Remediation handbook 3.
Detailed quantitative risk assessment of contaminated areas
Contents

  • Preface
  • Introduction
  • 1 Basics for risk assessment (Gy. Dura)
    • 1.1 Origin of risk
    • 1.2 Determination of the significance of chemical risks
    • 1.3 Definition of risk
    • 1.4 Definition of expressions
    • Bibliography
  • 2 Risk assessment: a versatile tool (Gy. Dura, K. Gruiz)
    • 2.1 Risk assessment and remediation programs
    • 2.2 Risk assessment-oriented environmental quality criteria and limit values
    • 2.3 Monitoring systems and risk assessment
    • 2.4 The role of risk assessment in the selection of remedial technologies
    • 2.5 Fields of application of risk assessment
    • 2.6 Semiquantitative evaluation of the risk in contaminated areas
    • Bibliography
  • 3 Principles of risk assessment (Gy. Dura)
    • 3.1 General principles of risk assessment
    • 3.2 Evaluation principles of environmental and health risk originating from chemical contamination
    • 3.3 Characteristic principles of the evaluation of risk originating from soil contamination
    • 3.4 Characteristic principles of the evaluation of risk originating from groundwater contamination
    • Bibliography
  • 4 Main components of risk assessment, with special regard to the quantitative assessment of human health risk (E. László)
    • 4.1 Identification of harmfulness
    • 4.2 Environmental exposure
      • 4.2.1 Direct determination of exposure
      • 4.2.2 Indirect determination of exposure
    • 4.3 Analysis of the dose-response relation, projection of experimental toxicological data on the doses tolerable for human health
      • 4.3.1 Categorisation of toxic effects
      • 4.3.2 No-observable-effect-levels
      • 4.3.3 Tolerable daily intake values (ADI, TDI, RfD)
      • 4.3.4 Carcinogen effects of chemical substances
    • 4.4 Characterisation of risk
    • Bibliography
  • 5 Evaluation of human health risk caused by chemical contaminants in soils (E. László, y. Dura)
    • 5.1 Relations of health-influencing and risk factors
    • 5.2 Tasks of the evaluation of health risk originating from the chemical contamination of soils
    • 5.3 Risk assessment step-by-step
      • 5.3.1 Technical guidances and other information sources for risk assessment
      • 5.3.2 Short overview of the harmfulness of contaminants, possible harmful impacts on health
      • 5.3.3 Description of the (deducted) origin of tolerable doses
      • 5.3.4 Observation data and reduction/averaging methods
      • 5.3.5 Setting up the scenario of exposure by considering the possible exposure types and situations
      • 5.3.6 Human biological dosimetric parameters of exposure
      • 5.3.7 How to calculate the level of exposure
      • 5.3.8 How to calculate the health risk ratio
      • 5.3.9 Genotoxic (neoplasm) risk of chemical substances
      • 5.3.10 Presentation of results
  • 6 Eco-toxicological investigations and the evaluation of environmental risk (K. Gruiz, Gy. Dura)
    • 6.1 Importance of eco-toxicological testing in the course of environmental risk assessment of contaminated sites
      • 6.1.1 The chemical time bomb and risk assessment
    • 6.2 Testing of extracts and original samples
    • 6.3 Test organisms, endpoints
    • 6.4 How to consider ecosystem characteristics in the course of risk assessment
      • 6.4.1 Formulation of goals
      • 6.4.2 Criteria for the selection of target organisms
      • 6.4.3 Conceptional model
    • 6.5 Strengths and weaknesses of different data types
    • Bibliography
  • 7 Computer programs supporting data processing (Zs. Vadász, Gy. Dura)
    • 7.1 Modelling of the chemical substance’s path from the pollution source to the receptor
    • 7.2 Data demand of risk assessment
      • 7.2.1 Data collection strategies
      • 7.2.2 Data quality and uncertainties
      • 7.2.3 General data demand
      • 7.2.4 Detailed data demand
    • 7.3 Characteristics of widely used risk assessment programs, recommended fields of application
  • 8 Short overview on the methodology of the evaluation of environmental and health risk of contaminated sites
    • 8.1 FAQ in connection with risk assessment
    • 8.2 Evaluation of environmental risk
    • 8.3 Evaluation of human health risk
    • 8.4 Verifiability of risk assessment
    • 8.5 Recommendations on the technical implementation of risk assessment


  • Annex (E. László, Zs. Vadász)
  • 1. Background information on the development of exposure assessment models
  • 2. Presentation of the HESP (Human Exposure to Soil Pollutants) model and the health risk values calculated by HESP
    • 2.1. Input data required by HESP
    • 2.2. Exposure elements of HESP
    • 2.3. Formulas used by HESP
    • 2.4. Comparative evaluation of the risk values calculated by HESP
    • Bibliography

Introduction

Risk assessment is on one hand a holistic science on the other it provides the scientific basis for the management of local, site-specific problems. The fact that (f. e.) computer models suitable for the evaluation of exposition were originally developed and used for research purposes makes this contradictory situation even more complicated. Authorities, industry and the environmental management sector soon realized that models suitable for risk assessment are useful tools for the support of decision making processes in the fields of the quantitative assessment of risks posed on the environment and human health, as well as of monitoring and the preparation of regulations in general.

Experts are aiming at the continuous improvement of the precision of simulation tools in order to gain more and more knowledge on environmental processes; at the same time they are aware of the limits of the exposition and risk assessment models developed for particular cases and can consider the uncertainty of the obtained results. Unfortunately the same models are often used as risk handling tools in decision-making without the necessary understanding of environmental processes and harmful impacts caused by chemical substances and without paying the required attention to the limits of modelling.

The main goal of risk assessment is to understand harmful biological and environmental impacts of chemical substances and the related processes (of these impacts) and to become able to give their definite description. Tools of risk assessment, environmental exposition models have become more and more complicated. As there are great differences between the qualifications of practical users it is to be feared that the already available knowledge on and the scientific assumptions of the mechanisms of biological impacts and the behaviour of chemical substances in the environment are not adequately taken into consideration or misinterpreted. Such inadequate use of investigation data can have a significant impact on the calculated risk values. It is well-known that the experience in and the knowledge of risk assessment processes are decisive issues in the determination of the quality of the calculated risk value. Risk assessment is an interdisciplinary and intersectoral task demanding mathematicians dealing with models, experts of the fields of environmental sciences, biology and toxicology, and further the experts in charge of surveillance tasks of environmental and public health authorities. These circumstances made the elaboration of an overview of the theoretical and technical fundamentals of model-using risk assessment essential.