Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p4
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 4/7)
Character Range: 1020904–1023988

Ridge National Laboratory) risk assessment information system, http://rais.ornl.gov/# (this database of physicochemical factors was completely reviewed in 2009 and so the outputs are now more consistent/reliable)
    * ATSDR (Agency for Toxic Substances and Disease Registry) toxicological profiles
    * Peer reviewed journals.

5.2              Hazard identification
Hazard identification is defined by enHealth (2012a), following Health Canada (1999), as the process of determining:
    * what types of (adverse) health effects might be caused by the chemical substance (contaminant)
    * how quickly the adverse health effects might be experienced and their duration.
In contaminated land health risk assessment, these will generally be determined with reference to the data sources listed in Table 4. The health effects of a substance are likely to have been researched using a number of methods and the data sources adopt a weight–of-evidence approach in recommending which research to rely on. The reviews provided by the data sources are carried out by expert panels and the level of expertise and effort expended in scrutinising the primary sources of information cannot generally be reproduced in a site-specific risk assessment. A brief explanation of the methods used to derive information on health effects is given here. The reader is referred to enHealth (2012a) for more detail.

Information on health effects is usually generated by studies using animals (in vivo studies), studies involving people (epidemiological studies) or laboratory experiments using cells or tissue rather than live animals (in vitro studies). Relevant and reliable data on people is available for only a very few chemicals, and therefore most health effect information is derived by extrapolation from animal and laboratory experiments. This produces considerable uncertainty, since animals and people will not necessarily have similar responses to a chemical substance.

Further uncertainty in contaminated land health risk assessment is introduced by the fact that toxicological research usually focuses on evaluating a specific substance, and does not account for the complexities introduced by the substance's presence in soil or in mixtures of substances.

Health effects can be broadly separated into acute and chronic effects. The distinction between acute and chronic exposure risks relates to the duration of exposure and timing for the onset of any health effects. Acute health effects occur within minutes, hours or days of a relatively short period of exposure, whilst chronic health effects occur as a result of prolonged or repeated exposures over many days, months or years and symptoms may not be immediately apparent.

    5.2.1          Acute effects
Acute toxicity information on chemicals is widely available because it is used for the classification of manufactured chemicals for supply. Studies of acute effects using animal experiments may produce information on oral, dermal and inhalation toxicity, skin and eye irritation and skin sensitisation.

Standard protocols