REGIONAL VARIATION IN POTABLE WATER NITRATE CONCENTRATION AND ITS EFFECT ON TOTAL DIETARY NITRATE INTAKE

Total dietary nitrate intake was assessed using 24-h urinary nitrate r ecoveries in seven regions within the UK. The overall median daily nit rate exposure was 2.1 mmol/24 h, and ranged from 1.4 (Mold, North Wale s) to 2.9 (Stoke. Industrial Midlands). The median water nitrate conce ntration in this study was 0.24 mM. Across the seven regions drinking water nitrate contributes an average of 17% of the total UK dietary ni trate exposure, in accordance with previous reports. If water nitrate concentrations were allowed to increase to 0.8 mM (EU upper limit) the n overall nitrate exposure would increase by 41%, An increase to 1.6 m M (the WHO guideline) would result in a doubling in daily nitrate expo sure.