Diesel Particulate Matter and Health Risk: What to do About it?

Transcription

1 Diesel Particulate Matter and Health Risk: What to do About it? Karl Bresee, B.Sc., PBD Ecotox, P. Biol. Karen Phillipps, B.Sc., M.Sc., DABT, UKRT, ERT Intrinsik Corp., Calgary, Alberta Envirotech, Calgary, AB April 4, 2018

2 Problem

3 Why look at Diesel Emissions and Particulates Sources o New transportation corridors o Large construction sites o Industrial applications o Mines for oil sands, coal or minerals o Marine traffic Receptors o Air quality concerns or impact assessments o Protection of human health

4 Outline What is it? Diesel Emissions and/or Diesel Particulate Matter Overview of Toxicity Studies & Guidelines Examples 1. Measured Data or Studies 2. Predicted Data o Local & Regional Scale Risk Characterization Parting Thoughts

5 What is it Made Of? CO VOCs PM Coarse Particulate (PM 10 ) Fine Particulate (PM 2.5 ) Ozone Ultrafine PM NOx Diesel Exhaust: A Complex Mixture PAHs Aldehydes Semivolatiles

6 Diesel Emissions vs. Diesel Particulate Matter Diesel Particulate Matter (DPM): particles emitted from diesel engines and equipment from friction (e.g., brakes) Includes particles of many sizes < 0.1 µm to 10 µm (ultrafine PM, PM 2.5 to PM 10 ) Ultrafine PM (< 1.0 µm) is predominant in DPM Elemental or Black Carbon (EC or BC) Black Carbon measurement of light-absorbing properties of soot. Elemental Carbon measurement of soot by thermal-optical techniques Source: HEI (2018) Composition of both DE and DPM influenced by engine type and fuel characteristics

7 Evaluation of Diesel Exhaust and Health Endpoint Acute (Short-term) Respiratory Effects Cardiovascular Effects Neurological Effects Chronic (Long-term) Respiratory Effects Cardiovascular Effects Neurological Effects Carcinogenicity Causality Determination Causal Likely Suggestive Likely Suggestive Inadequate Inadequate (other) Health Canada (2016) Weight of Evidence Summary For Diesel Exhaust (a mixture, not just DPM)

8 Health Canada Guidelines 2016 Included a review of health effects data and air quality modelling New short-term guideline of 10 µg/m 3 and long-term guideline of 5 µg/m 3 Both values for diesel exhaust particulate Key studies seem to involve exposure to DE mixtures and older engine technology (pre-2000) Not clear how values to be used with existing Canadian PM 2.5 standards No surrogates identified for ambient air monitoring

9 Other Regulatory Guidelines for DPM Agency Value (µm 3 ) Health Canada (acute, 1-hour) Health Canada (chronic, non-cancer) California OEHHA (chronic, non-cancer) US EPA (chronic, non-cancer) Short-term none available for comparison to Health Canada Long-term non-cancer values are the same

10 Relating Emissions to Guidelines Is it Possible? DPM guidelines - Are we comparing apples to apples? Toxicity studies relied upon by Health Canada and other Agencies involved older engine technology Health Effects Institute (HEI) and US EPA: data from older diesel engines and fuels may not be relevant Potential for co-exposure to other compounds in diesel exhaust mixtures (e.g. NO 2, formaldehyde) in key studies and in the population Uncertainty in study designs? What monitoring data should be compared (PM, EC, BC)? How should DPM be modelled?

11 Data What should we compare? No clearly agreed upon surrogate for DPM or method for assessing or modelling at this time (e.g. PM / EC / BC) National Air Pollutant Surveillance Program (NAPS) as of 2017, PM 2.5, PM 10 and particles in range of PM 2.5 to PM 10 are monitored Government of Alberta data available for total suspended particulate (TSP), PM 1, PM 2.5, PM 10 and particles in range of PM 2.5 to PM 10 British Columbia Ministry of the Environment data available for PM 2.5 and PM 10 Source: Creative Commons (2018) Ontario Ministry of the Environment monitors PM 2.5 Elemental Carbon (EC) and Black Carbon (BC) not commonly monitored

12 Example - Diesel PM International Europe has established network for monitoring of black carbon. Equivalent Black Carbon (EBC) - aerosol absorption coefficient is converted into EBC by correcting the online measurements with filter-based EC concentrations determined by thermo-optical analysis.

13 Example - Diesel PM Monitored data EBC Measurements can vary with time, sources, meteorology and other factors Correlate with PM Does EBC = DPM? Source: European Environment Agency (2013)

14 Example PM1 Monitored Data Jaffre et al. (2014) Study of railway diesel PM emissions in Seattle Measured PM 1 using 10- second averages over a 6- hour period Emissions from only 8 trains captured in Figure Health Canada 1-hour: 10 µg/m 3

15 Example Black Carbon Monitored Data Jeong et al. (2017). Ultrafine and Black Carbon samples from within a morning passenger commuter train in Greater Toronto Area, 10-car train pulled with diesel locomotive. Health Canada 1-hour: 10 µg/m 3 or 10,000 ng/m 3

16 Examples Predicted DPM Based on Monitored Location Sources Annual DPM Average (Range) μg/m 3 Ambient, Boston Urban, industrial (0.8 to 1.7) Ambient, Washington DC (based on EC) Urban, industrial, 1.4 (1 to 2.2) Ambient, South Coast Air Basin, California (based on EC) Urban, industrial, agricultural (2.4 to 4.5) Coastal Ambient DPM (predicted, based on EC) Urban, industrial, marine (0.79 to 1.24) HC Annual Guideline 5

17 Examples Predicted Data Local Scale Smaller-scale projects, limited sources and range of impact Project-Specific, Construction Site, Alberta (predicted within 500 m) Construction equipment: excavators, articulated trucks, tandem and flat bed rucks, concrete trucks, water trucks, pickup trucks, drill rigs, dozers, crane, logging truck, graders, rollers/compactors 1-hour (max) μg/m 3 Annual (Average) μg/m Project-specific, (predicted, based on EC) Marine traffic HC Annual Guidance Values 10 5

18 Predicted Hourly PM 2.5 [ug/m3] Example Predicted Data Regional Scale Comparison of Predicted Hourly PM 2.5 to Predicted PM Diesel y = 1.348x R² = or DPM=0.67x[PM 2.5 ] Predicted Hourly DPM [ugm3]

19 Predicted Annual PM2.5 [ug/m3] Example Predicted Data Regional Scale Comparison of Predicted Annual PM 2.5 to Predicted PM Diesel y = x R² = or DPM=0.72x[PM 2.5 ] Comparison of Predicted Annual PM 2.5 to Measured (includes forest fires) y = x R² = Predicted Annual DPM [ug/m3]

20 Ambient Air Concentration [µg/m3] Example Predicted DPM Regional Scale Calgary Predicted hourly diesel particulate matter Based on 95 th percentile of ambient PM 2.5 concentration Major assumption that conversion factor was 0.68 Modelled vs ambient depends on contributing sources Calgary Central 2 Calgary Central Inglewood Calgary NorthWest Calgary SouthEast Guideline

21 Ambient Air Concentration [µg/m3] Example Predicted DPM Regional Scale Calgary Predicted annual diesel particulate matter Based on annual average of ambient PM 2.5 concentration Major assumption that conversion factor 0.72 Modelled vs ambient depends on contributing sources Calgary Central 2 Calgary Central Inglewood Calgary NorthWest Calgary SouthEast Long-term Guideline

22 Risk Characterization Short Term Exposure Characterization of short-term risk is hindered with uncertainty surrounding exposure and toxicity. Potential for co-exposure to other compounds in diesel exhaust mixtures not accounted for (e.g. NO 2, formaldehyde, PAHs, aliphatic hydrocarbons, sulfate, nitrate and metals). The composition of diesel PM varies but generally consists of elemental carbon (EC) with adsorbed compounds such as organic compounds (including PAHs and aliphatic hydrocarbons), sulphate, nitrate, metals and other trace elements. Measured ambient PM 2.5 concentrations in Calgary meet CCME 24-hour CAAQS (i.e., 27 μg/m 3 ).

23 Risk Characterization Long Term Exposure More confidence can be placed in the long term limit of 5μg/m 3 Limit based on two key studies: Ishinishi et al. (1986, 1988). Health Canada (2016) selected the highest reported NOAEL of 460 µg/m³ as the point of departure, which was adjusted: Dosimetry model to adjust to human equivalent of 120µg/m³ Applied an uncertainty factor of 25 Adverse respiratory effects are predicted to range from 330 to 4,400 µg/m³ in humans (US EPA 2003). Measured ambient PM 2.5 concentrations in Calgary meet CCME annual CAAQS (i.e., 8.8 μg/m 3 ).

24 Parting Thoughts Exposure to diesel exhaust and DPM have been associated with adverse health effects (i.e., based on epidemiological and inhalation chamber studies). Health Canada and other agencies have developed guidelines BUT it is not clear what ambient or modelled data should be compared to these air quality guidelines. Measured and predicted data vary with methods used and diesel source type. Currently, certain projects not required to assess DPM like infrastructure projects (e.g., large interchanges or other transportation projects) but industrial applications are (e.g., oil sands mine or SAGD). Also construction emissions/activities in environmental assessments are requested to assess DPM.

25 Acknowledgements Karen Phillipps, M.Sc., DABT, ERT, Intrinsik Bart Koppe, B.Sc., PBD, P.Biol, Intrinsik Created by K. Phillipps, Intrinsik with: Health Canada (2016), WordClouds (2018)

26 References Environment and Climate Change Canada Air Pollutant Emission Inventory Report. ISSN: X. Available at: European Environment Agency Status of Black Carbon Monitoring in Ambient Air in Europe. EEA Technical Report. No 18/2013. Available at: European Environment Agency Emissions of Air Pollutants from Transport. Available at: Creative Commons Available at: Health Canada Human Health Risk Assessment for Diesel Exhaust. Fuels Assessment Section, Water and Air Quality Bureau, Healthy Environments and Consumer Safety Branch, Health Canada. March Cat: H129-60/2016E-PDF, ISBN: Ishinishi, N., Kuwabara, N., Nagase, S., Suzuki, T., Ishiwata, S., and Kohno, T Long-term inhalation studies on effects of exhaust from heavy and light duty diesel engines on F344 rats. In: Ishinishi N; Koizumi A; McClellan RO; Stober W (eds.). Carcinogenic and mutagenic effects of diesel engine exhaust: proceedings of the international satellite symposium on toxicological effects of emissions from diesel engines, July, Tsukuba Science City, Japan. Elsevier Science Publishers BV, Amsterdam, Netherlands. pp Cited in: Health Canada Ishinishi, N., Kuwabara, N., Takaki, Y., Nagase, S., Suzuki, T., Nakajima, T., Maejima, K., Kato, A. and Nakamura, M Long-term inhalation experiments on diesel exhaust. In: Diesel exhaust and health risk: results of the HERP studies. Research Committee for Health Effects Research Programme Studies, Automobile Research Institute, Inc., Tsukuba, Ibaraki, Japan. pp Cited in: Health Canada Jaffre, D.A., Hof, G., Malashanka, S., Putz, J. Thayer, J., Fry, J.L., Ayres, B., and J. R. Pierce Diesel particulate matter emission factors and air quality implications from inservice rail in Washington State, USA. Atmos Pollut 5: Jeong, C.H., Traub, A., and G.J. Evans Exposure to ultrafine particles and black carbon in diesel-powered commuter trains. Atmos Environ 155: Health Canada Human Health Risk Assessment for Diesel Exhaust. ISBN: HEI (Health Effects Institute) Diesel Exhaust. Available at: NIOSH (National Institute for Occupational Safety and Health) Diesel Aerosols and Gases in Underground Mines: Guide to Exposure Assessment and Control. Report of Investigations RI US EPA (United States Environmental Protection Agency) Health Assessment for Diesel Engine Exhaust. National Center for Environmental Assessment, Washington DC. EPA/600/8-90/057F. May US EPA Integrated Risk Information System Chemical Assessment Summary Diesel engine exhaust; CASRN N.A. National Centre for Environmental Assessment-RTP Office, Office of Research and Development, US Environmental Protection Agency. Available at: US EPA (United States Environmental Protection Agency) Particulate Matter (PM) Basics. Available at: US OSHA (United States Occupational Safety and Health Administration) Hazard Alert Diesel Exhaust/Diesel Particulate Matter. Available at: WordClouds by Zygomatic. Available at:

27 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Calgary Daily PM Daily Average PM2.5 Ambient Air Concentrations at Calgary Montoring Stations Calgary Central Inglewood Calgary SouthEast Calgary Central 2 Short-term PM2.5 Limit (27)

28 Ambient Air Concentration [µg/m 3 ] Calgary Annual PM Annual Average PM2.5 Concentrations for Calgary Ambient Air Monitoring Stations Calgary Central 2 Calgary Central Inglewood Calgary NorthWest Calgary SouthEast Long-term Guideline

29 DPM and Ultrafine Carbon Ultrafine PM = Elemental Carbon (soot) + Organic Carbon (condensed phase) Ultrafine particles have elemental carbon core Organic carbon fraction can bind with organic molecules including sulphur, hydrocarbons, PAHs, acids, alcohols, aldehydes Composition is variable depending on many factors Eg. Total carbon or black carbon estimates complicated by biomass burning and other sources

30 National PM 2.5 Monitoring ( ) Environment Canada (2018) report No data for DPM, EC, BC or ultrafine PM Emissions particles less than and equal to PM 2.5 decreasing (18% lower in 2016 than 1990) BUT emissions from construction and road dusts not decreasing

31 Diesel Exhaust and PM - International In Europe, PM 2.5 emissions from non-transport sectors are dominant sources Source: European Environment Agency (2017) Emissions of Air Pollutants from Transport