The Influence of Drinking Water Intake on Pollutant Levels in the Human Body: Evidence from NHANES Data

Most studies have focused on the levels of pollutants in drinking water and the health risks they pose. However, no studies have reported the effects of drinking water intake on pollutant levels in the human body. Therefore, this study collected data from National Health and Nutrition Examination Survey database to provide statistical evidence for the relationship between water intake and human pollutant levels. We analyzed 95 pollutants in human urine, blood, and serum. The study found that 82% (65/79) of urine pollutants unadjusted for creatinine showed a stable negative correlation with water intake, primarily due to the urine dilution effect caused by increased water consumption. Water intake was negatively correlated with cadmium, m-/p-xylene, and toluene in blood, but positively correlated with blood total mercury and methyl mercury. In summary, the habit of drinking more water may be beneficial to reduce levels of most pollutants in human urine (unadjusted for creatinine) and a small part in blood. Only a few pollutants, including total mercury and methyl mercury in blood, as well as benzophenone-3 in urine (both creatinine-adjusted and unadjusted), are positively related to water intake. The underlying mechanisms by which water intake influences pollutant levels in the human body require further investigation.