Background: The health risk associated with chronic exposure to organic solvents investigated in several epidemiologic studies indicates a significant relationship between solvent exposure and glomerulonephritis. Solvents are the most commonly used chemicals in industry. According to European statistics 43% of all solvent consumption takes place in the painting industry, 10% in metal cleansing, 6.7% in adhesives and 3.9 percent in the laundry (dry cleaning) industries. Although BUN and creatinine indicate massive loss of glomerular function, microalbumin is a sensitive urinary marker for nephrotoxins in the early detection of solvent-induced effects on the glomerulus. The purpose of our study was to use microalbumin, serum BUN and serum creatinine levels to identify occupational solvent-induced effects on the glomerulus.
Methods: Renal dysfunction was monitored by microalbumin, BUN and creatinine serum levels in a cohort study of 92 workers currently exposed to solvents (solvent group). A control group of 92 individuals were selected from parts of the same factory not exposed to solvents. All individuals in the study were men, without diabetes or hypertension. The percentage of smokers was equal between the two groups. The solvent group was selected using environmental monitoring of organic solvents in different parts of the painting room. The individuals were chosen by simple random selection. Exclusion factors included less than one year of work in the painting room, use analgesic or aminoglycoside one month before the study and medically diagnosed renal disease, such as glomerulonephritis or renal failure. Data was gathered using a questionnaire requesting demographic information, history of present and past diseases, present and past occupational history, drug history, history of illness in their colleagues and safety conditions at work (use of safety gloves, masks, clothing, goggles and general and local ventilation). The results analyzed with SPSS 11.5.
Results: Several studies showed that solvents cause renal disorder (tubular and glomerular), although glomerulonephritis is more prevalent. The mean age of the solvent group was 28.6 ±2.7 years and was 33.7 ±7 years in control group (p<0.05). The mean duration of solvent exposure was 4.8 ±1.5 years. Statistically meaningful differences were found between solvent and control groups for microalbuminuria, increased serum BUN and creatinine levels (p<0.05), although there was no significant correlation between these parameters and the duration of exposure (p>0.05).
Conclusion: The results suggest that kidney dysfunction results from chronic occupational exposure to solvents at levels found in automobile painting rooms in Iran. We recommend increased monitoring of workers using solvents and increased review and enforcement of safety regulations regarding such use of solvents.