Exposure to toluene in the air may occur in the occupational environment where toluene is frequently used as a solvent. And the high concentration of toluene may be measured in residence indoor air from the use of common household products and in residents near industrial complex. We may be exposed to toluene from many sources, including drinking water, food, air, and consumer products, and may also be exposed to toluene through breathing the chemical in the workplace or during deliberate glue sniffing or solvent abuse. Therefore the researches for exposure to toluene are needed, considering toluene has been known as a reproductive toxicant and central nervous system depression. Exposure assessment can be carried out directly such as personal exposure and biological monitoring or indirectly methods.
In this study, the toluene levels of personal exposures and urinary hippuric acids of biological monitoring were measured in occupational environments, area affected by industrial complex and general environments. And then relationship among them was regressed.
Average personal exposure levels of toluene in occupational environment, area affected by industrial complex and general environments were 33.69 ppm, 0.0305 ppm and 0.0096 ppm, respectively. And average hippuric acid, metabolite of toluene, concentrations were 1.02 g/g creatinine, 0.40 g/g creatinine and 0.25 g/g creatinine in occupational environments, near the industrial complex and general environments, respectively.
The regression equation between personal exposure and biological monitoring of toluene showed a decreasing trend in area affected by industrial complex and general environments, whereas showed the increasing trend in the occupational environments. Combining the total measured data, the coefficient of determination (R2) between personal exposure and biological monitoring on toluene was 0.41. This study suggested that relationship between personal exposure and biological monitoring could be obtained by combining the levels measured by general environments (low), area affected by industrial complex (medium) and occupational environments (high). With this relationship, reference values of urinary hippuric acid were estimated by standards or reference values of personal exposure to toluene.