title: Measurement of frequencies of HPRT mutants, chromosomal aberrations, micronuclei, sister-chromatid exchanges and cells with high frequencies of SCEs in styrene/dichloromethane-exposed workers.
abstract: Frequencies of HPRT mutants (MFs), chromosomal aberrations with or without gaps (CA+; CA-), aberrant cells (AC), micronuclei (MN), sister-chromatid exchanges (SCEs) and cells with high frequencies of SCEs (HFCs) were measured in lymphocytes collected from 46 workers occupationally exposed to styrene and dichloromethane (DCM = methylene chloride). These parameters were also determined in 23 controls. Time-weighted average (TWA) values for styrene and DCM exposure during an 8-h working day were respectively 70 mg/m3 (range: 0-598) and 108 mg/m3 (range: 0-742). These values correspond to TWA values of 17 ppm styrene and 31 ppm DCM. In exposed workers, all cytogenetic parameters were significantly enhanced (P < 0.0001; one-sided), but, due to the lack of appropriate control data, no definite conclusions could be drawn concerning the mutagenicity of styrene/DCM exposure. Duration of exposure was not correlated with genetic effects analyzed. The TWA value for styrene was not correlated with the extent of genetic damage detected, but the TWA value for DCM was positively correlated with the frequencies of chromosome aberrations (with gaps) and aberrant cells. These observations make it difficult to decide whether styrene or DCM, or both chemicals, induced the cytogenetic effects observed in exposed workers. Using the present styrene/DCM data, earlier ethylene oxide data and unpublished epichlorohydrin data, the relative sensitivity of the genetic endpoints to detect genotoxic exposure was: HFC > CA- > CA+ > SCE > MN > HPRT.
authors.affiliation: MGC-Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, The Netherlands.
authors.forename: A D
authors.initials: AD
authors.lastname: Tates
authors.forename: T
authors.initials: T
authors.lastname: Grummt
authors.forename: F J
authors.initials: FJ
authors.lastname: van Dam
authors.forename: F
authors.initials: F
authors.lastname: de Zwart
authors.forename: F J
authors.initials: FJ
authors.lastname: Kasper
authors.forename: R
authors.initials: R
authors.lastname: Rothe
authors.forename: H
authors.initials: H
authors.lastname: Stirn
authors.forename: A H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: A T
authors.initials: AT
authors.lastname: Natarajan
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis; D016902:Air Pollution, Indoor / Q000032:analysis; D000704:Analysis of Variance; D002869:Chromosome Aberrations; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D008214:Lymphocytes / Q000166:cytology / Q000201:enzymology; D008297:Male; D008752:Methylene Chloride / Q000032:analysis; D048629:Micronuclei, Chromosome-Defective / Q000648:ultrastructure; D015162:Micronucleus Tests; D008875:Middle Aged; D009153:Mutagens; D009154:Mutation; D016273:Occupational Exposure; D012854:Sister Chromatid Exchange; D012907:Smoking; D020058:Styrene; D013343:Styrenes; D013997:Time Factors
chemical_list: D000395:Air Pollutants, Occupational; D009153:Mutagens; D013343:Styrenes; D020058:Styrene; D008752:Methylene Chloride; D007041:Hypoxanthine Phosphoribosyltransferase