title: Maintenance of Low-Pressure Carburising Furnaces: A Source of PAH Exposure.
abstract: OBJECTIVE
  Low-pressure carburising is a new technology used to harden steel; the process has been shown to be a source of considerable polycyclic aromatic hydrocarbons (PAH) pollution. Some PAH are carcinogenic, and activities such as furnace maintenance may thus represent a risk to workers. Occupational exposure during these operations should therefore be assessed.
  
  
  METHODS
  In this study, the PAH-related carcinogenic risk associated with furnace maintenance was assessed by monitoring atmospheric levels of benzo[a]pyrene (BaP), a representative marker, alongside urinary levels of 3-hydroxybenzo[a]pyrene (3-OHBaP), one of its metabolites. PAH exposure levels were monitored during seven sampling campaigns in four different factories specialized in heat-treatment of mechanical workpieces for the automotive and helicopter industries. Two types of furnace were studied, and 37 individuals were monitored.
  
  
  RESULTS
  Values up to 20-fold the French regulatory value of 150 ng/m3 for atmospheric BaP, and, for urinary 3-OHBaP values up to 40-fold the French biological limit value (BLV) of 0.35 nmol/mol of creatinine were detected. Very high concentrations of BaP, close to or even exceeding those found in coal-tar pitch (up to about 20 g/kg), were measured in residues (tars, dusts) deposited inside the furnace. Even when adequate and suitable personal protective equipment was used, urinary 3-OHBaP values often exceeded the BLV. We hypothesize that this exposure is linked to insidious and fortuitous dermal contamination through contact with factory equipment and staining.
authors.affiliation: Institut National de Recherche et de Sécurité (INRS), 1, rue du Morvan, Vandœuvre-lès-Nancy 54519, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Champmartin
authors.affiliation: Institut National de Recherche et de Sécurité (INRS), 1, rue du Morvan, Vandœuvre-lès-Nancy 54519, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Jeandel
authors.affiliation: Institut National de Recherche et de Sécurité (INRS), 1, rue du Morvan, Vandœuvre-lès-Nancy 54519, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Monnier
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis*; D001564:Benzo(a)pyrene / Q000032:analysis; D015415:Biomarkers / Q000652:urine; D002273:Carcinogens / Q000032:analysis*; D003404:Creatinine / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D008283:Maintenance; D008297:Male; D008669:Metallurgy; D016273:Occupational Exposure / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D013232:Steel
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D002273:Carcinogens; D011084:Polycyclic Aromatic Hydrocarbons; D013232:Steel; D001564:Benzo(a)pyrene; D003404:Creatinine
keywords: 3-hydroxybenzo[a]pyrene; benzo[a]pyrene; dermal exposure; occupational exposure; polycyclic aromatic hydrocarbons; vacuum case hardening