Extensive iron and lead corrosion of the water distribution system in Flint, coupled with lead release, created “red water” complaints, rapid loss of chlorine disinfectant and an outbreak of Legionnaires Disease that killed 12 people. State and federal agencies have disbursed $450 million in aid so far. In August, the state of Michigan reached a mediated settlement in a civil suit and is expected to pay about $600 million to victims, many of whom are children.

“The Flint story is a cautionary tale of poor anticipation of risks, actions that were too little too late, reactionary and not driven by scientific data,” John R. Scully, University of Virginia Charles Henderson Chaired Professor of Materials Science and Engineering, said. Scully also serves as technical editor in chief of CORROSION Journal.

In a paper published Sept. 8 in the Proceedings of the National Academy of Sciences, Scully and Raymond J. Santucci, who earned his Ph.D. from UVA’s Department of Materials Science and Engineering in 2019, address unresolved scientific questions that can help avert future lead poisoning disasters. Lead poisoning from degrading lead pipes is a pervasive threat, and future incidents are likely.

“This requires a fresh perspective, to avoid just looking in the rearview mirror and instead focus on what lies around the curve ahead,” Scully said.

Commonly proposed strategies offer false comfort based on sparse water testing, rules of thumb, and traditional mitigation strategies rather than by rigorously challenged sound scientific principles, according to the paper’s authors.

“We need to better understand the scientific factors that govern lead release, and that starts with a better testing strategy and understanding of some fundamental truths,” Scully said.

Scully and Santucci argue that the people who manage and regulate public water systems should be using scientific data to predict the risks of lead release. Risk assessments based on scientific data should replace current reliance on water sampling, which is imprecise and often too late to prevent a disaster.

A predictive framework for lead corrosion would allow regulators and infrastructure managers to anticipate problems and manage the risk of water conditions associated with unacceptable lead release.

Santucci and Scully recommend better thermodynamic and kinetic calculations and models that can predict lead release and accumulation. The models proposed could generate risk assessments based on dynamic data such as water chemistry, reaction rates, scale formation and inhibitor corrosion mechanisms, as well as water stagnation and flow.

Citizen scientists can help meet the data-gathering challenge. “Rapid accurate testing, perhaps via mobile phone test kits, could provide more real-time data. Hand-held, mobile tech that enables citizens to monitor their own drinking water should have advanced already,” Scully said.

Santucci and Scully illustrate how chemical thermodynamics can predict the formation of thermodynamically stable lead-based compounds on lead pipe surfaces. Certain compounds form advantageous films that might act as kinetic barriers to hinder corrosion and function to sequester otherwise soluble lead.

“Stable film development depends on a certain equilibrium chemistry, with consequences for phosphate treatment,” Santucci said. “Add more phosphate and you can remove more soluble lead to form a protective lead phosphate film. Remove phosphate completely, and you then rely on hoping that other lead compounds (lead -carbonate, -sulfate, -oxide, etc.) can remove the levels of lead you need,” which is usually not the case.

In phosphate-treated water, a lead-phosphate film will form. “From our data, it is thermodynamically impossible to stay within the acceptable range of the EPA’s Lead and Copper rule without an inhibitor like phosphate. But it takes time for the scale to form. We need to explore new inhibitor chemicals and surface-altering agents that optimize the protective scale coverage on a pipe wall,” Santucci said.

The authors also suggest altogether new ideas to anticipate, monitor and prevent future lead in water crises. Artificial intelligence and machine learning could help identify relationships between water and pipe conditions and lead levels in drinking water. Santucci and Scully also propose a promising strategy of using isotope analysis to trace the sources of lead. “This strategy would enhance our understanding of how lead is released from lead pipes and other not so obvious sources, which is dearly lacking,” their paper states.

Public officials may argue that the investment in scientific research and modeling is unnecessary because lead-based pipes are being replaced, albeit at homeowners’ expense. Scully and Santucci disagree with that perspective. “Total replacement of lead service lines is a wonderful goal, but finding all sources of lead can be difficult,” Scully said.

Replacing lead in public water systems does not simply mean replacing lead pipes. Additional sources include lead-based solder used to join pipes together and commercial brass that commonly contains small amounts of lead, and lead ions that soak into the corrosion film of steel pipes over time. Partial replacement of lead pipes with other pipes such as steel or copper can actually increase lead release due to galvanic corrosion, a process where contact between two dissimilar metals causes protection of one and accelerated degradation of the other.

Santucci and Scully argue for holistic, kinetic models that incorporate the rate of lead release from all possible sources, under many real-world operating conditions.

“The root cause of the Flint water crisis can be found at the intersection of materials science, surface science, water chemistry and electrochemistry,” Scully said. “A better-informed society can prevent such disasters from happening in the future through improved risk assessment, anticipation and management of factors affecting lead release. We all have a part to play in averting future lead poisoning disasters.”

Major theories in human evolution argue that parents continuing to provide food to their offspring until they have grown up has enabled our species to have the largest brains of any species on the planet relative to our body size. Brains are expensive tissue and grow slowly leading to long childhoods. Ongoing parental care through long childhoods allow children time to learn the skills they need to survive in adulthood. Such long childhoods are rare across animals, equaled only by other great apes, like chimpanzees.

Chimpanzees may have long childhoods, but mothers rarely directly provide them with food after ages four to five years when they are weaned. Mostly mothers let their offspring forage for themselves. So then what do chimpanzee mothers provide their sons that gives them a competitive edge over orphaned sons? We do not yet know the answer but scientists do have some ideas.

“One idea is that mothers know where to find the best food and how to use tools to extract hidden and very nutritious foods, like insects, honey and nuts,” Crockford points out. “Offspring gradually learn these skills through their infant and juvenile years. We can speculate that one reason offspring continue to travel and feed close to their mothers every day until they are teenagers, is that watching their mothers helps them to learn.” Acquiring skills which enable them to eat more nutritious foods may be why great apes can afford much bigger brains relative to their body size than other primates.

“Another idea is that mothers pass on social skills,” Roman Wittig, last author on the study and director of the Ta? Chimpanzee Project, adds. “Again a bit like humans, chimpanzees live in a complex social world of alliances and competition. It might be that they learn through watching their mothers when to build alliances and when to fight.”

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Materials provided by Max Planck Institute for Evolutionary Anthropology. Note: Content may be edited for style and length.

A new University at Buffalo study based in Western New York is the first that simultaneously examined the preferences of community members and compared those with the community-based programs and resources available to identify the most viable strategies for addressing disparities in healthy food consumption.

Previous research has shown that only 12% and 7% of adults living at or below the poverty line meet fruit and vegetable recommendations, respectively.

“We continue to find that cost, food preferences, availability, access and limited food assistance eligibility and/or benefits are persistent barriers. Residents of underserved communities feel that increasing the affordability of fruits and vegetables through incentives, nutrition education, and increased access to healthy food options will help them to eat more fruits and vegetables,” said Christina Kasprzak, lead author on the study published in the Journal of Hunger & Environmental Nutrition.

“We also found that healthy food incentives, mobile produce markets, and nutrition education are acceptable and preferred food access strategies,” added Kasprzak, a PhD candidate in community health and health behavior in UB’s School of Public Health and Health Professions.

Researchers conducted 13 focus groups with 98 lower-income participants in urban areas of Western New York. Eight of the focus groups were conducted at local Women, Infant and Children (WIC) offices, while the remaining five were recruited by community organizations that serve lower-income families. The research team also interviewed 17 grocery store owners or managers, farmers, food distributors, and representatives from community organizations that currently or would be willing to address food access issues.

How to match needs

“Our research evaluated the capacity among local stakeholders to address the needs of lower-income communities, and made recommendations of how we can match this capacity to the preferences voiced in the focus groups with lower-income individuals,” Kasprzak said.

“By capitalizing on where there are matches between lower-income communities’ preferences and stakeholders we can ensure our efforts to expand healthy food access are viable,” Kasprzak said. “We don’t necessarily need to completely abandon the mismatches between programs and preferences, but we should heed community members’ suggestions for these programs and avoid blindly establishing programs that may not be fruitful.”

Cost, limited availability and accessibility, taste preferences and limited federal nutrition eligibility and benefits were the most frequently mentioned barriers to fruit and vegetable consumption. Study participants expressed frustration with having to decide between buying fresh produce and less healthy food options because of cost differences.

Another recurring theme among study participants was that they said they often had to travel outside their neighborhood, which required transportation, to find affordable and high-quality produce.

Researchers also reported that twice as many participants felt they lacked access to healthy food as those who said they had access.

What did participants say would help them buy and eat more fresh foods? Increasing the affordability, as well as nutrition education and recipe ideas. Some participants expressed a desire to learn healthier ways to prepare foods unique to their culture.

Include the working poor

Many participants favored increasing federal nutrition program benefits — such as Supplemental Nutrition Assistance Program (SNAP) — or expanding the eligibility requirements for these programs to include the working poor.

On the retail side, store owners and managers interviewed said they’d be willing to expand their fresh produce offerings to meet customers’ demands, while supporting efforts to improve the health of the community.

For corner stores — whose prices generally are known to be higher — owners wanted guidance on what to stock, how to price and promote those items, and where to source fruits and vegetables.

Farmers expressed a willingness to accept SNAP benefits for Community Supported Agriculture (CSA) shares, and to provide produce to urban corner stores.

Kasprzak was pleasantly surprised to learn that there is ample opportunity for local stakeholders to help lower-income communities access and eat more fruits and vegetables.

“By connecting the dots, we can potentially enhance the reach of existing programs that are preferred by these communities,” she said.

Ultimately, though, the barriers of cost of fruits and vegetables and limited eligibility and benefits for nutrition assistance programs are not wholly addressed by the food access programs discussed in the research paper, Kasprzak notes.

“For example, an incentive program makes fruits and vegetables more affordable but does not directly drive down the cost of produce. Therefore, more concerted efforts at the state or national level are needed.”

“We know that many of the programs that community members would like to see already exist, but budget and expertise to market these programs are often lacking in small organizations,” added Lucia Leone, PhD, the senior author on the paper and an assistant professor of community health and health behavior at UB. “Support from local policy makers is crucial for both getting the word out about these programs and ensuring their sustainability.”

Northwestern University materials scientists have developed new design principles that could help spur development of future quantum materials used to advance (IoT) devices and other resource-intensive technologies while limiting ecological damage.

“New path-breaking materials and computing paradigms are required to make data centers more energy-lean in the future,” said James Rondinelli, professor of materials science and engineering and the Morris E. Fine Professor in Materials and Manufacturing at the McCormick School of Engineering, who led the research.

The study marks an important step in Rondinelli’s efforts to create new materials that are non-volatile, energy efficient, and generate less heat — important aspects of future ultrafast, low-power electronics and quantum computers that can help meet the world’s growing demand for data.

Rather than certain classes of semiconductors using the electron’s charge in transistors to power computing, solid-state spin-based materials utilize the electron’s spin and have the potential to support low-energy memory devices. In particular, materials with a high-quality persistent spin texture (PST) can exhibit a long-lived persistent spin helix (PSH), which can be used to track or control the spin-based information in a transistor.

Although many spin-based materials already encode information using spins, that information can be corrupted as the spins propagate in the active portion of the transistor. The researchers’ novel PST protects that spin information in helix form, making it a potential platform where ultralow energy and ultrafast spin-based logic and memory devices operate.

The research team used quantum-mechanical models and computational methods to develop a framework to identify and assess the spin textures in a group of non-centrosymmetric crystalline materials. The ability to control and optimize the spin lifetimes and transport properties in these materials is vital to realizing the future of quantum microelectronic devices that operate with low energy consumption.

“The limiting characteristic of spin-based computing is the difficulty in attaining both long-lived and fully controllable spins from conventional semiconductor and magnetic materials,” Rondinelli said. “Our study will help future theoretical and experimental efforts aimed at controlling spins in otherwise non-magnetic materials to meet future scaling and economic demands.”

Rondinelli’s framework used microscopic effective models and group theory to identify three materials design criteria that would produce useful spin textures: carrier density, the number of electrons propagating through an effective magnetic field, Rashba anisotropy, the ratio between intrinsic spin-orbit coupling parameters of the materials, and momentum space occupation, the PST region active in the electronic band structure. These features were then assessed using quantum-mechanical simulations to discover high-performing PSHs in a range of oxide-based materials.

The researchers used these principles and numerical solutions to a series of differential spin-diffusion equations to assess the spin texture of each material and predict the spin lifetimes for the helix in the strong spin-orbit coupling limit. They also found they could adjust and improve the PST performance using atomic distortions at the picoscale. The group determined an optimal PST material, Sr3Hf2O7, which showed a substantially longer spin lifetime for the helix than in any previously reported material.

“Our approach provides a unique chemistry-agnostic strategy to discover, identify, and assess symmetry-protected persistent spin textures in quantum materials using intrinsic and extrinsic criteria,” Rondinelli said. “We proposed a way to expand the number of space groups hosting a PST, which may serve as a reservoir from which to design future PST materials, and found yet another use for ferroelectric oxides — compounds with a spontaneous electrical polarization. Our work also will help guide experimental efforts aimed at implementing the materials in real device structures.”

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Materials provided by Northwestern University. Original written by Alex Gerage. Note: Content may be edited for style and length.

The team found forecasts were 20% more accurate, and uncertainty was reduced by 15%, when incorporating information about the size and shape of the CMEs in the volunteer analysis. The data was captured by thousands of members of the public during the latest activity in the Solar Stormwatch citizen science project, which was devised by Reading researchers and has been running since 2010.

The findings support the inclusion of wide-field CME imaging cameras on board space weather monitoring missions currently being planned by agencies like NASA and ESA.

Dr Luke Barnard, space weather researcher at the University of Reading’s Department of Meteorology, who led the study, said: “CMEs are sausage-shaped blobs made up of billions of tonnes of magnetised plasma that erupt from the Sun’s atmosphere at a million miles an hour. They are capable of damaging satellites, overloading power grids and exposing astronauts to harmful radiation.

“Predicting when they are on a collision course with Earth is therefore extremely important, but is made difficult by the fact the speed and direction of CMEs vary wildly and are affected by solar wind, and they constantly change shape as they travel through space.

“Solar storm forecasts are currently based on observations of CMEs as soon as they leave the Sun’s surface, meaning they come with a large degree of uncertainty. The volunteer data offered a second stage of observations at a point when the CME was more established, which gave a better idea of its shape and trajectory.

“The value of additional CME observations demonstrates how useful it would be to include cameras on board spacecraft in future space weather monitoring missions. More accurate predictions could help prevent catastrophic damage to our infrastructure and could even save lives.”

In the study, published in AGU Advances, the scientists used a brand new solar wind model, developed by Reading co-author Professor Mathew Owens, for the first time to create CME forecasts.

The simplified model is able to run up to 200 simulations — compared to around 20 currently used by more complex models — to provide improved estimates of the solar wind speed and its impact on the movement of CMEs, the most harmful of which can reach Earth in 15-18 hours.

Adding the public CME observations to the model’s predictions helped provide a clearer picture of the likely path the CME would take through space, reducing the uncertainty in the forecast. The new method could also be applied to other solar wind models.

The Solar Stormwatch project was led by Reading co-author Professor Chris Scott. It asked volunteers to trace the outline of thousands of past CMEs captured by Heliospheric Imagers — specialist, wide-angle cameras — on board two NASA STEREO spacecraft, which orbit the Sun and monitor the space between it and Earth.

The scientists retrospectively applied their new forecasting method to the same CMEs the volunteers had analysed to test how much more accurate their forecasts were with the additional observations.

Using the new method for future solar storm forecasts would require swift real-time analysis of the images captured by the spacecraft camera, which would provide warning of a CME being on course for Earth several hours or even days in advance of its arrival.

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Materials provided by University of Reading. Note: Content may be edited for style and length.