Fluoride Study Methods Inadequate to Assess Drinking Water Effects

The methods used in this study are inadequate to assess the effects (positive or negative) of drinking water fluoride.

Pérez-Pérez N, Torres-Mendoza N, Borges-Yáñez A, Irigoyen-Camacho ME. Dental fluorosis: concentration of fluoride in drinking water and consumption of bottled beverages in school children. The Journal of Clinical Pediatric Dentistry. 2014 Summer;38(4):338-44.

OBJECTIVE: The purpose of the study was to identify dental fluorosis prevalence and to analyze its association with tap water fluoride concentration and beverage consumption in school children from the city of Oaxaca, who were receiving fluoridated salt.

STUDY DESIGN: A cross-sectional study was performed on elementary public school children. Dean’s Index was applied to assess dental fluorosis. The parents of the children who were studied completed a questionnaire about socio-demographic characteristics and type of beverages consumed by their children. A total of 917 school children participated in this study.

RESULTS: Dental fluorosis prevalence was 80.8%. The most frequent fluorosis category was very mild (41.0%), and 16.4% of the children were in the mild category. The mean water fluoride concentration was 0.43 ppm (±0.12). No association was detected between tap water fluoride concentration and fluorosis severity. The multinomial regression model showed an association among the mild fluorosis category and age (OR = 1.25, [95% CI 1.04, 1.50]) and better socio-economic status (OR = 1.78, [95% CI 1.21, 2.60]), controlling for fluoride concentration in water. Moderate and severe fluorosis were associated with soft drink consumption (OR = 2.26, [95% IC 1.01, 5.09]), controlling for age, socio-economic status, and water fluoride concentration.

CONCLUSIONS: The prevalence of fluorosis was high. Mild fluorosis was associated with higher socio-economic status, while higher fluorosis severity was associated with soft drink consumption.

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Arsenic Contamination and Remediation

Singh R, Singh S, Parihar P, Singh VP, Prasad SM Arsenic contamination, consequences and remediation techniques: a review. Ecotoxicology and Environmental Safety. 2015 Feb;112:247-70. doi: 10.1016/j.ecoenv.2014.10.009.

The exposure to low or high concentrations of arsenic (As), either due to the direct consumption of As contaminated drinking water, or indirectly through daily intake of As contaminated food may be fatal to the human health. Arsenic contamination in drinking water threatens more than 150 millions peoples all over the world. Around 110 millions of those peoples live in 10 countries in South and South-East Asia: Bangladesh, Cambodia, China, India, Laos, Myanmar, Nepal, Pakistan, Taiwan and Vietnam. Therefore, treatment of As contaminated water and soil could be the only effective option to minimize the health hazard. Therefore, keeping in view the above facts, an attempt has been made in this paper to review As contamination, its effect on human health and various conventional and advance technologies which are being used for the removal of As from soil and water.

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Antibody-Antigen Reaction for Rapid Detection of Water Contaminants

Xing C; Liu L; Song S; Feng M; Kuang H; Xu C. Ultrasensitive immunochromatographic assay for the simultaneous detection of five chemicals in drinking water. Biosensors & Bioelectronics 2015 Apr 15; Vol. 66, pp. 445-53. 

In this paper, we describe the development of a multicomponent lateral-flow assay based on an antibody-antigen reaction for the rapid and simultaneous detection of trace contaminants in water, including a heavy metal, algal toxin, antibiotic, hormone, and pesticide. The representative analytes chosen for the study were lead (Pb(II), microcystin-leucine-arginine (MC-LR), chloramphenicol (CAP), testosterone (T), and chlorothalonil (CTN). Five different antigens were immobilized separately in five test lines on a nitrocellulose membrane. The monoclonal antibodies specifically recognized the corresponding antigens, and there was no cross-reactivity between the antibodies in the detection assay. Samples or standards containing the five analytes were preincubated with the freeze-dried colloidal-gold-labeled monoclonal antibody conjugates to improve the sensitivity of the assay. The results were obtained within 20min with a paper-based sensor. The cut-off values for the strip test were 4ng/mL for Pb(II), 1ng/mL for MC-LR, 0.1ng/mL for CAP, 5ng/mL for T, and 5ng/mL for CTN. The assay was evaluated using spiked water samples, and the accuracy and reproducibility of the results were good. In summary, this lateral-flow device provides an effective and rapid method for the onsite detection of multiple contaminants in water samples, with no treatment or devices required.

Ultrasound Treatment of Drinking Water Treatment Sludge

Zhiwei Zhou, Yanling Yang, Xing Li, Yang Zhang, Xuan Guo. Characterization of drinking water treatment sludge after ultrasound treatment. Ultrasonics – Sonochemistry May 2015 24:19-26

Ultrasonic technology alone or the combination of ultrasound with alkaline or thermal hydrolysis as pretreatment for anaerobic digestion of activated sludge has been extensively documented. However, there are few reports on ultrasound as pretreatment of drinking water treatment sludge (DWTS), and thereby the characteristic variability of sonicated DWTS has not been fully examined. This research presents a lab-scale study on physical, chemical and biological characteristics of a DWTS sample collected from a water plant after ultrasonic treatment via a bath/probe sonoreactor. By doing this work, we provide implications for using ultrasound as pretreatment of enhanced coagulation of recycling sludge, and for the conditioning of water and wastewater mixed sludge by ultrasound combined with polymers. Our results indicate that the most vigorous DWTS disintegration quantified by particles’ size reduction and organic solubilization is achieved with 5W/ml for 30min ultra-sonication (specific energy of 1590kWh/kgTS). The Brunauer, Emmett and Teller (BET) specific surface area of sonicated DWTS flocs increase as ultra-sonication prolongs at lower energy densities (0.03 and 1W/ml), while decrease as ultra-sonication prolongs at higher energy densities (3 and 5W/ml). Additionally, the pH and zeta potential of sonicated DWTS slightly varies under all conditions observed. A shorter sonication with higher energy density plays a more effective role in restraining microbial activity than longer sonication with lower energy density.

Consumption of Untreated Drinking Water in Alaska Native Communities

Ritter TL, Lopez ED, Goldberger R, Dobson J, Hickel K, Smith J, Johnson RM, Bersamin A. Consuming untreated water in four southwestern Alaska Native communities: reasons revealed and recommendations for change. Journal of Environmental Health. 2014 Dec;77(5):8-13; quiz 52.

In this article, the authors provide the first in-depth account of why some Alaska Native people drink untreated water when treated water is available. Their qualitative research was conducted in four Alaska Native village communities that have treated water available from a centralized distribution point. Most respondents (n = 172; 82%) reported that some of their household’s drinking water came from an untreated source. Motives for drinking untreated water emerged from analysis of open-ended questions about drinking water practice and could be categorized into six themes: chemicals, taste, health, access, tradition, and cost. Importantly, some residents reported consuming untreated water because they both liked untreated water and disliked treated water. As such, interventions to increase safe water consumption should address this dichotomy by providing education about the benefits of treated water alongside the risks involved with drinking untreated water. Based on the findings, the authors provide specific recommendations for developing behavior change interventions that address influences at multiple social-ecological levels.

San Joaquin Valley Study of Low Birth Weight and Nitrate

If a forest fire is serious it can be seen from miles away. Perhaps when none is seen there is no serious fire there at all.

This abstract does not mention what constitutes an “unsafe level”. Presumably this would be the drinking water MCL of 10 mg/L but perhaps the “safe” level is higher than the MCL. Like most studies of this type the presumption is that there must be a problem we just have not looked close enough.

Blake SB. Spatial relationships among dairy farms, drinking water quality, and maternal-child health outcomes in the San Joaquin Valley. Public Health Nurs. 2014 Nov-Dec;31(6):492-9. doi: 10.1111/phn.12166.

OBJECTIVE: Access to clean and affordable water is a significant public health issue globally, in the United States, and in California where land is heavily used for agriculture and dairy operations. The purpose of this study was to explore the geographic relationships among dairy farms, nitrate levels in drinking water, low birth weight, and socioeconomic data at the ZIP code level in the San Joaquin Valley.

DESIGN AND SAMPLE: This ecological study used a Geographic Information System (GIS) to explore and analyze secondary data.

MEASURES: A total of 211 ZIP codes were analyzed using spatial autocorrelation and regression analysis methods in ArcGIS version 10.1.
RESULTS: ZIP codes with dairies had a higher percentage of Hispanic births (p = .001). Spatial statistics revealed that ZIP codes with more dairy farms and a higher dairy cow density had higher levels of nitrate contamination. No correlation was detected between LBW and unsafe nitrate levels at the ZIP code level.

CONCLUSION: Further research examining communities that use private and small community wells in the San Joaquin Valley should be conducted. Birth data from smaller geographic areas should be used to continue exploring the relationship between birth outcomes and nitrate contamination in drinking water.

Water and Sanitation of Costa Rica

Kathleen M. Bower. Water supply and sanitation of Costa Rica. Environmental earth sciences. 2014 Jan., v. 71, no. 1

Costa Rica is a developing country whose citizens pride themselves on care for the environment. Environmental care is only slowly spreading to include safe and reliable water supplies. Plentiful water resources are used for energy production, industry, municipal water supply, and agriculture. The amount and quality of water resources must be understood and protected for future sustainable use. Based on interviews and conversations, some Costarricense are aware of the need for protection of natural water resources through preservation of forests; other steps toward sustainable water use are not universally valued. Streams are not the preferred source of domestic water supply due to potential water contamination; mostly from untreated sewage, sediment and agricultural chemicals. Quantity and quality of ground water supplies, the current main source of domestic water, are being investigated by scientists of Costa Rica. While 99 % of the population has access to a known supply of domestic water, only 82 % of the population has consistent access to potable drinking water. The potable water supply is smaller in rural areas. Three percent of sewage in Costa Rica is treated before release to the environment. The Río Tárcoles water basin, underlying the largest urban area of Costa Rica, is probably the most polluted in Central America. More is spent for treatment of water-borne diseases than on water supply and sewage treatment. Other potential sources of water contamination are examined.

The paper is here (fee).