Urinary excretion of proteins and enzymes in workers exposed to hydrocarbons in a shoe factory.

A cross-sectional study was conducted to determine whether exposure to hydrocarbons in a shoe factory may produce renal effects that can be detected by determination of the urinary excretion of proteins and enzymes. The study population included 59 women who had been exposed to petroleum naphtha and toluene and 24 age-matched control women. The time-weighted average exposure to petroleum naphtha, toluene and ethylacetate was 1,619,81 and 160 mg/m3, respectively. The integrity of the renal structures or functions was assessed by measuring the urinary excretion of total protein, beta 2-microglobulin, retinol-binding protein, albumin, transferrin, lysozyme, lactate dehydrogenase and beta-N-acetylglucosaminidase (NAG). The only parameter that was significantly influenced by hydrocarbon exposure was the urinary activity of beta-N-acetylglucosaminidase. Although the health significance of this renal change, which was not accompanied by changes in the urinary excretion of low- or high-molecular-weight proteins, is unclear, the results of the present study are in agreement with our previous observations suggesting that long-term moderate exposure to solvents does not entail a significant risk for the development of nephrotoxicity.