Excretion of volatile nitrosamines in a rural population in relation to food and drinking water consumption

Urinary excretion of volatile nitrosamines was assessed in 59 non-smokers l iving in a rural county of Quebec, Canada. Water and food intakes were meas ured by means of a 24-hour recall. Nitrates were analyzed in the tap water of all participants (geometric mean = 2.0 mg nitrate-N/L) and dietary intak es of nitrate and vitamins C and E were estimated via a validated Canadian food database. Urine was collected over the same 24-hour period and analyze d for nitrates by hydrazine reduction and for volatile nitrosamines by gas- chromatography/mass spectrometry, N-Nitrosopiperidine (NPIP) was found in u rine samples from 52 of the 59 subjects. Geometric mean of NPIP urinary exc retion was 67 ng/day and maximum value was 1045 ng/day, No other volatile n itrosamine was detected. There was a correlation between urinary nitrate ex cretion and total nitrate intake (r = 0.71, P < 0.001), However, no relatio nship was found between urinary NPIP excretion and either nitrate excretion , dietary or water nitrate intakes. NPIP excretion was significantly correl ated to coffee intake (r = 0.40, P = 0.002) and this relation was not modif ied by vitamin intake. We conclude that nitrate intake is not related to ni trosamine excretion in this rural population. The influence of coffee consu mption on NPIP excretion deserves further attention. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.