GET WET!

They’re in our oceans and rivers. They’re in the food we eat and the water we drink. They’ve even been detected inside the human body. They’re called microplastics—particles of plastic so small they can’t be seen by the naked eye. While researchers have known for years that these microplastics exist in Flathead Lake, the concentrations and origins of the microplastic pollution have remained a mystery.

Now, thanks to a study conducted at the University of Montana’s Flathead Lake Biological Station, scientists have a greater understanding of the amount of microplastics polluting Flathead Lake, the likely sources of these microplastics and what can be done to prevent more from finding their way into the lake‘s world-renowned pristine water.

Recently published in the scientific journal Environmental Pollution, this microplastics study was led by FLBS visiting researcher Dr. Xiong Xiong from the Chinese Academy of Science’s Institute of Hydrobiology. Xiong came to FLBS in 2018 on a mission to learn more about microplastics in freshwater lakes in relatively unpopulated regions and to help provide insight to aid in their management.

“It looks quite clean, but if this clean lake is suffering from plastics, I want to check that,” Xiong said at the start of his study four years ago. “I think people think (plastic pollution) is more serious in the ocean, but many people live inland, and we need the freshwater. It may affect our daily life more directly than the plastic in the ocean.”

To conduct this study, Xiong joined FLBS Director Jim Elser and a team of biological station scientists to sample surface watersat 12 different locations around Flathead Lake over a one-year period. They then examined the samples for the occurrence, distribution and types of microplastics.

After analyzing the samples, the team discovered that, while levels of microplastic pollution measured in Flathead Lake were lower than in lakes in densely populated areas, Flathead had microplastic levels similar to or higher than lakes studied in other less-densely populated areas of the world.

In other words, Flathead Lake is now home to microplastics and new microplastic particles are arriving every day.

“Microplastics in lakes can interfere with food webs because animals like zooplankton and fish can ingest them,” Elser said. “They can carry toxins into the animal, displace real foods and physically damage digestive tissues.”

There are three main ways that microplastics reach Flathead Lake, according to the study. One way is atmospheric microplastic deposition. This occurs when microplastics are transported to Montana from other more populated areas by the atmosphere (e.g., wind and clouds) and then fall into Flathead Lake—either directly from the air (known as dry deposition) or through snow and rainfall (wet deposition).

Microplastics in dry deposition were highest in the fall season, while wet deposition was highest in the winter season.

“This study showed that microplastics are literally raining—and snowing—down on us out of the sky,” Elser said.

The other two other ways in which microplastics can enter Flathead Lake are through the lake’s major river inputs, which includes the Flathead River on the north end of the lake and lakeside sources near larger shoreline communities such as Polson, Bigfork and Lakeside.

At the mouth of the Flathead River, the biggest source of microplastics is most likely from plastic waste disposal, which in Flathead County is primarily landfill rather than recycling. Although landfills located in the Flathead Watershed are not open pit, microplastics are mobilized via leachate (water that picks up contaminants) and via the soil of the landfill when winds carry away dust.

Meanwhile, in the more highly populated shoreline areas of the lake, researchers found that concentrations of microplastics were especially high. In addition to plastic packaging, many of today’s clothes are made from fibrous plastics. These synthetic fabrics break apart on a microscopic level during washing and then are transported and deposited into our waters through home septic drain fields and community water treatment plants.

Plastic waste from other human activities also is worthy of attention. A variety of water activities such as kayaking, sailing, speedboating, water skiing and fishing are important outdoor pursuits in the Flathead Watershed. But these activities involve plastic boats, ropes, floats and fishing line that can degrade and transform into microplastics over time.

Though the levels of microplastics in Flathead Lake are relatively low, they are concerning. However, researchers are quick to point out that much can be done to reduce their presence in Montana’s waters.

“While we need to know more about microplastic impacts in our lakes, we know enough to act to reduce plastic inputs now,” Elser said. “Each of us can reduce our use of plastics, properly dispose of them and implement impactful approaches such as laundry filters. We can also encourage businesses to do the same and for governments to provide facilities and systems to better handle plastics in our watershed.” 

Fibrous microplastics can be reduced by improving laundry practices and wastewater treatment or by reducing the use of synthetic fiber material in favor of natural fiber clothing and materials. As an example, a recent study in California found that the adoption of in-line filters in washing machines had the potential to decrease annual synthetic microfiber emissions to natural environments by nearly 80%. 

Further strengthening disposal measures of plastic waste by both residents and visitors could greatly help reduce microplastic contamination in Flathead Lake. Such measures include better education about the harms of improper plastic disposal, enhancing plastic waste recycling in the region and reducing the overall use of plastic products, such as single-use plastics common in the food service industry.

When it comes to reducing atmospheric microplastic deposition, researchers said extensive solutions are needed. The total production of plastic waste in the United States is 42 million tons per year, which is much higher than other countries per capita. This suggests that, even in an area of relatively low population, Flathead Lake will remain at risk from microplastics arriving by air until nationwide measures can be taken.

Xiong and his research team said more studies are needed to better understand and address our microplastic problem, not only in the Flathead Watershed but also throughout the world. The good news is that, because human activities are indisputably the only source of microplastics, this is a problem that we have the power to solve.

FOR MORE INFORMATION:https://phys.org/news/2022-06-um-microplastic-pollution-flathead-lake.html

Even if society is able to slow all greenhouse gas emissions and get to “net zero” by mid-century as targeted by nations of the world in the UN Paris Agreement, there is a lag built into the climate system primarily as a result of ocean thermal inertia that means slow emerging changes such as deep ocean warming and sea-level rise will continue very long afterward.

Climate scientists argue in a new review paper that this means climate actions need to be established at multiple time scales. The paper has recently been published in Atmospheric and Oceanic Science Letters.

In the near term (∼2030), goals such as the United Nations Sustainable Development Goals (SDGs) will be critical. Over longer times (∼2050–2060 and beyond), global carbon neutrality targets may be met as countries continue to work toward reducing emissions. The climate actions need to extend far beyond the current period of focus to time scales of hundreds of years. On these time scales, preparation for “high impact, low probability” risks—such as an abrupt showdown of Atlantic Ocean circulation and irreversible ice sheet loss—should be fully integrated into long-term planning.

The global ocean, which covers some 70 percent of the Earth’s surface, is slower to absorb and release heat than land. The large mass and heat capacity also means the ocean is much more capable of storing heat than air or land, and the ocean is hence the most important controlling component of the Earth’s climate.

This “ocean thermal inertia” offers both good news and bad news with respect to climate change. It means that the planet is not heating up as fast as it would without an ocean. But it also means that even once we halt greenhouse gas emissions by about 2050 to 2060, as laid out in the United Nations Paris Agreement—like a speeding train taking time to slow down once the brakes are hit—the climate system will still continue to change for a considerable amount of time afterward.

The ocean will keep on warming as heat is transported downwards into deeper ocean waters, and the climate systemwill only re-stabilize when that deep ocean stops warming and the Earth reaches an equilibrium between incoming and outgoing heat.

“This process means that while surface warming may stabilize at about 1.5-2℃ when global emissions reach net-zero emissions, sub-surface ocean warming will continue for at least hundreds of years, yet we normally only talk about climate action on the scale of a few decades to the end of the century at the most,” said lead-author, Prof. John Abraham, a mechanical engineering researcher with the University of St. Thomas in Minnesota, “That needs to change.”

As a consequence, a system of scientific ocean monitoring with that time-scale in mind needs to be developed. Besides subsurface temperature and sea level, the tracking of ocean climate trends such as pH, sea ice, ocean surface heat flux, currents, salinity, carbon, will require long-duration consistent and calibrated measurements, and compared with temperature, these essential climate variables are currently much less observed.

“Changes to the ocean will also continue to impact extreme weather over these longer periods, as well as sea-level rise.” said Prof. Lijing Cheng, an ocean and climate scientist from Institute of Atmospheric Physics, Chinese Academy of Sciences. “And infiltration of sea water into fresh water supplies can affect coastal food supplies, aquifers, and local economies. Other impacts that are connected to ocean warming and so need to be considered for the very long term include more damaging storm surges, coastal erosion, marine heatwaves, ocean acidification, and marine oxygen depletion.”

“Clearly this later group of measures will take a much longer time to implement but will also provide much longer lasting benefits”, added Pennsylvania State University climatologist Michael E Mann, another co-author of the paper. “Multi-scale adaptation practices like this should be considered throughout the globe.”

Finally, the researchers argue, societies need to begin to consider ensuring they are resilient in the face of “high impact, low probability” events (an unlikely event that would have significant consequences if it happens), such as an abrupt showdown of Atlantic Meridional Overturning Circulation, large methane emissions from the seabed or thawing permafrost, passing a tipping point for losing a major ice sheet, or an abrupt shift and transition of ocean ecosystem including a major extinction event.

FOR MORE INFORMATION: https://phys.org/news/2022-06-climate-scientists-ocean-require.html

Research by Oregon State University has shed new light on the hazards associated with harmful algal blooms such as one four years ago that fouled drinking water in Oregon’s capital city of Salem.

The study led by Theo Dreher, emeritus professor of microbiology, involved sampling of cyanobacterial blooms from 10 Oregon lakes including Detroit Reservoir, which provides drinking water for Salem.

Genome sequencing and toxin analyses enabled Dreher and collaborators in the OSU colleges of Science and Agricultural Sciences to identify the precise types of toxins produced by specific organisms.

“This information is important for protecting public health, both with regard to consumption of drinking water and exposure to toxins through recreation on lakes,” Dreher said. “Two toxin-producing Dolichospermum cyanobacteria were present in Detroit Reservoir, one producing a type of cylindrospermopsin and another producing an uncommon form of microcystin. Occurrences of toxins had been known previously, but now we know the precise toxin types and the organisms making them.”

Cyanobacteria, often referred to as blue-green algae, are microscopic organisms ubiquitous in all types of water around the globe. They use sunlight to make their own food and in warm, nutrient-rich environments and can quickly multiply, resulting in blooms that spread across the water’s surface.

These harmful algal blooms, often abbreviated to HABs and which are of concern when visible in lake water, can form at any time of the year but most often between spring and fall.

In 2007 a national survey by the Environmental Protection Agency found microcystin, a recognized liver toxin and potential liver carcinogen, in one out of every three lakes that were sampled. Some strains of cyanobacteria can also produce neurotoxins, while most of the toxin-producing algae can cause gastrointestinal illness and acute skin rashes.

“Cyanobacterial HABs affect many of Oregon’s lakes each year,” Dreher said. “Some, but not all, of the blooms are toxic. Potential exposure to cyanotoxins is of public health concern, and blooms particularly pose a threat to dogs entering lakes.”

Among the 10 bodies of water in the research by Dreher and OSU colleagues Ryan Mueller and Ed Davis II, toxigenic Dolichospermum cyanobacteria caused blooms in four of them: Detroit Reservoir and Odell Lake in the Cascades, Lake Billy Chinook (Metolius Arm) in central Oregon and Junipers Reservoir, a private reservoir west of Lakeview in southern Oregon.

Analysis verified the presence and type of toxin. Microcystin was present in Odell Lake, Lake Billy Chinook and Junipers Reservoir.

“In early summer of 2018, low concentrations of microcystin and cylindrospermopsin cyanotoxins were found in finished tap water in Salem,” Dreher said. “A do-not-drink advisory was issued for vulnerable members of the population, particularly infants and pregnant women. Our research establishes the cyanobacteria and toxins that were involved in that emergency.”

Dreher notes that the Salem scare, along with the death of more than 30 steers from drinking cyanotoxin from Junipers Reservoir in June 2017, raised awareness of the hazards of cyanobacterial blooms in the state. The Oregon Legislature has since provided funding to the Department of Environmental Quality in an effort to improve the state’s ability to detect blooms and respond to them, he said.

“The good news is that not every cyanobacterial bloom that occurs in our lakes is toxic, although it is always wise to follow the rule of avoiding contact when there’s green growth in the water,” Dreher said.

If a person or a pet comes in contact with water that may contain harmful bacteria, the Centers for Disease Control and Prevention advises immediate rinsing with fresh water. Dogs should not be allowed to lick the contaminated water off their fur, the CDC adds, and a veterinarian should be called right away.

Anyone swallowing water near a harmful algal bloom should immediately call a doctor or poison control center. 

Amanda Foss of GreenWater Laboratories in Palatka, Florida, also took part in this research. The findings were published in Harmful Algae.

FOR MORE INFORMATION: https://phys.org/news/2022-06-hazards-posed-algal-blooms.html

Following a devastating wildfire in 2018 that raged through Paradise, California, volatile organic compounds (VOCs) were found to be contaminating the town’s water—and scientists suggest this problem may be widespread in other fire-prone areas. A feature article in Chemical & Engineering News, an independent news outlet of the American Chemical Society, examines how plastic pipes may be a key source of contamination and explores what can be done to protect vulnerable communities.

Testing revealed Paradise’s water contained VOCs (including benzene, naphthalene and toluene, among others) at levels exceeding U.S. Environmental Protection Agency standards, writes freelance contributor Robin Meadows. A team investigating the water contamination did not find VOCs in the treatment plants or mains but did detect them in the service lines, which are smaller pipes near or above ground typically made of plastics like polyvinyl chloride (PVC) and high-density polyethylene (HDPE). The researchers also found evidence that PVC and HDPE start to degrade and generate VOCs at high temperatures, but don’t need to burn to do so. Another study identified the VOCs in Paradise’s water and compared them to VOCs emitted from burned pipes and to other sources such as building materials. Their results suggest that the water sample was contaminated by a combination of plastic pipes and smoke.

While it is impractical and costly to eliminate plastic from service lines, experts say that some changes can help protect communities from their risks, such as burying them deeper to insulate them from the heat produced by fires. A network of isolation valves can help prevent contaminants from spreading throughout the water system in the event of a fire. In the future, sensors may be able to detect when pipes reach the threshold temperature for releasing VOCs. Beyond installing engineering systems, other strategies include managing vegetation, reducing the flammability of buildings and assessing individual community vulnerabilities. And after wildfires, water utility companies should act fast to test for contaminants in the water of burned homes and service lines, say experts.

FOR MORE INFORMATION: https://phys.org/news/2022-06-link-wildfires-contamination.html

The production of wild and farm-raised fish, shellfish and algae reached record levels in 2020, and future increases could be vital to fighting world hunger, the Food and Agriculture Organization said Wednesday.

Driven by sustained growth in aquaculture, global fisheries and aquatic farming together hauled in 214 million tonnes, the UN agency said in a report.

The total first-sale value of 2020 production topped $400 million, with $265 million coming from aquaculture, a sector poised for further expansion.

These trend lines are good news for a world facing price hikes and food shortages due to the war in Ukraine, disrupted supply chains, and inflation. 

“The growth of fisheries and aquaculture is vital in our efforts to end global hunger and malnutrition,” said FAO director Qu Dongyu. 

But overfished oceans, climate change and pollution—if left unaddressed—could threaten that potential, the UN agency warned.

“Aquaculture growth has often occurred at the expense of the environment,” Qu noted. 

Many shrimp farms in Vietnam, China and Cambodia, for example, have displaced mangrove forests that are nurseries for marine life and critical barriers against storm surges. 

Climate change poses additional challenges, experts say. 

“Warming waters will create environments where there’s more likelihood of bacterial disease,” said Josh Madeira, director of fisheries and aquaculture policy at the Monterey Bay Aquarium.

That means a sector already highly reliant on antibiotics will likely become even more so, he told AFP.

Production of aquatic animals in 2020—totalling 178 million tonnes—was evenly divided between fisheries and aquaculture, according to the FAO report.

The remaining 36 million tonnes was algae production.

Overfished stocks

Yields of fish, shrimp and other shellfish destined for human consumption are more than 60 percent higher than during the 1990s, far outpacing population growth, according to the report, released during the UN Ocean Conference in Lisbon.

On average, people worldwide consume over 20 kilos (44 pounds) of aquatic foods per year today, more than double the amount 50 years ago.

Globally, 17 percent of the protein consumed by humans comes from aquatic sources. In many Asian and African countries, that figure rises to more than 50 percent.

Wild and farmed food from the seas and inland waters are also a critical source of essential omega-3 fatty acids and micronutrients, recent research has shown.

“Aquatic foods are increasingly recognised for their key role in food security and nutrition,” Qu said. 

Nearly 90 percent of aquatic animal production is for human consumption, with the rest destined for non-food uses such as fishmeal and fish oil.

Asian countries were the source of 70 percent of the world’s fisheries and aquaculture of aquatic animals in 2020.

China remaines by far the top fisheries producer, followed by Indonesia, Peru, Russia, the United States and Vietnam.

So-called capture fisheries of commercial species in the wild—including tuna, cod, salmon and especially anchoveta—dropped by four percent in 2020 compared to the average of the previous three years.

Part of the drop can be attributed to COVID-related disruptions, but long-term decline is due to the pressures of overfishing, experts say. 

Catch levels peaked in the mid-1990s, and have—with fluctuations—stagnated since then.

“The FAO estimates that 34 percent of caught fish come from overfished stocks,” University of British Columbia economist and fisheries expert Rashid Sumaila told AFP.

“But they are very conservative,” he added. “Independent studies put that figure at 50 percent.”

Aggravating the problem is some $34 billion dollars annually in government subsidies. 

Earlier this month, the World Trade Organization (WTO) took preliminary steps to reduce these handouts to industry, but experts say the measures will have limited effect and take years to implement.

FOR MORE INFORMATION: https://phys.org/news/2022-06-aquaculture-aquatic-food-yields-high.html

New research, published in Scientific Reports by Smithsonian Tropical Research Institute (STRI) postdoctoral fellow Karina Chavarria and colleagues, shows that bacterial communities in streams adjacent to young secondary forests recover to resemble those of mature forest streams in as little as a decade after cattle has been removed from the land, and that these communities are robust throughout the year.

These results come at a critical time. 2021 marks the beginning of the United Nations Decade on Ecosystem Restoration, which aims to prevent, halt and reverse the degradation of ecosystems worldwide. The Agua Salud Project, a collaboration with the Panama Canal Authority and the Ministry of the Environment in Panama, and where this research took place, is one of the many initiatives at STRI aimed at understanding the drivers and consequences of environmental change.

Lessons learned from long term studies of forest ecosystems across different land uses and extreme weather events at Agua Salud inform our ability to restore and maintain tropical forests. With its various streams and rivers distributed throughout hundreds of hectares, Agua Salud also offers a unique platform for hydrological studies.

Water is a key resource for life on earth. People rely on streams and lakes for food and recreation. Microbes are less appreciated constituents of aquatic systems but are behind-the-scenes engineers that ensure water quality by cycling nutrients and energy. When streams become polluted or surrounding landscapes are degraded, microbial communities shift, risking their ability to help maintain natural processes and often allowing harmful bacteria to flourish. 

Chavarria and colleagues took weekly samples from streams surrounded by mature forest, young secondary forest, silvo- and traditional pasture over a two-year period at STRI’s Agua Salud site. They measured different aspects of water quality, and filtered water samples to extract and sequence the bacterial DNA in these streams.

They found similar communities in streams surrounded by young secondary and mature forests but different, less diverse communities in the cattle pasture stream. Notably, the bacterial community in the silvopasture stream shifted seasonally, with the wet season bacterial community being like the forests and the dry season community similar to the traditional pasture.

“Riparian forest helps to protect the silvopasture stream from the impacts of cattle in the wet season but in the dry season, when cows congregate in the stream to drink and seek shade as a way of avoiding the scorching sun, increased disturbance and fecal inputs make the bacterial community in the water more like that of traditional cattle pastures,” said STRI staff scientist Kristin Saltonstall, Chavarria’s advisor and collaborator on the project.

“It is important that cattle not access the streams, and that their drinking water is provided up slope during the dry season to ensure year-round water quality,” said Jefferson Hall, the director of Agua Salud and a collaborator on the project.

Silvopasture systems, where trees are planted on traditional cattle pastures and forest corridors are often maintained along streams, have gained a lot of attention in recent years. While the jury may still be out as to whether these systems provide all the environmental benefits claimed by promoters, it is clear that having a forest buffer around the stream is beneficial with respect to water quality and stream water bacterial communities.

“Our results add an important dimension to the growing body of research on the ability of biodiversity associated with young tropical secondary forests to recover rapidly, with implications for human health as well as a healthy environment,” said Chavarria.

Mitigation efforts taken during this Decade of Ecosystem Restoration will determine our quality of life for generations to come. Chavarria’s research provides hope, showing that passive reforestation, where forests are allowed to recover after cattle are removed, can restore many aspects of water quality in a matter of years. Studies such as this provide much needed data and demonstrate how science can inform policy and practice, contributing to a sustainable planet.

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is part of the Smithsonian Institution. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems.

FOR MORE INFORMATION: https://phys.org/news/2021-11-secondary-forests-fresh-sources-degraded.html

In an in-depth cross-country analysis considering the impacts of large-scale agriculture and industry on the human right to drinking water, Dr. Naho Mirumachi, Reader in Environmental Politics, from King’s College London has called for renewed political commitment to ensure everyone can enjoy access to clean, drinkable water.

There are Currently 2.2 billion people, or nearly a third of the global population, who lack safely managed drinking water. Of this figure, 450 million children face poor drinking water servicesand water scarcity, putting them in situations of high or extreme water vulnerability. The labor costs of water collection, including that of time spent to collect water and associated security risks, disproportionately fall on women and girls, affecting 8 out of 10 households without water.

Businesses from the food, textile, energy, industry, chemicals, pharmaceutical and mining sectors contribute to the majority of water use and pollution, which are often facilitated by foreign investment. These sectors are continuing to undertake activities, such as water intensive crop production, and withdraw from fresh water sources in areas where water access is already unreliable at a human cost. 

Consumption of one country can have an impact on another because of the global food trade. The water embedded in that food trade or, virtual water ‘trade’ means that countries are interdependent and have a high water footprint. The UK is the sixth largest net importer of virtual water in the world. Over half of that water footprint comes from countries facing water scarcity. The study, commissioned by the European Parliament’s Subcommittee on Human Rights, further highlights:

• It is estimated that global meat consumption will increase by 14% in the next decade as the population increases and income rises. Accordingly, a further 50% increase in food production is required by 2050 to feed the population. This growth in demand for agricultural products will strain the already unsustainable levels of water use.
• Temperature and precipitation changes resulting from climate change will contribute to the uncertainty of water availability and instances of drought and flooding. Water quality will be exacerbated by climate-induced algae blooms
• By 2040, water consumption in the energy sector will increase by about 60%.
• The demand for biofuels is underpinned by global shifts towards cleaner forms of energy. Biofuels impact other water uses, especially when these crops are irrigated for commercial production. There are concerns this will drive up prices and make food less affordable, in particular, for people below the poverty line.

Whilst behavior changes such as eating less red meat would ease pressure on production elsewhere, reduce virtual water ‘flows’ and relieve water stress, this alone is not enough. It is necessary to strengthen corporate due diligence and corporate accounting. Voluntary mechanisms will only go so far in addressing the impact of businesses on human rights. States need to put in place mandatory measures for corporate accountability.

The analysis was requested by the European Parliament’s Subcommittee on Human Rights, funded by the European Parliament, and the copyright is with them. The content of study is the sole responsibility of the authors, and any opinions expressed herein do not necessarily represent the official position of the European Parliament.

for more information: https://phys.org/news/2021-11-human-rights-millions-endangered-large-scale.html

Years ago, there was a time that kids from a rural village in South Africa still wanted to swim in the rivers nearby. But when they got out of the water, those with sensitive skin would have the worst rash ever, says Professor Philiswa Nomngongo from the University of Johannesburg’s (UJ) campus in the CBD. Nomngongo is the DSI/NRF SARChI Chair: Nanotechnology for Water, within the UJ Department of Chemical Sciences.

She grew up in the village of Flagstaff in the Wild Coast region of the Eastern Cape of South Africa. “In my village, there are streams and rivers. What happens is, those who do not have money to buy a tank for rainwater harvesting, they depend on the stream or river,” she says.

The people who have tanks will do their bathing, dishes and laundry with the convenient and relatively safe rainwater. Then they release their wastewater into the river nearby. “Downstream, someone else is drinking water from that river,” she adds.

Most rivers in South Africa may only be a few meters across, and about waist deep most of the year until flash floods arrive. And it’s not just people affecting water quality in such a village, it is livestock also. “When the cows walk in the water and it looks dirty, the villagers wait for the water to clear again, but the question is, is it clean? The challenge is, we always look to see if water is clear, rather than looking at the quality of that particular water,” she says.

Upstream from the city

People who live in large towns and cities may think that upstream contamination doesn’t affect them. After all, water treatment plants protect them, removing heavy metals, bacteria, viruses and more from their tap water. But the tap water in large towns and cities often come from rivers upstream. And there is another type of contamination that slips right through almost all water treatment plants—the medicines other people use upstream. They are not filtered by their wastewater treatment plants; the medicines end up in the rivers supplying drinking water to cities and towns downstream.

Pharma in our own taps

“What I can say to a city person is, not all clear water means clean. As researchers, we know the challenges with pollutants. Water treatment plants cannot remove pharmaceuticals. But we release pharmaceuticals ourselves into wastewater on a daily basis,” says Nomngongo.”In the cities, we get medications because we have medical aids (health insurance). Sometimes, we don’t care and say, “I am healed now’ and throw our medicines away. The easiest way to do it is to flush it down the toilet. We don’t think that this might come back to us through our own tap.”

Treatment plants only do so much

“The technologies at wastewater plants remove some pollutants, but not everything,” says Dr. Mpingana Akawa. She lives near the Orange River in Namibia. Dr. Akawa conducted the experimental work for the research as part of her Ph.D. studies at the university of Johannesburg.

“Pharmaceuticals are regarded as emerging organic pollutants. We need to remember that most pharmaceuticals are not regulated. Hence, there are no limits on how much should be in the effluent of a wastewater treatment plant before it is discharged into the environment. Because they are not regulated, people are not really monitoring these things before releasing the treated wastewater. I think that is where the whole problem is,” adds Akawa.

Stuck between need and pollution

One of the reasons pharmaceuticals in wastewater are not yet regulated, is because a ‘cocktail’ of many of these are released daily into rivers. Sometimes, this makes it very difficult to make rules about this, says Nomngongo. One reason water treatment plants are not designed to remove pharmaceuticals is because they are present in water at very low concentrations, she adds.

There is also the tension between individual medical treatment and collective water management. “Mothers living with HIV have to use Nevirapine to prevent transmitting the virus to their babies. If you started regulating ARVs, how would you regulate Nevirapine in wastewater? We are stuck between a need and pollution.”

Nevirapine is also used as part of combination therapy for people who are on antiretroviral treatments. “The wastewater from our homes goes to a wastewater treatment plant. There it is treated in multiple stages. In the end, the treated water is released into the nearest river. That is why most of these plantsare built close to a river or stream. And if that water is not treated well, it means that the river close by will be contaminated by some of the pollutants of the treatment plant,” she adds.

FOR MORE INFORMATION: https://phys.org/news/2021-11-hiv-drugs.html

Scientists are inching closer to revealing the elusive mechanisms that tiny marine species activate to transform organic contaminants in water into less toxic chemicals

Cup sea water in your hands and you will be holding a bustling world of single-cell organisms—thousands of them. 

Much like creatures of an undersea metropolis, microscopic photosynthetic microbes—phytoplankton—quietly float through the ocean, enhancing water quality. As the foundation for the ocean ecosystem, phytoplankton work tirelessly to fuel marine food webs and consume large amounts of carbon dioxide on scales equivalent to forests. But this is not all they can do. These tiny plants may turn organic contaminants into less toxic chemicals. 

Sounds simple, but it’s not. The processes involved remain elusive. 

Synthetic chemicals in the environment

Water pollution, once an invisible, silent threat, is now a top environmental concern worldwide. 

“Millions of tons of synthetic organic chemicals are used for industrial, agricultural and consumers’ purposes annually. These compounds partially find their way to the aquatic environment, impairing water quality and undermining aquatic life,” said Giulia Cheloni, an environmental scientist studying phytoplankton’s responses to carbon-based contaminants. 

These pollutants are described as contaminants of emerging concern because of their potential risk to human health and ecological impacts. They can be found in personal care products like fragrances, disinfectants and sunscreen agents, as well as household items such as solvents, fabric protectors and flame retardants. 

Can powerful phytoplankton clean up contaminants?

Scientists are studying how organic contaminants affect phytoplankton.

FOR MORE INFORMATION: https://phys.org/news/2021-11-smaller-grain-sand-phytoplankton-key.html

For more than a decade, fertilizer leaching and associated stormwater runoff were thought to be the major drivers of harmful algal blooms in Florida’s Indian River Lagoon. Despite the numerous residential fertilizer ordinances passed since 2011, water quality, harmful algal blooms, and seagrass loss, which has resulted in mass deaths of the threatened Florida manatee, have continued to worsen.

There are more than 300,000 septic systems permitted in six counties adjacent to the 156-mile-long Indian River Lagoon, which makes up 40 percent of Florida’s eastern coast, and in Indian River and Martin counties, septic systems represent more than 50 percent of wastewater disposal. Five inlets allow the lagoon’s waters to drain into the ocean, potentially impacting another important Florida ecosystem.    

To determine if septic systems in Indian River County contribute to nutrient enrichment of groundwaters and surface waters that discharge into the central Indian River Lagoon, researchers from Florida Atlantic University’s Harbor Branch Oceanographic Institute assessed water quality at 20 sites in four Indian River County sub-drainage basins.

For the study, published in the journal Marine Pollution Bulletin, they measured stable nitrogen isotopes in groundwater, surface water, and macrophyte tissue to identify nitrogen sources impacting the Indian River Lagoon. Sucralose, an artificial sweetener that is not completely broken down by septic systems or wastewater treatment plants, was used as a human wastewater tracer, and fecal indicator bacteria density was used as an indicator of wastewater pollution.

Results reveal that nitrogen enrichment of all sub-drainage basins in this study supports that even “properly functioning” septic systems contribute nitrogen to surficial (shallow) groundwater. Furthermore, shallow ecosystems without a significant source of flushing and dilution, such as the central Indian River Lagoon are more susceptible to inputs from contaminated groundwater. Evidence shows that this issue is likely widespread in the Indian River Lagoon, including its canals, tributaries and rivers.

Groundwater had significantly higher dissolved nutrient concentrations, nutrient ratios and more enriched stable nitrate isotopes than surface waters, indicating septic system-enriched groundwater as a nitrogen source to adjacent surface waters. This finding has implications for nutrient loading and pollution, as submarine groundwater discharge is a primary mechanism for nutrient and microbial transport to coastal waters.

FOR MORE INFORMATION: https://phys.org/news/2021-12-septic-pervasive-florida-indian-river.html