Sodium in drinking water in South Carolina.

The potential contribution of drinking water sodium to total consumption and to blood pressure levels is explored in a South Carolina survey. Most (96 per cent) of the population was served by drinking water containing less than 100 mg/l Na (median 14.8 mg/l). For households with water sources containing greater than or equal to 100 mg/l Na, drinking water accounted for approximately 8.5 per cent of total estimated consumption. After adjustment for age, sex, race, body mass index, education, and dietary sodium, a negative association between diastolic blood pressure and drinking water sodium levels was found.