Edoardo De Rosa

DNA single-and double-strand breaks by alkaline-and immuno-comet assay in lymphocytes of workers exposed to styrene

Occupational exposure to styrene was studied in 34 workers employed in the production of fiberglass-reinforced plastic sheets and compared to 29 unexposed healthy controls. We evaluated genotoxic effects induced by occupational styrene exposure in lymphocytes by alkaline version of the comet assay to detect single-strand breaks (SSBs), DNA oxidation products (formamido pyrimidine glycosilase (Fpg)- and endonuclease (Endo III)-sensitive sites) and DNA repair kinetics studies, as well as the neutral version of comet assay for DNA double-strand breaks (DSBs). An innovative aspect of this study was the use of immuno-comet assay, a new technique that recognizes DSBs with specific antibody by DAPI/FITC method. The battery of parameters included markers of external and internal exposure. Exposed workers showed significant high levels of SSBs (p<0.0001) and DSBs (p<0.0001) in neutral- and immuno-comet assay. A drastic decrease in DNA repair activity as compared to controls was observed (180 min vs. 35 min). Styrene workplace concentration significantly correlated with alkaline comet parameters (TM, p=0.013; TI, p=0.008), in negative with TL (p=0.022), and with DNA-base oxidation (TM Endo III, p=0.048 and TI Endo III, p=0.028). There was a significant negative correlation between urinary metabolites (MA+PGA) and TM Endo III (p=0.032) and TI Endo III (p=0.017).

The Importance of Sampling Time and Coexposure to Acetone in the Biological Monitoring of Styrene-Exposed Workers

Abstract Forty-four workers exposed to styrene and acetone in the fiberglass industry were monitored on Monday and Thursday for 8 hours using passive dosimeters. The charcoal discs of the passive dosimeters were analyzed by gas chromatography. The 8-hour time-weighted average (TWA) exposure values ranged from 10 to 522 and 14 to 1581 mg/m3 on Monday and from 9 to 423 and 10 to 579 on Thursday for styrene and acetone, respectively. Urine samples were collected at the end of the work shift and before the start of the work shift the next morning (Tuesday and Friday). Mandelic acid and phenylglyoxylic acid were measured in the urine using a high pressure liquid chromatography method; values were expressed in milligrams/gram creatinine. Styrene TWA exposure values significantly correlated with the sum of metabolites at the end of the workday (r = 0.60 on Monday and r = 0.77 on Thursday) and also the next morning (r = 0.87 on Tuesday and r = 0.84 on Friday). Mandelic acid was always correlated with exposure bet...