Daily Archives: October 26, 2014

Salton Sea Report: Back to the Future and the Iron Rice Bowl

Like clock work, another alarming report from the Pacific Institute (click here for news article). This time it is the Salton Sea. Everyone who is paying attention has known about the Salton Sea situation for decades. Improving water quality at the Salton Sea will be a massive undertaking, so it was a pretty safe topic for the Pacific Institute to promote (as opposed to Peter Gleick and global warming). It is near impossible to say anything positive about the Salton Sea situation.

But as a  politically motivated institute such a study continues the tradition of the iron rice bowl. An institute releases a study saying the obvious in an alarming way. Activists and politicians then use the media to promote the alarm. In this case, Senator Boxer right on cue to alarm citizens and indirectly push the water bond. Just wait, government agencies whose funding depends on such projects will soon chime in. And what happens when such an effort is funded at $billions? Who eventually benefits? Watch where the money really goes….

New Jersey Drinking Water and Infant Health Study Uninformative

Studies such as this have previously been done in a number of states, some more than 20 years in the past. It seems a whole new generation of epidemiologists still believe that such studies are informative. They all suffer from the same set of insurmountable limitations that make any conclusions speculative. A different research focus would be of more benefit than rediscovering the past.

Janet Currie, Joshua Graff Zivin, Katherine Meckel, Matthew Neidell and Wolfram Schlenker. Something in the water: contaminated drinking water and infant health. The Canadian Journal of Economics / Revue canadienne d’Economique. Vol. 46, No. 3 (August / août 2013)  791-810.

This paper provides estimates of the effects of in utero exposure to contaminated drinking water on fetal health. To do this, we examine the universe of birth records and drinking water testing results for the state of New Jersey from 1997 to 2007. Our data enable us to compare outcomes across siblings who were potentially exposed to differing levels of harmful contaminants from drinking water while in utero. We find small effects of drinking water contamination on all children, but large and statistically significant effects on birth weight and gestation of infants born to less educated mothers. We also show that those mothers who were most affected by contamination were the least likely to move between births in response to contamination.

Ce mémoire développe des estimations des effets d’une exposition in utero à de l’eau potable contaminée sur la santé du foetus. Pour ce faire, on examine l’ensemble des registres de naissance et des résultats de tests de l’eau potable dans l’état du New Jersey entre 1997 et 2007. Ces données permettent de comparer les résultats entre frères et soeurs qui ont potentiellement été exposés à des niveaux différents de contamination de l’eau potable quand ils étaient in utero. On détecte de petits effets de la contamination de l’eau sur tous les enfants, mais des effets importants et statistiquement significatifs sur le poids à la naissance et sur la gestation des nourrissons portés par des mères moins instruites. On montre aussi que ces mères qui sont les plus affectées par la contamination de l’eau sont celles qui sont le moins susceptibles de déménager entre les naissances en raison de la contamination.

Mathematics and Ecology: Understanding Cyanobacteria

Meredith L. Greer, Holly A. Ewing, Kathryn L. Cottingham, Kathleen C. Weathers. Collaborative Understanding of Cyanobacteria in Lake Ecosystems. The College Mathematics Journal. Vol. 44, No. 5 (November 2013) 376-385

We describe a collaboration between mathematicians and ecologists studying the cyanobacterium Gloeotrichia echinulata and its possible role in eutrophication of New England lakes. The mathematics includes compartmental modeling, differential equations, difference equations, and testing models against high-frequency data. The ecology includes observation, field sampling, and parameter estimation based on observed data and the related literature. Mathematically and ecologically, a collaboration like this progresses in ways it never would have if either group worked alone.

Faucet Aerators as a Source of Opportunistic Pathogens

Maria Luisa Cristina, Anna Maria Spagnolo, Beatrice Casini, Angelo Baggiani, Pietro Del Giudice, Silvio Brusaferro, Andrea Poscia, Umberto Moscato, Fernanda Perdelli, and Paolo Orlando. The Impact of Aerators on Water Contamination by Emerging Gram-Negative Opportunists in At-Risk Hospital Departments Infection Control and Hospital Epidemiology. DOI: 10.1086/674863

Objective. Our aim was to evaluate the impact of aerators on water microbiological contamination in at-risk hospital departments, with a view to quantifying the possible risk of patient exposure to waterborne microorganisms.

Design. We analyzed the microbiological and chemical-physical characteristics of hot and cold water in some critical hospital departments.

Setting. Two hospitals in northern Italy.

Methods. We took 304 water samples over a 1-year period, at 3-month intervals, from taps used by healthcare personnel for handwashing, surgical washing, and the washing of medical equipment. We analyzed heterotrophic plate counts (HPCs) at 36°C and 22°C, nonfastidious gram-negative bacteria (GNB-NE), and Legionella pneumophila.

Results. The percentages of positivity and mean values of HPCs at 22°C, HPCs at 36°C, and GNB-NE loads were significantly higher at outlet points than in the plumbing system. In particular, GNB-NE positivity was higher at outlet points than in the plumbing system in both the cold water (31.58% vs 6.58% of samples were positive) and hot water (21.05% vs 3.95%) supplies. Our results also revealed contamination by L. pneumophila both in the plumbing system and at outlet points, with percentages of positive samples varying according to the serogroup examined (serogroups 1 and 2–14). The mean concentrations displayed statistically significant (P < .001) differences between the outlet points (27,382.89 ± 42,245.33 colony-forming units [cfu]/L) and the plumbing system (19,461.84 ± 29,982.11 cfu/L).

Conclusions. These results reveal a high level of contamination of aerators by various species of gram-negative opportunists that are potentially very dangerous for immunocompromised patients and, therefore, the need to improve the management of these devices.

Chronic Kidney Disease and Ionicity?

This hypothesis seems to be a stretch too far.

Dharma-Wardana MW, Amarasiri SL, Dharmawardene N, Panabokke CR. Chronic kidney disease of unknown aetiology and ground-water ionicity: study based on Sri Lanka. Environmental Geochemistry And Health, 2014 Aug 14.

High incidence of chronic kidney disease of unknown aetiology (CKDU) in Sri Lanka is shown to correlate with the presence of irrigation works and rivers that bring-in ‘nonpoint source’ fertilizer runoff from intensely agricultural regions. We review previous attempts to link CKDU with As, Cd and other standard toxins. Those studies (e.g. the WHO-sponsored study), while providing a wealth of data, are inconclusive in regard to aetiology. Here, we present new proposals based on increased ionicity of drinking water due to fertilizer runoff into the river system, redox processes in the soil and features of ‘tank’-cascades and aquifers. The consequent chronic exposure to high ionicity in drinking water is proposed to debilitate the kidney via a Hofmeister-type (i.e. protein-denaturing) mechanism.

Determining Nutrient Standards in Yungui Plateau and Eastern Plain, China

Danfeng Ji, Beidou Xi, Jing Su, Shouliang Huo, Ji Wang, Fangfang Gong, Mingxiao Li, Xuan Jia, Daichun Wei. Structure equation model-based approach for determining lake nutrient standards in Yungui Plateau ecoregion and Eastern Plain ecoregion lakes, China. Environmental Earth Sciences; Oct2014, Vol. 72 Issue 8, 3067-3077

Predictive nutrient criteria method, combined with expert elicitation and structural equation model (SEM), was proposed in this study for establishing lake nutrient standard in Chinese lakes (Yungui Plateau ecoregion and Eastern Plain ecoregion). Expert elicitation was involved to quantify the probability of attainment of the designated-use (drinking water source) based on monitoring data. The experts scoring results were introduced to SEM to assess predictive relationships between candidate standard variables and the designated-use attainment. In Yungui ecoregion, the standardized effects of chlorophyll- a (Chl- a), chemical oxygen demand and total phosphorus (TP) on designated-use attainment were −0.41, −0.14, and −0.43, respectively. These result demonstrated that the two most predictive indicators for designated-use attainment were TP and Chl- a. In Eastern ecoregion, the standardized effects of TP, total nitrogen (TN), dissolved oxygen and water temperature ( T) on designated-use attainment were 0.77, −0.12, 0.13 and −0.02, respectively. The most predictive indicator was TP. The model was further used for estimating the designated-use attainment associated with various levels of candidate standards. TP, TN, Chl- a and Secchi depth (SD) were selected as standard indicators in Yungui ecoregion. TP, TN, and Chl- a were selected in Eastern ecoregion. In order to achieve the 85 % designated-use attainment, standard values of TP, TN, Chl- a and SD in Yungui ecoregion would be 0.02 mg/L, 0.2 mg/L, 1.4 μg/L, and 0.581 m; and standards of TP, TN, and Chl- a in Eastern ecoregion would be 0.039 mg/L, 0.95 mg/L, and 1.75 μg/L, respectively. Finally, the differences between standards in these two ecoregions were also analyzed.