EFFECTS ON THE KIDNEY OF OCCUPATIONAL EXPOSURE TO STYRENE

Objectives: To elucidate the extent of nephrotoxicity of long-term occ upational exposure to styrene. Methods: In all 10 styrene-exposed work ers (employed, mean age 12.6 years) and 15 nonexposed workers were stu died. Each participant collected multiple overnight and end-of-shift u rine samples. The sum of the urinary concentrations of mandelic acid a nd phenylglyoxylic acid (MAP) was determined to assess the absorbed do se of styrene. The urinary parameters alanine aminopeptidase (AAP), be ta-galactosidase (beta GAL), N-acetyl-beta-D-glucosaminidase (NAG), re tinol-binding protein (REP), and albumin (ALE) were determined to asse ss the effects on renal function and integrity. Results: The median co ncentration of MAP in urine was 175 mg/g urinary creatinine (CREAT-U; range 72-496 mg/g). The 8-h time-weighted average (8-h TWA) exposure t o styrene was estimated from the urinary concentration of MAP and rang ed from 21 to 405 mg/m(3). RBP showed a borderline correlation with th e dose of styrene. ALB in end-of-shift urine samples showed a borderli ne correlation with the absorbed dose of styrene. Conclusions: From th e borderline correlation of REP with the dose of styrene it was conclu ded that there might be a slight effect on the tubuli. The borderline correlation of ALB with the dose of styrene, together with the observa tion that five values were above the reference limit of the laboratory , suggests an effect on this parameter.