Hazard Assessment and Contaminated Sites - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 521

• relevance of the exposure routes used in the studies to a particular assessment and

the interrelationships of potential effects from different exposure routes;

• environmental conditions (pH, organic matter, clay content, temperature);

• the relevance to the assessment of the expected duration of exposure and

the exposure durations in the studies forming the basis of the dose-response
assessment; and

• the potential for differing susceptibilities in population subgroups (ibid , p. 7).

Both qualitative and quantitative toxicity information is evaluated in assessing
“the incidence of adverse effects occurring in humans at different exposure levels”
(US EPA 1989 , p 1.6).
Hazard Identification uses:

• Animal data. This is usually assessed by toxicological methods.

• Human data. This is usually assessed by epidemiological methods when groups

of people are involved, or by toxicological methods when using case studies and
acute chamber studies.

•

Other data. This includes data such as structure-activity data or in vitro data
assessed by toxicologists.

The data may come from a range of sources such as anecdotal data, case-report
data and data collected from epidemiological registries (such as cancer or pregnancy
outcome data). In each instance the quality of the study design and methodology and
the resulting data will need to be rigorously assessed.

12.3 Hazard Identification-Toxicology

This chapter on toxicological evaluation is based in part on the draft OECD
Monograph, Guidance Notes for the Analysis and Evaluation of Repeat-Dose
Toxicity Studies, prepared for the OECD by the Chemicals Unit, Department of
Health and Aged Care, Canberra, Australia, in cooperation with the US EPA and
the Canadian Pest Management Regulatory Agency (PMRA). It was published
as: Organisation for Economic Co-operation and Development OECD Series on
Pesticides No. 10 Guidance Notes for Analysis and Evaluation of Repeat-Dose
Toxicity Studies (2000). OECD, Paris.
This chapter focuses on chemical hazards and in particular on some of the prob-
lems and pitfalls which may arise during an assessment of possible contaminant-
related changes in parameters measured in toxicology studies conducted on a
contaminant.
Toxicology studies have been designed to permit determination of toxic effects
associated with exposure to chemical hazards. Such studies can provide information
relating to toxic effects and potential health hazards likely to arise from single or
repeated exposures, in terms of predicting potentially important toxicity end points