Drinking water consumption patterns in Sweden.

Estimates on drinking water consumption are necessary in risk assessments on microbial hazards in drinking water. Large differences in consumption habits between countries have been reported. In order to establish estimates for the Swedish population, water consumption data from a waterborne outbreak investigation (157 people), a small water consumption study (75 people) and a large study on health and environmental factors (10,957 people) were analysed. A lognormal distribution for the daily direct/cold water intake in litres with mu = - 0.299 and sigma = 0.570 was fitted to the quantitative data, representing the general population. The average daily consumption of tap water as plain drinking water and as heated tap water, e.g. in coffee and tea, was 0.86 +/- 0.48 l and 0.94 +/- 0.69 l, respectively. Women consumed more cold tap water than did men, while men appeared to have a higher consumption of heated tap water. Cold tap water intake was highest in the oldest age group, (> or =70 years). The consumption of bottled water was very low (mean 0.06 l/d) when compared to other countries.