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Probabilistic approaches in the effect assessment of toxic chemicals

What are the benefits and limitations?
  • Martin Scheringer
  • Dirk Steinbach
  • Beate Escher
  • Konrad Hungerbühler
Commentaries

Abstract

There is an ongoing discussion whether in the environmental risk assessment for chemicals the so called ‘deterministic’ approach using point estimates of exposure and effect concentrations is still appropriate. Instead, the more detailed and scientifically sounder probabilistic methods that have been developed over the last years are widely recommended. Here, we present the results of a probabilistic effect assessment for the aquatic environment performed for the pesticide methyl parathion and compare them with the results obtained with the common deterministic approach as described in the EU Technical Guidance Document. Methyl parathion was chosen because a sufficient data set (acute toxicity data for about 70 species) was available. The assumptions underlying the probabilistic effect assessment are discussed in the light of the results obtained for methyl parathion. Two important assumptions made by many studies are: (i) a sufficient number of ecologically relevant toxicity data is available, (ii) the toxicity data follow a certain distribution such as log-normal. Considering the scarcity of data for many industrial chemicals, we conclude that these assumptions would not be fulfilled in many cases if the probabilistic assessment was applied to the majority of industrial chemicals. Therefore, despite the well-known limitations of the deterministic approach, it should not be replaced by probabilistic methods unless the assumptions of these methods are carefully checked in each individual case, which would significantly increase the effort for the assessment procedure.

Keywords

Aquatic toxicity deterministic risk assessment effect assessment logit methyl parathion probabilistic risk assessment probit 

References

  1. Aldenberg T, Slob W (1993): Confidence Limits for Hazardous Concentrations Based on Logistically Distributed NOEC Data. Ecotox Environ Safety25, 4–63CrossRefGoogle Scholar
  2. Chapman PM, Caldwell RS, Chapman PF (1996): A Warning: NOECs are Inappropriate for Regulatory Use. Environ Toxicol Chem15, 77–79CrossRefGoogle Scholar
  3. Chapman PM, Fairbrother A, Brown D (1998): A Critical Evaluation of Safety (Uncertainty) Factors for Ecological Risk Assessment. Environ Toxicol Chem17, 99–108CrossRefGoogle Scholar
  4. CFR (1995): Code of Federal Regulations, Title 40, Part 132: Water Quality Guidance for the Great Lakes System. United States Government Printing OfficeGoogle Scholar
  5. Duke DL, Taggart M (2000): Uncertainty Factors in Screening Ecological Risk Assessments. Environ Toxicol Chem19, 1668–1680CrossRefGoogle Scholar
  6. EEA (1998): Chemicals in the European Environment: Low Doses, High Stakes? European Environment Agency, CopenhagenGoogle Scholar
  7. Emans HJB, v. d. Plassche EJ, Canton JH, Okkerman PC, Sparenburg PM (1993): Validation of some Extrapolation Methods Used for Effect Assessment. Environ Toxicol Chem12, 2139–2154CrossRefGoogle Scholar
  8. EU (1996): Technical Guidance Document in Support of Commission Directive 93/67/EEC on Risk Assessment for New Notified Substances and Commission Regulation (EC) 1488/94 on Risk Assessment for Existing Substances. Office for Official Publications of the European CommunitiesGoogle Scholar
  9. Forbes TL, Forbes VE (1993): A Critique of the Use of Distribution-Based Extrapolation Models in Ecotoxicology. Functional Ecology7, 249–254CrossRefGoogle Scholar
  10. Hammers-Wirtz M, Ratte HT (2000): Offspring Fitness in Daphnia: Is the Daphnia Reproduction Test Appropriate for Extrapolating Effects on the Population Level? Environ Toxicol Chem19, 1856–1866CrossRefGoogle Scholar
  11. Hertel R (1993): Environmental Health Criteria 145: Methyl parathion. World Health OrganizationGoogle Scholar
  12. Klepper O, Bakker J, Traast TP, Van de Meent D (1998): Mapping the Potentially Affected Fraction of Species (PAF) as a Basis for Comparison Ecotoxicological Risks between Substances and Regions. J Hazard Mat61, 337–344CrossRefGoogle Scholar
  13. Kooijman SALM (1987): A Safety Factor for LC50 Values Allowing for Differences in Sensitivity among Species. Wat Res21, 269–276CrossRefGoogle Scholar
  14. Koller G, Hungerbühler K, Fent K (2000): Data Ranges in Aquatic Toxicity of Chemicals. ESPR — Environ Sci & Pollut Res7, 135–143CrossRefGoogle Scholar
  15. Länge R, Hutchinson TH, Scholz N, Solbé J (1998): Analysis of the ECETOC Aquatic Toxicity (EAT) Database II: Comparison of Acute to Chronic Ratios for Various Aquatic Organisms and Chemical Substances. Chemosphere36, 115–127CrossRefGoogle Scholar
  16. Legierse K C H M (1998): Differences in Sensitivity of Aquatic Organisms to Organophosphorus pesticides, Ph.D. Dissertation, University of Utrecht, The Netherlands Newman MC, Ownby DR, Mézin LCA, Powell DC, ChristensenGoogle Scholar
  17. TRL, Lerberg SB, Anderson B-A (2000): Applying Species-Sensitivity Distributions in Ecological Risk Assessment: Assumptions of Distribution Type and Sufficient Numbers of Species. Environ Toxicol Chem19, 508–515CrossRefGoogle Scholar
  18. Power M, McCarthy LS (1997): Fallacies in Ecological Risk Assessment Practices. Environ Sci Technol31, 370A-375AGoogle Scholar
  19. Solomon KR et al. (1996): Ecological Risk Assessment of Atrazine in North American Surface Waters. Environ Toxicol Chem15, 31–76CrossRefGoogle Scholar
  20. Solomon KR (1996): Overview of Recent Developments in Ecotoxicological Risk Assessment. Risk Anal15, 627–633CrossRefGoogle Scholar
  21. Solomon KR, Giddings JM, Maund SJ (2001): Probabilistic Risk Assessment of Cotton Pyrethroids: I. Distributional Analysis of Laboratory Aquatic Toxicity Data. Environ Toxicol Chem20, 652–659CrossRefGoogle Scholar
  22. Steinbach D (1999): Diploma thesis. ETH ZürichGoogle Scholar
  23. Suter GW (1993): Ecological Risk Assessment. Lewis Publishers, Chelsea, MI, USAGoogle Scholar
  24. Suter GW (1998): Comments on the Interpretation of Distributions in ‘Overview of Recent Developments in Ecological Risk Assessment’. Risk Anal18, 3–4CrossRefGoogle Scholar
  25. Van der Hoeven N (2001): Estimating the 5-Percentile of the Species Sensitivity Distributions without any Assumptions about the Distribution. Ecotoxicology10, 25–34CrossRefGoogle Scholar
  26. Van Straalen NM, Denneman CAJ (1989): Ecotoxicological Evaluation of Soil Quality Criteria. Ecotox Environ Safety18, 241–251CrossRefGoogle Scholar
  27. Wagner C, Løkke H (1991): Estimation of Ecotoxicological Protection Levels from NOEC Toxicity Data. Wat Res25, 1237–1242CrossRefGoogle Scholar

Copyright information

© Ecomed Publishers 2002

Authors and Affiliations

  • Martin Scheringer
    • 1
  • Dirk Steinbach
    • 1
  • Beate Escher
    • 2
  • Konrad Hungerbühler
    • 1
  1. 1.Laboratory of Chemical EngineeringSwiss Federal Institute of Technology ZürichZürichSwitzerland
  2. 2.Swiss Federal Institute for Environmental Science and Technology (EAWAG) and Department of Environmental SciencesSwiss Federal Institute of Technology ZürichDübendorfSwitzerland

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