title: A review of the effectiveness of respirators in reducing exposure to polycyclic aromatic hydrocarbons for coke oven workers.
abstract: OBJECTIVE
  In 2011 recommendations for the prescription of lung cancer in coke oven workers were made in the UK. In the 1970s, a powered helmet respirator, the Airstream helmet, was introduced to the UK coking industry with the aim of reducing exposure to polycyclic aromatic hydrocarbons (PAH) aerosols and consequent lung cancer risks for workers on the coke oven tops. This review set out to identify the level of protection afforded by the Airstream helmet, when the helmets could be considered to have provided effective protection and whether the levels of protection have been maintained to the current time.
  
  
  METHODS
  Five approaches were taken to identify review material, including searching the peer-reviewed and grey literature; searching material held in the National Archive; using a Freedom of Information to the Health and Safety Executive; interviews with employees involved in the introduction of the Airstream helmet; and acquisition of company reports.
  
  
  RESULTS
  The two principal companies involved in coke production in the UK took different approaches to the introduction of the Airstream helmets. Because of this, it can only be considered that effective wearing occurred in the industry as a whole from 1982 onwards. Exposure measurements made by British Steel in the late 1970s suggested that the mean protection factor of the Airstream helmet was ~10 (5th percentile~2.5), regardless of whether exposure was assessed as the inhalable aerosol or other measures more specific to aerosol of PAH. More recent data collected using biological monitoring has identified that average urinary levels of 1-hydroxypyrene (1-HP) generally correspond with the inhalation occupational exposure limit for benzene soluble material. Although on occasions, relatively high air concentrations in-mask and urinary 1-HP concentrations have been identified, underlining the necessity to maintain close supervision of workers wearing respirators.
  
  
  CONCLUSIONS
  Overall, we concluded that the wearing of helmet respirators has effectively controlled long-term average exposure to PAH for most workers on coke ovens since 1982.
authors: 1.Research Management, Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK 2.Statistics and Toxicology, Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK joanne.crawford@iom-world.org.
authors: Joanne O
authors: JO
authors: Crawford
authors: 1.Research Management, Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK.
authors: Ken
authors: K
authors: Dixon
authors: 2.Statistics and Toxicology, Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK.
authors: Brian G
authors: BG
authors: Miller
authors: 1.Research Management, Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh EH14 4AP, UK.
authors: John W
authors: JW
authors: Cherrie
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D015415:Biomarkers / Q000652:urine; D003077:Coke; D004784:Environmental Monitoring / Q000379:methods; D019652:Extraction and Processing Industry; D006801:Humans; D019570:Inhalation Exposure / Q000517:prevention & control; D016273:Occupational Exposure / Q000032:analysis* / Q000517:prevention & control; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000633:toxicity; D011721:Pyrenes / Q000652:urine; D012134:Respiratory Protective Devices / Q000592:standards* / Q000706:statistics & numerical data; D006113:United Kingdom
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D003077:Coke; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; C033146:1-hydroxypyrene
keywords: coke ovens; polycyclic aromatic hydrocarbons; powered respirators