Immunologic and renal markers among photogravure printers exposed to toluene

Abstract

Objectives. This study assessed immunologic and early renal effects of chronic toluene exposure. Methods. In a longitudinal study of 92 printers and 74 referents, 145 subjects had pre- and poststudy samples of blood and urine taken for the following measurements: immunoglobulin E (IgE), antiglomerular basement membrane (anti-GBM) and antilaminin (anti-LAM) antibodies in blood; creatinine and β2-microglobulin in blood and urine; and microalbumin, N-acetyl-b-D-glucosaminidase (NAG) and alanine-aminopeptidase in urine. Creatinine clearance was calculated according to the Cockroft-Gault formula. Eight-hour personal air samples were collected twice to assess present exposure to toluene. A job-exposure matrix was developed to estimate past cumulative exposure. Information about potential confounders was recorded by questionnaire. Multiple regression analysis was performed to study dose-effect relations adjusted for age and smoking. Results. No subject was positive for anti-GBM antibodies, and only 12 were positive for anti-LAM. No relation was observed between the markers studied and present exposure to toluene except that creatinine clearance was higher among the exposed subjects than among the referents. A dose-response relation was observed between cumulative toluene exposure and both IgE and NAG excretion. No interaction was observed between hypertension and exposure, but the relationship with NAG did not persist when subjects with hypertension were excluded. Past or present exposure did not alter the 2-year trend of any marker studied. Conclusions. According to the results of this study, toluene at 50 ppm is not related to detectable renal dysfunction. The increased IgE levels associated with present and past exposure require further investigation.