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Space travel comes with risk − and SpaceX’s Polaris Dawn mission will push the envelope further than any private mission has before

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theconversation.com – Chris Impey, University Distinguished Professor of Astronomy, University of Arizona – 2024-09-06 07:30:06

Spacewalks are among the more dangerous activities associated with human spaceflight.

Ignatiev/E+ via Getty Images

Chris Impey, University of Arizona

Space is an unnatural environment for humans. We can’t survive unprotected in a pure vacuum for more than two minutes. Getting to space involves being strapped to a barely contained chemical explosion.

Since 1961, fewer than 700 people have been into space. Private space companies such as SpaceX and Blue Origin hope to boost that number to many thousands, and SpaceX is already taking bookings for flights to Earth orbit.

I’m an astronomer who has written extensively about space travel, including a book about our future off-Earth. I think a lot about the risks and rewards of exploring space.

As the commercial space industry takes off, there will be accidents and people will die. Polaris Dawn, planned to launch early in September 2024, will be a high-risk mission using only civilian astronauts. So, now is a good time to assess the risks and rewards of leaving the Earth.

Space travel is dangerous

Most Americans vividly recall the disasters that led to the loss of 14 astronauts’ lives. Two of the five space shuttles disintegrated, Challenger in 1986 soon after launch and Columbia in 2003 on reentry.

YouTube video
The Challenger and Columbia accidents are two of the most prominent examples of the risk that comes with human spaceflight.

In total, 30 astronauts and cosmonauts have died while training for or during space missions.

There have also been dozens of close calls. Two astronauts are currently staying on the International Space Station for an extra six months because NASA declared their Boeing Starliner vehicle unsafe for the return journey. Starliner has had many problems during its development, including flammable tape, stuck valves and inadequate parachute systems. But a critical thruster malfunction is what caused NASA to abandon it as a return vehicle.

It’s not always safe on the ground, either. In addition to the three Apollo 1 astronauts who died in a 1967 launch pad fire, about 120 people died in the launchpad explosion of an unmanned rocket in Russia in 1960, and hundreds died in 1996 when a Chinese rocket veered off course and crashed into a nearby village.

The fatality rate of people traveling in space is about 3%. That sounds low, but it’s higher than extreme sports such as BASE jumping or jumping off a cliff wearing a wingsuit. The only recreations that rival the risk of space travel are solo free-climbing and climbing above 19,685 feet (6,000 meters) in the Himalayas.

Civilians in space

The 2020s have kicked off the era of civilian astronauts. After the death of schoolteacher Christa McAuliffe in the Challenger disaster, NASA stopped sending civilians into space. But for commercial space companies, it’s part of the business model.

The first all-civilian crew to reach orbit rode a SpaceX Dragon spacecraft in 2021, the Inspiration 4 mission. Since 2020, 69 private astronauts have gone to space, although only 46 reached the Kármán line – the formal definition of the edge of space.

The commercial space industry’s safety record is not perfect. No civilian has died in space, but one pilot died and another was seriously injured in a test flight of Virgin Galactic’s SpaceShipTwo craft in 2014. This accident followed three deaths and three injuries in an explosion during a prelaunch test of the SpaceShipTwo rocket in 2007.

SpaceX, the largest commercial space company with 13,000 employees and a market value of US$180 billion, has seen no fatalities in flight, but it has recorded one death and hundreds of injuries in the workplace.

The Polaris Dawn mission was planned to launch Aug. 27, 2024, though a helium leak and bad weather has delayed it. It will push the envelope of risk for civilians in space. This SpaceX flight will reach an altitude of 435 miles (700 kilometers), higher than any astronauts since Apollo.

Four astronauts wearing white suits and helmets stand in front of a rocket on a launchpad.

The Polaris Dawn crew during their launch-day rehearsal.

Polaris Program/John Kraus, CC BY-NC-ND

The Polaris Dawn’s four-person civilian crew will receive a hefty dose of radiation, getting as much in a few hours as they would in 20 years on the Earth. NASA is doing research to understand the extent of the health risks from radiation.

The mission will also include a spacewalk – the first for nongovernment astronauts. It will use spacesuits never tested in space. Since the spacecraft they’re using – the SpaceX Dragon – has no airlock, the inside of the capsule will be exposed to the vacuum of space, with all the crew members wearing spacesuits.

Russian cosmonaut Alexei Leonov nearly died during the first spacewalk in 1965, and other spacewalks have led to temporary blindness, near drowning and nearly being lost in space forever. A spacesuit is like a miniature spacecraft, and it has to withstand rapid temperature changes of hundreds of degrees when moving in and out of direct sunlight. Even a small tear or puncture can be fatal.

But while space travel comes with dangers, it also has rewards. Since Polaris Dawn will travel higher than any previous mission that did not go to the Moon, the crew will be able to do research on high-radiation environments. They will investigate the effects of spaceflight on the human body and evaluate how future deep-space travelers might diagnose and treat themselves.

A less tangible but potentially profound benefit is the overview effect – many astronauts report a feeling of awe from experiencing the Earth from space.

Space boom

Space is booming – hopefully just metaphorically and not literally. SpaceX makes money by launching Starlink satellites and ferrying supplies and people to the International Space Station, with estimated revenues of $15 billion this year. Blue Origin sells rocket engines and has contracts with NASA.

Both companies sell rides into space to high-net-worth individuals, but that’s a small fraction of their revenues. Space tourism is not available to the masses yet. Virgin Galactic offers a short, suborbital ride for $450,000, but getting to Earth orbit will cost you $55 million.

The space tourism market was $750 million in 2023, and that’s projected to grow to $5.2 billion over the next decade. Reusable rockets have made the cost of launching a spacecraft 10 times cheaper than it was a decade ago.

For space tourism to take off with a demographic broader than multimillionaires and thrill-seekers, it needs to be safe – both in perception and in reality. Many space entrepreneurs expect space travel to follow aviation’s arc, which also started by attracting rich people and thrill-seekers.

Since 1930, improvements in technology and safety features have lowered the number of fatal accidents in the aviation industry per million miles flown by a factor of 3,000. A more realistic target may be to make space travel as safe as driving. That’s a more lenient target, since driving is more dangerous than flying. Your annual odds of dying in a car crash are 1 in 5,000, compared with annual odds of 1 in 11 million of dying in a plane crash.

In the United States, the government has kept regulations light on the commercial space industry to encourage entrepreneurs.

Elon Musk’s dreams of millions of passengers and a city on Mars may not become reality. But if the cost of a jaunt to Earth’s orbit comes down to the cost of a high-end cruise, many people could experience the thrill of weightlessness and of seeing the Earth as a beautiful planet from above.The Conversation

Chris Impey, University Distinguished Professor of Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The Conversation

Contaminated milk from one plant in Illinois sickened thousands with Salmonella in 1985 − as outbreaks rise in the US, lessons from this one remain true

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theconversation.com – Michael Petros, Clinical Assistant Professor of Environmental and Occupational Health Sciences, University of Illinois Chicago – 2025-05-07 07:34:00

A valve that mixed raw milk with pasteurized milk at Hillfarm Dairy may have been the source of contamination. This was the milk processing area of the plant.
AP Photo/Mark Elias

Michael Petros, University of Illinois Chicago

In 1985, contaminated milk in Illinois led to a Salmonella outbreak that infected hundreds of thousands of people across the United States and caused at least 12 deaths. At the time, it was the largest single outbreak of foodborne illness in the U.S. and remains the worst outbreak of Salmonella food poisoning in American history.

Many questions circulated during the outbreak. How could this contamination occur in a modern dairy farm? Was it caused by a flaw in engineering or processing, or was this the result of deliberate sabotage? What roles, if any, did politics and failed leadership play?

From my 50 years of working in public health, I’ve found that reflecting on the past can help researchers and officials prepare for future challenges. Revisiting this investigation and its outcome provides lessons on how food safety inspections go hand in hand with consumer protection and public health, especially as hospitalizations and deaths from foodborne illnesses rise.

Contamination, investigation and intrigue

The Illinois Department of Public Health and the U.S. Centers for Disease Control and Prevention led the investigation into the outbreak. The public health laboratories of the city of Chicago and state of Illinois were also closely involved in testing milk samples.

Investigators and epidemiologists from local, state and federal public health agencies found that specific lots of milk with expiration dates up to April 17, 1985, were contaminated with Salmonella. The outbreak may have been caused by a valve at a processing plant that allowed pasteurized milk to mix with raw milk, which can carry several harmful microorganisms, including Salmonella.

Overall, labs and hospitals in Illinois and five other Midwest states – Indiana, Iowa, Michigan, Minnesota and Wisconsin – reported over 16,100 cases of suspected Salmonella poisoning to health officials.

To make dairy products, skimmed milk is usually separated from cream, then blended back together in different levels to achieve the desired fat content. While most dairies pasteurize their products after blending, Hillfarm Dairy in Melrose Park, Illinois, pasteurized the milk first before blending it into various products such as skim milk and 2% milk.

Subsequent examination of the production process suggested that Salmonella may have grown in the threads of a screw-on cap used to seal an end of a mixing pipe. Investigators also found this strain of Salmonella 10 months earlier in a much smaller outbreak in the Chicago area.

Microscopy image of six rod-shaped bacteria against a black background
Salmonella is a common cause of food poisoning.
Volker Brinkmann/Max Planck Institute for Infection Biology via PLoS One, CC BY-SA

Finding the source

The contaminated milk was produced at Hillfarm Dairy in Melrose Park, which was operated at the time by Jewel Companies Inc. During an April 3 inspection of the company’s plant, the Food and Drug Administration found 13 health and safety violations.

The legal fallout of the outbreak expanded when the Illinois attorney general filed suit against Jewel Companies Inc., alleging that employees at as many as 18 stores in the grocery chain violated water pollution laws when they dumped potentially contaminated milk into storm sewers. Later, a Cook County judge found Jewel Companies Inc. in violation of the court order to preserve milk products suspected of contamination and maintain a record of what happened to milk returned to the Hillfarm Dairy.

Political fallout also ensued. The Illinois governor at the time, James Thompson, fired the director of the Illinois Public Health Department when it was discovered that he was vacationing in Mexico at the onset of the outbreak and failed to return to Illinois. Notably, the health director at the time of the outbreak was not a health professional. Following this episode, the governor appointed public health professional and medical doctor Bernard Turnock as director of the Illinois Department of Public Health.

In 1987, after a nine-month trial, a jury determined that Jewel officials did not act recklessly when Salmonella-tainted milk caused one of the largest food poisoning outbreaks in U.S. history. No punitive damages were awarded to victims, and the Illinois Appellate Court later upheld the jury’s decision.

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Raw milk is linked to many foodborne illnesses.

Lessons learned

History teaches more than facts, figures and incidents. It provides an opportunity to reflect on how to learn from past mistakes in order to adapt to future challenges. The largest Salmonella outbreak in the U.S. to date provides several lessons.

For one, disease surveillance is indispensable to preventing outbreaks, both then and now. People remain vulnerable to ubiquitous microorganisms such as Salmonella and E. coli, and early detection of an outbreak could stop it from spreading and getting worse.

Additionally, food production facilities can maintain a safe food supply with careful design and monitoring. Revisiting consumer protections can help regulators keep pace with new threats from new or unfamiliar pathogens.

Finally, there is no substitute for professional public health leadership with the competence and expertise to respond effectively to an emergency.The Conversation

Michael Petros, Clinical Assistant Professor of Environmental and Occupational Health Sciences, University of Illinois Chicago

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The post Contaminated milk from one plant in Illinois sickened thousands with Salmonella in 1985 − as outbreaks rise in the US, lessons from this one remain true appeared first on theconversation.com



Note: The following A.I. based commentary is not part of the original article, reproduced above, but is offered in the hopes that it will promote greater media literacy and critical thinking, by making any potential bias more visible to the reader –Staff Editor.

Political Bias Rating: Centrist

The article provides an analytical, factual recounting of the 1985 Salmonella outbreak, with an emphasis on public health, safety standards, and lessons learned from past mistakes. It critiques the failures in leadership and oversight during the incident but avoids overt ideological framing. While it highlights political accountability, particularly the firing of a public health official and the appointment of a medical professional, it does so in a balanced manner without assigning blame to a specific political ideology. The content stays focused on the public health aspect and the importance of professional leadership, reflecting a centrist perspective in its delivery.

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Predictive policing AI is on the rise − making it accountable to the public could curb its harmful effects

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theconversation.com – Maria Lungu, Postdoctoral Researcher of Law and Public Administration, University of Virginia – 2025-05-06 07:35:00

Data like this seven-day crime map from Oakland, Calif., feeds predictive policing AIs.
City of Oakland via CrimeMapping.com

Maria Lungu, University of Virginia

The 2002 sci-fi thriller “Minority Report” depicted a dystopian future where a specialized police unit was tasked with arresting people for crimes they had not yet committed. Directed by Steven Spielberg and based on a short story by Philip K. Dick, the drama revolved around “PreCrime” − a system informed by a trio of psychics, or “precogs,” who anticipated future homicides, allowing police officers to intervene and prevent would-be assailants from claiming their targets’ lives.

The film probes at hefty ethical questions: How can someone be guilty of a crime they haven’t yet committed? And what happens when the system gets it wrong?

While there is no such thing as an all-seeing “precog,” key components of the future that “Minority Report” envisioned have become reality even faster than its creators imagined. For more than a decade, police departments across the globe have been using data-driven systems geared toward predicting when and where crimes might occur and who might commit them.

Far from an abstract or futuristic conceit, predictive policing is a reality. And market analysts are predicting a boom for the technology.

Given the challenges in using predictive machine learning effectively and fairly, predictive policing raises significant ethical concerns. Absent technological fixes on the horizon, there is an approach to addressing these concerns: Treat government use of the technology as a matter of democratic accountability.

Troubling history

Predictive policing relies on artificial intelligence and data analytics to anticipate potential criminal activity before it happens. It can involve analyzing large datasets drawn from crime reports, arrest records and social or geographic information to identify patterns and forecast where crimes might occur or who may be involved.

Law enforcement agencies have used data analytics to track broad trends for many decades. Today’s powerful AI technologies, however, take in vast amounts of surveillance and crime report data to provide much finer-grained analysis.

Police departments use these techniques to help determine where they should concentrate their resources. Place-based prediction focuses on identifying high-risk locations, also known as hot spots, where crimes are statistically more likely to happen. Person-based prediction, by contrast, attempts to flag individuals who are considered at high risk of committing or becoming victims of crime.

These types of systems have been the subject of significant public concern. Under a so-called “intelligence-led policing” program in Pasco County, Florida, the sheriff’s department compiled a list of people considered likely to commit crimes and then repeatedly sent deputies to their homes. More than 1,000 Pasco residents, including minors, were subject to random visits from police officers and were cited for things such as missing mailbox numbers and overgrown grass.

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Lawsuits forced the Pasco County, Fla., Sheriff’s Office to end its troubled predictive policing program.

Four residents sued the county in 2021, and last year they reached a settlement in which the sheriff’s office admitted that it had violated residents’ constitutional rights to privacy and equal treatment under the law. The program has since been discontinued.

This is not just a Florida problem. In 2020, Chicago decommissioned its “Strategic Subject List,” a system where police used analytics to predict which prior offenders were likely to commit new crimes or become victims of future shootings. In 2021, the Los Angeles Police Department discontinued its use of PredPol, a software program designed to forecast crime hot spots but was criticized for low accuracy rates and reinforcing racial and socioeconomic biases.

Necessary innovations or dangerous overreach?

The failure of these high-profile programs highlights a critical tension: Even though law enforcement agencies often advocate for AI-driven tools for public safety, civil rights groups and scholars have raised concerns over privacy violations, accountability issues and the lack of transparency. And despite these high-profile retreats from predictive policing, many smaller police departments are using the technology.

Most American police departments lack clear policies on algorithmic decision-making and provide little to no disclosure about how the predictive models they use are developed, trained or monitored for accuracy or bias. A Brookings Institution analysis found that in many cities, local governments had no public documentation on how predictive policing software functioned, what data was used, or how outcomes were evaluated.

YouTube video
Predictive policing can perpetuate racial bias.

This opacity is what’s known in the industry as a “black box.” It prevents independent oversight and raises serious questions about the structures surrounding AI-driven decision-making. If a citizen is flagged as high-risk by an algorithm, what recourse do they have? Who oversees the fairness of these systems? What independent oversight mechanisms are available?

These questions are driving contentious debates in communities about whether predictive policing as a method should be reformed, more tightly regulated or abandoned altogether. Some people view these tools as necessary innovations, while others see them as dangerous overreach.

A better way in San Jose

But there is evidence that data-driven tools grounded in democratic values of due process, transparency and accountability may offer a stronger alternative to today’s predictive policing systems. What if the public could understand how these algorithms function, what data they rely on, and what safeguards exist to prevent discriminatory outcomes and misuse of the technology?

The city of San Jose, California, has embarked on a process that is intended to increase transparency and accountability around its use of AI systems. San Jose maintains a set of AI principles requiring that any AI tools used by city government be effective, transparent to the public and equitable in their effects on people’s lives. City departments also are required to assess the risks of AI systems before integrating them into their operations.

If taken correctly, these measures can effectively open the black box, dramatically reducing the degree to which AI companies can hide their code or their data behind things such as protections for trade secrets. Enabling public scrutiny of training data can reveal problems such as racial or economic bias, which can be mitigated but are extremely difficult if not impossible to eradicate.

Research has shown that when citizens feel that government institutions act fairly and transparently, they are more likely to engage in civic life and support public policies. Law enforcement agencies are likely to have stronger outcomes if they treat technology as a tool – rather than a substitute – for justice.The Conversation

Maria Lungu, Postdoctoral Researcher of Law and Public Administration, University of Virginia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The post Predictive policing AI is on the rise − making it accountable to the public could curb its harmful effects appeared first on theconversation.com



Note: The following A.I. based commentary is not part of the original article, reproduced above, but is offered in the hopes that it will promote greater media literacy and critical thinking, by making any potential bias more visible to the reader –Staff Editor.

Political Bias Rating: Center-Left

The article provides an analysis of predictive policing, highlighting both the technological potential and ethical concerns surrounding its use. While it presents factual information, it leans towards caution and skepticism regarding the fairness, transparency, and potential racial biases of these systems. The framing of these issues, along with an emphasis on democratic accountability, transparency, and civil rights, aligns more closely with center-left perspectives that emphasize government oversight, civil liberties, and fairness. The critique of predictive policing technologies without overtly advocating for their abandonment reflects a balanced but cautious stance on technology’s role in law enforcement.

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Worsening allergies aren’t your imagination − windy days create the perfect pollen storm

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theconversation.com – Christine Cairns Fortuin, Assistant Professor of Forestry, Mississippi State University – 2025-05-05 07:45:00

Windy days can mean more pollen and more sneezing.
mladenbalinovac/E+ via Getty Images

Christine Cairns Fortuin, Mississippi State University

Evolution has fostered many reproductive strategies across the spectrum of life. From dandelions to giraffes, nature finds a way.

One of those ways creates quite a bit of suffering for humans: pollen, the infamous male gametophyte of the plant kingdom.

In the Southeastern U.S., where I live, you know it’s spring when your car has turned yellow and pollen blankets your patio furniture and anything else left outside. Suddenly there are long lines at every car wash in town.

A car covered in yellow. Someone drew a smiley face with the words 'LOLLEN,' with LOL underlined.
On heavy pollen days, cars can end up covered in yellow grains.
Scott Akerman/Flickr, CC BY

Even people who aren’t allergic to pollen – clearly an advantage for a pollination ecologist like me – can experience sneezing and watery eyes during the release of tree pollen each spring. Enough particulate matter in the air will irritate just about anyone, even if your immune system does not launch an all-out attack.

So, why is there so much pollen? And why does it seem to be getting worse?

2 ways trees spread their pollen

Trees don’t have an easy time in the reproductive game. As a tree, you have two options to disperse your pollen.

Option 1: Employ an agent, such as a butterfly or bee, that can carry your pollen to another plant of the same species.

The downside of this option is that you must invest in a showy flower display and a sweet scent to advertise yourself, and sugary nectar to pay your agent for its services.

A bee noses into a white flower.
A bee enjoys pollen from a cherry blossom. Pollen is a primary source of protein for bees.
Ivan Radic/Flickr, CC BY

Option 2, the budget option, is much less precise: Get a free ride on the wind.

Wind was the original pollinator, evolving long before animal-mediated pollination. Wind doesn’t require a showy flower nor a nectar reward. What it does require for pollination to succeed is ample amounts of lightweight, small-diameter pollen.

Why wind-blown pollen makes allergies worse

Wind is not an efficient pollinator, however. The probability of one pollen grain landing in the right location – the stigma or ovule of another plant of the same species – is infinitesimally small.

Therefore, wind-pollinated trees must compensate for this inefficiency by producing copious amounts of pollen, and it must be light enough to be carried.

For allergy sufferers, that can mean air filled with microscopic pollen grains that can get into your eyes, throat and lungs, sneak in through window screens and convince your immune system that you’ve inhaled a dangerous intruder.

Tiny flowers on a live oak tree.
When wind blows the tiny pollen grains of live oaks, allergy sufferers feel it.
Charles Willgren/Flickr, CC BY

Plants relying on animal-mediated pollination, by contrast, can produce heavier and stickier pollen to adhere to the body of an insect. So don’t blame the bees for your allergies – it’s really the wind.

Climate change has a role here, too

Plants initiate pollen release based on a few factors, including temperature and light cues. Many of our temperate tree species respond to cues that signal the beginning of spring, including warmer temperatures.

Studies have found that pollen seasons have intensified in the past three decades as the climate has warmed. One study that examined 60 location across North America found pollen seasons expanded by an average of 20 days from 1990 to 2018 and pollen concentrations increased by 21%.

That’s not all. Increasing carbon dioxide levels may also be driving increases in the quantity of tree pollen produced.

Why the Southeast gets socked

What could make this pollen boost even worse?

For the Southeastern U.S. in particular, strong windstorms are becoming more common and more intense − and not just hurricanes.

Anyone who has lived in the Southeast for the past couple of decades has likely noticed this. The region has more tornado warnings, more severe thunderstorms, more power outages. This is especially true in the mid-South, from Mississippi to Alabama.

A map showing windiest events in the Southeast are over Alabama and Mississippi.
Severity of wind and storm events mapped from NOAA data, 2012-2019, shows high activity over Mississippi and Alabama. Red areas have the most severe events.
Christine Cairns Fortuin

Since wind is the vector of airborne pollen, windier conditions can also make allergies worse. Pollen remains airborne for longer on windy days, and it travels farther.

To make matters worse, increasing storm activity may be doing more than just transporting pollen. Storms can also break apart pollen grains, creating smaller particles that can penetrate deeper into the lungs.

Many allergy sufferers may notice worsening allergies during storms.

The peak of spring wind and storm season tends to correspond to the timing of the release of tree pollen that blankets our world in yellow. The effects of climate change, including longer pollen seasons and more pollen released, and corresponding shifts in windy days and storm severity are helping to create the perfect pollen storm.The Conversation

Christine Cairns Fortuin, Assistant Professor of Forestry, Mississippi State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The post Worsening allergies aren’t your imagination − windy days create the perfect pollen storm appeared first on theconversation.com



Note: The following A.I. based commentary is not part of the original article, reproduced above, but is offered in the hopes that it will promote greater media literacy and critical thinking, by making any potential bias more visible to the reader –Staff Editor.

Political Bias Rating: Centrist

The content is a scientific and educational article focusing on the biology of pollen, its effects on allergies, and the influence of climate change on pollen production. It presents factual information supported by research studies and references, without taking a partisan stance. While it acknowledges climate change as a factor, the discussion remains grounded in scientific observation rather than political opinion, leading to a neutral, centrist tone.

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