Benzo[a]pyrene in Drinking Water Document for Public Consultation Prepared by the Federal-Provincial-Territorial Committee on Drinking Water Consultation period ends May 6th, 2015 Benzo[a]pyrene For public consultation Benzo[a]pyrene in Drinking Water Document for Public Consultation Table of Contents Purpose of consultation .................................................................................................................... 1 Part I. Overview and Application................................................................................................. 2 1.0 Proposed guideline ............................................................................................................... 2 2.0 Executive summary .............................................................................................................. 2 2.1 Health effects ........................................................................................................... 2 2.2 Exposure .................................................................................................................. 3 2.3 Analysis and treatment ............................................................................................. 3 3.0 Application of the guideline................................................................................................. 3 3.1 Monitoring ............................................................................................................... 3 3.2 Mitigation ................................................................................................................. 4 Part II. Science and Technical Considerations ........................................................................... 5 4.0 Identity, use and sources in the environment ....................................................................... 5 4.1 Environmental fate ................................................................................................... 5 5.0 Exposure .............................................................................................................................. 5 5.1 Water ........................................................................................................................ 6 5.1.1 Leaching from coal tar linings ..................................................................... 6 5.2 Food ......................................................................................................................... 7 5.3 Air ............................................................................................................................ 7 5.4 Consumer products .................................................................................................. 7 5.5 Soil ........................................................................................................................... 7 5.6 Multi-route exposure from drinking water .............................................................. 8 6.0 Analytical methods .............................................................................................................. 8 7.0 Treatment technology and distribution system considerations ............................................ 9 7.1 Municipal scale ........................................................................................................ 9 7.1.1 Conventional coagulation/filtration and lime softening processes ............ 10 7.1.2 Activated carbon ........................................................................................ 11 7.1.2.1 Granular activated carbon .............................................................. 11 7.1.2.2 Powder activated carbon ............................................................ 12 7.1.3 Oxidation processes ................................................................................... 12 7.1.3.1 Chlorination/chloramination and mixed oxidants ...................... 12 7.1.3.2 Ozonation and advanced oxidation processes ............................ 13 7.1.3.3 UV and advanced oxidation processes ....................................... 13 7.1.4 Membrane processes .................................................................................. 14 ii Benzo[a]pyrene For public consultation 7.1.5 Emerging technologies............................................................................... 14 7.1.6 Distribution system considerations ............................................................ 14 7.2 Residential scale..................................................................................................... 16 8.0 Kinetics and metabolism .................................................................................................... 17 8.1 Absorption.............................................................................................................. 17 8.2 Distribution ............................................................................................................ 17 8.3 Metabolism ............................................................................................................ 18 8.4 Excretion ................................................................................................................ 19 8.5 PBPK models ......................................................................................................... 19 9.0 Health effects ..................................................................................................................... 20 9.1 Effects in humans ................................................................................................... 20 9.1.1 Acute toxicity ............................................................................................. 20 9.1.2 Subchronic and chronic toxicity and carcinogenicity ................................ 20 9.1.2.1 Tumorigenesis and carcinogenesis .............................................. 20 9.1.3 Reproductive and developmental toxicity ................................................. 21 9.2 Effects on experimental animals ............................................................................ 21 9.2.1 Acute toxicity ............................................................................................. 21 9.2.2 Short-term exposure ................................................................................... 21 9.2.2.1 Renal and hepatic toxicity ........................................................... 21 9.2.2.2 Cardiovascular toxicity ............................................................... 22 9.2.2.3 Neurotoxicity ............................................................................... 22 9.2.2.4 Immunotoxicity ........................................................................... 22 9.2.3 Long-term exposure and carcinogenicity ................................................... 23 9.2.3.1 Digestive tract tumours ............................................................... 23 9.2.3.2 Liver tumours .............................................................................. 24 9.2.3.3 Respiratory tract tumours ............................................................ 24 9.2.3.4 Skin tumours ............................................................................... 24 9.2.3.5 Other tumours .............................................................................. 24 9.2.4 Genotoxicity ............................................................................................... 24 9.2.5 Reproductive and developmental toxicity ................................................. 25 9.2.5.1 Reproductive toxicity .................................................................. 25 9.2.5.2 Developmental toxicity ............................................................... 26 9.3 Toxicogenomics ..................................................................................................... 27 9.4 Mode of action ....................................................................................................... 28 10.0 Classification and assessment ............................................................................................ 29 10.1 Cancer risk assessment .......................................................................................... 29 10.2 Non-cancer risk assessment ................................................................................... 31 10.3 International considerations ................................................................................... 31 11.0 Rationale ............................................................................................................................ 32 12.0 References .......................................................................................................................... 33 Appendix A: List of acronyms ....................................................................................................... 47 iii Benzo[a]pyrene For public consultation Appendix B: Provincial/territorial cost estimates .......................................................................... 48 iv March 2015 Benzo[a]pyrene in Drinking Water Purpose of consultation The Federal-Provincial-Territorial Committee on Drinking Water (CDW) has assessed the available information on benzo[a]pyrene with the intent of establishing a drinking water guideline. The purpose of this consultation is to solicit comments on: 1. the proposed guideline; 2. the approach used for its development; 3. the potential economic