title: Genotoxic effects of fumes from asphalt modified with waste plastic and tall oil pitch.
abstract: As the use of recycled materials and industrial by-products in asphalt mixtures is increasing, we investigated if recycled additives modify the genotoxicity of fumes emitted from asphalt. Fumes were generated in the laboratory at paving temperature from stone-mastic asphalt (SMA) and from SMA modified with waste plastic (90% polyethylene, 10% polypropylene) and tall oil pitch (SMA-WPT). In addition, fumes from SMA, SMA-WPT, asphalt concrete (AC), and AC modified with waste plastic and tall oil pitch (AC-WPT) were collected at paving sites. The genotoxicity of the fumes was studied by analysis of DNA damage (measured in the comet assay) and micronucleus formation in human bronchial epithelial BEAS 2B cells in vitro and by counting mutations in Salmonella typhimurium strains TA98 and YG1024. DNA damage was also assessed in buccal leukocytes from road pavers before and after working with SMA, SMA-WPT, AC, and AC-WPT. The chemical composition of the emissions was analysed by gas chromatography/mass spectrometry. The SMA-WPT fume generated in the laboratory induced a clear increase in DNA damage in BEAS 2B cells without metabolic activation. The laboratory-generated SMA fume increased the frequency of micronucleated BEAS 2B cells without metabolic activation. None of the asphalt fumes collected at the paving sites produced DNA damage with or without metabolic activation. Fumes from SMA and SMA-WPT from the paving sites increased micronucleus frequency without metabolic activation. None of the asphalt fumes studied showed mutagenic activity in Salmonella. No statistically significant differences in DNA damage in buccal leukocytes were detected between the pre- and post-shift samples collected from the road pavers. However, a positive correlation was found between DNA damage and the urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) after work shift, which suggested an association between occupational exposures during road paving and genotoxic effects. Our results indicate that fumes from SMA and SMA-WPT contain direct-acting genotoxic components.
authors.affiliation: New Technologies and Risks, Work Environment Development, Finnish Institute of Occupational Health, FI-00250 Helsinki, Finland.
authors.forename: Hanna K
authors.initials: HK
authors.lastname: Lindberg
authors.forename: Virpi
authors.initials: V
authors.lastname: Väänänen
authors.forename: Hilkka
authors.initials: H
authors.lastname: Järventaus
authors.forename: Satu
authors.initials: S
authors.lastname: Suhonen
authors.forename: Jonas
authors.initials: J
authors.lastname: Nygren
authors.forename: Mervi
authors.initials: M
authors.lastname: Hämeilä
authors.forename: Jarkko
authors.initials: J
authors.lastname: Valtonen
authors.forename: Pirjo
authors.initials: P
authors.lastname: Heikkilä
authors.forename: Hannu
authors.initials: H
authors.lastname: Norppa
mesh_terms: D000293:Adolescent; D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects* / Q000032:analysis; D001711:Biotransformation / Q000187:drug effects; D002460:Cell Line; D015331:Cohort Studies; D003247:Conservation of Natural Resources; D004249:DNA Damage / Q000187:drug effects*; D006801:Humans; D006838:Hydrocarbons / Q000009:adverse effects* / Q000032:analysis; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced; D015162:Micronucleus Tests / Q000379:methods; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism; D009153:Mutagens / Q000009:adverse effects* / Q000032:analysis; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D010969:Plastics / Q000009:adverse effects* / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects* / Q000032:analysis; D012486:Salmonella typhimurium / Q000235:genetics
chemical_list: D000395:Air Pollutants, Occupational; D006838:Hydrocarbons; D009153:Mutagens; D010969:Plastics; D011084:Polycyclic Aromatic Hydrocarbons; C006647:asphalt