64% of global agricultural land at risk of pesticide pollution?

The study, published in Nature Geoscience, produced a global model mapping pollution risk caused by 92 chemicals commonly used in agricultural pesticides in 168 countries.

The study examined risk to soil, the atmosphere, and surface and ground water.

The map also revealed Asia houses the largest land areas at high risk of pollution, with China, Japan, Malaysia, and the Philippines at highest risk. Some of these areas are considered “food bowl” nations, feeding a large portion of the world’s population.

University of Sydney Research Associate and the study’s lead author, Dr Fiona Tang, said the widespread use of pesticides in agriculture — while boosting productivity — could have potential implications for the environment, human and animal health.

“Our study has revealed 64 percent of the world’s arable land is at risk of pesticide pollution. This is important because the wider scientific literature has found that pesticide pollution can have adverse impacts on human health and the environment,” said Dr Tang.

Pesticides can be transported to surface waters and groundwater through runoff and infiltration, polluting water bodies, thereby reducing the usability of water resources.

“Although the agricultural land in Oceania shows the lowest pesticide pollution risk, Australia’s Murray-Darling basin is considered a high-concern region both due to its water scarcity issues, and its high biodiversity,” said co-author Associate Professor Federico Maggi from the School of Civil Engineering and the Sydney Institute of Agriculture.

“Globally, our work shows that 34 percent of the high-risk areas are in high-biodiversity regions, 19 percent in low-and lower-middle-income nations and five percent in water-scarce areas,” said Dr Tang.

There is concern that overuse of pesticides will tip the balance, destabilise ecosystems and degrade the quality of water sources that humans and animals rely on to survive.

The future outlook

Global pesticide use is expected to increase as the global population heads towards an expected 8.5 billion by 2030.

“In a warmer climate, as the global population grows, the use of pesticides is expected to increase to combat the possible rise in pest invasions and to feed more people,” said Associate Professor Maggi.

Dr Tang said: “Although protecting food production is essential for human development, reducing pesticide pollution is equivalently crucial to protect the biodiversity that maintains soil health and functions, contributing towards food security.”

Co-author Professor Alex McBratney, Director of the Sydney Institute of Agriculture at the University of Sydney, said: “This study shows it will be important to carefully monitor residues on an annual basis to detect trends in order to manage and mitigate risks from pesticide use.”

“We recommend a global strategy to transition towards a sustainable, global agricultural model that reduces food wastage while reducing the use of pesticides,” said the authors of the paper.

FOR MORE INFORMATION: University of Sydney

Stanford study reveals a deepening water crisis in Jordan – and a way forward

Dwindling water supplies and a growing population will halve per capita water use in Jordan by the end of this century. Without intervention, few households in the arid nation will have access to even 40 liters (10.5 gallons) of piped water per person per day.

Low-income neighborhoods will be the hardest hit, with 91 percent of households receiving less than 40 liters daily for 11 consecutive months per year by 2100.

Those are among the sobering predictions of a peer-reviewed paper by an international team of 17 researchers published March 29 in Proceedings of the National Academy of Sciences.

Jordan’s deepening water crisis offers a glimpse of challenges that loom elsewhere as a result of climate change, population growth, intensifying water use, demographic shocks and heightened competition for water across boundaries, said study co-author and Stanford hydrologist Steve Gorelick, who directs the Global Freshwater Initiative at Stanford’s Woods Institute for the Environment. The World Health Organization estimates half of humanity may live in water-stressed areas by 2025, and the United Nations anticipates water scarcity could displace 700 million people by 2030.

In Jordan, flows in the region’s biggest river system — the Jordan-Yarmouk — have declined as a result of upstream diversion in Israel and Syria. Groundwater levels in some areas have dropped by more than 1 meter per year, and a major aquifer along Jordan’s boundary with Saudi Arabia is heavily pumped on both sides of the border.

Demand for water has climbed largely because of population growth punctuated by waves of refugees, including more than 1 million Syrian refugees in the past decade.

Extreme water scarcity and wide disparities in public water supplies are potent ingredients for conflict. Jordan’s water situation — long deemed a crisis — is now on the brink of “boiling over” into instability, said lead study author Jim Yoon, a water security and resilience scientist at Pacific Northwest National Laboratory.

“Jordan’s unique role as a bastion of peace in the region makes these findings all the more cause for concern,” said Yoon, who began work on the study as a PhD student at Stanford University.

The U.N. has committed to ensuring sustainable freshwater management and universal access to clean water and sanitation as one of its 17 sustainable development goals. But until now, analytic frameworks have been lacking, said Gorelick, who led the Jordan Water Project and its continuation, the FUSE Project (Food-water-energy for Urban Sustainable Environments).

The new predictions derive from a first-of-its-kind computer model of Jordan’s freshwater system that simulates interactions among natural processes and human behaviors. Under a range of climate and socioeconomic scenarios, the researchers quantified the effects of maintaining status quo versus introducing measures such as fixing leaky pipes, eliminating water theft, raising tariffs for big water users and reallocating a quarter of water from farms to cities.

The team’s modeling suggests efforts to simultaneously increase supply, slash demand and reform distribution are likely to deliver “exponential” improvements in national water security.

Access to Jordan’s public water supply today is highly unequal, with wealthier households and firms often supplementing rationed municipal supplies with costly deliveries from private tanker truck operators. German economist and study co-author Christian Klassert said, “Avoiding large disparities in public water supply will be necessary to avoid water stress under growing water scarcity in Jordan and regions around the world.”

The many facets of Jordan’s water crisis make it an especially valuable place to explore the impacts of individual versus simultaneous interventions, Gorelick said. Now that a model exists for this complex environment, it can be adapted with relative ease to other regions.

The single most effective step Jordan can take is to increase supply through large-scale desalination. One proposal among many Jordan has pursued to this end since the 1960s would desalinate water from the Red Sea in the south, transport freshwater north to the capital city Amman and dispose of the leftover highly saline water in the rapidly shrinking Dead Sea.

While water policy debates often present selected supply and demand interventions as opposing alternatives, the authors write, suites of interventions in both modes actually work best in concert.

“You would think that any one of these interventions would have a greater impact. But it turns out you have to do everything,” Gorelick said.

For a country whose economic output per person is less than one-tenth that of the U.S., the scale and cost of near-total reform of its water sector are particularly daunting. “In water-scarce regions where sustainability planning is most needed, it is challenging to think beyond how to distribute scarce freshwater tomorrow, next month, and to some extent, in the next several years,” Gorelick said. “It’s in these places where our long-term policy evaluations are most valuable.”

FOR MORE INFORMATION: Stanford University

Even small levels of nitrate in drinking water results in smaller babies

Full Disclosure | EWG

It appears that the weight of newborn babies decreases if even small amounts of nitrates are present in the drinking water that mothers drink before and during pregnancy. This is shown by a major new register-based study carried out by researchers at the universities in Aarhus and Chicago, USA. They now question whether the threshold value is too high.

The more nitrate there is in mothers’ drinking water, the smaller the babies they give birth to. But alarmingly, the declining birth weight can also be registered when the women are exposed to nitrate levels below the EU’s threshold of 50 milligrams of nitrate per litre.

This is shown by a register-based study of more than 850,000 births in Denmark carried out in a Danish-American partnership led by Professor Torben Sigsgaard from the Department of Public Health at Aarhus University and Professor Leslie Stayner and Dr. Vanessa Coffman from the Division of Epidemiology and Biostatistics at the University of Illinois at Chicago, School of Public Health.

On the basis of Danish registry data, the research group concluded that babies born to mothers whose drinking water contains between 25 and 50 milligrams of nitrates per litre — i.e. from half of the current threshold value up to the maximum limit — on average weigh ten grams less than babies born to mothers with smaller amounts of nitrate in the tap water. Not only did the babies weigh less, they were also slightly shorter, while their head size was unaffected by the amount of nitrate — which is the form of nitrogen run off from the agricultural sector that most frequently appears in groundwater.

According to Professor Torben Sigsgaard from Aarhus University, it is difficult to say whether we should be concerned about public health in areas with high amounts of nitrate:

“The difference in body length and weight doesn’t sound like much at first as it’s on average only ten grams, but this is not insignificant if the newborn also begins life as underweight for other reasons. Birth weight is generally recognised as having a life-long impact on a person’s health and development,” says Torben Sigsgaard.

“There is no doubt that the results of the study challenge the threshold value that is in place throughout the Western world, and that any changes will be a bit like turning around a supertanker. But it’s important to discuss these results,” he adds with reference to the WHO, EU and American authorities who all view drinking water as harmful when the content of nitrates is higher than fifty milligrams per litre.

The study was initiated because it has long been known that very high nitrate concentrations may lead to people being exposed to nitrite. This inhibits the body’s ability to absorb oxygen and can lead to the dangerous blue-baby syndrome, or methemoglobinemia to give it its medical name. Nitrate in drinking water is also suspected of causing other chronic diseases, including bowel cancer. Research has also documented how, depending on local geological and geochemical conditions in theearth, the fertiliser used in agriculture more or less percolates down to the groundwater.

“With the study, we’ve established that there is a need to explore the effect of the low nitrate concentrations in the drinking water, if we’re to assess the adequacy of the current threshold values — and this is possible thanks to the unique Danish registers. It wouldn’t be possible to carry out corresponding studies on the basis of US data alone, because such data simply doesn’t exist,” says Torben Sigsgaard.

The research results — more information

The register-based study compares data from more than 850,000 births in Denmark during the period 1991-2011 including the weight, height and head size of the newborn babies — before in turn comparing this with the content of nitrate in drinking water via the parents’ place of residence and the GEUS Jupiter register, which contains information about the quality of drinking water in Danish households based on more than 300,000 nitrate samples from routine water quality monitoring. GEUS stands for Geological Survey of Denmark and Greenland.

Vanessa Coffman and Leslie Stayner from the University of Illinois, Chicago (UIC) and Jörg Schullehner and Birgitte Hansen from GEUS, were important partners on the project. Additional contributions came from colleagues at Aarhus University, including the “Drinking water group” under the Center for Integrated Register-based Research (CIRRAU), as well as researchers from the University of Copenhagen.

The study is financed by the National Institute of Environmental Health Sciences (NIEHS), USA.

Journal Reference:

  1. Vanessa R. Coffman, Anja Søndergaard Jensen, Betina B. Trabjerg, Carsten B. Pedersen, Birgitte Hansen, Torben Sigsgaard, Jørn Olsen, Inger Schaumburg, Jörg Schullehner, Marie Pedersen, Leslie T. Stayner. Prenatal Exposure to Nitrate from Drinking Water and Markers of Fetal Growth Restriction: A Population-Based Study of Nearly One Million Danish-Born ChildrenEnvironmental Health Perspectives, 2021; 129 (2): 027002 DOI: 10.1289/EHP7331

FOR MORE INFORMATION: Aarhus University

MIT engineers make filters from tree branches to purify drinking water

Xylem tissue in gymnosperm sapwood

The interiors of nonflowering trees such as pine and ginkgo contain sapwood lined with straw-like conduits known as xylem, which draw water up through a tree’s trunk and branches. Xylem conduits are interconnected via thin membranes that act as natural sieves, filtering out bubbles from water and sap.

MIT engineers have been investigating sapwood’s natural filtering ability, and have previously fabricated simple filters from peeled cross-sections of sapwood branches, demonstrating that the low-tech design effectively filters bacteria.

Now, the same team has advanced the technology and shown that it works in real-world situations. They have fabricated new xylem filters that can filter out pathogens such as E. coli and rotavirus in lab tests, and have shown that the filter can remove bacteria from contaminated spring, tap, and groundwater. They also developed simple techniques to extend the filters’ shelf-life, enabling the woody disks to purify water after being stored in a dry form for at least two years.

The researchers took their techniques to India, where they made xylem filters from native trees and tested the filters with local users. Based on their feedback, the team developed a prototype of a simple filtration system, fitted with replaceable xylem filters that purified water at a rate of one liter per hour.

Their results, published today in Nature Communications, show that xylem filters have potential for use in community settings to remove bacteria and viruses from contaminated drinking water.

The researchers are exploring options to make xylem filters available at large scale, particularly in areas where contaminated drinking water is a major cause of disease and death. The team has launched an open-source website, with guidelines for designing and fabricating xylem filters from various tree types. The website is intended to support entrepreneurs, organizations, and leaders to introduce the technology to broader communities, and inspire students to perform their own science experiments with xylem filters.

“Because the raw materials are widely available and the fabrication processes are simple, one could imagine involving communities in procuring, fabricating, and distributing xylem filters,” says Rohit Karnik, professor of mechanical engineering and associate department head for education at MIT. “For places where the only option has been to drink unfiltered water, we expect xylem filters would improve health, and make water drinkable.”

Karnik’s study co-authors are lead author Krithika Ramchander and Luda Wang of MIT’s Department of Mechanical Engineering, and Megha Hegde, Anish Antony, Kendra Leith, and Amy Smith of MIT D-Lab.

Clearing the way

In their prior studies of xylem, Karnik and his colleagues found that the woody material’s natural filtering ability also came with some natural limitations. As the wood dried, the branches’ sieve-like membranes began to stick to the walls, reducing the filter’s permeance, or ability to allow water to flow through. The filters also appeared to “self-block” over time, building up woody matter that clogged the conduits.

Surprisingly, two simple treatments overcame both limitations. By soaking small cross-sections of sapwood in hot water for an hour, then dipping them in ethanol and letting them dry, Ramchander found that the material retained its permeance, efficiently filtering water without clogging up. Its filtering could also be improved by tailoring a filter’s thickness according to its tree type.

The researchers sliced and treated small cross-sections of white pine from branches around the MIT campus and showed that the resulting filters maintained a permeance comparable to commercial filters, even after being stored for up to two years, significantly extending the filters’ shelf life.

The researchers also tested the filters’ ability to remove contaminants such as E. coli and rotavirus — the most common cause of diarrheal disease. The treated filters removed more than 99 percent of both contaminants, a water treatment level that meets the “two-star comprehensive protection” category set by the World Health Organization.

“We think these filters can reasonably address bacterial contaminants,” Ramchander says. “But there are chemical contaminants like arsenic and fluoride where we don’t know the effect yet,” she notes.

Groundwork

Encouraged by their results in the lab, the researchers moved to field-test their designs in India, a country that has experienced the highest mortality rate due to water-borne disease in the world, and where safe and reliable drinking water is inaccessible to more than 160 million people.

Over two years, the engineers, including researchers in the MIT D-Lab, worked in mountain and urban regions, facilitated by local NGOs Himmotthan Society, Shramyog, Peoples Science Institute, and Essmart. They fabricated filters from native pine trees and tested them, along with filters made from ginkgo trees in the U.S., with local drinking water sources. These tests confirmed that the filters effectively removed bacteria found in the local water. The researchers also held interviews, focus groups, and design workshops to understand local communities’ current water practices, and challenges and preferences for water treatment solutions. They also gathered feedback on the design.

“One of the things that scored very high with people was the fact that this filter is a natural material that everyone recognizes,” Hegde says. “We also found that people in low-income households prefer to pay a smaller amount on a daily basis, versus a larger amount less frequently. That was a barrier to using existing filters, because replacement costs were too much.”

With information from more than 1,000 potential users across India, they designed a prototype of a simple filtration system, fitted with a receptacle at the top that users can fill with water. The water flows down a 1-meter-long tube, through a xylem filter, and out through a valve-controlled spout. The xylem filter can be swapped out either daily or weekly, depending on a household’s needs.

The team is exploring ways to produce xylem filters at larger scales, with locally available resources and in a way that would encourage people to practice water purification as part of their daily lives — for instance, by providing replacement filters in affordable, pay-as-you-go packets.

“Xylem filters are made from inexpensive and abundantly available materials, which could be made available at local shops, where people can buy what they need, without requiring an upfront investment as is typical for other water filter cartridges,” Karnik says. “For now, we’ve shown that xylem filters provide performance that’s realistic.”

Journal Reference:

  1. Krithika Ramchander, Megha Hegde, Anish Paul Antony, Luda Wang, Kendra Leith, Amy Smith, Rohit Karnik. Engineering and characterization of gymnosperm sapwood toward enabling the design of water filtration devicesNature Communications, 2021; 12 (1) DOI: 10.1038/s41467-021-22055-w

FOR MORE INFORMATION:  Massachusetts Institute of Technology

‘Climbing droplets’ could lead to more efficient water harvesting

Dr. Xianming Dai, assistant professor of mechanical engineering in the Erik Jonsson School of Engineering and Computer Science, and his research team have been working to develop technology that harvests clean water from the air without using external energy.

University of Texas at Dallas researchers have discovered that a novel surface they developed to harvest water from the air encourages tiny water droplets to move spontaneously into larger droplets.

When researchers placed microdroplets of water on their liquid-lubricant surface, the microdroplets propelled themselves to climb, without external force, into larger droplets along an oily, ramp-shaped meniscus that forms from the lubricant around the larger droplets. The “coarsening droplet phenomenon” formed droplets large enough for harvesting.

“This meniscus-mediated climbing effect enabled rapid coalescence on hydrophilic surfaces and has not been reported before. We have discovered a new physical phenomenon that makes it possible to harvest water more rapidly from air without external force,” said Dr. Xianming Dai, assistant professor of mechanical engineering in the Erik Jonsson School of Engineering and Computer Science, who led the work. “If we don’t have this new phenomenon, the droplets would be too small, and we could hardly collect them.”

Microdroplets of water on a hydrophilic SLIPS surface (left) propel themselves to climb, without external force, into larger droplets along an oily, ramp-shaped meniscus that forms from the lubricant around the larger droplets. On the right, the video clip shows how microdroplets behave on a solid slippery surface.

The findings, published March 25 in Cell Reports Physical Science, could solve key problems in harvesting water from air. Many droplets that condense from water vapor in the air are too small to be collected, and they can cover a surface in a way that impedes further condensation.

Developing new technologies that harvest water from the atmosphere is a growing field of research as more and more people live in areas where fresh water is in short supply. Scientists estimate that 4 billion people live in regions with severe freshwater shortages for at least one month each year. This number is predicted to rise to between 4.8 billion and 5.7 billion by 2050. Reasons include climate change, polluted water supplies and increased demand due to both population growth and changes in usage behavior.

The key to the microdroplet’s self-climbing action is a surface that Dai and his colleagues previously developed. Their liquid lubricant, a hydrophilic slippery liquid-infused porous surface (SLIPS), has a unique hydrophilic nature for water harvesting and rapidly directs water droplets into reservoirs.

Researchers discovered the self-propelling droplet phenomenon on their surface by accident. They were testing different lubricants to determine which could best facilitate water harvesting when they saw the smaller water droplets propel themselves into larger droplets. That led them to collaborate with Dr. Howard A. Stone, chair of mechanical and aerospace engineering at Princeton University and an expert in fluid dynamics, to investigate the underlying physics of the phenomenon.

“Dr. Dai and his team led this work. The ideas are creative, and they made a series of observations in the laboratory that allowed them to understand the underlying physics and its potential applications,” Stone said. “They reached out to me to discuss the mechanism, and we had several Skype or Zoom meetings and email exchanges. It was all very interesting and stimulating. I enjoyed very much seeing the ideas evolve into the published paper.”

As water vapor condenses on the liquid-lubricant surface, oil from the lubricant forms a meniscus, or curvature, around the droplets. The meniscus looks like an upward-curving ramp, which acts like a bridge along which microdroplets spontaneously climb toward and coalesce with larger water droplets, a process the researchers call the coarsening effect. The properties of the lubricated surface prevent the water droplets from being completely submerged in the oil, so they can float on the oil, allowing them to climb.

“The oil meniscus acts like a bridge, so the droplet can climb on it,” Dai said. “The small droplet actively looks for a larger one. After they are connected by the bridge, they become one.”

As tiny water droplets condense from air on a cooled surface, they become thermal barriers that prevent further condensation. By allowing for rapid water droplet collection, the coarsening droplets help clear surfaces for new droplets to form, which facilitates faster, more efficient water harvesting.

The self-propelled coarsening droplet on hydrophilic SLIPS shows rapid removal of condensed submicrometer-sized droplets regardless of how the surface is oriented, which presents a promising approach compared to other surfaces used for water harvesting.

“We cannot harvest a large amount of water unless we have a rapid harvesting process. The problem with other surfaces is that the small water droplets may evaporate before they can be harvested,” Dai said.

“Based on our experimental data, the coarsening surface enhanced the water harvesting rate 200% higher than its counterparts,” said Zongqi Guo, a mechanical engineering doctoral student and co-lead author. Dai and his colleagues continue to work on ways to use their lubricant to make sustainable water harvesting systems that are mobile, smaller in size, lower in weight and less expensive.

“If we can do that, we can harvest water anywhere that has air, which is particularly important in regions where water is scarce,” Dai said.

The research was funded by the National Science Foundation and the Army Research Office.

Journal Reference:

  1. Zongqi Guo, Lei Zhang, Deepak Monga, Howard A. Stone, Xianming Dai. Hydrophilic slippery surface enabled coarsening effect for rapid water harvestingCell Reports Physical Science, 2021; 100387 DOI: 10.1016/j.xcrp.2021.100387

FOR MORE INFORMATION: University of Texas at Dallas

Hopes Low for Progress at India, Pakistan’s First River-Sharing Talks in Three Years

Reuters

NEW DELHI (Reuters) – An Indian official played down on Tuesday prospects for a breakthrough at the first talks in three years with neighbouring Pakistan aimed at resolving long-running disputes over hydroelectric projects on the shared Indus River.

Pakistan is concerned that India’s plans for hydroelectric plants in the disputed Himalayan region of Kashmir will damage the flow of the river, which feeds 80% of its irrigated agriculture, along with tributaries.

India has defended the construction of its Pakal Dul and Lower Kalnai dams, saying they are allowed by the Indus Water Treaty brokered by the World Bank.

“It is our job to find a middle path. But to say we can achieve something is maybe a bit too optimistic,” an Indian official involved in the talks in New Delhi told Reuters.

“There are many things on which we can’t compromise,” added the official, who spoke on condition of anonymity because of the sensitive nature of the discussions.

India issued no statement on the talks, which are set to end on Wednesday.

The talks come after a gap of three years because of tension over Kashmir, the Muslim-majority territory both south Asian nations claim in full.

In recent weeks, the nuclear-armed rivals have taken tentative steps to improve ties, such as a rare military pact last month to stop firing on the Kashmir border that has killed scores of civilians.

FOR MORE INFORMATION: https://www.usnews.com/news/world/articles/2021-03-23/hopes-low-for-progress-at-india-pakistans-first-river-sharing-talks-in-three-years

The water fight over the shrinking Colorado River

Marsha with her cattle
Marsha Daughenbaugh depends on the Colorado River to grow feed for her cattle

Scientists have been predicting for years that the Colorado River would continue to deplete due to global warming and increased water demands, but according to new studies it’s looking worse than they thought.

That worries rancher Marsha Daughenbaugh, 68, of Steamboat Springs, who relies on the water from the Colorado River to grow feed for her cattle.

“That water is our lifeblood and without it we would not have the place that we do,” says Daughenbaugh, who was raised on this ranch and is hoping to pass it down to her children and the next generation.

“Ranching is not only an economic base for us, it’s a way of life.”

Three generations of ranchers in Steamboat Springs
Three generations of ranchers have grown up relying on water from the Colorado River to support their way of life

But with a two-decade drought in the southwestern US and record-low snowfalls, that lifestyle could be in jeopardy.

“Things seem to be happening even faster than the models or scientists were warning just a few years ago,” says Brad Udall, a water and climate scientist at Colorado State University. “If you’re not worried about all this, you’re not paying attention.”

Recent reports show that the river’s water flows were down 20% in 2000 and by 2050 that number is estimated to more than double.

This aerial view shows the Colorado River, south of Las Vegas, on 6 February, 2020.
This aerial view shows the Colorado River, south of Las Vegas

It’s a problem we can’t engineer our way out of any longer, Udall says.

“We have massive dams on the Colorado River already. A bigger bank account with less income doesn’t do you a whole lot of good,” he warns.

Many, like Jim Lochhead, agree there is only one solution – use less water.

“Despite the complexities of how we reach the solutions, the problem is really quite simple. It’s a mass balance equation. We have too many demands and not enough water,” says Lochhead, CEO of Denver Water, Colorado’s largest water utility.

“And so at the end of the day, demands overall will need to be reduced and managed in order to keep the bank account solvent.”

Jim Lochhead poses in front of a Colorado River dam
Jim Lochhead says water use needs to go down in order to manage the deficit

But limiting water usage will be tricky.

The Colorado River provides water to more than 40 million people across seven southwestern states, 29 tribal nations and Mexico – and a lot of major cities in those states are heavily dependent on that water.

In Las Vegas, 90% of its water supply comes from the river. In Phoenix and Denver it’s 50% and in Los Angeles it’s 25%.

According to a 1922 agreement, each of these seven states have a legal right to a certain amount of the river’s water. But this compact was made under the assumption that there was more water than there actually was.

The Colorado River seen from the Grand Canyon
Here is what the Colorado River looks like from the Grand Canyon

“On paper we’ve allocated 30% more water than what’s in the river today,” says Eric Kuhn, the former General Manager of the Colorado River District.

“And the science suggests that we got a situation where climate change has impacted it even more. The river is probably a third smaller than what was anticipated when the contract was negotiated.”

That means officials will have to figure out how to share an amount of water that in reality doesn’t exist – and is shrinking.

Another factor in this equation are the various tribes who have legal rights to 20% of the river’s water, yet don’t have equal access.

Shanna Yazzie of the Navajo Nation is one such example.

Every day, the 39-year-old has to leave her home with buckets to go get water from a local water tank. She’s not alone. One-third of the 350,000 residents on the Navajo Indian Reservation don’t have running water.

Shanna Yazzie fills a bucket of water from the local water tank
image captionShanna Yazzie has no running water at home and gets her water from a nearby water tank

“We work, I would say, eight times harder than anybody just to make sure we have water, and pre-planning throughout the day, pre-planning throughout the week. When and where am I going to get water?” says Yazzie.

And during the global pandemic, limited water access has been even more frustrating.

“My kids and myself are all at home, all the time and we are relying on that water more and more each week,” Yazzie says. “And when we go to get water we have to ask, is it going to be safe, are there lots of people out there at the water point? There are so many more factors now.”

When the 1922 agreement was signed, not a single tribe had a seat at the table. Daryl Vigil, co-director of Water and Tribes in the Colorado River Basin, calls this “the institutional theft of tribal water”.

Sadly, Vigil says, this fight for water access is still ongoing.

“Somebody is using tribal water for free and you know once again tribes are not able to utilise that on their own reservations. And what is the impact of those things?” he asks. “Tribes and tribal sovereigns are still 19 times more likely not to have indoor plumbing, I mean in 2021.”

While tribes fight for more water access, those in the agricultural community are fighting to keep the water they have.

More than 70% of the Colorado River’s flow is consumed by agriculture. But as the river dries, eventually a lot of it will have to leave these communities to sustain cities and suburbs, meaning less water for farmers and ranchers like Marsha Daughenbaugh.

Marsha Daughenbaugh and her family at her ranch
Marsha Daughenbaugh hopes to pass her ranch on to her children

But Daughenbaugh is not naive. She knows there are a lot of competing stakeholders and not enough supply to go around, so collaboration, she says, will be key.

“There are so many diverse interests against this water that we just have to work together regardless of what industry we are coming from,” she says.

One of the proposed ideas is to pay farmers and ranchers to use less water to build up reservoirs in times of crisis but at what cost is unclear.

The river’s existing management guidelines are set to expire in 2026, meaning these hard questions about conservation can’t be put off much longer.

FOR MORE INFORMATION: BBC: The water fight over the shrinking Colorado River

Water: the game changer for food systems

A Food Systems Summit will be convene as part of the Decade of Action to achieve the Sustainable Development Goals (SDGs) by 2030.

The culminating Summit gathering will take place in New York in September 2021 in conjunction with the UN General Assembly. This will be preceded by a pre-Summit gathering in Italy in July 2021.

The Food Systems Summit Dialogues will offer a powerful opportunity for people everywhere to have a seat at the table at this milestone UN Summit. Dialogues will bring together a diversity of stakeholders, including voices that are seldom heard, and provide an important opportunity for participants to debate, collaborate, and take action towards a better future.

Water: The Game Changer for Food Systems – a Global Summit Dialogue
Dr. Agnes Kalibata, UN Secretary General’s Special Envoy to the Food Systems Summit; and Gilbert F. Houngbo, UN-Water Chair and President of the International Fund for Agriculture Development, are convening an online global dialogue on water on 27 April. The dialogue will explore the fundamental inter-connections between food systems and water systems, and their relations to other areas fundamental to the Sustainable Development Goals, such as energy, climate, and the environment.

Participants will be invited to explore how water is an essential ingredient for sustainable food systems to:

  • ensure access to safe and nutritious food for all
  • shift to sustainable consumption patterns
  • boost nature-positive production
  • advance equitable livelihoods
  • and build resilience to vulnerabilities, shocks and stress

The event will also build on the learnings that are arising on water and food systems in national and regional dialogues. Major water challenges that are threatening local and international food systems will be unpacked.

  • Find more information about the Water: The Game Changer for Food Systems – a Global Summit Dialogue here.

FOR MORE INFORMATION: United Nations Water

New UNICEF publication address water insecurity

The world is in a water crisis, and children’s lives and futures are at risk. Todayover 1.42 billion people – including 450 million children – live in areas of high or extremely high water vulnerability.

Decades of water misuse, over-extraction and contamination of freshwater supplies have exacerbated water stress. Simultaneously, demand for water is rising due to rapid population growth, urbanization and increasing water needs from a range of sectors including agriculture, industry and energy. Climate change further compounds water scarcity through changing precipitation patterns and extreme weather events.

In conjunction to World Water Day, UNICEF launched Water Security for All, a programmatic and advocacy initiative to address water insecurity and the global water crisis.

FOR MORE INFORMATION: United Nations Water

Scientists develop eco-friendly pollen sponge to tackle water contaminants

A team of scientists led by Nanyang Technological University, Singapore (NTU Singapore) has created a reusable, biodegradable sponge that can readily soak up oil and other organic solvents from contaminated water sources, making it a promising alternative for tackling marine oil spills.

Made of sunflower pollen, the sponge is hydrophobic — it repels water — thanks to a coat of natural fatty acid on the sponge. In lab experiments, the scientists showed the sponge’s ability to absorb oil contaminants of various densities, such as gasoline and motor oil, at a rate comparable to that of commercial oil absorbents.

Oil spills are difficult to clean up, and result in severe long-lasting damage to the marine ecosystem. Conventional clean-up methods, including using chemical dispersants to break oil down into very small droplets, or absorbing it with expensive, unrecyclable materials, may worsen the damage.

So far, the researchers have engineered sponges that measure 5 cm in diameter. The research team, made up of scientists from NTU Singapore and Sungkyunkwan University in South Korea, believes that these sponges, when scaled up, could be an eco-friendly alternative to tackle marine oil spills.

Professor Cho Nam-Joon from the NTU School of Materials Science and Engineering, who led the study, said: “By finetuning the material properties of pollen, our team successfully developed a sponge that can selectively target oil in contaminated water sources and absorb it. Using a material that is found abundantly in nature also makes the sponge affordable, biodegradable, and eco-friendly.”

This study builds on NTU’s body of work on finding new uses for pollen, known as the diamond of the plant kingdom for its hard exterior, by transforming its tough shell into microgel particles. This soft, gel-like material is then used as a building block for a new category of environmentally sustainable materials.

Last year, Prof Cho, together with NTU President Professor Subra Suresh, led a research team to create a paper-like material from pollen as a greener alternative to paper created from trees. This ‘pollen paper’ also bends and curls in response to changing levels of environmental humidity, a trait that could be useful for soft robots, sensors, and artificial muscles.

Prof Cho, who also holds the Materials Research Society of Singapore Chair in Materials Science and Engineering, added: “Pollen that is not used for plant pollination is often considered biological waste. Through our work, we try to find new uses for this ‘waste’ and turn it into a natural resource that is renewable, affordable, and biodegradable. Pollen is also biocompatible. It does not cause an immunological, allergic or toxic reaction when exposed to body tissues, making it potentially suitable for applications such as wound dressing, prosthetics, and implantable electronics.”

The findings were published in the scientific journal Advanced Functional Materials in March.

Building a sponge from pollen

To form the sponge, the NTU team first transformed the ultra-tough pollen grains from sunflowers into a pliable, gel-like material through a chemical process akin to conventional soap-making.

This process includes removing the sticky oil-based pollen cement that coats the grain’s surface, before incubating the pollen in alkaline conditions for three days. The resulting gel-like material was then freeze-dried.

These processes resulted in the formation of pollen sponges with 3D porous architectures. The sponges were briefly heated to 200°C — a step that makes their form and structure stable after repeatedly absorbing and releasing liquids. Heating also led to a two-fold improvement in the sponge’s resistance to deformation, the scientists found.

To make sure the sponge selectively targets oil and does not absorb water, the scientists coated it with a layer of stearic acid, a type of fatty acid found commonly in animal and vegetable fat. This renders the sponge hydrophobic while maintaining its structural integrity.

The scientists performed oil-absorption tests on the pollen sponge with oils and organic solvents of varying densities, such as gasoline, pump oil, and n-hexane (a chemical found in crude oil).

They found that the sponge had an absorption capacity in the range of 9.7 to over 29.3 g/g.* This is comparable to commercial polypropylene absorbents, which are petroleum derivatives and have an absorption capacity range of 8.1 to 24.6 g/g.

They also tested the sponge for its durability and reusability by repeatedly soaking it in silicone oil, then squeezing the oil out. They found that this process could go on for at least 10 cycles.

In a final proof-of-concept experiment, the team tested the ability of a sponge 1.5cm in diameter and 5mm in height to absorb motor oil from a contaminated water sample. The sponge readily absorbed the motor oil in less than 2 minutes.

“Collectively, these results demonstrate that the pollen sponge can selectively absorb and release oil contaminants and has similar performance levels to commercial oil absorbents while demonstrating compelling properties such as low cost, biocompatibility, and sustainable production,” said Prof Cho, the corresponding author of this study.

Going forward, the researchers plan to scale up the size of pollen sponges to meet industry needs. They are also looking to collaborate with non-governmental organisations and international partners to conduct pilot tests with pollen sponges in real-life environments.

“We hope our innovative pollen materials can one day replace widely-used plastics and help to curb the global issue of plastic pollution,” said Prof Cho.

*g/gis a unit of measurementfor absorption capacity. It refers to how many grams of the contaminant can adhere to per gram of the material that absorbs

FOR MORE INFORMATION: Nanyang Technological University