The Kingston Inner Harbour : A case study in aquatic risk assessment

Transcription

1 The Kingston Inner Harbour : A case study in aquatic risk assessment Dr. Tamsin Laing Environmental Sciences Group, Royal Military College Ph x 6580 Tamsin.Laing@rmc.ca Iris Koch, Tamsin Laing, David Burbridge, Megan Lord-Hoyle, Ken Reimer and Viviane Paquin Environmental Sciences Group, Royal Military College of Canada, Kingston, Ontario

2 Kingston Inner Harbour The Great Cataraqui River is the gateway to the Rideau Canal which was given UNESCO World heritage status in 2007

3 Physical Characteristics Average Depth: 1.2m (3.6 ft) Width: 1.6 km (south) 0.3 km (north) Watershed Drainage Area: 930 km 2 Flushing Rate: approximately 76 times per year from north to south Nutrient-rich

4 Kingston Inner Harbour: 1924

5 Historical Sources of Contaminants A Legacy of the Past Federal Sediment Dump Belle Park Landfill Davis Tannery Frontenac Smelting Works Light Industries Fuel Depot Sewer Outfalls Coal Gasification Plant

6 Kingston Inner Harbour Belle Park landfill Davis Tannery

7 Coal Gas / Distribution Areas Former Location of Coal Gasification Plant

8 Cataraqui River Stakeholder Group Formed June 2006 to provide guidance to assess sediment contamination and develop management strategy

9 Overall project aims Identified in 2006 and reaffirmed at each meeting of the CRSG 1. Identify risks to human and ecological health 2. Delineate areas of unacceptable risk 3. Identify and contain all offsite sources of contaminants 4. Identify sustainable, risk-based remediation options 5. Engage the community throughout the remediation process

10 FCSAP 10 Step process for Aquatic Contaminated Sites

11 Literature review summary There have been extensive studies on various aspects of the KIH Land use, flora and fauna Contaminant sources and pathways Water quality Sediment quality Sediment pore water quality Biological effects Water quality is generally good Sediments contain a number of contaminants area SW of Belle Park is the main area of concern

12 Importance of Sediments Integrate and accumulate inputs over long periods of time Act as habitat and food for many aquatic organisms (often base of food chain) Act as source and sink for nutrients Act as source and sink for chemical contaminants

13 Canadian Sediment Quality Guidelines SQG derived using National Status and Trends Program (modified NSTP) approach: collect co-occurring chemical and biological data to establish an association b/w [chemical] and any adverse biological effect spiked-sediment toxicity test (SSTT) approach for independent evaluation TEL (ISQG) - concentration below which adverse biological effects are expected to occur rarely PEL - concentration above which adverse effects are expected to occur frequently Serve as scientific benchmarks for evaluating potential for adverse biological effects but can be very conservative

14 Conceptual Example of Effect Ranges for a Sediment-Associated Chemical (ISQG)

15 Sediment Contamination in the KIH Is there potential for risk? contaminants of potential concern (CoPCs) are: As Cr Cu Pb Hg Zn Sb DDT Chlordane PAHs PCBs Reference Area Impacted Area 1020 sediment sample analytical results that meet rigorous QA/QC standards are included in the KIH sediment database

16 Copper

17 Lead

18 Zinc

19 Antimony

20 Arsenic

21 Mercury

22 Chromium Chromium is the most widespread contaminant

23 PCBs

24 PAHs

25 DDT

26 Chlordane

27 KIH reference locations Northern KIH in area that receives ongoing urban inputs Upstream of historical contaminant point sources QAQC screening completed

28 How deep is the contamination? Profiles in sediment cores The lack of sediments containing lower levels of chromium near the surface suggests little dilution with clean sediments due to continual sediment mixing and resuspension of contaminated sediments.

29 Chapter II. Spatial extent of contaminants Summary 1. Cr, Pb, Cu, As, Hg, Zn, Sb, DDT, chlordane, PCBs, and PAHs Exceed guideline values and/or Occur at significantly higher levels (p<0.05) at impacted sites vs. reference sites 2. PCBs, DDT, chlordane and organic mercury are substances that may biomagnify. 3. Dilution effects with clean sediments are limited due to low-energy flow and resuspension of contaminated sediments.

30 Risk Assessment Human health risk assessments (HHRAs) and ecological risk assessments (ERAs) - tools used to estimate the potential for adverse effects from a contaminant. Receptors (human) RISK Contaminant Sources Exposure Pathways The mere presence of a chemical does not necessarily mean there is a risk.

31 Chapter IV: Human Health Risk Assessment Direct Sediment Exposure Pathways Indirect Sediment Exposure Pathways 1. Incidental Ingestion of sediments 3. Uptake of COCs in sediment into biota 2. Dermal contact with sediment 4. Resuspension of bottom sediments Dust Swimming Fishing Playing at the beach Uptake of COCs through food chain Walking/Wading Kayaking/Rowing/ Canoeing/Sailing As, Cr, Cu, Hg, Pb, Sb, Zn, Chlordane, DDT, PCBs, PAHs Biological Uptake

32 Estimated Daily Intake Calculated for each CoPC and exposure pathway CoPC Concentration x Exposure Factors x Relative Absorption Factor Ingestion Total EDI (LADD) = As, Cu, Cr, Hg, Pb, Zn, Sb, DDT, chlordane, PCBs and PAHs Body Weight Hazard Quotient for Noncarcinogens HQ= EDI/TRV (toxicity reference value) HQ>0.2 = risk Incremental Lifetime Cancer Risk for Carcinogens ILCR= LADD x CSF (cancer slope factor) ILCR> than 1 in 100,000 = risk

33 Risk Characterization CoPC Adult HQ Teen HQ Child HQ Toddler HQ As <0.2 < Cr(III) <0.2 <0.2 <0.2 <0.2 Hg <0.2 < Pb <0.2 <0.2 < Sb <0.2 < Cu <0.2 <0.2 <0.2 <0.2 Zn <0.2 <0.2 <0.2 <0.2 DDT <0.2 <0.2 <0.2 <0.2 Chlordane <0.2 <0.2 <0.2 <0.2 PCBs Naphthalene <0.2 <0.2 <0.2 <0.2 Pyrene <0.2 <0.2 <0.2 <0.2 Cancer ILCR 8 in 100,000 Hg, Pb do not pose risk when background is included Cancer ILCR for PAHs Oral: < 1 in 100,000 Dermal: 4 in 100

34 Contribution to risk As Pb 22% 42% 58% 78% Hg 2% PCBs 1% 10% Sb 18% 98% 89% 82% Sediment Ingestion Dermal Contact with Sediment Fish Consumption

35 Summary of HHRA As, PCBs, Sb and PAHs present risk for recreational users of the KIH Sb data highly variable and localized Major contributors to risk are Fish consumption for PCBs Results support fish advisories Dermal exposure to sediments for As, Sb, and PAHs

36 Chapter III: COA WOE for biological effects Bioaccumulation Sediment toxicity Tests Benthic Community Impairment Results are based on 347 biological tissue samples comprising over 15 species of biota, 58 toxicity samples, and alkalinity Cr 2 = BC benthic community assemblage samples 2 % clay 4 BC2 6 BC9 BC7 BC4 BC1 BC3 BC6 % silt % sand BC =

37 Receptor types - aquatic

38 Sediment Toxicity Tests Multiple contaminant exposure and uptake pathways are assessed due to differences among the organisms in diet and microhabitat Midge: Chironomus riparius 10 d survival & growth Chironomus tentans, 20 day survival & growth Amphipod: Hyalella azteca 28 d survival & growth Mayfly: Hexagenia spp. 21 d survival & growth Oligochaetes: Tubifex tubifex 28 d survival & growth Collaborative study with Environment Canada.

39 Toxicity summary Parks Near N of Belle Anglin Canada Park Bay, waterlot, and Douglas eastern NW Fluhrer KIH: Transport no Canada Park: evidence toxicity waterlot: of toxicity effects mixed effects toxicity Legend Significant: multiple tests/endpoints exhibit major toxicological effects Potential: multiple tests/endpoints exhibit minor toxicological effects and/or one test/endpoint exhibits major effects Negligible: minor toxicological effects observed in no more than one endpoint Reference Map from Golder (2012) Toxicity identification evaluation (TIE) tests for one sample suggested that toxicity could be due to photoreactive PAH compounds, multiple toxicants

40 Major Taxonomic Groups in Benthic Community Samples Collected in the KIH Benthic communities in the KIH are dominated by organisms that are tolerant of organic (i.e. nutrient) pollution.

41 Benthic community Parks Near Note Anglin Canada that many Bay, waterlot, studies Douglas NW did Fluhrer Transport not look Canada Park: at smaller benthic waterlot: invertebrates community most stations (<500µm), effects show negligible which effects dominate the KIH Legend Significant: multiple significant differences in benthic indices Potential: multiple slight differences in more than one index and/or one major difference Negligible: equivalent to reference station or slight difference in no more than one index Reference Map from Golder (2012) Statistical analyses suggest differences in benthic assemblages can be explained by both habitat features and contamination variables

42 COA weight of evidence: benthic effects Northern KIH (all sediment north of Belle Island): Adverse effects unlikely. Eastern KIH: Adverse effects unlikely. Parks Canada water lot: Potential effects. Some evidence of toxicity, benthic effects. Northern Transport Canada water lot: Adverse effects unlikely. West Central KIH: Adverse effects unlikely. Southwestern KIH: Adverse effects likely in vicinity of Anglin Bay, Douglas Fluhrer Park

43 Study area Reference area Fish [PCB] IJC guideline Average fish [PCB] elevated above the IJC GLWQA criteria and CTRG guideline at sites south of Belle Park PCB concentrations are up to 6 times those in reference fish

44 Chapter IV : Ecological Risk Assessment Sampled Modeled As, Cr(III), Cu, Pb, Hg, Zn, Sb, DDT, chlordane, PCBs, PAHs

45 Estimated Daily Intake EDI Calculated for each CoPC and exposure pathway CoPC Concentration x Exposure Factors x Relative Absorption Factor e.g. Ingestion Total EDI = Body Weight Hazard Quotient HQ= EDI/TRV (toxicological reference value) HQ>1.0 = potential ecological risk

46 ERA Risk Characterization Potential risk from Cr(III) Potential risk from PCBs No risk for any other receptor or CoPC

47 Risk Characterization for Fish Tissue-based Hazard Indices CoPC Site Reference As <1 <1 Cu <1 <1 Pb <1 2.1 Zn <1 <1 Hg <1 <1 PCBs <1 <1 Other CoPCs could not be assessed

48 48 Brown Bullhead Recognized as sentinel species of environmental contamination: small home range bottom-feeder/bottom-dweller Brown bullhead

49 Direct evidence of ecological effects in Brown Bullhead

50 High Frequency of Deformities in Brown Bullhead South of Belle Park 80 percent of brown bullhead caught south of Belle Park showed deformities Compared with 10% from reference area Much greater severity of deformities for fish from the impacted area

51 Causation for brown bullhead deformities Currently unknown. Further study is likely to be inconclusive regarding causation. Likely due to either contaminated sediments or combined sewer overflows. Both will be addressed under the KIH management plan.

52 Summary of HHRA and ERA 1. Non-cancer risk to humans: a. PCBs via fish ingestion, all receptors b. Sb for children and toddlers (large uncertainty) 2. Cancer risk to humans: a. As via sediment ingestion and dermal exposure b. PAHs via dermal exposure 3. Ecological risk to mink from PCBs, and to mallard duck from Cr(III) 4. Direct evidence of ecological effects on brown bullhead

53 FCSAP 10 Step process for Aquatic Contaminated Sites Classified as a class1, high priority for action site based on a scoring of 79.8 by ESG and confirmed by HC, EC, and DFO expert support

54 Is there a continuing source? Orchard Marsh Davis Tannery

55 Source control: Historical VS ongoing inputs Orchard Marsh and Kingscourt Storm sewer Emma Martin Park and Rowing Club Coal gasification plant Legacy contaminants in sediments are the main source of bioavailable contaminants Potential ongoing sources will be addressed as part of the RAP Study in progress

56 KIH Report Application of the Canada-Ontario Decision Making Framework to the contaminated Sediments in the Kingston Inner Harbour Chapter I: Literature review. Chapter II: Spatial distribution of contaminants in sediments of the Kingston Inner Harbour. Chapter III: Ecological effects: Evaluation of bioaccumulation of contaminants in biota, sediment toxicity, and benthic community structure. Chapter IV: Human Health and Ecological Risk Assessment. Updated Chapter V: An options analysis of management scenarios for the Kingston Inner Harbour.

57 Overall project aims Identified in 2006 and reaffirmed at each meeting of the CRSG 1. Identify risks to human and ecological health 2. Delineate areas of unacceptable risk 3. Identify and contain all offsite sources of contaminants 4. Identify sustainable, risk-based remediation options 5. Engage the community throughout the remediation process

58 Questions?