Gh. Eduljee et Aj. Gair, VALIDATION OF A METHODOLOGY FOR MODELING PCDD AND PCDF INTAKE VIA THEFOODCHAIN, Science of the total environment, 187(3), 1996, pp. 211-229
The US EPA foodchain exposure methodology has been assessed, linking b
ackground concentrations of polychlorinated dibenzo-p-dioxins (PCDDs)
and polychlorinated dibenzofurans (PCDFs) in the atmosphere with event
ual intake of these chemicals by humans via the foodchain. The methodo
logy is assessed against background environmental concentrations of PC
DD/Fs and the background daily adult intake of PCDD/Fs in the UK diet
comprising meats, vegetables, dairy produce, fish and miscellaneous fo
od groups. The environmental fate and transport of PCDD/Fs is estimate
d for each of the seventeen, 2,3,7,8-positional PCDD/F isomers individ
ually from the atmospheric burden in the atmosphere and into the envir
onmental medium or food product of interest. The model predicts PCDD/F
deposition rate and soil concentration to within +/-50% of the measur
ed I-TEQ values. For grass, the model underpredicts PCDD/F concentrati
ons but the lack of a reliable and coherent data set precludes further
investigation as to the likely causes. The model performs well on foo
d products, with the exception of potatoes (underpredicts by a factor
of 20) and 'other' vegetables (underpredicts by a factor of 3). The to
tal modelled PCDD/F intake via the diet is 61 pg I-TEQ day(-1) as oppo
sed to the measured intakes of 69 pg I-TEQ day(-1) (excluding plant fo
ods) and 81 pg day(-1) (including data for plant foods measured in a p
revious survey, and not representative of contemporary exposures). The
major contributor to total PCDD/F intake is via milk and milk product
s, accounting for about 40% of the daily dietary intake. 'Hidden' fats
and oils account for 35% of the PCDD/F intake, followed by the ingest
ion meat and meat products (12%). As a group, vegetables do not appear
to contribute significantly to the total adult background intake of P
CDD/Fs via the diet.