Objective To estimate the exposure from the ingestion of drinking water and to explore the method for improving the accuracy of health risk assessment.

Methods Based on existing survey data in China, exposure parameters from the ingestion of drinking water were aggregated by life stages to estimate the exposure of Chinese people.

Results The daily drinking water intake per unit of body weight for Chinese children, adolescents, middle-aged and elderly people was 0.073, 0.027, 0.018 and 0.017 L/(kg·d), respectively; and the exposure parameter estimated by drinking water ingestion was 0.024 L/(kg·d).

Conclusions The estimation of exposure parameter in Chinese people based on life stages was disparity from foreign parameter, as well as from Chinese adult parameter. Referring to foreign parameters directly in health risk assessment for Chinese people, or not measuring the early exposure under the age of 18 accurately, the estimated health risk value would be inaccurate. Carrying out a national survey on exposure parameters estimated by several stages of life as soon as possible was proposed in this paper, and the method of aggregating exposure parameters in several stages of life was used to improve the accuracy of health risk assessment in China.