Gustavo Lagos

Daily intakes of metals in drinking water are of extreme importance in risk assessment to human health. Some papers focused on this topic, but most of them did not consider the effect of age, gender and work location on daily intakes of metals in drinking water. The objective of present paper is to estimate the levels of Cu, Zn and As ingestion in drinking water in Shanghai, China and the effect of age, gender and work location on daily intakes of these metals. It was also the first time that such a detailed investigation on daily intakes of metals in drinking water was carried out in China in recent years. Drink/Sample (D/S) method was used to estimate the daily intakes of Cu, Zn and As in drinking water. The mean concentrations of Cu, Zn and As in drinking water were 10.8 microg/l, 0.29 mg/l and 0.91 microg/l, which were lower than U.S. EPA's Drinking Water Equivalent Level (DWEL) and WHO guideline values. The average daily intakes of Cu, Zn and As in drinking water was 21.12 microg/d, 0.65 mg/d, and 1.83 microg/d, which were on average 0.01%, 1.1% and 1.5% of the provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee. There was a significant difference in daily intake of Zn for different work locations (P=0.04). But no other significant differences in daily intakes of metals in drinking water were found according to age, gender and work location.

Daily exposures to chemicals in drinking water are of importance in risk assessment to human health. However, exposure assessment of chemicals in drinking water has seldom been performed in China. Until now, no such a detailed exposure assessment was reported in China. The aim of the present paper is to describe the scenes of daily exposure to Cu and Zn in drinking water by the population of Shanghai, China in the summer of 2003. A total of 163 volunteers and/or homes were selected to be statistically representative of the population of Shanghai, China. The Modified Consumption Habit Exposure Model (CHEM) method combined with the measurement of metals concentrations in stagnant water and actual ingested water was used to describe the daily exposure. The Consumption Habit Exposure Model method results showed that water consumption ranged from 1.7 to 2.2 L/day, varied with different age, gender and work location groups. Chemical results showed that the average Cu and Zn concentrations in stagnant water were much higher than those in actual ingested water (13.5 μ g/L and 1.55 mg/L vs. 10.8 μ g/L and 0.29 mg/L). Exposure assessment results also showed that volunteers had the highest exposure from the time of after breakfast to before dinner, and had the lowest exposure during the 15 minutes before sleeping. It was also showed that there were few volunteers directly exposed to stagnant water, although six hours stagnant time can be reached in most of the homes in Shanghai in the morning. The mean daily exposures to Cu and Zn were 0.36 μ g/kg/day and 0.01 mg/kg/day. Daily intakes of Cu and Zn from drinking water by Shanghai people were 1.8% and 4.4% of the World Health Organization recommendations for minimum total intakes of Cu and Zn for adults, respectively.

Several families of Talca city, Chile complained to health authorities for what they attributed to consumption of copper (Cu)-contaminated drinking water. We assessed the situation 6–12 mo after the initiation of complaints by characterizing the symptoms reported, the chemistry of drinking water, and the Cu concentration in stagnant drinking water. After completing a census, 1778 households accepted participation and were categorized as follows: category 1, Cu plumbing for tap water and dwellers reporting health complaints (HC); category 2, Cu plumbing for tap water and dwellers reporting no HC; category 3, plastic plumbing for tap water and dwellers reporting no HC. Questionnaires recorded characteristics of households and symptoms presented by each member of the family in the last 3 mo. The Cu concentration in drinking water was measured in a subsample of 80 homes with Cu pipes. In category 1, participants presented significantly more abdominal pain, diarrhea, and/or vomiting (gastrointestinal [GI] symptoms) in comparison to category 3 and to categories 2 plus 3. The stagnant Cu concentrations measured in drinking water in all houses studied were below the US Environmental Protection Agency guideline value (<1.3 mg Cu/L). In summary, data obtained by interviews suggested that individuals in some areas of Talca city were suffering more GI symptoms potentially related to Cu excess, but measurement of Cu concentration in stagnant tap waters ruled out the association between Cu exposure and GI symptom reports at the time of this study. The dose-response curves for GI symptoms and Cu exposure now available were crucial in the analyses of results.