title: Health implications of PAH release from coated cast iron drinking water distribution systems in The Netherlands.
abstract: BACKGROUND
  Coal tar and bitumen have been historically used to coat the insides of cast iron drinking water mains. Polycyclic aromatic hydrocarbons (PAHs) may leach from these coatings into the drinking water and form a potential health risk for humans.
  
  
  OBJECTIVE
  We estimated the potential human cancer risk from PAHs in coated cast iron water mains.
  
  
  METHODS
  In a Dutch nationwide study, we collected drinking water samples at 120 locations over a period of 17 days under various operational conditions, such as undisturbed operation, during flushing of pipes, and after a mains repair, and analyzed these samples for PAHs. We then estimated the health risk associated with an exposure scenario over a lifetime.
  
  
  RESULTS
  During flushing, PAH levels frequently exceeded drinking water quality standards; after flushing, these levels dropped rapidly. After the repair of cast iron water mains, PAH levels exceeded the drinking water standards for up to 40 days in some locations.
  
  
  CONCLUSIONS
  The estimated margin of exposure for PAH exposure through drinking water was > 10,000 for all 120 measurement locations, which suggests that PAH exposure through drinking water is of low concern for consumer health. However, factors that differ among water systems, such as the use of chlorination for disinfection, may influence PAH levels in other locations.
authors: KWR Watercycle Research Institute, Nieuwegein, The Netherlands. mirjam.blokker@kwrwater.nl
authors: E J Mirjam
authors: EJ
authors: Blokker
authors: Bianca M
authors: BM
authors: van de Ven
authors: Cindy M
authors: CM
authors: de Jongh
authors: P G G Nellie
authors: PG
authors: Slaats
mesh_terms: D060766:Drinking Water / Q000032:analysis*; D006801:Humans; D007501:Iron; D009426:Netherlands; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014881:Water Supply / Q000592:standards*
chemical_list: D060766:Drinking Water; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D007501:Iron