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  • More Efficient Farming Methods Improve River Water Quality

    The Illinois River has seen an improvement in water quality due to the reduction of a key pollutant: nitrates. A recent study conducted by researchers from the University of Illinois College of Agricultural, Consumer and Environmental Sciences has found that nitrate levels in the Illinois River between 2010-2014 were 10% less than average nitrate levels recorded between 1980 an the early 1990s.


    The US Environmental Protection Agency (EPA) ultimately is striving to reduce the levels of nitrates and phosphorus by 45% in the Mississippi River, which will in turn help reduce the extent of the 'dead zone' — a seasonally hypoxic area — that forms in the Gulf of Mexico as a result of high nitrate loads that flow from tributaries such as the Illinois River into the Mississippi River and then into the Gulf. The state of Illinois together with other states across the Mid-west have implemented strategies to reduce these nitrate loads in an effort to limit the impact on inshore coastal waters.

    "The recent reduction in nitrate load in the Illinois River is a promising sign," says the study's lead author, Greg McIsaac, a researcher at the University of Illinois, who notes that the study concluded before nitrate records for 2015 were made available. "Now that these data are available, we know that the Illinois River nitrate load from 2011 to 2015 was 15% lower than the load measured in the baseline period from 1980 to 1996. This 15% reduction is a milestone that the state hoped to achieve for all its rivers by 2025," he says.

    Besides assessing nitrate level trends in the Illinois River between 1976-2014, the researchers also tried to pin-point the causes of any changes in nitrate loads and/or concentrations. They looked at nitrate levels in treated wastewater that was discharged into the Illinois River by water treatment facilities in the Greater Chicago area between 1983-2014, as well as annual agricultural records, such as fertilizer sales, crop yields and livestock numbers to determine agricultural nitrogen residues in soil for each year — or the amount of nitrogen that is available to plants in the form of manure, fertilizer, or by biological fixation, yet not taken up by plants or harvested with the grain. A large portion of these nitrogen residues remain in soils as nitrates, which can wash into rivers through runoff or by leaching through soils into groundwater.
    According to co-author, Mark David, a biogeochemist at the University of Illinois, the highest levels of residual agricultural nitrogen were recorded in the late 1980s, after a period of extensive drought which saw poor corn yields.

    "Beginning around 1990, the residual agricultural nitrogen began to decline, most likely due to improved fertilizer management and higher corn yields. Since 1980, the amount of nitrogen fertilizer sold in the watershed remained relatively constant, but corn yields increased by about 50%," says David. "This means that more of the nitrogen fertilizer applied was taken up by the corn and harvested in the grain and less was left in the soil or washed down the river."

    After analyzing the nitrate data, the researchers determined that yearly nitrate loads correlated with the rate of river flow, as well as nitrate discharges from Chicago's wastewater treatment works and agricultural nitrogen residues. Similarly, nitrate concentrations were correlated with agricultural nitrogen residues and nitrates in Chicago wastewater discharges, however, they did not correlate with river flow rates.

    Precipitation together with the rate of river flow have a strong influence on nitrate loads in rivers, yet both tend to be considerably erratic. According to McIsaac, considering that the 5-year average river flow rate for the period 2007-2011 was the highest on record since measurements began in 1939, it is encouraging that nitrate loads have recently declined despite river flow rates being higher than normal.

    In terms of nitrate concentrations, we have seen a more consistent decline since around 1990, when high concentrations were the norm. According to McIsaac, the disparity between nitrate loads and nitrate concentrations can be attributed to the fact that nitrate load is affected by both nitrate concentrations and river flow rates — with precipitation having a strong influence over the latter. Nitrate concentrations, on the other hand, are not. Stronger flow rates enable the river to carry greater loads of nitrates, yet the nitrate concentrations do not necessarily change.

    What is the outlook for the future? According to the authors, there are a number of factors that will determine whether nitrate loads and concentrations will continue to drop in the years ahead.

    "If the annual river flows return to their 1976-2005 average values, and if nitrogen fertilizer efficiency remains high or continues to improve, there likely will be a decline in nitrate loads in the Illinois River," David explains. "On the other hand, if river flows remain high, which may be a consequence of climate change, meeting the nitrate reduction goals will likely require more conservation effort than originally proposed."

    Journal Reference

    Gregory F. McIsaac, Mark B. David, and George Z. Gertner. Illinois River

    nitrate-nitrogen concentrations and loads: Long-term variation and association with watershed nitrogen inputs. Journal of Environmental Quality. 6 May, 2016.

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  • Coal Ash Ponds Leak Long-lasting Toxic Substances

    A recent study of unlined coal ash ponds sited near twenty-one power stations across five south eastern states in the US has found that they leak toxins that consistently contaminate nearby groundwater and surface freshwater systems with long-lasting effects.

    Researchers from Duke University found high concentrations of heavy metal contaminants, including selenium and arsenic, in freshwater samples taken from all the test sites. In 29% of the water samples concentrations of toxic trace elements were above the EPA safety standards set for both ecological health and drinking water.

    "In all the investigated sites, we saw evidence of leaking," said co-author, Avner Vengosh, a professor of geochemistry and water quality in Duke University's Nicholas School of the Environment. "Some of the impacted water had high levels of contaminants.

    The results of the study, which was recently published online in Environmental Science & Technology, do not include drinking water wells; however, according to Vengosh, these will be assessed in a follow-on study.

    coal ash

    During 2015 the research team analyzed water samples taken from 39 surface water bodies together with coal ash pond seep samples from 7 different sites. In addition, they examined state records of  water quality data recorded at 156 shallow wells dug to monitor groundwater quality adjacent to coal ash ponds at 14 power plants in North Carolina.

    While shallow groundwater monitoring wells are generally only 30-50 feet deep and do not reach the same depth as most drinking water wells, which tend to be between 100-300 feet deep, according to Vengosh, these contaminants can still potentially leach to greater depths and contaminate drinking water wells.

    The study shows that this contamination is not only widespread, but also the toxins tend to persist in the environment for a very long time. Many of the study sites are no longer in use and coal ash is no longer dumped there, yet surface water bodies, and even groundwater in one case, showed evidence of contamination.

    "The degree to which leakage affects the concentration of toxins in nearby waters varies because of several factors, including the nature of the coal ash, processes in the pond and the flow through the local soil," said Jennie Harkness, a doctoral student at the Nicholas School and the lead author of the study.

    While in certain cases coal ash ponds may legally release liquid effluent into surrounding surface water systems via regulated outlets, the data from this study show that effluent is also being released in ways that are not permitted, posing a threat to both aquatic ecosystems and drinking water resources.

    The site with the highest levels of heavy metal contaminants present in shallow groundwater wells was located adjacent to a Tennessee ash disposal site that is no longer in use. Water samples showed that levels of iron, lead, zinc, cadmium, selenium and nickel exceeded safety standards set for drinking water quality and health of aquatic life. According to Vengosh, the study's findings show that even if these coal ash ponds were removed we would still be left with a legacy of groundwater contamination as a result of decades of leaking, which would require a mammoth effort to address.

    Journal Reference

    Jennifer Harkness, Barry Sulkin and Avner Vengosh.  Evidence for Coal Ash Ponds Leaking in Southeastern United States. Environmental Science and Technology, (online June 10, 2016). DOI: 10.1021/acs.est.6b017276

  • Aquatic Food Chains Threatened by Hydropower Hydropeaking

    Aquatic insect populations have declined in many rivers downstream from hydroelectric dams, threatening fish and other wildlife that depend on them for survival. Now researchers from the US Geological Survey (USGS) together with collaborators from Oregon-, Utah- and Idaho State Universities, have found that hydropeaking — a practice widely used in the management of hydroelectric dams that involves increasing river flow rates during the daytime when demand for electricity is high — is likely the cause. Their findings suggest that these negative impacts could be mitigated if alternative hydropower methods were used.

    Aquatic insects form a vital part of food webs in freshwater ecosystems and provide the primary source of food for many different species, including fish, reptiles, bats and birds, as well as other wildlife. The study, which was recently published online in the scientific journal BioScience, assessed the impact that sudden changes in water levels have on aquatic insects at all stages of their lifecycle, and provides the foundation for determining how to improve the health of rivers downstream from hydropeaking dams all over the world.

    usgs insects

    The study was partly assisted by data collected in a citizen science project where educational groups, river guides and other citizen scientists collected over 2,500 insect samples from a stretch of Colorado River downstream from the Glen Canyon Dam in the Grand Canyon. The researchers compared insect diversity of 16 large dammed river systems across the western regions of the US that have varying degrees of hydropeaking to assess how the impact of abrupt changes in water levels affected river health.

    "For the first time, this study determines the ecological impacts of hydropeaking separated from other dam-imposed stressors, and identifies the specific cause-and-effect relationships responsible for biodiversity loss below hydroelectric dams," explains lead author Ted Kennedy, a USGS scientist. "These results may help resource managers improve river health while still meeting societal needs for renewable hydroelectricity."

    Hydroelectric power provides approximately 19% of the electricity used globally, and far exceeds that produced by wind, solar or other renewable energy sources combined. Many hydroelectric dams practice hydropeaking, where the volume of water released can vary dramatically within a day, resulting in large hourly shifts in river levels that create artificially induced tides along the shoreline of rivers, which freshwater organisms simply are not adapted to cope with.

    Many insects of ecological importance, such as mayflies, stoneflies and caddisflies, attach their eggs onto a substrate such as aquatic vegetation or rocks that are submerged just beneath the surface of the water, where the eggs soon hatch. But should water levels drop rapidly, exposing the eggs to the sun and air, they can become desiccated causing the larvae to die within the egg before hatching.

    "These large daily rises and peaks in river flows due to hydropower dams are not normal. Prior to the construction of dams, there were almost no major daily changes in river levels in places like the Grand Canyon," said David Lytle, a professor at Oregon State University and co-author of the paper. "This can interrupt the egg-laying practices of some species, and the impact of this was poorly appreciated. Until now, no one really looked at this aspect, and our results show that it causes serious problems for river health."

    For decades, aquatic scientists have been puzzled by the conspicuous absence of stoneflies, mayflies and caddisflies on the Colorado River in the Grand Canyon. This study sheds light on the reason for their absence — the hydropeaking activities of Glen Canyon Dam is partly responsible. The researchers suggest some mitigation measures that dam managers may want to consider, including maintaining low, stable water levels in rivers during times when power demands are low, such as over weekends, to give insects a couple of days to successfully lay (and hatch) their eggs.

    "If mitigation flows are successful, a more diverse community of aquatic insects should improve the health of the Colorado River ecosystem in Grand Canyon, including the largest remaining population of endangered humpback chub," said Kennedy.

    With over 2,500 samples collected by citizen scientists over a 3-year period, this project highlights the important contribution that citizen science makes to research of this nature. The research team partnered with Grand Canyon Youth who provided over 150 samples, to the project — watch them in action here. Having this extensive dataset enabled scientists to reach scientific conclusions which would otherwise have not have been possible.

    "Many urgent questions in ecology remain unanswered, because scientists are bumping up against data limitations where it is impossible for them to collect sufficient data to answer complex questions across large landscapes," notes Kennedy, pointing out that this study highlights the powerful contribution citizen scientists can make to fundamentally advancing knowledge and gaining valuable new scientific insights.

    Journal Reference
    Kennedy TA et al. Flow Management for Hydropower Extirpates Aquatic Insects, Undermining River Food Webs. BioScience (2016) 66(6) doi: 10.1093/biosci/biw059

  • The Dark Side of Anti-Bacterial Soap

    Almost every home in the US uses a variety of household products that contain the anti-bacterial agent triclosan. It is commonly used in the soaps we use for washing our hands or washing our laundry, the toothpaste we use for brushing our teeth, as well as a host of other everyday cleaning products. Consequently, as we go about our daily hygiene or cleaning routine, we are more than likely adding triclosan into our freshwater sources via our wastewater.

    Triclosan is routinely added to toothpaste, antibacterial soaps, household detergents, paints, carpets, and even toys, and while the germ-wary consumer may find some comfort in knowing their family is protected from germs, the reality is that most of these products, especially antibacterial soaps, don't offer much more protection than using normal soap and water.
    Yet triclosan poses a problem — not only does it kill bad bacteria, it also kills beneficial bacteria. Research has shown that triclosan has given rise to antibiotic resistance, making treatment of common ailments and illnesses with antibiotics less effective. Triclosan also poses an environmental risk; it is harmful to algae, and can disrupt normal hormone functioning -- and thus development -- in wildlife. The FDA is busy conducting studies to determine the health risk it poses on humans.

    Credit: https://www.flickr.com/photos/usdagov/ Credit: https://www.flickr.com/photos/usdagov/

    While it is believed that the majority of triclosan is removed during the wastewater treatment process, the US Geological Survey (USGS) has found traces of triclosan in approximately 58% of streams tested.

    "What you use has an impact even though you're probably not thinking about it," says Monica Mendez, an associate professor in the Department of Biology and Chemistry at Texas A&M International University, and lead author of a research paper that was recently published in the Journal of Environmental Quality. "If a river happens to be a source of irrigation, could triclosan possibly get into our food?" Mendez asks.

    In order to gain a better understanding of how tricolosan-contaminated water affects soils and plants that are irrigated with it, Mendez and her research team used triclosan-contaminated water to irrigate tomatoes, onions and exposed soil. When the crops were harvested, the researchers detected triclosan in all edible parts of both plants. However, this was at levels considered safe for human consumption.

    The researchers also found that even though triclosan broke down rapidly in soils, it never broke down completely. Instead, it breaks down into other harmful hormone disrupting compounds that can be even more detrimental than triclosan.

    The researchers are also concerned about the effect that triclosan has on bacterial communities living in soils, which are necessary for healthy plant growth. Because triclosan indiscriminately targets both good and bad bacteria, it not only kills disease-causing bacteria, but beneficial bacteria too. Plants tend to flourish in soils that have a thriving and diverse microbial community, but these bacterial communities can be negatively impacted by triclosan.

    "We know that triclosan decreases the diversity of bacterial communities," says Mendez, "But we still need to figure out which good bacteria we are losing."

    This is the first study that measures the effects of long-term, repeated exposure to triclosan on soils and plants. Mendez hopes that future studies will assess the impact that triclosan has on soil microbes.

    "Because we're all concerned about disease-causing bacteria, we generally ignore what happens below ground," Mendez says. "Water and soil come together. We need to look at the quality of both, because food is important."

    Journal Reference
    Monica O. Mendez, Erika M. Valdez, Eileen M. Martinez, Melissa Saucedo, Brittan A. Wilson. Fate of Triclosan in Irrigated Soil: Degradation in Soil and Translocation into Onion and Tomato. Journal of Environment Quality, 2016; 45 (3): 1029 DOI: 10.2134/jeq2015.07.0386

  • Surge in Water Use in North Dakota Attributed to Oilfield Expansion and Influx of Temporary Oilfield Workers

    The surge in water use in North Dakota's rapidly expanding oil industry is not only due to increasing demand as a result of more oil wells, but is also attributed to the influx of people to the Bakken oil shale region, according to a study recently conducted by the US Department of Energy (DOE).

    The recent expansion of oil fields in the Bakken shale region has drawn thousands of oil workers into the area. Between 2010-1012, approximately 24,000 temporary oil industry workers flocked into the area, boosting Williams County's existing permanent population of 27,000 considerably.

    According to Corrie Clark, an environmental systems engineer in the Argonne National Laboratory's Environmental Science Division, and a co-author of the paper which was recently published in Environmental Science & Technology: "It is estimated that the average household in the North Dakota Bakken region uses about 80 to 160 gallons of water a day. If each new temporary worker used 80 gallons a day, their total would be more than half the water used for hydraulic fracturing alone. If they used 160 gallons a day, it would exceed the total amount of water used for hydraulic fracturing. Either way, water use by new temporary workers accounts for a big share of the region's increased water use."

    The Bakken shale consists of an oil deposit that lies beneath parts of Montana and North Dakota (US), and Manitoba and Saskatchewan (Canada). The annual water consumption for hydro-fracking has risen dramatically since 2008 when annual consumption was 770 million gallons; by 2012 the annual water consumption for hydro-fracking had shot up to 4.27 billion gallons per year.

    Over the same four year period, the number of newly drilled oil wells increased more than fourfold, rising from 401 in 2008 to 1801 in 2012. Hydraulic fracturing (or hydro-fracking) — a technique commonly used for oil extraction in shale formations — involves pumping large volumes of water into the wellbore under pressure to fracture the shale rock deep under ground, which releases the natural gas and oil locked within. However, the expansion of oil wells is not the only reason for increased water consumption as a result of oil development in the region.

    The study, titled "Water Use and Management in the Bakken Shale Oil Play in North Dakota," notes that due to the unusually high salinity levels found in this formation, well operators need to conduct routine maintenance flushing of 10-15% of the wells in North Dakota's Bakken region to prevent build-up of natural salts. The use of this additional maintenance water is apparently unique to wells within the Bakken shale deposit.

    Typically, within the Bakken shale deposit, the frequency of maintenance flushing tends to increase the further west wells are located. Although the publicly available data of water usage for maintenance flushing is limited, the study estimates that this ranges between 400-1400 gallons per day per well that requires flushing.

    Wastewater production from fracking operations is also higher in the Bakken shale than other deposits, and has risen from 1.1 million gallons for wells drilled in 2008 to 2.9 million gallons for those drilled in 2012, with most of this water being supplied by Lake Sakakawea. Yet, while the increase in water use from the lake as a result of oil development and associated population growth does not currently pose an issue in terms of continued water availability, Clark points out that by studying the impact that the expansion of the oil industry has on water usage in the Bakken region may assist with determining the impact in other shale deposits.

    "While no other play may have experienced an increase in local population as proportionally large and easy to define as the Bakken, temporary oilfield service populations have an impact everywhere," according to the study. "More data collection and further study in the Bakken and elsewhere are needed to better understand, quantify and minimize water impacts of unconventional oil and gas development in the future."

    Journal Reference

    R. M. Horner, C. B. Harto, R. B. Jackson, E. R. Lowry, A. R. Brandt, T. W. Yeskoo, D. J. Murphy, and C. E. Clark. Water Use and Management in the Bakken Shale Oil Play in North Dakota. Environmental Science & Technology 2016 50 (6), 3275-3282. DOI: 10.1021/acs.est.5b04079
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  • Groundwater Contamination: When Water's Not Fit to Drink

    Contamination of groundwater sources poses serious consequences in the future, especially in light of increasing droughts, which is placing more pressure on dwindling water resources that we direly need to protect at all costs. A recent report titled 'Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites', commissioned by the National Research Council, revealed that groundwater at more than 126,000 sites around the U.S. is contaminated.  These sites are all in need of remediation, with 10% of the contaminated sites being classified as ''complex'', and which were unlikely to be remediated for at least another 50 to 100 years.

    The estimated cost of remediating these contaminated sites is over $110 billion, according to the report, and does not take technical problems associated with rehabilitation of ''complex'' sites into account, or the rehabilitation of groundwater at sites that may become contaminated in the future.

    The U.S. Government has initiated a series of groundwater cleanup programs at both state and national level focusing on reducing the environmental and health risks associated with groundwater contamination. Some of the areas that have been addressed include cleanup of Superfund sites; environmental remediation of sites where hazardous waste is stored, treated, or disposed of; remediation of areas contaminated by leaks from damaged underground storage tanks; as well as remediation of government and military facilities, and industrial operations.

    credit: Ryan Griffis - https://www.flickr.com/photos/grifray/3623554655/ credit: Ryan Griffis - https://www.flickr.com/photos/grifray/3623554655/

    It is estimated that about 3.4% of the active cleanup sites are sites that fall under the jurisdiction of the U.S. Department of Defense, who have already spent $30 billion to remediate their sites of hazardous waste. However, many of their sites pose the highest challenges both in terms of technology needed and costs associated with successful cleanup operations and remediation efforts.

    "The complete removal of contaminants from groundwater at possibly thousands of complex sites in the U.S. is unlikely, and no technology innovations appear in the near time horizon that could overcome the challenges of restoring contaminated groundwater to drinking water standards," said Michael Kavanaugh, from Geosyntec Consultants, Inc. and chair of the committee that produced the report. "At many of these complex sites, a point of diminishing returns will often occur as contaminants in groundwater remain stalled at levels above drinking water standards despite continued active remedial efforts. We are recommending a formal evaluation be made at the appropriate time in the life cycle of a site to decide whether to transition the sites to active or passive long-term management."

    Taxpayers will foot a large portion of the cleanup bill, as many of the sites that are considered ''complex'' are on public land, or fall under the jurisdiction of government agencies.
    The terminology used in cleanup operations is often misleading, as very often closed sites still have levels of contamination that require monitoring and management well into the future, as well as funding to do so. Half of the Superfund sites that have been removed from the list still require ongoing monitoring, evaluation and management of contaminated groundwater according to the report, which recommends that the different phases in the cleanup process together with progress reports should be clearly defined to increase public and stakeholder awareness.

    According to Kavanaugh:

    "The central theme of this report is how the nation should deal with those sites where residual contamination will remain above levels needed to achieve restoration. In the opinion of the committee, this finding needs to inform decision making at these complex sites, including a more comprehensive use of risk assessment methods, and support for a national research and development program that leads to innovative tools to ensure protectiveness where residual contamination persists. In all cases, the final end state of these sites has to be protective of human health and the environment consistent with the existing legal framework, but a more rapid transition will reduce life-cycle costs. Some residual contamination will persist at these sites and future national strategies need to account for this fact."

    In the event of a major storm or natural disaster, this can lead to further problems. For example, in the wake of Hurricane Sandy affected residents were not only exposed to flaking paint from damaged homes, putting them and especially their children at risk of lead poisoning; lead dust from contaminated Superfund sites was washed off site by storm surge or blown off site by strong winds. When disturbed, these highly toxic contaminants pose a risk wherever they settle, both on the soil surface, and to groundwater sources below the soil. This clearly illustrates the importance of remediating contaminated sites to prevent the contaminants from migrating offsite, where they are far more difficult, if not impossible, to manage.

    If you know or suspect your are being exposed to such water, a system like a Berkey water filter can filter out contaminants from these affected sources.

    Further Reading:
    National Research Council. Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites. Washington, DC: The National Academies Press, 2013. doi:10.17226/14668.

  • Elevated Risk of Bladder Cancer in New England Linked to Arsenic in Private Drinking Water Wells

    A recent study has revealed that the increased risk of bladder cancer observed in residents of New Hampshire, Vermont and Maine over the last 50 years is likely due to high levels of arsenic found in private drinking water wells, particularly in wells that were dug between 1900 and 1950, and was not believed to be due to other bladder cancer risk factors such as occupational exposure to arsenic or smoking.

    The study, which was conducted by a team of researchers from the National Cancer Institute (NCI), together with researchers from the Geisel School of Medicine at Dartmouth, New Hampshire; the US Geological Survey (USGS); and the health departments of Maine, Vermont and New Hampshire, was published in the Journal of the National Cancer Institute.


    New England has seen higher than normal mortality rates due to bladder cancer for more than fifty years. Bladder cancer rates in Vermont, Maine and New Hampshire have been around 20% higher than that generally recorded across the United States, with higher than normal bladder cancer rates being found in both men and women. What distinguishes this region from many others is that a high percentage of the population living there obtain their drinking water from private wells, which are not serviced by municipal water utilities and are not subjected to EPA regulations for drinking water quality. These wells could be contaminated with arsenic, which is known to increase the risk of bladder cancer when present in drinking water at high concentrations.

    Arsenic in these drinking water wells can stem from two sources: 1) it can occur naturally in soils and rock, leaching into the water from underground; or 2) it can originate from arsenic-laden pesticides that were extensively used on crops in the early 1900s.

    "Arsenic is an established cause of bladder cancer, largely based on observations from earlier studies in highly exposed populations," said Debra Silverman, Sc.D., chief of the Occupational and Environmental Epidemiology Branch, NCI, and senior author on the study. "However, emerging evidence suggests that low to moderate levels of exposure may also increase risk."

    Comparing a sample of 1,213 New England residents that had recently been diagnosed with bladder cancer against a sample of 1,418 residents without bladder cancer living in the same region, the researchers determined that while smoking and occupational exposure increased the risk of bladder cancer in this population, the associated risk due to these factors was still the same as that of people living elsewhere, which according to Silverman: "suggests that neither risk factor explains the excess occurrence of bladder cancer in northern New England."

    Using current arsenic levels and historical data, the research team estimated the total amount of arsenic ingested by each person via their drinking water consumption. They found that the risk of bladder cancer increased as the cumulative exposure to arsenic increased. When the researchers focused on subjects who obtained drinking water from private water wells, they found that residents who consumed high amounts of water were nearly twice as likely to succumb to bladder cancer as those who consumed the least amount of water.

    If water was consumed from dug wells — shallow wells, with a depth of less than 50 feet that are more vulnerable to arsenic contamination from human sources — this association was even stronger still. This risk was significantly higher in people who had been using dug wells as their drinking water source before arsenic-based pesticides were banned in 1960 compared to those that began using dug wells for drinking water later.

    While the threat of arsenic exposure from dug wells is lower now since arsenic-laden pesticides have been banned and dug wells are less common than they were in the past, arsenic exposure in private drinking wells that are drilled deep into fractured underground rock still poses a public health threat. The EPA has set the drinking water standard for arsenic at 10 micrograms/L for municipal water utilities; owners of private drinking wells are encouraged to have their drinking water tested and to take measures to limit their exposure, such as making use of an effective drinking water filter (such as a Big Berkey System with Black Berkey filters) that is capable of removing arsenic from drinking water.

    Journal Reference

    Baris D… Silverman DT, et al. Elevated Bladder Cancer in Northern New England: The Role of Drinking Water and Arsenic. Journal of the National Cancer Institute, May 2016 DOI: 10.1093/jnci/djw099

  • BPA, a Chemical Commonly Found in Plastics, Linked to Pre-term Births

    Bisphenol A, more commonly known as BPA, is a chemical pollutant that is known to have many serious health implications. Now, new research has revealed that it may also be responsible for pre-term births.

    A recent study conducted by Ramkumar Menon, an assistant professor in the department of obstetrics and gynecology at The University of Texas Medical Branch at Galveston, together with collaborators from Winthrop University Hospital and Kaiser Permanente Southern California, has found that moms-to-be who had higher concentrations of BPA in their bloodstream were more likely to give birth early compared to pregnant women who had lower concentrations of BPA in their blood, indicating that BPA may be a contributing factor in premature births.

    attribution: https://www.flickr.com/photos/21524179@N08/ attribution: https://www.flickr.com/photos/21524179@N08/

    For the study, which recently appeared in The Journal of Maternal-Fetal & Neonatal Medicine, the researchers analyzed blood samples taken from expectant women as they were admitted into hospital during labor, as well as from fetal amniotic fluid samples collected during the birth.
    BPA is a widespread environmental contaminant that is widely used in the manufacture of plastic food containers and beverage bottles, as well as plastic linings in tins used to package canned foods. BPA can leach into food packaged in these containers, and this release can be increased when packaged food is heated in a microwave oven or other heat source. BPA can also leach out of plastic beverage bottles when exposed to heat (including sunlight) during transportation and preparation, compromising products that are considered healthy, such as bottled water for example. Because it is so widely used, women are continually exposed to the contaminant.

    "In fact, BPA is so widely used that nearly all women have some level of exposure," said Menon.

    BPA is similar in structure to the hormone estrogen, which it mimics within the female body, binding to estrogen receptors, including receptors that control inflammation. This can result in abnormal inflammation, which can increase the risk of complications associated with pregnancy, including water breaking earlier than expected and premature birth. This study is the first to investigate the role of high BPA concentrations in the blood to increased risk of premature birth.

    "Widespread use of BPA in materials of our daily life and our findings that all patients have some level of exposure suggests that contact with these materials is unavoidable," Menon said. "This suggests that a better understanding of how BPA may alter maternal physiology is needed to minimize the risk of adverse pregnancy outcomes."

    The researchers are now busy conducting studies on cells taken from fetal membranes and the uteruses of pregnant women to determine the molecular pathways and to identify potential targets that can be used for medical intervention.

    Journal Reference:

    Faranak Behnia, Morgan Peltier, Darios Getahun, Cheryl Watson, George Saade, Ramkumar Menon. High bisphenol A (BPA) concentration in the maternal, but not fetal, compartment increases the risk of spontaneous preterm delivery. The Journal of Maternal-Fetal & Neonatal Medicine, 2016; 1 DOI: 10.3109/14767058.2016.1139570

  • The Importance of Maintaining Ecological Balance in Freshwater Systems

    Plants are primary producers that provide food and nutrients that support herbivores and ultimately predators as well. Without plant life, nothing else would survive. In aquatic systems, plant life consists of single celled microscopic plankton, as well as vascular plants. Both play a key role in freshwater ecology.

    Healthy Freshwater System

    Nutrients are essential for both plant and animal growth. Herbivores get their nutrients from plants, and carnivores get their nutrients from herbivores. But as primary producers, plants and algae get their nutrients from the environment in the form of nitrates, phosphates and minerals. By transforming these nutrients into carbon by harnessing energy from the sun in the process of photosynthesis, plants are able to sustain other life on earth.

    In a healthy, balanced freshwater ecosystem, photosynthesizing aquatic plants absorb nutrients and carbon dioxide from the water column in the presence of sunlight, transforming them into carbon and releasing oxygen in the process. This oxygen allows aquatic animals, such as fish and freshwater invertebrates to survive underwater. Should oxygen be depleted, these aquatic organisms would die. The animals in turn release carbon dioxide which is absorbed by the plants. The ecosystem is healthy and balanced.

    Unhealthy Freshwater System

    Nutrients occur naturally in the environment as a result of decomposition and other processes, but are also added to the environment by man made activities. These include runoff of fertilizer and animal waste products from agricultural practices, from sewage runoff and discharge from wastewater treatment plants, which can result in nutrient loading. When excessive nutrients flow into a waterway, both unicellular algae and aquatic plants take advantage of the available nutrients and will flourish, removing these 'contaminants' from the water in the process.

    However, when conditions are favorable, aquatic plants can quickly multiply to form dense algal blooms or mats of weed that cover the surface of a pond or lake. The system rapidly becomes unbalanced, often with dire consequences.

    In the case of unicellular algae, the algal cells rapidly grow and reproduce while nutrients and light are abundant, but once the nutrients in the surface water are depleted they have to move deeper to find nutrients to sustain them. Eventually there is insufficient nutrients in the surface layers, and as light cannot penetrate the deeper water layers, there is insufficient light in the deeper, nutrient rich layers. When this point is reached, the algae cells die off and sink to the bottom of the lake, where they decompose. Oxygen is stripped from the water during the decomposition process, resulting in water that is low in oxygen, which can result in mass mortality of fish and other aquatic organisms that require oxygen to survive.

    Aquatic plants, especially fast growing non-native species that herbivores tend to avoid, can also spread rapidly, clogging waterways and making it difficult for fish and other organisms to move about with ease. Aquatic organisms may die or move away. A once thriving ecosystem, home to a rich biodiversity and abundant wildlife is reduced to a monoculture of impenetrable aquatic weed.

    Balance is Key

    Aquatic plants play a vital role in maintaining ecosystem health and supporting biodiversity. However, it is essential that the ecosystem remains in balance for it to function effectively.
    Algal blooms and the spread of invasive aquatic plants are both likely to occur more frequently in the future as a result of climate change, more intensive agricultural activities, ecological imbalances, and/or as a result of invader species changing ecosystem dynamics. We therefore need to find creative ecologically sound solutions to maintain balanced freshwater ecosystems and to protect biodiversity.

  • Fertilizing Crops Today Will Contaminate Drinking Water Supplies for Decades

    Dangerously high concentrations of nitrates in water originating from application of fertilizer to crops is likely to persist in drinking water supplies for decades, posing a serious health risk — including increased potential for blue baby syndrome, according to a recently published study conducted by scientists from the University of Waterloo, Canada.

    Nitrogen from nitrogen-based fertilizers, which are commonly applied to agricultural crops to enhance growth and productivity in an effort to increase yields, has been washing into freshwater systems through run-off, and leaching into private water wells for over 80 years. As a result, even if farmers stopped using nitrogen-rich fertilizers today, nitrate concentrations in these freshwater systems will remain at elevated levels for several decades, according to the report, which was published in Environmental Research Letters.

    By Lynn Betts - U.S. Department of Agriculture, Natural Resources Conservation Service. Photo no. NRCSIA99241, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6303636 By Lynn Betts - U.S. Department of Agriculture, Natural Resources Conservation Service. Photo no. NRCSIA99241, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6303636

    The scientists found that nitrogen is accumulating in soils, effectively creating a source of nitrates that will continue to pollute surface and ground water systems for a very long time.

    "A large portion of the nitrogen applied as fertilizer has remained unaccounted for over the last decades," said Nandita Basu, a professor in the Department of Earth and Environmental Sciences and Civil and Environmental Engineering. "The fact that nitrogen is being stored in the soil means it can still be a source of elevated nitrate levels long after fertilizers are no longer being applied."

    This research study is the first to provide direct evidence of the impact of broad-scale nitrogen use in the Mississippi River Basin.

    Iowa's largest supplier of drinking water, Des Moines Water Works, is suing three counties further upstream for failing to take adequate measures to reduce dangerously high nitrate levels in surface waters, which are more than double the safety standard set for drinking water, and which according to the researchers will most likely stay high for many years to come. This oversight has forced Des Moines Water Works to spend millions on upgrading their water treatment facilities in order to supply consumers with water that is safe to drink.

    Professor Basu together with her fellow researchers analyzed historical data from more than 2000 soil samples taken across the Mississippi River Basin. Their results revealed that nitrogen systematically accumulated in agricultural soils over time. In many cases, nitrogen accumulation was not evident in the upper soil layer, but rather at 10-40 inches (25-100 cm) below the soil surface.

    "We hypothesize that this accumulation occurred not only because of the increased use of fertilizers, but also increases in soybean cultivation and changes in tillage practices over the past 80 years," said Kim Van Meter, a doctoral student in the Department of Earth and Environmental Sciences in the Faculty of Science.

    Results from their modeling simulations suggest that the accumulated 'legacy' nitrogen could continue to leach into freshwater systems more than 30 years after farmers stop applying nitrogen to their fields.

    Unfortunately this has ramifications for both environmental and human health. Elevated nitrogen levels in freshwater and marine systems causes hypoxic conditions that result in dead zones where no life can survive, and negatively impacts the quality of drinking water. Exposure to high levels of nitrates in drinking water can cause serious health issues, including blue baby syndrome that can be fatal to infants.

    Over the last forty years or so, policymakers and farmers have been working together to limit the amount of nitrogen fertilizer leaching from fields to underground and surface water systems. Yet, even with these measures, some areas have nitrate concentrations that are more than 10 times the safety standard set for drinking water.

    "The presence of this legacy nitrogen means it will take even longer for best management practices to have a measurable benefit," said Professor Basu, also a member of the Water Institute. "If we're going to set policy goals, it's critical we quantify nitrogen legacies and time lags in human impacted landscapes."

    Journal Reference:

    K J Van Meter, N B Basu, J J Veenstra, C L Burras. The nitrogen legacy: emerging evidence of nitrogen accumulation in anthropogenic landscapes. Environmental Research Letters, 2016; 11 (3): 035014 DOI: 10.1088/1748-9326/11/3/035014

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