement of the above pollutants showed that the average occupational exposure to Cd, Pb, and all organic compounds fell within the acceptable range of occupational exposure standard, while the measured values for Co, Ni, Mn, and Cr(VI) exceeded the standard limit. According to calculations, the highest carcinogenic risk (CR) was seen in the plating (airplane) workshop for exposure to Cr(VI) (7.58E-01), and the lowest CR was observed in the electronic workshop for exposure to Pb (7.75E-08). The highest non-carcinogenic hazard (HQ) was found in the welding workshop for exposure to Co (1.00E + 04), while the lowest HQ was related to toluene in the fabrication workshop (9.10E-03). Considering the high rate of exposure indicators, CR and HQ exceeded the standards set by the American Environmental Protection Agency (EPA) in most workshops. Accordingly, company managers should take the necessary measures to reduce the vulnerability of individuals working in areas with unacceptable CR and HQ.

Blood serum levels of selected biomarkers of oxidative stress among printing workers occupationally exposed to low-levels of toluene and xylene

Printing workers (PWs) are exposed to a mixture of solvents, yet the health risks associated with such exposuer are unknown. This study aimed to compare the serum levels of selected biomarkers of oxidative stress among occupationally exposed PWs to low-level of toluene and xylenes and unexposed controls. Associations between levels of such biomarkers and occupational exposures to toluene and xylene were also investigated. Urinary levels of hippuric acid (HA) and methyl hippuric acids (MHAs) as exposure biomarkers of toluene and xylenes, respectively, and serum levels of oxidative stress biomarkers, including total antioxidant capacity (TAC), malondialdehyde (MDA), and the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), were measured among the 84 subjects, comprising 44 PWs and 40 unexposed subjects. Mean concentrations of urinary HA and MHAs of PWs showed a significant increase compared with the unexposed controls. Although levels of urinary biomarkers of exposure to toluene (HA) and xylenes (MHAs) were well below the biological exposure indices (BEIs; ACGHI), PWs presented significantly increased serum levels of MDA, and significantly decreased serum activities of SOD and GPx compared to the unexposed controls. However, for serum TAC and CAT activity, no significant difference was observed between the two groups. Correlation analyses indicated that urinary levels of HA and MHAs were positively correlated with MDA levels and negatively correlated with GPx and SOD. Our study suggested that the alterations evidenced in serum levels of MDA, SOD, and GPx could be involved in the oxidative stress caused by co-exposure to low levels of toluene and xylene. Further investigation is needed to clarify the effect of low-level occupational exposure to solvents among PWs.

Toluene and Heavy Metals in Small Automotive Refinishing Shops and Personal Protection of the Workers in Nakhon Si Thammarat, Thailand

Chemical contamination and safe work practices of workers in automotive refinishing shops have been extensively studied in industrialized countries, but the evidence in developing countries is limited. This study aimed to evaluate chemical contamination and the use of personal protective equipment (PPE) of workers in local small-scale automotive refinishing shops in Nakhon Si Thammarat, Thailand. Airborne toluene and heavy metals, i.e., lead, chromium, and cadmium, were measured in 3 automotive refinishing shops. Toluene exposure assessed by urinary hippuric acid (n = 27) and metal contamination on workers' hands (n = 24) were also determined. Information on the use of PPE and personal hygiene practices of the workers was collected by questionnaires. Average ambient levels of toluene (0.04–18.26 ppm) and the metals (Pb: ND-26.34, Cr: 0.02–4.46, and Cd: ND-1.44 µg/m³) in all sites did not exceed the national standard levels of 200 ppm for toluene (1998) and 50, 12, and 5 µg/m³ for Pb, Cr, and Cd, respectively (2017). The mean ambient levels of these chemicals were highest in paint spray booths followed by nonpainting areas and office rooms, respectively. The highest level of urinary hippuric acid (1.13 g/g creatinine) was found in a painter but did not exceed the recommended biological exposure index of 1.6 g/g creatinine (2014). In contrast, the highest levels of lead and chromium detected on the workers' hands were found in body repair technicians. Direct hand contact without using gloves was suggested as a primary cause of metal contamination.