Normalizing dietary exposure across age by scaling to body size
05 July 2012, PDF |
14 pages |
Bokkers BGH, Bakker MI
RIVM Report 320103005
It is usually assumed that the higher dietary exposure to substances (in mg/kg bw) in young individuals compared to adults is the resultant of a relatively high consumption needed for growth. When this relatively high exposure of young individuals temporarily exceeds the human limit value, the assessment of possible health risks is not straightforward. The aim of this study was to find a way of scaling exposure in order to reduce the effect of age on the dietary intake. Several (allometric) scaling approaches were applied to explore their impact on age-related intake patterns. It was demonstrated that allometric scaling reduces the effect of body weight. Nevertheless, the results indicate that the higher exposure in young individuals is not only the resultant of a relatively high consumption needed for growth, but still contains influences of body weight. Therefore the conclusion was drawn that a different scaling of dietary exposure is not expedient. It is advised that, when a human limit value is exceeded for a relatively short period, the characteristics (e.g. accumulating properties) of the compound and the design of the toxicological studies informing the human limit value are examined closely to assess the health risk.