Monthly Archives: November 2011

Aisopou et al 2011: In-pipe water quality monitoring in water supply systems under steady and unsteady state flow conditions: A quantitative assessment.

A. Aisopou, I. Stoianov, and N.J. Graham. In-pipe water quality monitoring in water supply systems under steady and unsteady state flow conditions: A quantitative assessment. Water Research 2011 Nov 6.

Monitoring the quality of drinking water from the treatment plant to the consumers tap is critical to ensure compliance with national standards and/or WHO guideline levels. There are a number of processes and factors affecting the water quality during transmission and distribution which are little understood. A significant obstacle for gaining a detailed knowledge of various physical and chemical processes and the effect of the hydraulic conditions on the water quality deterioration within water supply systems is the lack of reliable and low-cost (both capital and O & M) water quality sensors for continuous monitoring. This paper has two objectives. The first one is to present a detailed evaluation of the performance of a novel in-pipe multi-parameter sensor probe for reagent- and membrane-free continuous water quality monitoring in water supply systems. The second objective is to describe the results from experimental research which was conducted to acquire continuous water quality and high-frequency hydraulic data for the quantitative assessment of the water quality changes occurring under steady and unsteady-state flow conditions. The laboratory and field evaluation of the multi-parameter sensor probe showed that the sensors have a rapid dynamic response, average repeatability and unreliable accuracy. The uncertainties in the sensor data present significant challenges for the analysis and interpretation of the acquired data and their use for water quality modelling, decision support and control in operational systems. Notwithstanding these uncertainties, the unique data sets acquired from transmission and distribution systems demonstrated the deleterious effect of unsteady state flow conditions on various water quality parameters. These studies demonstrate: (i) the significant impact of the unsteady-state hydraulic conditions on the disinfectant residual, turbidity and colour caused by the re-suspension of sediments, scouring of biofilms and tubercles from the pipe and increased mixing, and the need for further experimental research to investigate these interactions; (ii) important advances in sensor technologies which provide unique opportunities to study both the dynamic hydraulic conditions and water quality changes in operational systems. The research in these two areas is critical to better understand and manage the water quality deterioration in ageing water transmission and distribution systems.

Click here to obtain the full paper (fee).

Will USEPA place a moratorium on hydraulic fracturing?

USEPA claims they have authority under the Safe Drinking Water Act (SDWA) to make sure hydraulic fracturing operations do not pollute drinking waters when diesel fuels are used in the processes.

The agency plans to issue guidelines to states for issuing permits for use of hydraulic fracturing involving diesel.  Although such guidelines are not technically regulations, a state could set its own regulations….

USEPA says not to worry, no moratorium will be placed on hydraulic fracturing….but time will tell…..as guidelines are often morphed into future regulations….

Click here for a recent article.

Moonshine still found in Massachusetts Water Plant

Click here for a most unusual hobby at a water plant.  Perhaps this operator (or former operator) was just trying to sell moonshine to raise money for state infrastructure spending.    (Did the special committee think of this?)

Portland, Oregon seeks variance for Bull Run Watershed

The State of Oregon intends to issue a grant to the City of Portland from the requirement to treat the Bull Run Watershed source for Cryptosporidium.

A public hearing is scheduled for December 14 from 5 to 7 pm in the Portland State Office Building, 800 N.E. Oregon Street, Room 1B.

Written comments may be submitted until 5 pm January 3, 2012.  Submit written comments to:

Oregon Health Authority-Public Health Division, Office of Environmental Public Health, Drinking Water Program, 800 N.E. Oregon St., Suite 640, Portland, OR 97232.

Click here for a copy of the Notice of Intent and information on submitting written comments.

After reviewing the comments a final order will be issued effective Jan. 31, 2012.

Chevrier et al 2011: Urinary Biomarkers of Prenatal Atrazine Exposure and Adverse Birth Outcomes in the PELAGIE Birth Cohort

C. Chevrier, G. Limon, C. Monfort, F. Rouget, R. Garlantézec, C. Petit, G. Durand, S. Cordier. Urinary Biomarkers of Prenatal Atrazine Exposure and Adverse Birth Outcomes in the PELAGIE Birth Cohort. Environmental Health Perspectives, 119(7):1034-1041.

Background: Despite evidence of atrazine toxicity in developing organisms from experimental studies, few studies—and fewer epidemiologic investigations—have examined the potential effects of prenatal exposure.

Objectives: We assessed the association between adverse birth outcomes and urinary biomarkers of prenatal atrazine exposure, while taking into account exposures to other herbicides used on corn crops (simazine, alachlor, metolachlor, and acetochlor).

Methods: This study used a case-cohort design nested in a prospective birth cohort conducted in the Brittany region of France from 2002 through 2006. We collected maternal urine samples to examine pesticide exposure biomarkers before the 19th week of gestation.

Results: We found quantifiable levels of atrazine or atrazine mercapturate in urine samples from 5.5% of 579 pregnant women, and dealkylated and identified hydroxylated triazine metabolites in 20% and 40% of samples, respectively. The presence versus absence of quantifiable levels of atrazine or a specific atrazine metabolite was associated with fetal growth restriction [odds ratio (OR) = 1.5; 95% confidence interval (CI), 1.0–2.2] and small head circumference for sex and gestational age (OR = 1.7; 95% CI, 1.0–2.7). Associations with major congenital anomalies were not evident with atrazine or its specific metabolites. Head circumference was inversely associated with the presence of quantifiable urinary metolachlor.

Conclusions: This study is the first to assess associations of birth outcomes with multiple urinary biomarkers of exposure to triazine and chloroacetanilide herbicides. Evidence of associations with adverse birth outcomes raises particular concerns for countries where atrazine is still in use.

Click here for the full paper (free).

 

Cragin et al 2011: Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water

This study, despite the typical limitations, has received some press (click here).

L.A. Cragin, J.S. Kesner, A.M. Bachand, D.B. Barr, J.W. Meadows, E.F. Krieg, and J.S. Reif Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water. Environmental Research 2011 Nov;111(8):1293-301.

Abstract: Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated “dose” of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine “dose” from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles.

Click here for full paper (fee).

 

Valerio et al 2010: Diversity and impact of prokaryotic toxins on aquatic environments: a review

E. Valerio, S. Chaves, and R. Tenreiro. Diversity and impact of prokaryotic toxins on aquatic environments: a review. Toxins (Basel) 2010 Oct;2(10):2359-410.

Centro de Recursos Microbiológicos (CREM), Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal; Email: evalerio@fct.unl.pt.

Abstract: Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some of the most common toxins present in water are produced by several cyanobacterial species. As a result, their blooms create major threats to animal and human health, tourism, recreation and aquaculture. Quite a few cyanobacterial toxins have been described, including hepatotoxins, neurotoxins, cytotoxins and dermatotoxins. These toxins are secondary metabolites, presenting a vast diversity of structures and variants. Most of cyanobacterial secondary metabolites are peptides or have peptidic substructures and are assumed to be synthesized by non-ribosomal peptide synthesis (NRPS), involving peptide synthetases, or NRPS/PKS, involving peptide synthetases and polyketide synthases hybrid pathways. Besides cyanobacteria, other bacteria associated with aquatic environments are recognized as significant toxin producers, representing important issues in food safety, public health, and human and animal well being. Vibrio species are one of the most representative groups of aquatic toxin producers, commonly associated with seafood-born infections. Some enterotoxins and hemolysins have been identified as fundamental for V. cholerae and V. vulnificus pathogenesis, but there is evidence for the existence of other potential toxins. Campylobacter spp. and Escherichia coli are also water contaminants and are able to produce important toxins after infecting their hosts. Other bacteria associated with aquatic environments are emerging as toxin producers, namely Legionella pneumophila and Aeromonas hydrophila, described as responsible for the synthesis of several exotoxins, enterotoxins and cytotoxins. Furthermore, several Clostridium species can produce potent neurotoxins. Although not considered aquatic microorganisms, they are ubiquitous in the environment and can easily contaminate drinking and irrigation water. Clostridium members are also spore-forming bacteria and can persist in hostile environmental conditions for long periods of time, contributing to their hazard grade. Similarly, Pseudomonas species are widespread in the environment. Since P. aeruginosa is an emergent opportunistic pathogen, its toxins may represent new hazards for humans and animals. This review presents an overview of the diversity of toxins produced by prokaryotic microorganisms associated with aquatic habitats and their impact on environment, life and health of humans and other animals. Moreover, important issues like the availability of these toxins in the environment, contamination sources and pathways, genes involved in their biosynthesis and molecular mechanisms of some representative toxins are also discussed.

Click here for the full paper (free).