Category Archives: Inorganic contaminants

Is Trace Lithium in Tap Water Beneficial?

Small associations from ecological studies are questionable whether the effect is negative or as in this case positive.

Fajardo VA, LeBlanc PJ, Fajardo VA. Trace lithium in Texas tap water is negatively associated with all-cause mortality and premature death. Applied physiology, nutrition, and metabolism 2017 Dec 5. doi: 10.1139/apnm-2017-0653.

Lithium in tap water was previously found to have life-extending effects across 18 Japanese municipalities. Using a larger dataset with several Texas counties, our study shows that lithium concentrations in tap water are negatively associated with all-cause mortality (r = -0.18, p = 0.006, 232 counties) and years of potential life lost (r = -0.22, p = 0.001, 214 counties). Thus, our present findings extend and reinforce lithium’s purported life-prolonging effect in humans.

California to Withdraw Hexavalent Chromium MCL

Household Polyphosphate Additives as a Source of Phosphate Intake, Slovenia

Jereb G, Poljšak B, Eržen I. Contribution of Drinking Water Softeners to Daily Phosphate Intake in Slovenia. International journal of environmental research and public health. 2017 Oct 6;14(10). pii: E1186. doi: 10.3390/ijerph14101186.

The cumulative phosphate intake in a typical daily diet is high and, according to several studies, already exceeds recommended values. The exposure of the general population to phosphorus via drinking water is generally not known. One of the hidden sources of phosphorus in a daily diet is sodium polyphosphate, commonly used as a drinking water softener. In Slovenia, softening of drinking water is carried out exclusively within the internal (household) drinking water supply systems to prevent the accumulation of limescale. The aim of the study was to determine the prevalence of sodium phosphates in the drinking water in Slovenia in different types of buildings, to determine residents’ awareness of the presence of chemical softeners in their drinking water, and to provide an exposure assessment on the phosphorus intake from drinking water. In the current study, the presence of phosphates in the samples of drinking water was determined using a spectrophotometric method with ammonium molybdate. In nearly half of the samples, the presence of phosphates as water softeners was confirmed. The measured concentrations varied substantially from 0.2 mg PO4/L to 24.6 mg PO4/L. Nearly 70% of the respondents were not familiar with the exact data on water softening in their buildings. It follows that concentrations of added phosphates should be controlled and the consumers should be informed of the added chemicals in their drinking water. The health risks of using sodium polyphosphate as a drinking water softener have not been sufficiently investigated and assessed. It is highly recommended that proper guidelines and regulations are developed and introduced to protect human health from adverse effects of chemicals in water intended for human consumption.

Bromide in Drinking Water Sources, Pennsylvania

Good KD, Vanbriesen JM. Power plant bromide discharges and downstream drinking water systems in Pennsylvania. Environmental science and technology. 2017 Sep 25. doi: 10.1021/acs.est.7b03003.

Coal-fired power plants operating wet flue gas desulfurization (FGD) have recently been implicated in increasing bromide levels in drinking water sources, which affect formation of disinfection by-products. Bromide was not included as a regulated constituent in the recent steam electric effluent limitations guidelines and standards (ELGs) since the U.S. EPA analysis suggested few drinking water facilities would be affected by bromide discharges from power plants. The present analysis uses a watershed approach to identify Pennsylvania drinking water intakes downstream of wet FGD discharges and considers the population served by these systems, providing context for the potential extent of the effects of coal-fired power plant discharges on downstream drinking water plants and consumers of publicly-supplied drinking water. Twenty-two (22) public drinking water systems serving 2.5 million people were identified as being downstream of at least one wet FGD discharge. During mean August flow conditions in receiving rivers, the median bromide concentration contributions at intake locations ranged from 5.2 to 62 µg/L for the Base scenario (including only natural bromide in coal) and 16 to 190 µg/L for the Bromide Addition scenario (natural plus added bromide for mercury control); ranges depend on bromide loads and receiving stream dilution capacity.

No Clear Association Between Manganese Exposure and Cognitive Development in Sample of School-Age Children

Bouchard MF, Surette C, Cormier P, Foucher D. Low level exposure to manganese from drinking water and cognition in school-age children. Neurotoxicology. 2017 Jul 15. pii: S0161-813X(17)30154-7. doi: 10.1016/j.neuro.2017.07.024.

BACKGROUND: Manganese (Mn) is an element found in the environment and certain geographic areas have elevated concentrations in soil and water du to natural conditions or anthropic activities. A growing body of data suggests that exposure to manganese in drinking water could be neurotoxic.

OBJECTIVE: Firstly, we aimed to examine the association between exposure to manganese from drinking water and cognition in children consuming well water. Secondly, we also aimed to examine the relation between cognition and manganese concentrations in children’s hair, nail, and saliva.

METHODS: A total 259 children from 189 households consuming well water were included in the present study (ages 5.9 to 13.7 years). We assessed children’s cognition with the WISC-IV, and we used five indicators of manganese exposure: concentration in tap water, intake from the consumption of water divided by child’s weight, manganese concentration in children’s hair, toe nail, and saliva. We used General Estimating Equation analysis to assess the relation between manganese exposure indicators and IQ scores, adjusting for potential confounders, and taking into account family clusters.

RESULTS: Drinking water manganese concentrations were generally low, with 48% of children consuming water <5>g/L, 25% >50>g/L, and 4% >400>g/L. Results differed by sex. In girls, higher manganese concentration in water, hair, and toe nail were associated with poorer Performance IQ scores but this was significant only for toe nail (for a 10-fold increase in manganese, β: -5.65, 95% CIs: -10.97, -0.32). Opposite associations were observed in boys, i.e., better Performance IQ scores with higher manganese concentration hair, toe nail, and water, the latter being significant (β: 2.66, 95% CIs: 0.44, 4.89). Verbal IQ scores did not seem to be associated with manganese exposure indicators.

CONCLUSIONS: Drinking water manganese levels were considerably lower than in previous studies reporting neurotoxic effects. There was no clear indication of an association between exposure to manganese and cognitive development in this sample of school-age children although the data suggest there might be sex-specific associations. Given the low levels of exposure and sex-specific associations, a larger sample size would have been required to increase the statistical power and better characterize the relations.

Galvanic Corrosion of Lead by Iron

Trueman BF, Sweet GA, Harding MD, Estabrook H, Bishop DP, Gagnon GA. Galvanic Corrosion of Lead by Iron (Oxyhydr)oxides: Potential Impacts on Drinking Water Quality. Environmental science and technology. 2017 May 30. doi: 10.1021/acs.est.7b01671.

Lead exposure via drinking water remains a significant public health risk; this study explored the potential effects of upstream iron corrosion on lead mobility in water distribution systems. Specifically, galvanic corrosion of lead by iron (oxyhydr)oxides was investigated. Coupling an iron mineral cathode with metallic lead in a galvanic cell increased lead release by 531 µg L-1 on average-a nine-fold increase over uniform corrosion in the absence of iron. Cathodes were composed of spark plasma sintered Fe3O4 or α-Fe2O3 or field-extracted Fe3O4 and α-FeOOH. Orthophosphate immobilized oxidized lead as insoluble hydroxypyromorphite, while humic acid enhanced lead mobility. Addition of a humic isolate increased lead release due to uniform corrosion by 81 µg L-1 and-upon coupling lead to a mineral cathode-release due to galvanic corrosion by 990 µg L-1. Elevated lead in the presence of humic acid appeared to be driven by complexation, with 208Pb and UV254size-exclusion chromatograms exhibiting strong correlation under these conditions (R2average = 0.87). A significant iron corrosion effect was consistent with field data: lead levels after lead service line replacement were greater by factors of 2.3 – 4.7 at sites supplied by unlined cast iron distribution mains compared with the alternative, lined ductile iron.

Manganese in Drinking Water and Cognitive Abilities

Rahman SM, Kippler M, Tofail F, Bölte S, Derakhshani Hamadani J, Vahter M. Manganese in Drinking Water and Cognitive Abilities and Behavior at 10 Years of Age: A Prospective Cohort Study. Environmental health perspectives. 2017 May 26;125(5):057003. doi: 10.1289/EHP631.

BACKGROUND: Cross-sectional studies have indicated impaired neurodevelopment with elevated drinking water manganese concentrations (W-Mn), but potential susceptible exposure windows are unknown.

OBJECTIVES: We prospectively evaluated the effects of W-Mn, from fetal life to school age, on children’s cognitive abilities and behavior.

METHODS: We assessed cognitive abilities and behavior in 1,265 ten-year-old children in rural Bangladesh using the Wechsler Intelligence Scale for Children (WISC-IV) and the Strengths and Difficulties Questionnaire (SDQ), respectively. Manganese in drinking water used during pregnancy and by the children at 5 y and 10 y was measured using inductively coupled plasma mass spectrometry.

RESULTS: The median W-Mn was (range 0.001-6.6) during pregnancy and  at 10 y. In multivariable-adjusted linear regression analyses, restricted to children with low arsenic (As) exposure, none of the W-Mn exposures was associated with the children’s cognitive abilities. Stratifying by gender (p for interaction in general  showed that prenatal W-Mn was positively associated with cognitive ability measures in girls but not in boys. W-Mn at all time points was associated with an increased risk of conduct problems, particularly in boys (range 24-43% per mg/L). At the same time, the prenatal W-Mn was associated with a decreased risk of emotional problems [odds ratio (OR)=0.39 (95% CI: 0.19, 0.82)] in boys. In girls, W-Mn was mainly associated with low prosocial scores [prenatal W-Mn: OR=1.48 (95% CI: 1.06, 1.88)].

CONCLUSIONS: Elevated prenatal W-Mn exposure was positively associated with cognitive function in girls, whereas boys appeared to be unaffected. Early life W-Mn exposure appeared to adversely affect children’s behavior.