Category: The Conversation – USA

Source: The Conversation – USA (2) – By Amy Myers Jaffe, Director, Energy, Climate Justice, and Sustainability Lab, and Research Professor, New York University; Tufts University

Oil is a global market, so when prices rise in one place, they rise everywhere. The current war against Iran has already raised oil prices significantly.

Mideast oil production has been slowed by efforts to close the Strait of Hormuz, a key route for oil tankers from the Middle East to the rest of the world, as well as by attacks – and fears of attacks – on oil production, storage and shipment installations.

And this war has also disrupted the flow of liquefied natural gas from Qatar, which controls almost 20% of the global market. That also affects the world economy and supply chains. And shortages of natural gas affect production of fertilizer and aluminium, as well as other key materials.

As a professor who has been studying oil price shocks for two decades, I’m often asked about the effects of rising oil prices on the U.S. economy. The answer to that question has changed over the past two decades.

The global economic picture

Countries that import much of their oil have to pay other countries for that imported oil.

That was a problem for the U.S. back in the 1970s through the early 2000s. The U.S. sent billions of dollars a year abroad to oil-producing countries in the Middle East, Africa and Latin America. That money built up other countries’ economies or sloshed around as financial surpluses that fueled financial market exuberance and asset bubbles that could suddenly pop.

Oil imports increased the U.S. trade deficit in the 1970s and beyond. And as a result, U.S. industries suffered from high energy costs, which forced closures of major U.S. steel plants and iron and copper mines. Falling purchases of cars and other durable goods also stimulated worker layoffs.

A shift in US production

Now, however, the United States is a major producer and exporter of oil and refined petroleum products. Every day, on average, the U.S. exports over 6 million barrels of refined products and over 4 million barrels of crude oil.

The U.S. does still import some crude oil, most of which is heavy oil from Canada handled at certain American refineries on the U.S. Gulf Coast. Factoring in those imports, net U.S. oil trade balance is a positive 2.8 million barrels per day, as contrasted with the mid-2000s, when the balance was a deficit of 12 million barrels per day.

U.S. production comes from 32 states – though mainly from the biggest producers: Texas, New Mexico, North Dakota, Alaska, Oklahoma and Colorado. Because that revenue comes to companies in the U.S., the nation’s gross domestic product is less vulnerable to oil price increases than in the past, when high prices meant more U.S. dollars flowing overseas.

A changed economy

In addition to being less dependent on imports, the U.S. economy is much less oil-intensive than it used to be, producing more economic value with far less oil use today than in the past.

And researchers at the U.S. Federal Reserve report that gasoline prices haven’t been a major contributor to U.S. inflation in recent years. That’s because there are lots of ways Americans use less gasoline, including telecommuting and remote work, online shopping and using electric vehicles and delivery trucks that run on batteries or other fuels.

Still, other economists disagree and say current oil prices, which are above $100 a barrel, could increase current U.S. inflation rates by as much as 1 percentage point.

The mental toll

Though the U.S. is economically less vulnerable to oil-price shocks, there is also a psychological factor. It’s hard not to feel pessimistic when gasoline prices at the local pump are already rising: Bulk market prices are already soaring amid hedging trades and speculative fervor among traders and wholesalers and on U.S. commodity futures markets.

Americans feel pessimistic about consumer spending when gasoline prices are rising. And a study found that high gas prices even make people feel unhappy.

Research also shows that people tend to put off major durable goods purchases, such as automobiles, when oil prices rise sharply. That could mean bad news for the U.S. auto industry.

But it is also possible that high gasoline prices might encourage more Americans to consider buying electric cars. That could help the car companies that were having difficulty moving their electric-vehicle inventories. And for people who own electric vehicles, the war and its resulting price increases can be a reminder of the benefits of living gasoline-free.

More broadly, the war might be yet another reminder of the benefits of diversifying energy sources away from fossil fuels. As my research shows, oil price shocks generally lead to greater investment in clean technologies.

Amy Myers Jaffe does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. US is less prone to oil price shocks than in past decades – https://theconversation.com/us-is-less-prone-to-oil-price-shocks-than-in-past-decades-277709

Source: The Conversation – USA (2) – By Dan McGrath, Associate Professor of Cryospheric Sciences, Colorado State University

Every summer, people living near the Mendenhall River in Juneau, Alaska, keep a close eye on the water level. When the river level begins to rise rapidly, it’s a sign that Suicide Basin, a small glacier-dammed lake 5 miles up the mountains, has broken through the glacier again and a glacial lake outburst flood is underway.

After nearly 15 straight years of ever-larger and more damaging floods in Alaska’s capital city, the U.S. Army Corps of Engineers is discussing an ambitious and expensive solution: create a permanent drain from the lake that would prevent it from reaching outburst stage.

The initial cost estimates for the project range from US$613 million to $1 billion.

Suicide Basin is just one example of a growing problem from glacial lakes that threaten communities around the world, particularly in the Himalayas and Andes, and is transforming Alaska’s landscape as global temperatures rise.

In a new study, colleagues and I documented the evolution of 140 of the largest glacial lakes in Alaska between 2018 and 2024. We found they are expanding about 120% faster on average today than they were from 1986 to 1999 – more than twice as fast.

Using ice thickness data to reconstruct the shape of the land beneath these glaciers, we found that these glacial lakes could become more than four times larger than they are today as the glaciers melt, increasing the potential for damage to downstream ecosystems and infrastructure from glacial lake outburst floods.

The hazards of glacial lakes

Glacial lakes, often the color of aquamarine gems and sparkling with icebergs, are common around the margins of glaciers around the world. Years of satellite images have documented a dramatic increase in their number, area and volume – a direct response to glaciers retreating as global temperatures rise.

Tenuously held back by moraines – the jumble of rock and sediment deposited by glaciers at their edges – or dammed by glacier ice, these lakes are anything but stable.

Between 1985 and 2020, ice-dammed lakes in Alaska alone broke through their barriers and drained more than 1,150 times. Alaska’s vast landscape and low population density means that the impact of these drainages on human infrastructure was fairly minimal, with a few notable exceptions, including Suicide Basin and Snow Lake, on the Kenai Peninsula.

However, the enormous amount of icy water rushing down rivers with each outburst can transform ecosystems, altering river channels through erosion and sediment deposition, tearing out trees and other vegetation, and damaging fish habitat.

A recent study found that glacial lake outburst floods from moraine-dammed lakes are occurring at an accelerating rate. In the steep, narrow valleys of the Himalayan Mountains, the impact of these events are acute: destroyed hydropower stations, roads and entire villages wiped away, taking hundreds of lives over the years.

More than 15 million people globally live in areas at risk of glacial lake outburst floods. Mapping where these lakes might form and expand can help people living downstream prepare. That’s what we did in Alaska.

Mapping Alaska’s expanding lakes

Glacial lakes can form in a variety of settings: on the surface of glaciers, in side valleys, and at the terminus, or toe, of the glacier. We found that the fastest-growing lakes are those at the toe, and in our work, we showed that many of these lakes reside in deep depressions carved by glacial flow.

We mapped these depressions – known as glacial-bed overdeepenings – by subtracting ice thickness estimates from surface elevations measured by satellites.

We found that more than 80% of the lake growth has occurred in the mapped basins, illustrating how this approach can help locate glacial lakes that are likely to form and expand in the future.

With this information, we found that existing glacial lakes in the region may ultimately expand fourfold, growing by as much as 1,640 square miles (4,250 square kilometers). A glacial lake at the terminus of Malaspina Glacier, the largest glacier by area in southeast Alaska, could expand to cover an additional 570 square miles (1,475 square kilometers) alone. That would create what would be the second-largest lake in Alaska.

As glaciers continue to retreat, new basins will be exposed, many of which could fill with water. In total, more than 5,500 square miles (about 14,200 square kilometers) of overdeepened basins exist in Alaska, pointing to a landscape that is going to look very different in the coming decades to centuries.

When a glacier terminates in a lake, the warmth of the water can speed up the ice’s melting, making the glacier flow faster, thin and retreat, thereby expanding the size of the lake. We found that glaciers that terminate in lakes are shrinking 23% to 56% faster than land-terminating glaciers.

The future as glaciers retreat

Future climate projections combined with sophisticated glacier models indicate that glaciers will cumulatively retreat by 26% to 41% by 2100, spelling the loss of 49% to 83% of all glaciers globally.

This is concerning for numerous reasons. Glacier mass loss is currently the largest contributor to sea-level rise. Melting glaciers also change the water quantity and timing of ice melt that feed major rivers, particularly Asian rivers such as the Indus and Ganges. And they create hazards, such as the outburst floods that originate from glacial lakes.

The landscapes that we know and love are transforming before our eyes, and with these changes come growing concerns about hazards.

Dan McGrath receives funding from the U.S. Geological Survey.

– ref. Alaska’s glacial lakes are expanding, increasing the risk of destructive outburst floods – https://theconversation.com/alaskas-glacial-lakes-are-expanding-increasing-the-risk-of-destructive-outburst-floods-275799

Source: The Conversation – USA (2) – By Jim Franklin, Professor of Accounting, Western Governors University School of Business

The days are getting longer and W-2s are blooming, which can only mean one thing – the U.S. tax season is here.

Many Americans may receive a bigger tax refund than in previous years as a result of changes under what has been dubbed “One Big Beautiful Bill Act,” a package of tax breaks and spending cuts that President Donald Trump signed into law on July 4, 2025.

The act renewed tax cuts originally put in place in 2017 that had been set to expire at the end of 2025. Had that happened, one estimate shows the average individual filer would have seen a US$2,955 increase to their tax bill starting in 2026.

That hike would have come from factors including higher individual tax rates, while the standard deduction and child tax credit would have been slashed in half.

Instead, many filers can expect the new law to reduce their taxes for 2025 and beyond, with numerous provisions in place for the next three years.

Trump’s tax and spending package has introduced a variety of provisions aimed at benefiting a broad cross-section of individual taxpayers. The changes under the act are retroactive, meaning that even though the law was signed in July, taxpayers can treat the provisions as if they went into effect at the start of 2025.

Here are some of the new things 2025 filers should know about:

1. Increased deduction of state and local taxes

People subject to steep local and/or state taxes can now deduct a significantly larger portion of those assessments.

Allowable property, sales or income taxes paid to state and local governments in 2025 are deductible up to $40,000, or $20,000 for married filing separately. That’s up from the previous maximum of $10,000 and $5,000, respectively.

Higher income taxpayers – those with modified adjusted gross income exceeding $500,000, or $250,000 for those married filing separately – won’t be able to take full advantage of the $40,000 deduction. OB3 calls for gradual reductions in the deduction amount as income level rises.

In 2030, the state and local deduction reverts to the previous $10,000 limit, or $5,000 married filing separately.

2. Tip income deduction

Workers in approved occupations, such as hospitality, cosmetology or personal training, who receive qualified tips will be able to deduct up to $25,000 in tip income from their taxes for the first time.

This new deduction is phased out for single filers with a modified adjusted gross income over $150,000 and married couples filing jointly over $300,000.

This tax break is available through 2028.

3. Overtime pay deduction

Have earnings from working overtime? From 2025 through 2028, filers can take a deduction for pay exceeding their regular rate.

For example, if an employee typically earns $20 per hour and earns $30 per hour when working overtime, they qualify for a deduction of the extra $10. The maximum annual deduction is $12,500, rising to $25,000 for joint filers.

As with many of these deductions, there is a phaseout for taxpayers with modified adjusted gross income over $150,000, or $300,000 for joint filers.

4. ‘Made in America’ car deduction

Purchased a new vehicle for personal use or thinking about buying one soon? From 2025 through 2028, buying a vehicle made in the United States means the filer can deduct vehicle loan interest.

Vehicles that qualify include cars, minivans, vans, SUVs, pickup trucks and motorcycles that underwent final assembly in the U.S.

The maximum annual deduction is $10,000. The deduction starts to phase out for taxpayers with modified adjusted gross income over $100,000; $200,000 for joint filers.

5. New deduction for seniors

For tax years 2025 through 2028, individuals older than 65 are eligible for a deduction up to $6,000 or $12,000 total for a married couple when both spouses qualify. The deduction begins to phase out when modified adjusted gross income exceeds $75,000 or $150,000 for joint filers.

It’s important to note that this deduction is in addition to the existing senior deduction that was passed under a prior law.

This article is for informational purposes only and does not constitute professional tax advice. Please seek a qualified tax professional for advice based on your individual tax circumstances.

Jim Franklin does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Big beautiful refund? 5 tax code changes that may put more money in your pocket – https://theconversation.com/big-beautiful-refund-5-tax-code-changes-that-may-put-more-money-in-your-pocket-275528

Source: The Conversation – USA – By Casey Ryan Kelly, Professor of Communication Studies, University of Nebraska-Lincoln

When Secretary of Defense James Mattis addressed the intensification of U.S. combat operations against the Islamic State group in 2017, he assured the American public of his commitment to “get the strategy right” while maintaining “the rules of engagement” to “protect the innocent.”

Mattis’ professional tone was a stark contrast to Secretary Pete Hegseth’s remarks following the first days of the joint U.S.-Israeli combat operations in Iran.

On March 2, 2026, after bragging about the awe-inspiring lethality of U.S. “B-2s, fighters, drones, missiles,” Hegseth casually brushed aside concerns about long-term geopolitical strategy, declaring “no stupid rules of engagement, no nation-building quagmire, no democracy building exercise, no politically correct wars. We fight to win.”

Admonishing the press for anything less than total assent, he commanded, “to the media outlets and political left screaming ‘endless wars:’ Stop. This is not Iraq.”

Two days later, Hegseth gloated about “dominance” and “control,” while asserting that the preoccupation of the “fake news media” with casualties was motivated by liberal media bias and hatred of President Trump.

“Tragic things happen; the press only wants to make the president look bad,” he said. He dismissed concerns about the rules of engagement, declaring that “this was never meant to be a fair fight. We are punching them while they are down, as it should be.”

I’m a communication scholar who has studied MAGA rhetoric for a decade. I have observed how Hegseth and other officials in the second Trump administration refuse to abide by what recurring rhetorical situations – urgent public matters that compel speech to audiences capable of being influenced – typically demand of public officials.

The theme of this administration is that no one is going to tell it what to say or how to say it. It will be encumbered neither by norms nor the exigencies that compel speech in a democratic society.

The big man

When the U.S. goes to war, the public expects the president and the defense secretary to convince them of the appropriateness of the action. They do this by detailing the justification for military action, but also by addressing the public in a manner that conveys the seriousness and competence required for such a grave task as waging war.

But during the first week of the Iran war, Hegseth’s press briefings deviated from the measured tone expected from high-ranking military officials.

Hegseth flippantly employed villainous colloquialism – “they are toast and they know it,” “we play for keeps,” and “President Trump got the last laugh” – delivered with a combative tone that communicated masculine self-assurance.

Many observers were taken aback by his haughty tone, hypermasculine preoccupation with domination, giddiness about violence and casual attitude toward death.

During Trump’s first term, this penchant for rule-breaking was by and large isolated to the president, whose transgressions were part of his populist appeal.

Although Trump’s first cabinet members agreed on most political objectives, they attempted to rein in what they saw as the president’s more dangerous whims.

But with loyalty as the new bona fide qualification for administration officials, Trump’s second cabinet is populated with a large contingent of right and far-right media personalities like Hegseth, including Kash Patel, Sean Duffy and Mehmet Oz.

The anti-institutional ethos of far-right media explains why these officials refuse to conform to “elite” expectations and instead speak in a manner that is bombastic, outrageous and perverse.

Among them, there is little reverence for what they may perceive of as emasculating rules of tradition and politeness in a media marketplace where “owning,” “dominating,” and “triggering” your enemy is precious currency. Far-right media personalities are adept at commanding attention with showmanship and swagger.

Trump appears to have chosen Hegseth for precisely this reason: He performs the role of the big man to perfection.

‘Kill talk’

Hegseth’s language choices and petulant tone do not demonstrate an ignorance of what rhetorical situations demand of him; instead, they reflect a refusal to be emasculated by such cumbersome norms.

When making statements about the first week of the war, Hegseth grinned as he delivered action-movie one-liners, like “turns out the regime who chanted ‘Death to America’ and ‘Death to Israel’ was gifted death from America and death from Israel.”

Hegseth engaged in what is known as “kill talk,” a verbal strategy, typically directed at new military recruits, that denies the enemy’s humanity and disguises the terrible costs of violence. His repetition of words like “death,” “killing,” “destruction,” “control,” “warriors” and “dominance” framed violence in heroic terms that are detached from the realities of war.

In my view, Hegseth addressed the public as a squad leader addresses military recruits. Hegseth apparently delighted in dispensing death and elevating and glorifying war. He said virtually nothing of long-term strategy beyond “winning.”

In the MAGA media world, winning is really all that matters. If winning is the only goal, then war is, by profound inference, a game, a test of masculine fortitude.

This point was made clear when the White House posted a video that interspersed footage of airstrikes on Iran with “killstreak animation” from the popular video game Call of Duty: Modern Warfare. In the game, when a player kills multiple opponents without also dying, they are rewarded with the ability to conduct a missile strike to exterminate an opposing team. Again, this message gamifies violence and obscures the destructive toll of war.

Informed by the contemptuous hypermasculinity of far-right media culture, all this taboo behavior and glorified portrayals of death convey one fundamental message: When the public most needs explanation and justification for the actions of their government, the powerful owe the public neither explanation – nor comfort.

Casey Ryan Kelly does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. I’ve studied MAGA rhetoric for a decade, and this is what I see in Hegseth’s boasts, action-movie one-liners and gloating over dominance – https://theconversation.com/ive-studied-maga-rhetoric-for-a-decade-and-this-is-what-i-see-in-hegseths-boasts-action-movie-one-liners-and-gloating-over-dominance-277731

Source: The Conversation – USA (2) – By Wangda Zuo, Professor of Architectural Engineering, Penn State

The electricity needed to power new Pennsylvania data centers already in advanced stages of planning could power 11 million homes – nearly twice the total number of households in the state.

Companies that want to build data centers to expand their cloud and artificial intelligence computing are drawn to Pennsylvania due to its proximity to major East Coast cities, relatively affordable land and electricity, and legacy industrial infrastructure. For instance, there is a plan to turn an abandoned steel mill in Pittsburgh into a high-density data center that can leverage the existing infrastructure for electricity and water supply.

If all data centers in advanced planning are built, it could total about 13 gigawatts of electrical capacity.

As more data centers are proposed across the state, residents and policymakers are asking important questions: How much energy and water will these data centers use? And what can be done to manage their environmental footprint?

As a professor of architectural engineering at Penn State, my research focuses on optimal design and control of data center cooling systems. I know that a key part of the answer to minimizing the negative effects of data centers lies in cooling.

Data centers generate a lot of heat

Every bit of electricity that a data center consumes is converted into heat that must be removed and released into the environment. Cooling systems, including chillers and cooling towers, are mission-critical infrastructure.

Without effective cooling, temperatures in computing devices would quickly rise to damaging levels, forcing systems to shut down. In November 2025, the Chicago Mercantile Exchange experienced a major outage when a data center’s cooling system failed. It halted trading for hours.

Data centers currently account for about 4.4% of total U.S. electricity consumption and are projected to rise to 6.7% to 12.0% in 2028, according to Lawrence Berkeley National Laboratory.

They also consumed nearly 211 billion gallons of water in 2023, most of it indirect and tied to electricity generation. Within individual facilities, cooling alone accounts for about 40% of total electricity use

How efficiently Pennsylvanians cool data centers has major implications for energy consumption, water demand and community impacts.

The challenges of cooling

AI workloads demand a lot of computing power and therefore generate more heat that must be removed.

Traditional air-cooled systems rely on powerful fans and mechanical chillers, both of which consume significant amounts of electricity.

During Pennsylvania’s hot and humid summers, cooling energy needs for data centers can rise sharply. This increased demand on electricity requires costly infrastructure upgrades, and the cost is often shared by all users including residents, which raises concerns of fairness.

Water is another concern. Many large facilities use evaporative cooling towers that consume millions of gallons of water per day. In regions facing periodic droughts or stressed water supplies, this can frustrate local communities.

Noise is a third, often overlooked issue. Most complaints from people who live near data centers are not about servers but about cooling systems. Large cooling tower fans, rooftop air-handling units and dry coolers generate continuous low-frequency noise. Chillers and compressors add vibration and tonal hum. In quiet rural or suburban settings – especially at night – this steady sound can travel surprisingly far.

Pennsylvania’s climate presents both challenges and opportunities when it comes to cooling data centers. Cold winters can support energy-efficient cooling for part of the year. However, hot and humid summers limit the effectiveness of those free cooling strategies.

At the same time, many proposed sites sit near legacy industrial infrastructure, including abandoned coal mines, that could enable innovative approaches.

Turning heat into opportunity

Improving cooling efficiency is a straightforward way to minimize the negative impact of data centers.

In a U.S. Department of Energy project my team worked on, we demonstrated a 74% cooling energy reduction in a Massachusetts data center. This was achieved by using a digital twin of the data center. A digital twin is a virtual representation of a real system. Using this digital twin, we were able to identify and fix different faults in the cooling system. We also used the digital twin to optimize the control set points based on the data center workload and weather conditions to meet the cooling needs with much less energy.

In addition, more saving can be achieved by integrating the digital twins with AI, which can perform the optimal cooling control with minimal human interventions. This concept – I call it “AI for sustainable AI” – aims to reduce the environmental footprint of the very systems powering the AI revolution. We are currently working with the Alerify data center in Harrisburg to reduce its cooling energy consumption using this technology.

Pennsylvania also has potential for geothermal cooling from its abandoned mines across the state. An example is Iron Mountain’s underground data center in western Pennsylvania, about an hour north of Pittsburgh. The data center is located 220 feet below ground in a former limestone mine. The stable and naturally cool subterranean environment – around 52 degrees Fahrenheit (11 degrees Celsius) – and underground lake reduce reliance on conventional mechanical cooling.

Beyond efficiency, reusing waste heat can transform how we think about data centers. In Idaho, a startup is using server waste heat to support hydroponic greenhouses for year-round food production. In Paris, excess data center heat has warmed swimming pools used during the 2024 Olympics, and one of Meta’s data centers in Denmark supplies heat to a district heating network serving roughly 11,000 local homes. In Colorado, the National Laboratory of the Rockies recovers heat from its high-performance computing systems to warm building spaces and melt snow.

There are also opportunities in food processing and aquaculture. In Norway, waste heat from a data center is used to warm water for land-based fish farming. Studies suggest that the waste heat from data centers could also support food-drying processes for coffee beans, fruits and vegetables.

To be economically viable, these solutions often require a constant heating demand located adjacent to the data center, which may not be readily available in some cases.

Data centers will likely play a growing role in Pennsylvania’s economy. The question is not whether they will use energy and generate heat – they inevitably will. The question is whether we design them to simply release that heat into the air and water, or design cooling systems to harness it for more sustainable uses.

Read more of our stories about Philadelphia and Pennsylvania, or sign up for our Philadelphia newsletter on Substack.

Wangda Zuo receives funding from National Science Foundation, U.S. Department of Energy, and Penn State.
He is a Fellow American Society of Heating, Refrigerating and Air-Conditioning Engineers.
Besides his academic position at Penn State University, he is CTO and Co-founder of Glacian Technologies Inc, which is a Pen State spin-off company. He also holds a joint appointment at the U.S. Department of Energy’s National Laboratory of the Rockies.

– ref. Abandoned Pennsylvania mines and waste-heat recycling could make the state’s massive new data centers far more sustainable – https://theconversation.com/abandoned-pennsylvania-mines-and-waste-heat-recycling-could-make-the-states-massive-new-data-centers-far-more-sustainable-273180

Source: The Conversation – USA (2) – By Allie Mazurek, Engagement Climatologist and Researcher, Colorado Climate Center, Colorado State University

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

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Why do we see snow on mountaintops that are closer to the Sun but not near the ground? – Ms. Drew’s third grade class, Beechview Elementary School, Farmington Hills, Michigan

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There’s not much better than a bluebird day in the mountains – a crisp, sunny day accompanied by a fresh blanket of snow. But why doesn’t the Sun quickly melt all that high altitude snow away?

It all boils down to our atmosphere, which is what I research as a scientist in Colorado. Let’s dive in!

Our atmosphere: Earth’s armor

Earth’s atmosphere begins right at its surface and extends to outer space, and it is filled with a mixture of many different gases. Gases in the atmosphere include the oxygen we breathe and the water vapor that makes it rain and snow. They are essential to supporting life on Earth in several ways.

One of the most important jobs those gases have is to protect us from harmful things in space, including our closest star: the Sun.

The Sun’s radiation provides heat to our planet, but too much of it can be a problem. If you’ve ever gotten a sunburn, then you’re already familiar with this idea.

Some of our atmospheric gases limit the amount of radiation from the Sun that can reach the Earth’s surface by absorbing some of it, which prevents temperatures from being way too warm in the daytime. At night, certain atmospheric gases also trap some of the heat that the Earth’s surface releases as it cools down, protecting us from unsurvivable cold.

The way the atmosphere regulates Earth’s temperatures is known as the greenhouse effect. You’ll often hear this term used alongside climate change or global warming. That is because global warming is caused by enhancing the greenhouse effect: As people burn fossil fuels in cars and factories, the amount of greenhouse gases in the atmosphere increases. These extra gases allow the Earth’s atmosphere to trap more heat, causing an increase in temperatures.

The atmosphere likes to stay grounded

If you were to compare the Earth’s atmosphere along a Caribbean beach to that surrounding the top of Mount Everest, it would look quite different.

That is because as you go higher up in the atmosphere, it gets “thinner,” meaning that there are less gases present at higher elevations and altitudes.

Why? Blame it on gravity.

In the same way that gravity keeps people and objects from flying away to outer space, Earth’s gravitational force pulls on the gases in our atmosphere, trying to keep them as close to Earth as possible.

As a result, there are fewer gas molecules in the atmosphere as you go higher up in altitude, making the air thinner, or less dense. Humans can sometimes experience altitude sickness at high elevations because there is less oxygen present in the air as a result of this phenomenon.

Closer to the Sun, but still cold and snowy?

Our high-elevation mountains protrude into higher altitudes of the atmosphere, where the air has fewer gas molecules. While this thinner air allows more of the Sun’s radiation to pass through compared with the atmosphere at sea level, thinner air tends to be colder for two reasons:

First, collisions between gas molecules generate heat, and if you have fewer molecules available to run into each other, that heat generation is lower.

Second, a thinner atmosphere is less effective at maintaining heat because there are fewer molecules available to trap and hold on to heat.

Colder temperatures can create more opportunities for precipitation to fall in the form of snow rather than rain, which is why some mountains can be so snowy.

And if the ground is habitually covered in snow, as is the case in many mountain ranges, it can be even easier to maintain cooler temperatures. That’s because snow-covered surfaces are very reflective, making them highly effective at causing the Sun’s incoming rays to bounce back toward space instead of getting absorbed by the ground.

So if you visit the mountains to have fun in the snow, be sure to pack your jacket, but don’t forget that sunscreen too.

Allie Mazurek does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Why do mountaintops stay snowy, even though they’re closer to the Sun? – https://theconversation.com/why-do-mountaintops-stay-snowy-even-though-theyre-closer-to-the-sun-277560

Source: The Conversation – USA (3) – By Adetola F. Louis-Jacques, Associate Professor of Obstetrics and Gynecology, University of Florida

Only three of the 14 counties in north-central Florida provide full access to obstetric care. Six have low access to care – meaning there are fewer than two hospitals offering obstetric care or birth centers per 10,000 births and fewer than 60 obstetric providers. The remaining five counties are maternity care deserts. Approximately 3,400 women of childbearing age live in those deserts.

In 2024, a report found that hospitals across Florida were discontinuing obstetric care due to lack of funding. Eighteen of the state’s 21 rural hospitals no longer provide obstetric care.

To address this gap in care, in February 2025 the University of Florida established the OB/GYN Mobile Outreach Clinic. The mobile clinic provides comprehensive maternal health services, including prenatal and postpartum care, breastfeeding support, family planning, annual gynecological exams and preventive health screenings. The only services not offered on-site are deliveries.

We are the director and assistant director of the clinic and a at the University of Florida. Outside of our work with the mobile clinic, we also research interventions to improve maternal health in low-resource settings.

We launched the clinic in February 2025. By the end of 2025, we had provided care to 194 women in 616 visits.

Based on our experience, we believe that mobile clinics focused on maternal health could be an effective way to reach more rural and low-income communities.

Maternity deserts across the US

Two and a half million American women of childbearing age – nearly 4% – live in a maternity care desert: a county without a single hospital, birthing center or obstetric health care professional.

Over the past decade, the closure of hundreds of obstetric units has exacerbated this problem, particularly in rural regions. Women in maternity care deserts travel an average of 35 miles to reach a birthing hospital, compared to an average of 9 miles for women in full-access counties.

The maternal mortality rate in the U.S., which peaked during COVID, remains higher than that of most other high-income nations. Access to timely prenatal and postpartum care is crucial to preventing pregnancy-related deaths. Studies have shown that traveling longer distances for obstetric care is associated with worse infant and maternal health outcomes.

Our mobile model

Mobile health clinics are vehicles, such as buses or vans, equipped with medical tools and supplies to deliver health care services.

The University of Florida OB/GYN Mobile Outreach Clinic is a retrofitted bus with two exam rooms, an ultrasound machine and supplies for serum and urine testing for prenatal labs. A small dispensary allows providers to give prenatal vitamins and medications for common conditions, such as vaginitis or urinary tract infections. This reduces the need for patients to make additional pharmacy or lab visits or pay for medication.

Care provided at the mobile clinic is free to the patient. If patients are eligible for Medicaid or other health insurance, our team assists them in applying for benefits. In 2023, about 1 in 7 women of childbearing age in Florida were uninsured.

Operating on a different model

The Mobile Outreach Clinic operates twice weekly in consistent, rotating locations, including northeast Gainesville in Alachua County, Lake City in Columbia County, Bronson in Levy County and Trenton in Gilchrist County. Of these locations, only Levy County is a maternity care desert, but all of these locations were selected to care for patients of low socioeconomic status and limited access to care.

We set up the clinic at sites that are already trusted or frequently visited by our target population. This includes family resource centers, churches and public libraries. Patients and families know they can expect us on a consistent day of the week. A core principle of our program is that we show up, no matter what. This ethos has helped us establish and maintain trust with our patients.

Appointments are walk-in or scheduled, with wait times significantly shorter than traditional clinics. Patients are scheduled within a week, generally through referrals from trusted partner agencies or from other patients.

Unlike traditional clinics, which schedule for 15- to 20-minute appointments, the mobile clinic allots 30-60 minutes for patient visits. This allows time to address social needs, transportation barriers, food insecurity or housing needs. The clinical care team is led by nurse midwives and includes a physician assistant, certified nurse-midwives, nurses, a nurse practitioner and lactation consultant, medical assistants and promotoras, community health workers who act as peer educators and patient liaisons in Hispanic communities. Maternal-fetal medicine physicians review ultrasound images remotely.

Operating outside a traditional clinical setting sometimes requires our staff to be flexible and creative to meet the needs of our patients. For instance, the week before Thanksgiving, our clinic was at capacity while parked in a church lot in Trenton. One of our patients needed a nonstress test, and with space limited, the nurse and health educator interpreter worked together to complete the test in a quiet area within the church. The patient received timely care despite the full schedule and space constraints.

Taking health care to the streets

Currently, there are approximately 3,600 mobile health clinics in the United States, with 1,319 tracked through the Mobile Health Map.

These clinics can provide a wide range of services, from disaster relief and mental health care to mammography and dental care, to primary and preventive care. They particularly target low-income and uninsured populations. A study of 811 mobile clinics found that among patients treated between 2007 and 2017, 36% were from rural areas, 38% were homeless, 55% were low income and 56% were uninsured.

Mobile health clinics have been shown to improve health by delivering regular care directly to populations that would not have access otherwise.

In a survey of mobile clinic users, patients reported receiving holistic care, feeling safer than they’d felt in other health care settings and interacting with staff who were mindful of health care costs.

Regardless of insurance status, patients said they were able to maintain continuity of care, meaning the mobile clinic managed their care consistently and was able to share their records with new providers to ensure they received appropriate care.

Expanding mobile health to pregnant patients

Unfortunately, only 128 of the 1,319 mobile clinics tracked in the mobile health map provide maternal and infant health services, and the services they offer pregnant, postpartum and newborn patients are generally quite limited. As maternity care deserts expand, mobile health clinics could offer a practical solution for meeting prenatal and postpartum care needs.

We believe our model could be replicated elsewhere, and other similar clinics are already up and running, such as the University of Arizona Mobile Health Program.

The primary challenge for mobile clinics is funding, as they are typically free to patients and supported through grants. With projected recent changes to Medicaid and ACA marketplace coverage, even more patients may face limited access to prenatal and postpartum health care.

Studies on mobile health clinics have identified several additional challenges associated with this model of care. Mobile clinics are not equipped to manage emergent complications, complex medical procedures or labor and delivery.

They also face staffing limitations, particularly in finding health care professionals who understand and enjoy the unique opportunities and challenges inherent in providing care on a mobile clinic, in addition to their scheduled clinic or hospital shifts.

But our hope is that as our clinic and others like it demonstrate an improvement in health care in maternal care deserts, increased awareness and support may help expand this model to more communities.

Read more stories from The Conversation about Florida.

Adetola F. Louis-Jacques receives funding from NIH, Direct Relief/CVS Foundation, Children’s Trust of Alachua County

The OBGYN Mobile Outreach Clinic receives funding from Direct Relief/CVS Foundation.

Arielle Ayotte does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Mobile clinics offer a practical way to improve health care access in maternity care deserts – https://theconversation.com/mobile-clinics-offer-a-practical-way-to-improve-health-care-access-in-maternity-care-deserts-274476

Source: The Conversation – USA (3) – By Corey D. B. Walker, Dean and Wake Forest Professor of the Humanities, Wake Forest University

As the United States marks the 250th anniversary of the Declaration of Independence, debates about religious freedom continue to occupy the center of American public life.

Since taking office for a second time, the Trump administration has issued a number of executive orders on religion that raise new questions about religious freedom. On May 1, 2025, the administration established the Religious Liberty Commission. The commission will advise the White House on policies intended to protect the free exercise of religion and to prevent discrimination against people of faith by the federal government.

The administration has also issued executive orders to “eradicate anti-Christian bias” and to broaden protections against religious discrimination across federal agencies.

Some scholars argue that these actions signal a broad effort to reshape how religious freedom is interpreted and practiced, with a pronounced emphasis on favoring Christianity.

Debates over religion in public life are not new. As a scholar of religious freedom, I have long been interested in how the early debates about religious freedom at the nation’s founding can help people better understand the present moment.

The early correspondence of James Madison – who went on to become the fourth U.S president and played a key role in the drafting of the Constitution and Bill of Rights – wrestles with the tensions of religion and public life. It can be instructive for Americans today.

A society in flux

Long before the First Amendment enshrined the right of religious freedom, religion was a subject of intense conflict.

The Declaration of Independence invokes God in phrases such as “Nature’s God,” “Creator” and “divine Providence.” But these words did not settle hard questions about religion in public life. The disputes continued and shaped debates about religious freedom.

Madison spent much of his life engaging these important issues.

Colonial Virginia was a hotbed of conflict over the authority of the Church of England. In the decades before the American Revolution, dissenting religious groups were punished by Colonial authorities for practicing their faith. Baptist and Presbyterian preachers were fined and jailed by local authorities for preaching without licenses. Some were imprisoned near the Madison family plantation at Montpelier.

The religious intolerance in Virginia left a deep impression on Madison. It heightened his attention to the dangers of religious authority allied with state power.

He shared his concerns with his friend and future U.S. Attorney General William Bradford, whom he met during his years at the College of New Jersey, now Princeton University.

In a 1773 letter to his “Dear Billey,” Madison posed a critical question as Bradford began his legal studies. He asked, “Is an Ecclesiastical Establishment absolutely necessary to support civil society in a supream Government? & how far it is hurtful to a dependant State?” Simply put, Madison was asking whether government-authorized religion strengthens society or threatens it.

Madison also condemned the jailing of dissenting preachers by Colonial authorities. These actions, he wrote, reflected “that diabolical Hell conceived principle of persecution.” For Madison, such persecution was blatantly unjust. It damaged religion and civil society. Madison feared established religion because it threatened personal conscience and political liberty.

Near the end of his letter, Madison asked Bradford “to pity me and pray for Liberty of Conscience.” This line reflects his growing belief that faith should be guided by personal conviction, not political power.

The people and religious freedom

These experiences shaped Madison’s opposition to an official state religion and his defense of the free exercise of religion. For Madison, religion could flourish only under conditions of freedom, not compulsion.

Although initially skeptical about adding a Bill of Rights to the Constitution, Madison eventually supported these amendments, including the First Amendment. It begins with prohibiting the federal government to sanction any official religion: “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof …”

For Madison, prohibiting Congress from establishing religion and protecting the free exercise of religion were not abstract ideals. They were responses to the oppression of religious minorities he witnessed in Virginia.

But Madison realized that written guarantees were not enough. Such “parchment barriers,” as he referred to declarations like the Bill of Rights, were necessary but not sufficient to guard against political excess.

In “Federalist No. 10,” part of a series of essays written to support the Constitution, Madison warned about the dangers of factions and intolerance. A dominant religious group could marginalize others. A “religious sect may degenerate into a political faction,” he warned. In his view, a religious faction with political power can create a political tyranny, especially when it claims to act in God’s name.

Madison understood that religious freedom did not mean protecting one faith against others. Religious freedom is best secured in a nation that respects religious diversity in all of its variety, including the right to no religion at all. The point was not to privilege any tradition but to protect all traditions.

Madison and our moment

Madison’s vision is instructive in this moment when debates on religious freedom often center on Christianity, especially in disputes over education, rights and discrimination.

For Madison, religious freedom was not about political domination. It served as a constitutional ally for the foundational principle of liberty and a safeguard for democracy.

Returning to Madison is not an exercise in nostalgia. It is a civic responsibility.

His legacy reminds Americans that religious freedom is not about power or privilege. Religious freedom affirms a broader and deeper vision of American democracy where all beliefs, and none, can coexist in a diverse and evolving society.

Corey D. B. Walker does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. What James Madison can teach Americans about religious freedom today – https://theconversation.com/what-james-madison-can-teach-americans-about-religious-freedom-today-272909

Source: The Conversation – USA – By Phil Starks, Associate Professor of Biology, Tufts University

Most people know only two things about the appendix: You don’t need it – and if it bursts, you need surgery fast.

That basic story traces back at least to Charles Darwin, the English naturalist who developed the theory of natural selection. In “The Descent of Man,” he described the appendix as a vestige: a leftover from plant-eating ancestors with larger digestive organs. For more than a century, that interpretation shaped both textbook and casual medical wisdom.

But the evolutionary story of the appendix turns out to be much more complicated.

Along with our colleague Helene M. Hartman, a student preparing for a career in health care, we combined our expertise in behavioral ecology, biology and history to review the scientific literature on the appendix, expecting a simple answer.

Instead, we found an organ that evolution kept reinventing, more interesting than most people imagine.

How did the appendix evolve?

The appendix is a small pouch branching off the first section of the large intestine. Its shape and structure vary widely across species – a clue that evolution may have tinkered with it more than once.

Some species, including certain primates such as humans and great apes, have a long, cylindrical appendix. In others, including several marsupials such as wombats and koalas, the appendix appears shorter or more funnel-shaped. Still others, including some rodents and rabbits, have differently proportioned or branching structures. This structural diversity suggests that evolution has modified the organ under different ecological conditions.

That suspicion is supported by evolutionary analyses. Comparative studies show that an appendix-like structure evolved independently in at least three distinct lineages of mammals – marsupials, primates and glires, a group that includes rodents and rabbits. A broader evolutionary survey found that the appendix evolved separately at least 32 times across 361 mammalian species.

When a trait evolves repeatedly and independently, biologists call this convergent evolution. Convergence does not mean a structure is indispensable. But it does suggest that, under certain environmental conditions, having that structure provided a consistent enough advantage for evolution to favor it again and again.

In other words, the appendix is unlikely to be a useless evolutionary accident.

What does the appendix do?

The appendix supports the immune system. It contains gut-associated lymphoid tissue – immune cells embedded in the intestinal wall that help monitor microbial activity in the gut. In early life, this tissue exposes developing immune cells to intestinal microbes, helping the body learn to distinguish between harmless symbionts and harmful pathogens.

The appendix is particularly rich in structures called lymphoid follicles during childhood and adolescence, when the immune system is still maturing. These immune components participate in mucosal immunity, which helps regulate microbial populations along the intestinal lining and other mucosal surfaces. Lymphoid follicles produce antibodies, such as immunoglobulin A, to neutralize pathogens.

Researchers have also proposed that the appendix acts as a microbial refuge. Some have suggested that biofilms – thin, structured communities of bacteria – line the appendix. During severe gastrointestinal infections that flush much of the gut microbiome from the colon, beneficial bacteria sheltered within these biofilms may survive and help repopulate the intestine afterward. Those beneficial microbes assist with digestion, compete with pathogens and interact with the immune system in ways that reduce inflammation and promote recovery.

These hypotheses motivated a question our team explored: If the appendix helps preserve microbial stability, could removing it subtly affect reproductive fitness?

Older clinical concerns suggested that appendicitis or appendectomy might impair fertility by causing inflammation and scarring – known as tubal adhesions – in the fallopian tubes. Such scarring could physically obstruct the egg’s passage to the uterus. But several large studies have since found no decrease in fertility after appendectomy – in some cases, researchers found a small increase in pregnancy rates.

The appendix appears to have multiple functions, including immune and microbial ones. Affecting fertility, however, does not seem to be one of them.

Evolutionary importance and modern life

While the appendix has an interesting past, with evolution continually reinventing it, its modern importance is modest at best. Darwin underestimated the organ’s history, but his instinct wasn’t far off in the medical present: Some parts of human biology mattered more in the environments people evolved in than in the lives they lead today.

Early humans lived in environments with little sanitation and strong social contact – perfect conditions for outbreaks of pathogens that cause diarrhea. An appendix that quickly restored the microbiome after infection could significantly improve survival. But over the past century, clean water, improved sanitation and antibiotics have sharply reduced deaths from diarrheal diseases in high-income countries.

As a result, the evolutionary pressures that once favored the appendix have largely disappeared. Meanwhile, the medical risks of keeping the appendix – most notably appendicitis – remain. Modern surgery typically treats an infected appendix by removing it. A structure that was once a global evolutionary advantage is now more of a medical liability.

This mismatch between past adaptations and present environments illustrates a core principle in evolutionary medicine: Evolution optimizes for survival and reproduction in ancestral environments, not for health, comfort or longevity in modern ones.

Evolution operates at the level of populations over generations, favoring traits that increase average reproductive success, even if those traits sometimes harm individuals. Medicine works the other way around – helping individuals thrive in the present world rather than survive the past one.

The appendix is not an IKEA spare part included “just in case,” but
neither is it essential today. Human biology has many traits that were once beneficial, now marginal – and understanding them allows medicine to make better modern decisions.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. What does the appendix do? Biologists explain the complicated evolution of this inconvenient organ – https://theconversation.com/what-does-the-appendix-do-biologists-explain-the-complicated-evolution-of-this-inconvenient-organ-277012

Source: The Conversation – USA – By Yaw Edu Essandoh, Ph.D. Student in Public and Environmental Affairs, Indiana University

Every morning, people fasten their watch, slip on a bracelet and head out the door without thinking much about what they might encounter along the way. The air they breathe, the dust on their hands and the surfaces they touch all feel ordinary. Yet many chemical exposures happen quietly, without smell, taste or warning.

What if something as simple as a silicone band around your wrist could help track those invisible exposures?

Environmental monitoring has traditionally relied on snapshots of exposure from a water sample collected on a single day, a blood sample drawn at one point in time, or soil tested from a specific location. But exposure unfolds gradually as people move through different environments and come into contact with air, dust and surfaces throughout the day.

New noninvasive monitoring tools aim to capture that longer-term picture.

As synthetic chemicals such as “forever chemicals,” known as perfluoroalkyl and polyfluoroalkyl substances (PFAS), become more widespread in everyday environments, scientists are increasingly focused on understanding how exposure to these substances occurs in daily life.

Traditional monitoring misses everyday reality

Traditional monitoring methods are essential for identifying contamination, but they capture exposure as a moment rather than something that unfolds over time.

In studies involving people, measuring exposure often requires invasive procedures such as blood draws, which can be expensive, logistically challenging and, for some participants, uncomfortable enough to discourage involvement.

Early in my environmental chemistry research, I noticed something that didn’t quite add up. People living in the same agricultural community, or animals sharing the same landscape, often showed very different chemical profiles even when environmental measurements looked similar. The surroundings hadn’t changed much; daily behavior had.

Movement through different spaces, time spent indoors or outdoors, contact with treated surfaces and interactions with consumer products all shape exposure in ways a single sample can’t fully capture. That realization raised a larger question: If exposure unfolds gradually, how can scientists measure it using tools designed for specific moments? Answering that question requires a shift away from isolated measurements and toward approaches that reflect lived experience.

What noninvasive tools change

That question led me to work with passive, noninvasive monitoring tools, including silicone wristbands. Rather than actively collecting samples, these tools absorb chemicals from the surrounding environment over time, similar to how skin or fur interacts with air, dust and surfaces.

Silicone wristbands work because they are made of a silicone polymer called polydimethylsiloxane, or PDMS, that can absorb many organic chemicals from the surrounding environment. As the band is worn, compounds from air, dust and surfaces gradually diffuse into the silicone over time.

The material acts somewhat like a sponge, passively collecting traces of chemicals the wearer encounters during daily activities. After the wristband is worn for several days or weeks, researchers can extract those compounds in the laboratory and analyze them to better understand patterns of exposure.

Silicone wristbands are one example of a broader group of passive, noninvasive monitoring tools designed to observe how chemicals accumulate over time. Other approaches, including passive air samplers placed in homes or small wearable devices, follow similar principles by absorbing compounds from the surrounding environment.

Researchers have used noninvasive tools in community studies to track exposure without medical procedures, lowering barriers to participation and reducing the burden on volunteers. For example, scientists have applied these approaches to study exposure among adolescent girls in agricultural communities, firefighters and occupants in office buildings.

Researchers have also adapted similar ideas for animal and wildlife studies. Instead of drawing blood, scientists may use wearable tags, collars or passive samplers placed in an animal’s environment, such as nesting areas or habitats, to understand how chemicals accumulate over time. These approaches can offer insight into exposure across different ecosystems while minimizing stress on animals.

Like any method, passive monitoring has limitations. Some chemicals are more difficult to capture than others, and environmental conditions such as temperature, sunlight or airflow can influence how efficiently samplers absorb pollutants. Wearable devices also reflect exposure over a specific period, meaning they cannot provide a complete lifetime record.

These approaches do not replace traditional monitoring. Instead, they add context, showing how exposure accumulates across time and space rather than appearing suddenly at a single sampling point.

Why this matters now

In the United States, PFAS contamination has become a growing public concern, from drinking water advisories to product restrictions and cleanup efforts. Federal agencies, including the Environmental Protection Agency, have highlighted the persistence of these chemicals and their widespread presence in the environment.

Much of the public conversation focuses on where PFAS are found in water systems, soils or consumer products. Understanding exposure, however, also requires attention to how people and ecosystems encounter these chemicals in everyday settings.

Noninvasive monitoring tools may help fill that gap. They offer ways to better understand cumulative exposure, identify overlooked pathways and inform environmental health and conservation decisions. For wildlife, these methods may allow researchers to detect emerging risks earlier without adding pressure to species already facing habitat loss and climate stress.

Although these approaches are becoming more common in environmental health research, they are still emerging compared with traditional sampling methods. Costs, the need for standardized protocols and differences in how various chemicals interact with passive materials can slow wider adoption. As researchers continue refining these tools, they can complement rather than replace established monitoring strategies.

Yaw Edu Essandoh does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Silicone wristbands can help scientists track people’s exposure to pollutants like ‘forever chemicals’ – https://theconversation.com/silicone-wristbands-can-help-scientists-track-peoples-exposure-to-pollutants-like-forever-chemicals-275520