HEALTH CANADA UPDATE Geoenvirologic Workshop June 4, 2015 Contaminated Sites Division Health Canada Presented by: Jo-Ann Aldridge
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Geoenvirologic Workshop
June 4, 2015
Contaminated Sites Division
Health Canada
Presented by: Jo-Ann Aldridge
HEALTH CANADA UPDATE
PRESENTATION OUTLINE • Health Canada Contaminated Sites Division Mandate • Published Guidance Documents • Updates in progress • Guidance in progress • New tools
CONTAMINATED SITES DIVISION MANDATE
• Guidance, training and advice on human health risk
assessment to federal departments that manage or own
federal contaminated sites.
• Review of NCSCS spreadsheets to confirm site eligibility
for FCSAP funding
• CSD provides expert support
functions to fulfill Health Canada’s
obligations under the Canadian
Environmental Assessment Act.
NCSCS – National Contaminated Sites Classification System
FCSAP – Federal Contaminated Sites Action Plan
CSD – Contaminated Sites Division
PUBLISHED HEALTH CANADA GUIDANCE
• Part I: PQRA (V2.0)
• Part II: Toxicity Reference Values (V2.0) (being updated)
• Part III: Guidance on Peer Review of HHRA
• Part VI: Spreadsheet Tool for PQRA
• Part V: DQRACHEM (chemical)
• Part VI: DQRARAD (radiation)
• Part VII: Soil Vapour Intrusion (being updated)
• Country Foods Supplemental Guidance
• DQRA Peer Review Checklist
• How to develop an SOW for PQRA & DQRA
http://hc-sc.gc.ca/ewh-semt/contamsite/docs/index-eng.php
PQRA – preliminary quantitative risk assessment
HHRA – human health risk assessment
DQRA – detailed quantitative risk assessment
SOW – statement of work
GUIDANCE DOCUMENT UPDATES
• Air Quality Guidance
• Removal of summary table and update science
• Vapour Intrusion Guidance
• Removal of summary table and update science
• PQRA Part 2
• Updating TRVs
• In the interim, use the published document and new values
from Health Canada, other regulatory agencies, CCME
• Environmental Site Investigation Guidance Document
is in final stages of revision at the CCME
NEW GUIDANCE
• New guidance document on short term exposure to carcinogens:
Health Canada. 2013. Federal Contaminated Sites Risk Assessment in
Canada. Interim Guidance on Human Health Risk Assessment for Short-
Term Exposure to Carcinogens at Contaminated Sites.
• HC Guidance documents listed at:
http://hc-sc.gc.ca/ewh-semt/contamsite/docs/index-eng.php
Contact: cs-sc@hc-sc.gc.caGUIDANCE IN PROGRESS • Bioavailability Considerations • Sediment Guidance • Dust Guidance • Dose Averaging for Non-Carcinogens Note: drafts of these documents are not available at this time
BIOAVAILABILITY GUIDANCE • Taped webinar available • Brief Summary: • Literature-based values are not recommended unless there is sufficient scientific rationale for their use • Site-specific in vivo or in vitro tests are useful • No specific protocols are currently recommended • Adjust absolute bioaccessibility (directly measured) relative to the (likely) bioavailability of the contaminant in the key TRV study
SEDIMENT GUIDANCE • Guidance on evaluating exposure to sediments via direct contact (i.e., dermal contact, incidental ingestion, inhalation of particulates/volatiles). • Focus on unique considerations not addressed in other guidance.
DUST GUIDANCE
• CSD identified a need to provide guidance on how to
assess indoor settled dust in a risk assessment and
derivation of a conceptual model
• Guidance would require:
• assessment on how to incorporate background levels of dust
into an HHRA
• discussion of sampling and analysis methodology
• identification of screening concentrations of substancesDOSE AVERAGING FOR NON CARCINOGENS • Taped training is available Considerations for Short term exposure to chemicals: Issues with Remote Sites • Many sites are accessed infrequently but most guidance relates to chronic exposure • The risk assessment equations for chronic exposure cannot just be adjusted to reflect short term exposure • Risk assessments need to consider the human health toxicology
TOOLS Conceptual Site Model Builder Vapour Intrusion Toolkit
HELP
Conceptual Site Model Builder
Geology Presets Site Presets
Parking Lot Airport Industrial Residential on grade
Paved Auto Repair Shop Junkyard Tank Storage 1
Gravel Campsite Landfill Tank Storage 2
Grass Commercial Mine Wood Treatment
Grass (Patchy) Commercial on grade Parkland
Shoreline Dugout Playground
Valley Farm Rail yard
Firing Range Residential
Contamination Transport
Stratigraphy Geography Vegetation Receptors Improvements Other
Sources Mechanism
Version 1.0
HOMEHelp HELP
Step 1 – Select Preset
Select a base from Geography Presets” or “Site
Presets” links on the Home Screen.
Copy and paste selected slide to a new
PowerPoint Presentation
Step 2 – Stratigraphy
Copy and paste desired stratigraphy elements
from the Stratigraphy slide to the newly created
slide.
HOMEConceptual Site Model - Example 1 HELP
Landfill ATV
Playground
Leaky Used
Hunter Oil Drums
Moose
Organic Sand
Sand
Clay Lens
Gravel Vapor Vapor
Plume Plume
Water Table
LNAPL
Dissolved Plume
Dissolved Plume
Bedrock
HOMEHELP
Vapour Intrusion Toolkit - Input
HOMEHELP
Vapour Intrusion Toolkit - Output
HOMEChemical Information
Molecular weight HELP
=
MW [g/mole] 78.1
P = Pure chemical vapour pressure [atm] 0.125
S = Pure chemical aqueous solubility [mg/L] 1780
H' = Dimensionless Henry's Law constant 0.225
= Mole fraction
Xi [dimensionless] 1
Koc = Organic carbon-water partitioning coefficient [g/kg-OC per mg/L-water] 79.4328235
Diffusion coefficient in
Dair
= air [m2/sec] 8.80E-04
water Diffusion coefficient in
D
= water [m2/sec] 9.80E-08
* Chem parameters vary by subfraction for fuel mixtures and chemical information for each of
these subfractions can be found in the Chem_data sheet.
Building Information
Lcrack = the enclosed space foundation thickness [m] 0.1
AB = the surface area of the enclosed space in contact
with soil [m2] 106
the enclosed space
Vapour VB = volume [m3]
ER = the enclosed-space air exchange rate [d-1]
258.64
8.4
the building perimeter
Intrusion Xcrack = [m] 40
ΔP = the indoor-outdoor pressure difference [g/m-s2]
Toolkit –
4000
Zcrack = the foundation depth below grade [m] 0.1499
Acrack = area of cracks (m2) 0.09945
Summary & n = building crack ratio (fraction of enclosed space surface area open for vapour
intrusion) [m2/m2] 0.00038
Constants Soil Information
LT the distance to the vapour source below the
= foundation [m]
LGW depth to groundwater source below the
= foundation [m] 1.8501
hc = the thickness of the capillary fringe [m] 0.375
hv = the thickness of the vadose zone [m] 1.4751
the soil permeability (near foundation) to air flow
kv = [m2] 1E-13
foc = the fraction of organic carbon in soil [g-C/g-soil] 0.006
ρb = soil bulk density [g-soil/cm3-soil], [kg/L] 1.6
total porosity
θ = [dimensionless] 0.399
θw = water-filled porosity [dimensionless] 0.148
air-filled porosity
θa = [dimensionless] 0.251
θm_cap = capillary transition zone water porosity 0.332
θm_cra crack dust water-filled HOME
ck
= porosity 0
θCONTAMINATED SITES CONTACTS Regional Health Risk Assessment and Toxicology Specialists BC Region • Jo-Ann Aldridge (604-666-5714), jo-ann.aldridge@hc-sc.gc.ca • Deanna Lee (604-666-2823), deanna.lee@hc-sc.gc.ca National Capital Region • Sanya Petrovic, Senior Technical Advisor (604-250-1695) • Luigi Lorusso, Senior Remediation Advisor (613-941-3677) General Enquiries & Publications: cs-sc@hc-sc.gc.ca
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