Development of Soil-to-Terrestrial Invertebrate Uptake Factors to Improve Estimation of Ecological Risk on DFO Lightstation Sites in Atlantic Canada

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1 Development of Soil-to-Terrestrial Invertebrate Uptake Factors to Improve Estimation of Ecological Risk on DFO Lightstation Sites in Atlantic Canada May 2012

2 BACKGROUND

ERA for Lightstation Sites in Atlantic Canada Client: Department of Fisheries and Oceans (DFO) through Public Works and Government Services Canada (PWGSC) Project

3 ERA for Lightstation Sites in Atlantic Canada Client: Department of Fisheries and Oceans (DFO) through Public Works and Government Services Canada (PWGSC) Project Objectives: Complete Phase III intrusive investigations to provide delineation of metal, petroleum, or other impacts in soil Conduct HHERA using historical and current data

ERA for Lightstation Sites in Atlantic Canada Ecological Risk Assessment Primary contaminants of concern and potential sources: Metals: lead, mercury, zinc Lead-based paints Battery use and

4 ERA for Lightstation Sites in Atlantic Canada Ecological Risk Assessment Primary contaminants of concern and potential sources: Metals: lead, mercury, zinc Lead-based paints Battery use and disposal Mercury baths Petroleum Hydrocarbons Fuel storage/use Polychlorinated Biphenyls Transformer/electronics disposal Paints Suitability of habitat to support realistic ecological receptors

small animal prey Ingestion of water, sediments, plants, invertebrates or fish

5 ERA for Lightstation Sites in Atlantic Canada Exposure pathways Ingestion and/or dermal contact with soil Ingestion of terrestrial invertebrates, vegetation and small animal prey Ingestion of water, sediments, plants, invertebrates or fish (freshwater and marine) Dermal contact with water or sediments (freshwater and marine)

ERA for Lightstation Sites in Atlantic Canada Risk Characterization Total EHQ sum of EHQ soil ingestion EHQ terrestrial plant ingestion EHQ terrestrial invertebrates ingestion EHQ terrestrial small

6 ERA for Lightstation Sites in Atlantic Canada Risk Characterization Total EHQ sum of EHQ soil ingestion EHQ terrestrial plant ingestion EHQ terrestrial invertebrates ingestion EHQ terrestrial small mammal ingestion EHQ marine invertebrates ingestion EHQ marine fish ingestion For some ecological receptors the terrestrial invertebrate ingestion pathway represents a substantial contribution to the overall exposure, in some cases up to approximately 95% of the total EHQ

ERA for Lightstation Sites in Atlantic Canada Ingestion of terrestrial invertebrates Ingestion of terrestrial invertebrates was historically assessed through applying soil-to-terrestrial invertebrate

7 ERA for Lightstation Sites in Atlantic Canada Ingestion of terrestrial invertebrates Ingestion of terrestrial invertebrates was historically assessed through applying soil-to-terrestrial invertebrate uptake factors obtained from Sample et al., (1998). However data are: from multitude of geographic locations and soil types with multitude of potential sources of metal contamination, not necessarily relevant to paint as a primary source.

8 ERA for Lightstation Sites in Atlantic Canada Ingestion of terrestrial invertebrates A similar approach to that of Sample et al., (1998) was used to develop site-specific soil-to-terrestrial invertebrate uptake factors for lightstations in Atlantic Canada Soil and terrestrial invertebrate sample pairs were collected at various lightstation sites across Atlantic Canada Results pooled together to generate uptake factors applicable to this area for sites with similar potential contamination sources

Soil-to-Earthworm Uptake Factors Factors for ERA focusing on earthworms as model soil invertebrate: Availability of data and models to predict contaminant uptake Perceived

9 Soil-to-Earthworm Uptake Factors Factors for ERA focusing on earthworms as model soil invertebrate: Availability of data and models to predict contaminant uptake Perceived importance of earthworms in food webs, and acceptance as standard in ERA Approach could potentially be extended to other types of terrestrial invertebrates such as slugs or insects

Soil-to-Earthworm Uptake Factors Soil and terrestrial

lightstation sites across Atlantic Canada In 2010, 59

lightstation sites by Stantec, AMEC, Dillon and CRA,

10 Soil-to-Earthworm Uptake Factors Soil and terrestrial invertebrate sample pairs were collected at various lightstation sites across Atlantic Canada In 2010, 59 terrestrial invertebrate samples were collected at 21 lightstation sites by Stantec, AMEC, Dillon and CRA, targeting areas of: Low metal concentration Medium metal concentration High metal concentration

11 Soil-to-Earthworm Uptake Factors Worms depurated for 24 hours to clear gut contents Worm and soil sample pairs submitted for trace metal analysis Based on results reported by the laboratory Worms were assumed to be adequately depurated when tissue samples contained less than 250 mg/kg aluminum

12 Soil-to-Earthworm Uptake Factors Of 59 worm samples collected, 23 were reported to contain less than 250 mg/kg aluminum and as such considered to be adequately depurated These results were pooled together to derive soil to terrestrial invertebrates relationship Earthworm tissue metal concentration plotted as a function of soil metal concentration

13 Soil-to-Earthworm Uptake Factors - Aluminum Invertebrate Concentration (mg/kg ww) Invertebrate Aluminum Concentration = 250 mg/kg ww Soil Concentration (mg/kg)

14 Soil-to-Earthworm Uptake Factors - Arsenic Invertebrate Concentration (mg/kg ww) y = x R² = Soil Concentration (mg/kg)

15 Soil-to-Earthworm Uptake Factors - Cadmium Invertebrate Concentration (mg/kg ww) Soil Concentration (mg/kg)

16 Soil-to-Earthworm Uptake Factors - Copper Invertebrate Concentration (mg/kg ww) Sample et al., 1998 y = x R² = Soil Concentration (mg/kg)

17 Soil-to-Earthworm Uptake Factors - Lead Invertebrate Concentration (mg/kg ww) y = x R² = Soil Concentration (mg/kg)

18 Soil-to-Earthworm Uptake Factors - Zinc Invertebrate Concentration (mg/kg ww) Sample et al., 1998 y = x R² = Soil Concentration (mg/kg)

19 Soil-to-Earthworm Uptake Factors - Summary Metal Recommended Approach Equation Predicting Earthworm Concentration or Recommended Value (mg/kg ww) Aluminum Aluminum was used as a marker for gut soil content. Only earthworms containing <250 mg Al/kg wet tissue were included in the analysis Antimony Regression Sb tissue = Sb soil Arsenic Regression As tissue = As soil Barium Regression Ba tissue = Ba soil Beryllium Cadmium No beryllium was detected in properly depurated earthworms. Mean value used; slope of regression w a s s l i g h t l y n e g a t i v e, b u t n o t significantly different from zero in properly depurated earthworms. <

20 Soil-to-Earthworm Uptake Factors - Summary Metal Chromium Recommended Approach Mean value used; slope of regression w a s s l i g h t l y n e g a t i v e, b u t n o t significantly different from zero in properly depurated earthworms. Equation Predicting Earthworm Concentration or Recommended Value (mg/kg ww) 0.47 Cobalt Regression Co tissue = Co soil Copper Regression Cu tissue = Cu soil Lead Regression Pb tissue = Pb soil Mercury Mercury was not measured. Sample et al., (1998) Molybdenum Regression Mo tissue = Mo soil Nickel Selenium No nickel was detected in properly depurated earthworms. Mean value used; slope of regression w a s s l i g h t l y n e g a t i v e, b u t n o t significantly different from zero in properly depurated earthworms. <

21 Soil-to-Earthworm Uptake Factors - Summary Metal Silver Thallium Tin Uranium Vanadium Recommended Approach No silver was detected in properly depurated earthworms. No thallium was detected in properly depurated earthworms. Tin was generally not detected, and was always <0.5 mg/kg, in properly depurated earthworms. Uranium was generally not detected, and was always <0.2 mg/kg, in properly depurated earthworms. Vanadium was generally not detected, and was always <1 mg/kg, in properly depurated earthworms. Equation Predicting Earthworm Concentration or Recommended Value (mg/kg ww) <0.05 <0.05 <0.5 <0.2 <1 Zinc Regression Zn tissue = Zn soil

22 CONCLUSION

23 Soil to Invertebrates Uptake Factors Conclusions Regression equations derived for: Antimony Barium Copper Molybdenum Arsenic Cobalt Lead Zinc Other metals were either not detected in earthworm tissue or did not present a significant relationship with soil concentration Results for lead and zinc show that the predicted metal concentrations from Sample et al., 1998 significantly under-predict metal concentrations found in earthworms in Atlantic Canada lightstation properties.

24 Acknowledgements DFO and PWGSC Tasha Andrews and Heather McCleave May 2012

SILLIKER, Inc. Southern California Laboratory 6360 Gateway Drive, Cypress, CA Tel. 209/ Fax. 714/

SILLIKER, Inc. Southern California Laboratory 6360 Gateway Drive, Cypress, CA Tel. 209/ Fax. 714/ 6360 Gateway Drive, 90630 95073 Page 1 of 8 CI-516 Cistanche 361439388 ICP MS Full Mineral Screen EPA 3050/6020 USP730 BRN Aluminum 2.2 ppm (w/w) Antimony Arsenic 0.06 ppm (w/w) Barium 0.09 ppm (w/w) Beryllium