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Big Berkey Water Filters

  • Devastating Ocean Dead Zone in the Gulf of Mexico Likely to be Around for a While

    Improving the water quality in the Gulf of Mexico is likely to take decades, a new study released by scientists from the University of Waterloo has revealed. And, just recently a state of emergency was declared in Florida as the algae bloom is having a large impact on the state.  As the Washington Post reports:

    "The red tide has made breathing difficult for locals, scared away tourists, and strewn popular beaches with the stinking carcasses of fish, eels, porpoises, turtles, manatees and one 26-foot whale shark."

    The results of the study, which was recently published in Science, indicate that policy goals set for decreasing the size of the dead zone in the northern Gulf of Mexico are probably unrealistic without major shifts in agricultural management practices as well as improvements to how freshwater systems are managed.

    Large concentrations of nitrogen transported from streams and rivers across the US corn belt into the ocean is believed to have fueled algal blooms in the northern Gulf of Mexico, which strip oxygen from the water as they die off, resulting in an extensive hypoxic 'dead zone' where marine life struggle to survive due to the very low oxygen levels.

    800px-Sediment_in_the_Gulf_of_Mexico_(2) Rivers throughout the region ran high, likely carrying more sediment than usual into the Gulf. The rivers also carry nutrients like iron from soil and nitrogen from fertilizers. These nutrients fuel the growth of phytoplankton, tiny, plant-like organisms that grow in the ocean surface waters. Phytoplankton blooms colour the ocean blue and green and may be contributing to the colour seen here.

    According to Kimberley Van Meter, a postdoctoral fellow in the Department of Earth and Environmental Sciences at Waterloo and lead author of the study:

    "Despite the investment of large amounts of money in recent years to improve water quality, the area of last year's dead zone was more than 22,000 km2--about the size of the state of New Jersey."

    After analyzing agricultural data spanning more than two centuries, the researchers found that nitrogen has accumulated in the soil and groundwater over the years due to intensive agricultural practices, and as a result of this reservoir, the rate of nitrogen flow to the coast is not likely to abate anytime soon, but rather will continue for decades.

    Water quality in the northern Gulf of Mexico has increasingly deteriorated since the 1950's, primarily due to the widespread application of commercial fertilizers to crops as well as intensive livestock farming across the Mississippi River Basin. Commercial fertilizers and manure both contain high levels of nitrogen — a plant nutrient that is used to boost crop production. However, when nitrogen is present in high concentrations it can pose both an environmental and human health risk.

    When farmers do take measures to reduce their nitrogen input it takes a long time before this has any beneficial affect on water quality.

    "We are seeing long time lags between the adoption of conservation measures by farmers and any measurable improvements in water quality," said Prof. Nandita Basu, an associate professor in the departments of Earth and Environmental Sciences and Civil and Environmental Engineering at Waterloo, and co-author of the study.

    After modeling several scenarios, the study shows that even with best-case scenarios, where conservation measures are implemented with immediate effect, it is likely to take around 30 years for the excess nitrogen that has accumulated within agricultural soils and underground water reservoirs to be depleted.

    According to Basu, this problem is not limited to the Mississippi River Basin. As the global population grows, and with it the need for intensive agricultural practices to be able to produce enough food to meet the increased food demands, nitrogen is accumulating in soils and groundwater across the world, threatening coastal ecosystems the world over.

    The scientists are currently expanding their analysis to include phosphorus, another plant nutrient that is a major contributor to algal blooms in inland freshwater systems such as the Great Lakes.

    Journal Reference:

    K. J. Van Meter, P. Van Cappellen, N. B. Basu. Legacy nitrogen may prevent achievement of water quality goals in the Gulf of Mexico. Science, 2018; eaar4462 DOI: 10.1126/science.aar4462

  • Breaking it Down: What are the Chemical Byproducts of the Water Treatment Process?

    Synthetic chemicals are found everywhere in our modern everyday life. They are in the clothing we wear, as well as in cosmetics, personal care products and medications that we use everyday. But we tend to give little thought to what happens to these chemicals when we flush them away, assuming they are harmless once they disappear down the sink.

    The reality is that most wastewater treatment facilities do not have the capacity to remove synthetic organic chemicals such as those used in personal care products, pharmaceuticals and opioids. So, what happens to them?

    Because wastewater treatment plants are not capable of removing these chemicals, trace amounts remain in the effluent that wastewater treatment facilities discharge into streams, rivers and lakes. Although these concentrations are extremely minute, mere nanograms or micrograms, very little is known about how the risk they pose to the environment or to human health.

    Credit: Sarah Bird/Michigan Tech Credit: Sarah Bird/Michigan Tech

    What is more worrying, is that even less is known about the environmental and human health risk posed by chemical byproducts formed during the water treatment process, where thousands of potentially harmful byproducts can be formed in just a few minutes.

    A new study, which was recently published in the American Chemical Society's journal Environmental Science and Technology, has sought to shed more light on the mechanisms that enable the formation of chemical byproducts during the wastewater treatment process looking at acetone as a case study to determine the chemical byproducts that are created as acetone breaks down during advanced oxidation wastewater treatment process.

    Chemically speaking, acetone has rather a simple structure, which makes it the ideal candidate for modeling chemical reaction pathways — the various ways a chemical can break down into free-radicals and chemical byproducts — in order to predict what byproducts and free-radicals can form.

    "When we do water treatment using advanced chemical oxidation, those oxidants destroy target organic compounds but create byproducts," explains Daisuke Minakata, assistant professor of civil and environmental engineering at Michigan Technological University and lead author of the study. "Some byproducts may be more toxic than their parent compound. We need to understand the fundamental mechanisms of how the byproducts are produced and then we can predict what to be produced from many other chemicals. We found more than 200 reactions involved in acetone degradations based on computational work."

    The researchers then compared the results predicted by their model to ten byproducts observed in an earlier experimental study, and found that the modeled results were similar to those observed in the experimental study.

    Advanced oxidation is an important water treatment method that is effective at removing contaminants. However, many communities, particularly those living in arid regions, are facing water scarcity and are forced to recycle treated wastewater for reuse. Should synthetic organic chemicals together with the byproducts that form during the oxidation process remain in the water, animals and people who consume that water will also consume the chemicals present in the water.

    In other areas, wastewater from communities living upstream is discharged into rivers and lakes. Communities living further downstream may depend on that water as a source of drinking water. As conventional water treatment processes are incapable of effectively removing all the organic chemicals, these consumers are exposed to the chemicals that remain in the water.

    According to the authors: "Advanced oxidation can effectively target specific organic chemicals to remove them from water. Modeling reaction pathways is critical to help water treatment managers understand how best to wield the knife, as it were."

    For the study, the team calculated the chemical reaction pathways using Michigan Tech's Superior supercomputer, however the model is limited to organic contaminants that have a simple structure like acetone. Organic chemicals tend to have much more complex structures, making their reaction pathways nigh impossible for even a supercomputer like Superior to compute.

    According to the authors: "Understanding the mechanisms of chemical byproduct formation isn't just important for water treatment; it's also advancing what we know about chemical reactions in the atmosphere and inside our bodies."

    Journal Reference:

    Divya Kamath, Stephen P. Mezyk, Daisuke Minakata. Elucidating the Elementary Reaction Pathways and Kinetics of Hydroxyl Radical-Induced Acetone Degradation in Aqueous Phase Advanced Oxidation Processes. Environmental Science & Technology, 2018; DOI: 10.1021/acs.est.8b00582

  • Pesticides Feminizing Male Frogs, Impairing Reproduction

    A new study conducted by a team of Swedish and British scientists has revealed that linuron, an endocrine-disrupting chemical used in pesticides, impairs the fertility of male frogs and causes tadpoles to develop ovaries rather than testicles, resulting in a skewed sex ratio where females frogs are more common than males.

    Biodiversity is decreasing at an alarming rate globally, with amphibians being one of the most rapidly disappearing groups of animals. Current estimates suggest that nearly 40% of all documented amphibian species are threatened, largely due to habitat degradation and habitat loss, but other contributing factors include climate change, pollution and disease.

    Many different pesticides are used in agriculture to control weeds and insect pests. These chemicals can leach through soils into groundwater or get washed off the surface of the soil with runoff, to contaminate ponds and other surface waterbodies where frogs congregate to breed. Some pesticides contain endocrine-disrupting chemicals which can disrupt hormone functioning of animals who are exposed to them.


    For the study, which focused on the endocrine disrupting affects of linuron on the West African clawed frog, the researchers exposed tadpoles to concentrations of the chemical similar to what they measured in ponds where the tadpoles naturally occurred. They found that when tadpoles where exposed to linuron they were more likely to develop ovaries than testicles. The scientists also found that the sex ratio became skewed, with a higher percentage of females in the population compared to males.

    The researchers also found that once the tadpoles became adult frogs, fertility in males became impaired and some gender-specific features became more like that of female frogs. The researchers suggest a likely explanation for their observations is that chemicals used in pesticides inhibit the functioning of the male hormone testosterone, causing frogs to effectively become feminized.

    The study was conducted in the Department of Environmental Toxicology at Uppsala University, whose laboratory specializes in testing the chemical affects on frogs throughout their lifecycle. By testing the affects of the pesticide on the West African clawed frog, the scientists have developed a system that can be used to test the affect of endocrine disrupting chemicals on other amphibians as well as other animal species. The results of this study highlight the importance of looking at the impacts throughout an animal's lifecycle to determine the affect of pesticide chemicals and other contaminants on the reproductive capacity of amphibians.

    According to ecotoxicologist, Cecilia Berg, who lead the study, Sweden has not approved the use of the chemical linuron, however it is used in other countries in Europe, as well as in North America.

    "The results of the study are important, since they contribute knowledge that risk assessment authorities in the EU can use as a basis for assessing the health and environmental risks of pesticides. The European Commission is currently taking several measures to improve pesticide risk assessment. A new report from the European Food Safety Authority (EFSA), for instance, points to the need to assess the risks of pesticide use to amphibians - something that isn't being done today," Berg says.

    Considering that the pesticide is also used in the North America, the potential environmental health risks apply in the US too.  We recommend that the public use a water filter such as a berkey to remove potentially health damaging pesticides from their water to remove any potential disclosure.

    Journal Reference

    F. Orton, M. Säfholm, E. Jansson, Y. Carlsson, A. Eriksson, J. Fick, T. Uren Webster, T. McMillan, M. Leishman, B. Verbruggen, T. Economou, C. R. Tyler, C. Berg. Exposure to an anti-androgenic herbicide negatively impacts reproductive physiology and fertility in Xenopus tropicalis. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-27161-2

  • Desire to Live Longer Drives Bottled Water Market

    While many people who buy bottled water realize that it may not be healthy for them or the environment, they do so because of their fear of dying, a new study has revealed.

    According to the study, which was recently published in the Journal Applied Environmental Education & Communication, bottled water marketing campaigns target our deepest psychological vulnerability, triggering our subconscious fear of dying, which drives consumers to purchase billions of liters of bottled water every year.


    "Bottled water advertisements play on our greatest fears in two important ways," says Stephanie Cote, who conducted the research while a graduate student at Waterloo. "Our mortality fears make us want to avoid risks and, for many people, bottled water seems safer somehow, purer or controlled. There is also a deeper subconscious force at work here, one that caters to our desire for immortality."

    According to a Euromonitor report, in 2013 Canadians alone purchased nearly two and a half billion liters of bottled water. Despite rigorous and ongoing campaigns aimed at curbing bottled water consumption, this figure is expected to increase to three billion liters for 2018, equating to a monetary value of $3.3 billion Canadian dollars.

    In the US, the figure is far higher. In 2016, Americans consumed 12.8 billion gallons of bottled water. The global consumption of bottled water is staggering. In 2012, 288 billion liters of bottled water were consumed across the world, and this was projected to increase to 391 billion liters by 2017. Bottled water advertising campaigns are clearly very effective.

    For the study, the researchers applied Terror Management Theory (TMT), a concept commonly used in social psychology, which argues that in an effort to repress both our conscious and subconscious fear of dying we develop defenses that can influence certain behaviors, including our consumption choices, financial security and status.


    The team analyzed the content used in bottled water advertising campaigns, including web content, images and video content that imparted explicit and implicit meanings, while at the same time assessing the effectiveness of anti-bottled water drives. They found that anti-bottled water campaigns struggled to compete with advertising messaging put out by big corporates.

    "Our results demonstrate that corporate campaigns appeal to people who measure their personal value by their physical appearance, fitness levels, material and financial wealth, class, and status," said Sarah Wolfe, a researcher in Waterloo's Faculty of Environment, and co-author of the paper. "Pro-bottle water advertisements rely heavily on branding, celebrity, and feel-good emotions that trigger our group identities and patriotism."

    In order for anti-bottled water drives to be more effective, there clearly needs to be a change tactics with messaging that extends beyond the economical, environmental and ethical benefits of drinking tap water. Consumers need to receive a clear message that it is not only healthier and way more cool to drink filtered tap water than bottled water, people who do so are likely to live longer.

    It has been shown that in most cases bottled water is no purer than tap water. Furthermore, plastic water bottles can leach out contaminants such as BPA, as well as release microplastic fibers into the water. The reality is that anyone wanting to live a long, healthy life should be drinking filtered municipal water using a system like the berkey water filter rather than bottled water, and should not be swayed by big corporations with even bigger advertising budgets.

    Journal Reference

    Stephanie Cote, S. E. Wolfe. Evidence of mortality salience and psychological defenses in bottled water campaigns. Applied Environmental Education & Communication, 2017; 1 DOI: 10.1080/1533015X.2017.1399836

  • Wastewater from Oil and Gas Operations not Ideal for Suppressing Dust on Roads

    Thirteen US states allow wastewater from oil and gas operations to be applied to roads as a dust suppressant or deicing mechanism. However, a study that was recently published in Environmental Science & Technology suggests that using oil and gas wastewater as a dust suppressant is far from ideal and that there is a need for a safer, non-toxic yet affordable alternative.

    The researchers assessed state regulations pertaining to the use of wastewater for deicing and dust suppression and found that thirteen states permitted its use for this purpose, while four others could allow it to be spread on road surfaces under regulations related to land spreading.


    The oil and gas wastewater used for deicing and dust suppression on roads originates from conventional vertically drilled oil and gas wells as apposed to fracking fluids used in the hydraulic fracturing oil extraction process.

    "Oil and gas wastewaters are known to have high salt, organic and radioactivity concentrations," said lead author, Travis Tasker, a graduate student in environmental engineering at Penn State. "When we found out that this wastewater was being spread on roads, we wanted to evaluate its potential to cause biological toxicity and accumulate in road material or migrate into water resources."

    Oil and gas wastewater is loaded with salt, containing high levels of sodium, magnesium, calcium and strontium, which make it effective at suppressing dust and deicing roads. It also contains other toxic contaminants — such as radium, a known carcinogen — that can be harmful to the environment and/or human health, especially in large concentrations.

    "We would like to do experiments to test how effective the wastewaters are at suppressing dust in comparison to other commercial products," said Nathaniel Warner, assistant professor of environmental engineering, Penn State. "If the salts in the wastewaters are just as effective, then new regulations or additional treatment prior to spreading could help reduce the concentration of other contaminants of concern that exist in wastewaters, but not in commercial products."

    The research team sampled wastewater spread on roads in towns in Pennsylvania and then did laboratory simulations to determine where the pollutants in the wastewater would end up. The lab experiments showed that while rain washed salts off the road surface, some heavy metals such as lead did not wash away but rather remained behind, And in the case of radium, some of it is washed away during rain events, but some remained on the road surface.

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    Radium, heavy metals and organic materials are all contaminants that could potentially pollute surface water and groundwater systems, and ultimately drinking water supplies. Salt is also a drinking water contaminant when it occurs at high concentrations.

    Yet while conventional methods used to treat wastewater can remove a number of these contaminants, it cannot reduce the level of salt. The researchers recommend that if wastewater is used as a deicing or dust suppressing agent on roadways it should at least be treated to remove radium and organic materials before it is applied to road surfaces. However, they would prefer to see alternative cost-effective alternatives being developed to replace wastewater use on roads, as the alternatives currently available are too costly for many municipalities to afford, meaning they either have to use oil and gas wastewater to treat roads or not treat the roads at all.

    Journal Reference

    T. L. Tasker, W. D. Burgos, P. Piotrowski, L. Castillo-Meza, T. A. Blewett, K. B. Ganow, A. Stallworth, P. L. M. Delompré, G. G. Goss, L. B. Fowler, J. P. Vanden Heuvel, F. Dorman, N. R. Warner. Environmental and Human Health Impacts of Spreading Oil and Gas Wastewater on Roads. Environmental Science & Technology, 2018; DOI: 10.1021/acs.est.8b00716

  • Cheaper to Remove Rather than Repair Dams, Study Finds

    A study that was recently conducted by researchers from Portland State University has found that removing aging dams across the country instead of repairing them could save billions of dollars, but cautions that more research is needed surrounding the factors that are driving efforts to remove dams across the country.

    The study, which was recently published online in the scientific journal River Research and Applications, assessed currently available nation-wide data on dams and compared characteristics and trends of dams which have been demolished to those which have been left standing.

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    If the current trend in dam demolition continues, the researchers estimate that anywhere between 4,000 - 36,000 dams will have been demolished by 2050.

    According to the study, the maximum cost of demolishing 36,000 dams is estimated to be around US$25.1 billion, which is significantly cheaper than the estimated cost of repairing these dams.

    According to estimates proposed by The American Society of Civil Engineers, it will cost more than US$45 billion to upgrade and repair around 2,170 dams considered high-risk to life and property should they fail. However, the cost of rehabilitating all the derelict dams in the US to bring them up to a condition deemed safe is higher still, estimated to be around US$64 billion.

    "I think it's time for a re-invigorated public process around managing the risks dams and aging dam infrastructure pose to public safety throughout the U.S.," said Zbigniew Grabowski, a Ph.D. candidate in PSU College of Liberal Arts and Science's Earth, Environment & Society program and lead author author of the study. "It's difficult to assess the actual public safety hazards and the most cost-effective ways of mitigating those hazards because the data on dams and dam removals has not been systematically compiled in a way that allows for robust analysis by government agencies or independent researchers."

    The researchers found that a disproportionately higher number of hydropower and water-supply dams were removed, suggesting more discussion is needed over the factors that drive dam removal.


    According to Grabowski, the decision to remove or rehabilitate a dam often hinges on cost-benefit tradeoffs between the environmental, social and economic impact of the dam in question. But, he says that we should also focus on public safety when making these decisions, as from a safety perspective it simply may not make sense to repair many of these dams.

    The study suggests several recommendations to improve the decision-making process, including:

    1.  Data collection methods used to track records of dams that are rehabilitated or removed need to be standardized and made available to the public to allow researchers to undertake more effective comparative research and for decision-makers at local, state and national levels to be able to make more informed management decisions.

    2.  Researchers and officials responsible for dam policy need to look at the broader picture when making decisions regarding the future of dams by taking a multi-disciplinary approach that draws knowledge from disciplines such as ecological restoration, dam safety engineering, technology and social science, while also considering communities that are affected by the presence or removal of dams.

    Journal Reference

    1. Zbigniew J. Grabowski, Heejun Chang, Elise L. Granek. Fracturing dams, fractured data: Empirical trends and characteristics of existing and removed dams in the United States. River Research and Applications, 2018; DOI: 10.1002/rra.3283

  • Road Salt Found in Drinking Water Wells at Adirondack Park

    A study conducted by the Adirondack Watershed Institute at Paul Smith's College has found salt in 63 drinking wells located downslope of roads and highways where road salt is routinely applied. More than 50% of the wells sampled were polluted with salt at levels deemed to pose a health risk (> 20 parts per million — the EPA safety standard for sodium in drinking water), with the concentrations as high as 748 parts per million detected in drink recorded.

    "The actual number of wells that are contaminated is way, way more than what we sampled," said Dan Kelting, institute executive director. "So it is a much bigger issue."

    Excessive intake of sodium is associated with serious health issues, including an increase in blood pressure, which in turn poses an increased risk of suffering from heart disease and heart failure, stroke and other vascular diseases, as well as kidney problems.

    Funding for the study was provided by AdkAction, a non-profit organization representing the residents of Adirondack Park, and the Fund for Lake George.

    Drinking water samples were collected from 358 wells located within the Adirondack Park by volunteers and tested for salt. Most of the samples came from the eastern region of the park, particularly areas surrounding North Creek and the Saranac Lakes.

    Of the 112 samples collected from wells located downslope that received runoff from roads where very little to no salt was applied, only 10% had elevated levels of sodium.

    Of the 132 drinking water wells located upslope of roads treated with salt and which therefore received no runoff from roadways, salt levels were below the EPA recommended level of 20 ppm, with the maximum level being 17 ppm and the median just 3 ppm.

    Nearly 193,000 tons of road salt is applied to roadways in the Adirondacks every year in an effort to prevent vehicles from skidding on the slippery iced road surfaces in winter. According to Kelting, nearly seven million tons of salt has been spread on local roads since 1980, ultimately being washed off these surfaces with runoff into waterways and drinking water wells.

    Most of this road salt — around 110,000 tons per year — is spread over state roadways, which make up about a quarter of the roads in the Adirondacks. These tarred roads have higher speed restrictions than local sand or plowed roads, where speed limits are lower.

    Kelting says the results of the study have been forwarded to state officials, and the Health Department has offered and begun free testing of drinking water wells to homeowners who are affected by the runoff.

    Besides posing a health risk to humans, salt can also have a negative ecological impact in freshwater ecosystems. Because salty water is denser than normal freshwater it tends to sink when it flows into a lake. This prevents water in lakes from mixing once ice melts in spring, which in turn can affect oxygen and nutrient levels in lakes, with dire consequences for aquatic life such as fish.

  • Buyer Beware: Not all Water Filters are Created Equal for Microcystin Removal

    Water filters that are designed to remove harmful contaminants from drinking water are not necessarily all created equal, a new study has revealed.

    Researchers from The Ohio State University assessed the ability of three popular water filter pitchers to remove microcystins from drinking water. Microcystins are toxins which accumulate in water during harmful algal blooms and pose both an environmental and public health risk. The ability to remove these toxins varied depending on the type of water filter, and while one excelled, two allowed the harmful toxins to pass through the filter to effectively pose a health risk to whoever consumed the drinking water.

    (Side note: For information on how the Berkey water filter performs removing this algae, please see Berkey's official statement on Algae Bloom and Microcystin Removal.)

    Toxic microcystin bacteria float, along with a dead fish, on the surface of this lake. Toxic microcystin bacteria float, along with a dead fish, on the surface of this lake.

    The study, which was recently published in Water Science Technology: Water Supply, found that the first water purifier, which consisted primarily of coconut-based active carbon, filtered the water the fastest but only removed a maximum of 50% of the microcycstin toxins from the water as it passed through the filter. However, the purifier with the slowest action, whose filter was constructed out of a blend of activated carbon, removed the microcystins to undetectable levels.

    "Because drinking-water treatment plants also use activated carbon, I figured that these home filters might also remove some microcystins, but I wasn't expecting results this good and such big differences among the pitchers," said Justin Chaffin, the study's lead author and a senior researcher and research coordinator at Ohio State's Stone Laboratory, a research hub located at Lake Erie serving scientists researching issues that affect the Great Lakes.

    The Danger of Microcystins

    Harmful cynobacterial blooms pose a health risk to consumers who drink water contaminated with the toxins. Microcystins are one of the most commonly found toxins that occur following harmful algal blooms, and pose a substantial risk to wildlife, pets and humans. Exposure to these toxins can result in anything from a mild rash on the skin to more serious health issues or even death due to kidney or liver damage.

    In 2014, microcystin contamination of the drinking water supply to Toledo, Ohio, left over 400,000 residents without water for days on end.

    "Since then, many residents drink bottled water and others rely on these filtration pitchers as backup, in case the water treatment plants miss a return of the microcystins," even though there have been no similar threats since then, said Chaffin. "At public events, residents kept asking me 'Does my water pitcher remove microcystins?' and my answer was always, 'I don't know'".

    So, in order to get answers to these questions, Chaffin set about designing a study that would test the effectiveness of water pitchers at removing these toxins. Although no brand names are mentioned in the study, the researchers divulge that they are commonly available in retail stores and range in price from around $15 to $50. Anyone interested in learning more can analyze the study results a little closer to compare features of the filters to help make an informed decision when purchasing a water filter, Chaffin suggested, alluding to the fact that you get what you pay for.

    <!--StartFragment-->Common water pitcher filters.  Image courtesy of <a href="" rel="nofollow"></a><!--EndFragment--></p>

    Common water pitcher filters. Image courtesy of

    "In general, the cheaper the pitcher, the worse job it did filtering out the toxins," Chaffin said.

    Pitcher Testing Results - Removal of Microcystin

    Using contaminated water collected from Lake Erie, the researchers diluted microcystins to various concentration levels before running the samples through the three common water purifying pitchers. They found that the purifier with filter media consisting of a blend of different activated carbon types, and which filtered the water the slowest, consistently proved more effective at removing the toxins from the water.

    The water purifiers work on the principle that contaminants bind to the activated carbon as the water passes through the filter. The researchers found that when microcystin concentrations were 3.3 micrograms per liter — equivalent to the microcystin levels reported during the do-not-drink advisory at Toledo in 2014 — microcystin levels were reduced by all water pitchers, but were only undetectable in the purifier that took the longest to filter the water.

    "Contact time really seems to matter. If you run the water through really fast, the microcystins and other organic molecules don't have time to bind to the carbon molecule and stick to the filter," Chaffin explained.

    Filter time varied between pitchers, with the most effective at removing the toxins taking over six minutes to filter a liter of water, the second best taking nearly four minutes to filter a liter of water, while the least effective purifier took just under two minutes to filter a liter. The purifier that was least effective had a filter constructed entirely out of cocunut-based active carbon, while the more effective purifiers filters consisted of a blend of different types of activated carbon.

    To test whether the toxins remained bound to the filters the researchers ran purified deionized water through each of the water filters, then tested the water for the presence of microcystins. They found none, suggesting that once removed, the toxins remain bound to the filter.

    However, Chaffin recommends that water filter pitchers be used as a safety net by consumers who are concerned that microcystins may pass through water treatment facilities undetected rather than to purify water when a do-not-drink advisory has been issued and bottled water is recommended.

    "But when there isn't a warning, these filters are much cheaper and better for the environment in the long run than bottled water," said Chaffin. "You aren't creating mountains of empty bottles."

    Water Pitchers Vs Berkey - Microcystin Removal

    The study found that water pitcher filters with filter media consisting of a blend of different activated carbon types, and which filtered the water the slowest, consistently proved more effective at removing the toxins from the water. This data further supports Berkeys official statement on microystin removal.

    The Black Berkey contact time is considered one of the longest, if not the longest in the filtration industry. Also, the Black Berkey filters use a combination of approx 6 different types of filter ingredients, which allow the filters to last for approx 6000 gallons per set of 2. In comparison, many of these water pitcher filters in this test need to be replaced every 100 gallons. Finally, the black berkeys match or outperform the chemical and contaminant removal rates of water pitcher filters across the board.

    Journal Reference

    Justin D. Chaffin, Erica L. Fox, Callie A. Nauman and Kristen N. Slodysko. The ability of household pitcher-style water purifiers to remove microcystins depends on filtration rate and activated carbon source. Water Science & Technology: Water Supply, (2018) In Press.

  • Beavers Dam Good at Cleaning Water

    Beavers dam building antics can help keep rivers clean and reduce the amount of valuable soil that is lost from farms with runoff, a new study has revealed.

    For the study, scientists from the University of Exeter analyzed the impact a family of captive beavers had on cleaning up a river. The beavers where confined in a 2.5 hectare enclosure on a stretch of river and used in a trial river cleanup coordinated by the Devon Wildlife Trust. The study demonstrates that the beavers significantly reduced the flow of nutrients and soil from nearby farmland into the river system. Just a single beaver family removed significant levels of nitrogen, phosphorus and sediment from water as it flowed through enclosure.


    The beaver family have been living within the fenced off site on a West Devon river since 2011, have constructed 13 dams which has stemmed the flow of water, creating several deep ponds along what used to be a shallow stream.

    The scientists measured the nitrogen, phosphorus and suspended sediment levels in the water as it flowed into the site, and again as it flowed out after passing through the beaver's dams and ponds. They then compared the before and after measurements, and also measured how much nitrogen, phosphorus and sediment was trapped by the beavers dams in each pond.

    They found that the beaver's dams had trapped more than 100 tonnes of sediment, of which 70% consisted of soil originating from intensively farmed grassland fields further upstream. They found that the trapped sediment contained high levels of nutrients (nitrogen and phosphorus) that pose both an environmental and health threat in high concentrations.

    "It is of serious concern that we observe such high rates of soil loss from agricultural land, which are well in excess of soil formation rates," said Professor Brazier. " However, we are heartened to discover that beaver dams can go a long way to mitigate this soil loss and also trap pollutants which lead to the degradation of our water bodies. Were beaver dams to be commonplace in the landscape we would no doubt see these effects delivering multiple benefits across whole ecosystems, as they do elsewhere around the world."

    A 2009 study estimated that soil loss from agricultural land in the United Kingdom equated to a financial cost of forty five million pounds, largely due to the negative impacts of nutrient and sediment pollution further downstream. Clearly beavers can play are positive role in keeping our waterways clean and healthy.

    The Devon Wildlife Trust has been running beaver trials in fenced off enclosures on local rivers for seven years, and in 2015 also began running a similar project using a wild population of beavers living on River Otter in East Devon.

    According to Peter Burgess, Director of Conservation and Development at the Devon Wildlife Trust, their partnership with the researchers from Exeter University is shedding light on the important contribution beavers can make in keeping freshwater systems healthy and sustainable for the benefit of both wildlife and humans. He finds it 'truly inspiring' to have their observations confirmed by robust scientific research.

    Journal Reference

    Alan Puttock, Hugh A. Graham, Donna Carless, Richard E. Brazier. Sediment and Nutrient Storage in a Beaver Engineered Wetland. Earth Surface Processes and Landforms, 2018; DOI: 10.1002/esp.4398

  • Current Water Treatment Methods May Pose a Health Risk

    The quality of drinking water in public distribution networks across the country has recently fallen under the spotlight following the Flint water crisis where an entire community was exposed to dangerously high levels of lead. There are concerns that Flint is not the only city with alarmingly high lead levels in its drinking water, spurring the initiation of an ongoing research project to assess the scope of the problem.

    Harmful Chemicals May be Generated in the Water Treatment Process

    Now, another study, which was recently published in the scientific journal, Proceedings of the National Academy of Sciences, identifies other harmful chemical contaminants that are of concern, including some that are actually created during the treatment process that is supposed to render water safe to drink.

    During filtration, water passes through filters, some made of layers of sand, gravel, and charcoal that help remove even smaller particles. Filtration and later chemical treatment (e.g., chlorine) played a role in reducing the number of waterborne disease outbreaks in the early 1900s. During filtration, water passes through filters, some made of layers of sand, gravel, and charcoal that help remove even smaller particles. Filtration and later chemical treatment (e.g., chlorine) played a role in reducing the number of waterborne disease outbreaks in the early 1900s.

    During the water treatment process, water treatment plants commonly use oxidization methods to remove toxic compounds from the water during the water treatment process. This oxidizes these compounds, transforming them into chemicals that are supposedly less harmful, known as 'transformation products'. While previous studies have focused on byproducts formed during conventional water treatment processes such as chlorination, we still have very little understanding of products that form when newer treatment processes, such as oxidation using hydrogen peroxide and ultraviolet light, are implemented. This is particularly relevant for the treatment of recycled wastewater.

    "Typically, we consider these transformation products to be less toxic, but our study shows that this might not always be the case," says lead author Carsten Prasse, assistant professor in the Department of Environmental Health and Engineering at the Johns Hopkins Whiting School of Engineering and the university's Bloomberg School of Public Health. "Our results highlight that this is only half of the story and that transformation products might play a very important part when we think about the quality of the treated water."

    Prasse, together with his research team, examined phenols — some of the most commonly occurring organic chemicals in drinking water due to the fact that they are found in a wide range of products, including pesticides, dyes, pharmaceuticals, personal care and hygiene products, and also in chemicals that naturally occur in water.


    The team then conducted some chemical sleuth work, replicating the water treatment process typically used by treatment plants and borrowing a method used by biochemists, to determine what compounds the phenols transformed into.

    They found that after treatment, phenols formed 2-butene-1,4-dial — a harmful compound that can damage DNA in human cells. Prasse points out that furan, a toxin found in car exhaust fumes and cigarette smoke, also converts to 2-butene-1,4-dial when absorbed by the human body, which may explain why it is so harmful to our health.

    After testing the effects of 2-butene-1,4-dial on proteins found in mouse livers, the researchers discovered that it had an effect on 37 proteins, which are responsible for a variety of biological processes, including energy metabolism, and the synthesis of proteins and steroids in the body.

    They also found that 2-butene-1,4-dial bonded with an enzyme that played a critical role in 'cell suicide', which if inhibited could result in cells proliferating unchecked, fueling cancer growth. It also interfered with compounds responsible for controlling metabolism, which could result in health issues such as diabetes and obesity. According to Prasse, the link between pesticide exposure and obesity has already been established, and studies such as this may help explain this connection.

    Prasse hopes that these methods may be expanded to assess the prevalence of other compounds besides phenols in drinking water in the future.

    Treating water to make it safe to drink is extremely challenging as contaminants originate from a wide range of sources, including agriculture, wastewater, bacteria and plants, and while its relatively easy to remove chemical contaminants, it's not always clear what compounds are being formed in the treatment process, and whether these are harmful or not.

    It is estimated that by 2050 two-thirds of the world's human population will depend on drinking water that contains agricultural runoff and/or wastewater from factories and urban areas. So effective water purification methods that are safe will become even more essential in the future.

    "The next steps are to investigate how this method can be applied to more complex samples and study other contaminants that are likely to result in the formation of similar reactive transformation products," says Prasse. "Here we looked at phenols. But we use household products that contain some 80,000 different chemicals, and many of these end up in wastewater. We need to be able to screen for multiple chemicals at once. That's the larger goal."

    Journal Reference

    Carsten Prasse, Breanna Ford, Daniel K. Nomura, David L. Sedlak. Unexpected transformation of dissolved phenols to toxic dicarbonyls by hydroxyl radicals and UV light. Proceedings of the National Academy of Sciences, 2018; 115 (10): 2311 DOI: 10.1073/pnas.1715821115

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