Hazard Assessment and Contaminated Sites - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 562

Hazard The capacity of an contaminant to produce a particular type of adverse
health or environmental effect, e.g., One hazard associated with benzene is that it
can cause acute myeloid leukemia; or
The disposition of a thing, a condition or a situation to produce an adverse health
or environmental effect; or an event, sequence of events or combination of cir-
cumstances that could potentially have adverse consequences (adapted from ACDP
1996 ).
Hazard identification The identification, from animal and human studies, in vitro
studies and structure-activity relationships, of adverse health effects associated with
exposure to a contaminant (IEH 1999 ).
Health Health is a state of complete physical, mental and social well being and
not merely the absence of disease or infirmity (WHO 1946 ).
Health Risk Assessment The process of estimating the potential impact of a
chemical, biological, physical or social agent on a specified human population
system under a specific set of conditions and for a certain timeframe.
Health Risk Management The process of evaluating alternative actions, selecting
options and implementing them in response to Human Health Risk Assessment.
The decision making will incorporate scientific, technological, social, economic and
political information. The process requires value judgements, e.g., on the tolerability
and reasonableness of costs.
Immunotoxicity The ability to produce an adverse effect on the functioning of
organs and cells involved in immune competence (IEH 1999 ).
LD 50 The quantity of a contaminant that, when applied directly to test organisms,
via inhalation, oral or dermal exposure is estimated to be fatal to 50% of those
organisms under the stated conditions of the test.
Number of microorganisms of a particular species that are fatal in 50% of the
host organisms.
LED 10 Lowest Effective Dose. The lower 95% confidence limit on a dose associ-
ated with an estimated 10% increased tumour or relevant non-tumour response (US
EPA 1996 ).
LOEL Lowest Observed Effect Level. The lowest concentration or amount of a
contaminant, found by experiment or observation, that causes alterations of mor-
phology, functional capacity, growth, development or life span of target organisms.
WHO ( 1990 ) define it as the lowest dose of a contaminant which causes changes
distinguishable from those observed in normal (control) animals.
LOAEL Lowest Observed Adverse Effect Level. The lowest concentration or
amount of a contaminant, found by experiment or observation, that causes adverse
alterations of morphology, functional capacity, growth, development or life span of
target organisms.
Life-time Covering the average life span of an organism (e.g., 70 years for
humans).