Acrylamide in children--exposure assessment via urinary acrylamide metabolites as biomarkers.

Acrylamide (AA), a substance classified as probably carcinogenic to humans, was detected for the first time in food products in 2002. AA can be primarily found in foods containing carbohydrates and proteins, where it is formed during the heating process. Exposure assessment based on food consumption data revealed an average daily intake of AA between 0.3 and 0.8 microg/kg BW/day. These data have been confirmed by human biomonitoring using haemoglobin adducts of AA in blood or the specific mercapturic acids in urine. However, human biomonitoring data on the internal exposure of children were only sporadically available. Especially data about the excretion of both relevant mercapturic acids were missing. The mercapturic acids other than the haemoglobin adducts give the recent AA exposure of the last 24h. In this study, we quantify the internal exposure of AA and the genotoxic metabolite glycidamide (GA) in 110 children with regard to their exposure through diet and/or environmental tobacco smoke.

METHODS

Hundred and ten 5-6-year-old children were randomly selected. Their dietary habits as well as their exposure to the environmental tobacco smoke were assessed by means of a questionnaire. By means of spot urine samples, mercapturic acids of acrylamide (AAMA) and mercapturic acids of glycidamide (GAMA) were analysed with LC-ESI-MS/MS.

RESULTS

Median (95th percentile) urinary levels were 36.0 (152.7) microg AAMA/l and 13.4 (55.9) microg GAMA/l. Based on the metabolite levels, the median uptake of acrylamide was calculated to be 0.54 microg/kg BW/d. A number of associations with the consumption of French fries, various potato products, as well as fried cereals could be found. Significant results were found for French fries. No correlations between the exposure to environmental smoke and cotinine levels in urine were found.

CONCLUSIONS

This is the first study to show the presence of AAMA and GAMA in urine specimens of 110 children, thus providing evidence for a background exposure by nutrition. Median (95th percentile) uptake of AA in children was 0.54 (1.91) microg/kg bodyweight and day, exceeding exposure in adults by 50%. These findings support the efforts to minimize AA formation and contamination in food. Comparing our findings with that of other human studies, there are hints that children have a higher AA intake than adults and that children more effectively oxidize AA. Both findings indicate that children might be the most vulnerable group of the population.