Contributions of Chemistry to Sustainable
Food Production
Freie Universitat Berlin, August 1999
Thursday August 12, 9:00 - 13:00
Inorganic Chemistry Lecture Hall
Progress in Codex with the Acute Dietary Intake Assessment
of Pesticide Residues
Denis Hamilton, Animal & Plant Health Service, Department of Primary
Industries, 80 Ann St, Brisbane, Queensland 4000 AUSTRALIA, Email:
[email protected]
Abstract
The Joint FAO/WHO Meeting on Pesticide Residues (JMPR) will, for the
first time in 1999, systematically estimate the acute intake of pesticide
residues in food.
JMPR has already established acute reference doses (RfDs) for 15 pesticides
and decided that acute RfDs were unnecessary for 6 others. The acute
RfD is an estimate of the amount of a substance in food or drinking-water,
expressed on a body-weight basis, that can be ingested over a short
period of time, usually during one meal or one day, without appreciable
health risk to the consumer. The acute RfD provides the reference
point in the acute risk assessment.
Residue levels in food and food consumption data are needed to assess
residue intake. Regional diets, based on information supplied by national
governments to WHO (World Health Organization), describe typical commodity
unit weights and large portion size for each food (97.5th percentile
for eaters on a single day, i.e mean + 2 � SD). The calculation of
intake relies on the large portion size for a food and also on the
commodity unit weight for those foods eaten as single units of a fruit
or vegetable.
Maximum residue levels likely to occur in the edible portions of food
commodities are obtained from supervised residue trials and food processing
studies. JMPR will use all available data to make the best possible
estimate.
A variability factor is applied for those foods typically consumed
as single units, e.g. apples, carrots, because a single unit may have
a residue level of up to 3-10 times that of the lot or composite sample.
In the absence of specific data, a default variability factor of 10
is chosen for moderately sized units and 5 for large fruits such as
melons.
Calculated intake = {(max residue � unit weight � variab factor) +
STMR � (portion size - unit weight)} � bodyweight
STMR: supervised trials median residue representing the typical residue
in the edible portion of composite sample resulting from the maximum
registered use.
The calculated intake is acceptable if it does not exceed the acute
RfD.
The calculation is strongly driven by the first term - (max residue
� unit weight � variab factor).
JMPR will include the results of its acute risk assessments in the
1999 report, which will be sent to national governments for comment
and then for formal consideration at the 2001 meeting of the Codex
Committee on Pesticide Residues (CCPR).
