Tag Archives: drinking water quality

Tap Water Quality within a New Residential Green Building

Salehi M, Abouali M, Wang M, Zhou Z, Nejadhashemi AP, Mitchell J, Caskey S, Whelton AJ. Case study: Fixture water use and drinking water quality in a new residential green building. Chemosphere. 2017 Nov 30;195:80-89. doi: 10.1016/j.chemosphere.2017.11.070.

Residential plumbing is critical for the health and safety of populations worldwide. A case study was conducted to understand fixture water use, drinking water quality and their possible link, in a newly plumbed residential green building. Water use and water quality were monitored at four in-building locations from September 2015 through December 2015. Once the home was fully inhabited average water stagnation periods were shortest at the 2nd floor hot fixture (90 percentile of 0.6-1.2 h). The maximum water stagnation time was 72.0 h. Bacteria and organic carbon levels increased inside the plumbing system compared to the municipal tap water entering the building. A greater amount of bacteria was detected in hot water samples (6-74,002 gene copy number/mL) compared to cold water (2-597 gene copy number/mL). This suggested that hot water plumbing promoted greater microbial growth. The basement fixture brass needle valve may have caused maximum Zn (5.9 mg/L), Fe (4.1 mg/L), and Pb (23 μg/L) levels compared to other fixture water samples (Zn ≤ 2.1 mg/L, Fe ≤ 0.5 mg/L and Pb ≤ 8 μg/L). At the basement fixture, where the least amount of water use events occurred (cold: 60-105, hot: 21-69 event/month) compared to the other fixtures in the building (cold: 145-856, hot: 326-2230 event/month), greater organic carbon, bacteria, and heavy metal levels were detected. Different fixture use patterns resulted in disparate water quality within a single-family home. The greatest drinking water quality changes were detected at the least frequently used fixture.

Drinking Water Quality in Rural Oaxaca, Mexico

Rowles LS 3rd, Alcalde R, Bogolasky F, Kum S, Diaz-Arriaga FA, Ayres C, Mikelonis AM, Toledo-Flores LJ, Alonso-Gutiérrez MG, Pérez-Flores ME, Lawler DF, Ward PM, Lopez-Cruz JY, Saleh NB. Perceived versus actual water quality: Community studies in rural Oaxaca, Mexico. Sci Total Environ. 2017 Dec 6;622-623:626-634. doi: 10.1016/j.scitotenv.2017.11.309.

Compromised water quality risks public health, which becomes particularly acute in economically marginalized communities. Although the majority of the clean-water-deprived population resides in Sub-Saharan Africa and Asia, a significant portion (32 million) lives in Meso- and Latin-America. Oaxaca is one of the marginalized southern states of Mexico, which has experienced high morbidity from infectious diseases and also has suffered from a high rate of infant mortality. However, there has been a paucity of reports on the status of water quality of culturally diverse rural Oaxaca. This study follows community-based participatory research methods to address the data gap by reporting on water quality (chemical and microbiological) and by exploring social realities and water use practices within and among communities. Surveys and water quality analyses were conducted on 73 households in three rural communities, which were selected based on the choice of water sources (i.e., river water, groundwater, and spring water). Statistically significant variations among communities were observed including the sanitation infrastructure (p-value 0.001), public perception on water quality (p-value 0.007), and actual microbiological quality of water (p-value 0.001). Results indicate a high prevalence of diarrheal diseases, a desire to improve water quality and reduce the cost of water, and a need for education on water quality and health in all the surveyed communities. The complexities among the three studied communities highlight the need for undertaking appropriate policies and water treatment solutions.

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.

Providing Safe Drinking Water to Slum Households, Siliguri, West Bengal, India

Bhar D, Bhattacherjee S, Mukherjee A, Sarkar TK, Dasgupta S. Utilization of safe drinking water and sanitary facilities in slum households of Siliguri, West Bengal. Indian J Public Health. 2017 Oct-Dec;61(4):248-253. doi: 10.4103/ijph.IJPH_345_16.

BACKGROUND: With the rapid expansion of urban population, provision of safe water and basic sanitation is becoming a challenge; especially in slums. This is adversely affecting the health of the people living in such areas.

OBJECTIVES: The study was conducted to measure the proportion of households using improved drinking water and sanitation facilities and to determine the association between diarrhea in under-five children with water and sanitation facilities.

METHODS: A community-based, cross-sectional study was conducted among 796 slum households in Siliguri from January to March 2016 by interviewing one member from each household using a predesigned and pretested questionnaire based on the WHO/UNICEF Joint Monitoring Program Core questions on drinking water and sanitation for household surveys.

RESULTS: A majority 733 (92.1%) of slum households used an improved drinking water source; 565 (71%) used public tap. About two-thirds (65.7%) household used improved sanitation facilities. About 15.8% households had reported diarrheal events in children in the previous month. Unimproved drinking water sources (AOR = 4.13; 1.91, 8.96), houses without piped water supply (AOR = 4.43; 1.31, 15.00), and latrines located outside houses (AOR = 3.61; 1.44, 9.07) were significantly associated with the diarrheal events in children.

CONCLUSION: The utilization of improved drinking water source was high but piped water connection and improved sanitary toilet used was low. Association between diarrheal events and type of drinking water sources and place of sanitation might suggest fecal contamination of water sources. Awareness generation through family-centered educational programs could improve the situation.

Impact of water quality on corrosion of cast iron pipes

Hu J, Dong H, Xu Q, Ling W, Qu J, Qiang Z. Impacts of water quality on the corrosion of cast iron pipes for water distribution and proposed source water switch strategy. Water research. 2017 Oct 31;129:428-435. doi: 10.1016/j.watres.2017.10.065.

Switch of source water may induce “red water” episodes. This study investigated the impacts of water quality on iron release, dissolved oxygen consumption (ΔDO), corrosion scale evolution and bacterial community succession in cast iron pipes used for drinking water distribution at pilot scale, and proposed a source water switch strategy accordingly. Three sets of old cast iron pipe section (named BP, SP and GP) were excavated on site and assembled in a test base, which had historically transported blended water, surface water and groundwater, respectively. Results indicate that an increasing Cl or SO42- concentration accelerated iron release, but alkalinity and calcium hardness exhibited an opposite tendency. Disinfectant shift from free chlorine to monochloramine slightly inhibited iron release, while the impact of peroxymonosulfate depended on the source water historically transported in the test pipes. The ΔDO was highly consistent with iron release in all three pipe systems. The mass ratio of magnetite to goethite in the corrosion scales of SP was higher than those of BP and GP and kept almost unchanged over the whole operation period. Siderite and calcite formation confirmed that an increasing alkalinity and hardness inhibited iron release. Iron-reducing bacteria decreased in the BP but increased in the SP and GP; meanwhile, sulfur-oxidizing, sulfate-reducing and iron oxidizing bacteria increased in all three pipe systems. To avoid the occurrence of “red water”, a source water switch strategy was proposed based on the difference between local and foreign water qualities.

Point-of-use filters as a screening method for suspect compounds in drinking water

Newton SR, McMahen RL, Sobus JR, Mansouri K, Williams AJ, McEachran AD, Strynar MJ.
Suspect screening and non-targeted analysis of drinking water using point-of-use filters.Environ Pollut. 2017 Nov 25;234:297-306. doi: 10.1016/j.envpol.2017.11.033.

Monitored contaminants in drinking water represent a small portion of the total compounds present, many of which may be relevant to human health. To understand the totality of human exposure to compounds in drinking water, broader monitoring methods are imperative. In an effort to more fully characterize the drinking water exposome, point-of-use water filtration devices (Brita® filters) were employed to collect time-integrated drinking water samples in a pilot study of nine North Carolina homes. A suspect screening analysis was performed by matching high resolution mass spectra of unknown features to molecular formulas from EPA’s DSSTox database. Candidate compounds with those formulas were retrieved from the EPA’s CompTox Chemistry Dashboard, a recently developed data hub for approximately 720,000 compounds. To prioritize compounds into those most relevant for human health, toxicity data from the US federal collaborative Tox21 program and the EPA ToxCast program, as well as exposure estimates from EPA’s ExpoCast program, were used in conjunction with sample detection frequency and abundance to calculate a “ToxPi” score for each candidate compound. From ∼15,000 molecular features in the raw data, 91 candidate compounds were ultimately grouped into the highest priority class for follow up study. Fifteen of these compounds were confirmed using analytical standards including the highest priority compound, 1,2-Benzisothiazolin-3-one, which appeared in 7 out of 9 samples. The majority of the other high priority compounds are not targets of routine monitoring, highlighting major gaps in our understanding of drinking water exposures. General product-use categories from EPA’s CPCat database revealed that several of the high priority chemicals are used in industrial processes, indicating the drinking water in central North Carolina may be impacted by local industries.

Improving Private-Well Water Quality, North Carolina

MacDonald Gibson J, Pieper KJ. Strategies to Improve Private-Well Water Quality: A North Carolina Perspective. Environmental health perspectives. 2017 Jul 7;125(7):076001. doi: 10.1289/EHP890.

BACKGROUND: Evidence suggests that the 44.5 million U.S. residents drawing their drinking water from private wells face higher risks of waterborne contaminant exposure than those served by regulated community water supplies. Among U.S. states, North Carolina (N.C.) has the second-largest population relying on private wells, making it a useful microcosm to study challenges to maintaining private-well water quality.

OBJECTIVES: This paper summarizes recommendations from a two-day summit to identify options to improve drinking-water quality for N.C. residents served by private wells.

METHODS: The Research Triangle Environmental Health Collaborative invited 111 participants with knowledge of private-well water challenges to attend the Summit. Participants worked in small groups that focused on specific aspects and reconvened in plenary sessions to formulate consensus recommendations.

DISCUSSION: Summit participants highlighted four main barriers to ensuring safe water for residents currently relying on private wells: (1) a database of private well locations is unavailable; (2) racial disparities have perpetuated reliance on private wells in some urbanized areas; (3) many private-well users lack information or resources to monitor and maintain their wells; and (4) private-well support programs are fragmented and lack sufficient resources. The Summit produced 10 consensus recommendations for ways to overcome these barriers.

CONCLUSIONS: The Summit recommendations, if undertaken, could improve the health of North Carolinians facing elevated risks of exposure to waterborne contaminants because of their reliance on inadequately monitored and maintained private wells. Because many of the challenges in N.C. are common nationwide, these recommendations could serve as models for other states.