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Air Pollution, Evolution, and the Fate of Billions of Humans

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The threat of air pollution grabs our attention when we see it — for example, the tendrils of smoke of Australian brush fires, now visible from space, or the poisonous soup of smog that descends on cities like New Delhi in the winter.

But polluted air also harms billions of people on a continuing basis. Outdoors, we breathe in toxins delivered by car traffic, coal-fired plants and oil refineries. Indoor fires for heat and cooking taint the air for billions of people in poor countries. Over a billion people add toxins to their lungs by smoking cigarettes — and more recently, by vaping.

Ninety-two percent of the world’s people live in places where fine particulate matter — the very small particles most dangerous to human tissues — exceeds the World Health Organization’s guideline for healthy air. Air pollution and tobacco together are responsible for up to 20 million premature deaths each year.

Airborne toxins damage us in a staggering number of ways. Along with well-established links to lung cancer and heart disease, researchers are now finding new connections to disorders such as diabetes and Alzheimer’s disease.

Scientists are still figuring out how air pollution causes these ailments. They are also puzzling over the apparent resilience that some people have to this modern onslaught.

Some researchers now argue that the answers to these questions lie in our distant evolutionary past, millions of years before the first cigarette was lit and the first car hit the road.

Our ancestors were bedeviled by airborne toxins even as bipedal apes walking the African savanna, argued Benjamin Trumble, a biologist at Arizona State University, and Caleb Finch of the University of Southern California, in the December issue of the Quarterly Review of Biology.

Our forebears evolved defenses against these pollutants, the scientists propose. Today, those adaptations may provide protection, albeit limited, against tobacco smoke and other airborne threats.

The dense foliage of tropical forests gave chimpanzees and gorillas a refuge from dust. But the earliest humans, wandering the open grasslands, had nowhere to hide.

Dust was not the only hazard. The lungs of early humans also may have been irritated by the high levels of pollen and particles of fecal matter produced by the savanna’s vast herds of grazing animals.

Dr. Finch and Dr. Trumble maintain that scientists should consider whether these new challenges altered our biology through natural selection. Is it possible, for instance, that people who are resilient to cigarette smoke have inherited genetic variants that protected their distant ancestors from cave fires?

One way to answer these questions is to look at genes that have evolved significantly since our ancestors moved out of the forests.

One of them is MARCO, which provides the blueprint for production of a molecular hook used by immune cells in our lungs. The cells use this hook to clear away both bacteria and particles, including silica dust.

Later, our ancestors added to airborne threats by mastering fire. As they lingered near hearths to cook food, stay warm or keep away from insects, they breathed in smoke. Once early humans began building shelters, the environment became more harmful to their lungs.

“Most traditional people live in a highly smoky environment,” Dr. Finch said. “I think it has been a fact of human living for us even before our species.”

Smoke created a new evolutionary pressure, he and Dr. Trumble believe. Humans evolved powerful liver enzymes, for example, to break down toxins passing into the bloodstream from the lungs.

Gary Perdew, a molecular toxicologist at Penn State University, and his colleagues have found evidence of smoke-driven evolution in another gene, AHR.

This gene makes a protein found on cells in the gut, lungs and skin. When toxins get snagged on the protein, cells release enzymes that break down the poisons.

Other mammals use AHR to detoxify their food. But the protein is also effective against some of the compounds in wood smoke.

Compared to other species, the human version produces a weaker response to toxins, perhaps because AHR protein is not the perfect protector — the fragments it leaves behind can cause tissue damage.

Our species arrived at the Industrial Revolution two centuries ago with bodies that had been shaped for millions of years by this highly imperfect process.

Clean water, improved medicines and other innovations drastically reduced deaths from infectious diseases. The average life expectancy shot up. But our exposure to airborne toxins also increased.

“If we compressed the last five million years into a single year, it wouldn’t be until Dec. 31, 11:40 p.m., that the Industrial Revolution begins,” Dr. Trumble said. “We are living in just the tiniest little blip of human existence, yet we think everything around us is what’s normal.”

The Industrial Revolution was powered largely by coal, and people began breathing the fumes. Cars became ubiquitous; power plants and oil refineries spread. Tobacco companies made cigarettes on an industrial scale. Today, they sell 6.5 trillion cigarettes every year.

Our bodies responded with defenses honed over hundreds of thousands of years. One of their most potent responses was inflammation. But instead of brief bursts of inflammation, many people began to experience it constantly.

Many studies now suggest that chronic inflammation represents an important link between airborne toxins and disease. In the brain, for example, chronic inflammation may impair our ability to clear up defective proteins. As those proteins accumulate, they may lead to dementia.

Pathogens can hitch a ride on particles of pollutants. When they get in our noses, they can make contact with nerve endings. There, they can trigger even more inflammation.

“They provide this highway that’s a direct route to the brain,” Dr. Fox, of the University of California, Los Angeles, said. “I think that’s what makes this a particularly scary story.”



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Mercury Systems Receives $4.7 Million AI Processing Technology Order

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Mercury Systems Receives $4.7 Million AI Processing Technology Order





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Australia Investigates Why a Cruise Ship Allowed Infected Passengers to Disembark: Live Coverage

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Saudi Arabia, battered by virus, declares a cease-fire in Yemen.

Saudi Arabia on Wednesday announced that the kingdom and its allies would observe a unilateral cease-fire in the war in Yemen starting at noon on Thursday, a move that could pave the way for ending the brutal five-year-old conflict.

Saudi officials said that the cease-fire was intended to jump-start peace talks brokered by the United Nations and that it had been motivated by fears of the coronavirus spreading in Yemen, the poorest country in the Arab world.

The gesture is the first by any government entangled in an international armed conflict to halt hostilities at least in part because of the pandemic. The secretary general of the United Nations, António Guterres, pleaded for a worldwide cease-fire two weeks ago, citing the pandemic.

As many as 150 members of the Saudi royal family are believed to have contracted the coronavirus, including members of the family’s lesser branches, according to a person close to the family.

The senior Saudi who is the governor of Riyadh, Prince Faisal bin Bandar bin Abdulaziz Al Saud, is in intensive care with Covid-19, according to two doctors with ties to the King Faisal hospital and two others close to the royal family. Prince Faisal is a nephew of King Salman.

King Salman, 84, has secluded himself in an island palace near the city of Jeddah on the Red Sea. His son, Crown Prince Mohammed bin Salman, the 34-year old de facto ruler, has retreated with many of his ministers to the remote site on the same coast.

“That ship obviously has huge exposure to coronavirus,” he said. “Why wasn’t anybody tested?”

The U.S. death toll, now growing by well over a thousand a day, has continued to mount with no sign of abating soon. And although President Trump tweeted on Monday about a light at the end of a tunnel, scientists say it will be a very, very long one.

In announcing the state of emergency this week, Mr. Abe warned citizens to avoid closed spaces where crowds meet in close proximity — places like nightclubs, karaoke bars and live music halls.

One municipality is taking matters into its own hands. Gotemba, a city of about 88,000 in the foothills of Mount Fuji, is offering owners of businesses such as bars and nightclubs a maximum of 1 million yen (about $9,200) in compensation for closing between April 16 and 30.

The White House’s coronavirus response coordinator suggested on Wednesday that the strict measures being taken by Americans to stem the spread of the virus may be leveling new cases in large metropolitan areas like New York, Detroit, Chicago and Boston.

But the coordinator, Dr. Deborah Birx, also emphasized that “there is still a significant amount of disease.”

Here’s what else is happening in the United States:

Replying to criticism from President Trump, the head of the World Health Organization made an impassioned plea for solidarity on Wednesday, warning that politicizing the coronavirus pandemic would result in “many more body bags.”

Mr. Trump unleashed a tirade against the organization on Tuesday, accusing it of acting too slowly to sound the alarm, and of treating the Chinese government too favorably. While the president, who threatened to withhold American funding for the W.H.O., spoke in unusually harsh terms, he was not alone in such criticism.

Critics say that the W.H.O. has been too trusting of the Chinese government, which initially tried to conceal the outbreak. Others have faulted the organization for not moving faster in declaring a global health emergency. But the agency’s defenders say that its powers over any individual government are limited.

Asked about Mr. Trump’s comments on Wednesday, Dr. Tedros Adhanom Ghebreyesus, the W.H.O. director-general, said, “We want to learn from our mistakes,” but added, “for now, the focus should be on fighting this virus.”

“Please don’t politicize this virus,” Dr. Tedros said. “If you want to be exploited and you want to have many more body bags, then you do it. If you don’t want many more body bags, then you refrain from politicizing it.”

Dr. Tedros also singled out the Taiwanese government, which has been frozen out of the W.H.O. following pressure from Beijing, when he said for the first time that he had been targeted by racist comments and death threats that originated in the country.

“They didn’t disassociate themselves,” he said of Taiwanese officials. “They even started criticizing me in the middle of all that insult and slur, but I didn’t care.”

Taiwan’s president, Tsai Ing-wen, hit back on Thursday. “Taiwan has always opposed all forms of discrimination,” she wrote on Facebook. “For years, we have been excluded from international organizations, and we know better than anyone else what it feels like to be discriminated against and isolated.”

The pandemic has played a critical role in this drama, but there is also a lot of jockeying among the three oil superpowers: Saudi Arabia and Russia, two longtime petro-rivals, and the United States, whose rising prominence as an oil exporter has disrupted the industry.

It is far from clear that the G20 meeting will calm volatile markets. The fact that the meeting is occurring, though, may signal the beginning of a very different approach.

“A lot of countries, including those with strong free-market beliefs and credentials, seem to be coming over to the view that the global oil business needs to be managed to an extent, at least from time to time,” said Bhushan Bahree, an executive director at IHS Markit, a research firm.

How to celebrate in coronavirus times.

Stay-at-home orders don’t have to put a damper on your special days. Here’s some ways to celebrate birthdays, weddings, and the upcoming spring holidays.

With more than one million people worldwide ill from the coronavirus, there is an urgent search for any drug that might help.

Reporting was contributed by Elaine Yu, Motoko Rich, Hisako Ueno, Makiko Inoue, Rory Smith, Tariq Panja, Livia Albeck-Ripka, Carl Zimmer, James Gorman, Michael Levenson, Dan Barry, Ben Hubbard, Stanley Reed, Clifford Krauss, Andrew E. Kramer, Dionne Searcey, Ruth Maclean, Denise Grady, Katie Thomas and Patrick J. Lyons.





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Poachers Kill More Rhinos as Coronavirus Halts Tourism to Africa

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The past few weeks have not been easy for Nico Jacobs, founder of Rhino 911, a nonprofit that provides emergency helicopter transport for rhinoceroses in need of rescue in South Africa. That’s because times are much worse for the rhinos.

Since South Africa announced a national lockdown on March 23 to limit the spread of the new coronavirus, Mr. Jacobs has had to respond to a rhino poaching incident nearly every day. On March 25, he rescued a 2-month-old white rhino calf whose mother had been killed by poachers. The next day he was called to rescue two black rhinos whose horns had been hacked off by poachers. When he finally tracked them down it was too late — both were dead.

“Just as soon as the lockdown hit South Africa, we started having an incursion almost every single day,” Mr. Jacobs said.

At least nine rhinos have been poached in South Africa’s North West province since the lockdown, he said, “and those are just the ones we know about.”

“These animals are not just protected by rangers, they’re also protected by tourist presence,” said Tim Davenport, who directs species conservation programs for Africa at the Wildlife Conservation Society. “If you’re a poacher, you’re not going to go to a place where there are lots of tourists, you’re going to go to a place where there are very few of them.”

Rangers and private game guards could be next.

South Africa, Botswana, Tanzania, Kenya and other African countries rely on tourism to fund wildlife conservation. In South Africa, for example, about 85 percent of 2018 funding for the country’s wildlife and public lands management authority, South Africa National Parks, came from tourism-related sources, such as park entry fees and trophy hunting permits.

Without that revenue, many parks, private reserves and community conservancies may not be able to pay employees.

Lynne MacTavish, the operations manager at Mankwe Wildlife Reserve in South Africa’s North West province, is doing everything she can to avoid such a scenario. Her 4,750-hectare reserve should be crawling with visiting researchers and tourists. But since the coronavirus arrived, it’s just been her and a skeleton crew.

“We’re in a situation of zero income, and our expenses are actually going up all the time just trying to fight off the poachers and protect the reserve,” Ms. MacTavish said. “To say it’s desperate is an understatement. We’re really in crisis here.”

To avoid layoffs, Ms. MacTavish has stopped collecting a salary and has cut the pay of her fellow managers by 30 percent. But that will only keep the reserve above water for another three or four months. If things don’t improve, she may be forced to make difficult decisions.

“Our staff is made up of people from all parts of Southern Africa, and collectively they are supporting 131 dependents. Many of these dependents are from Malawi and Zimbabwe and other countries facing starvation,” Ms. MacTavish said. “They rely heavily on us in order to feed their families, and we can’t just turn our back on them.”

If the economic situation doesn’t improve, Ms. MacTavish expects to see more poaching in the coming months. “We’ve had a few incursions recently, but I’m expecting an onslaught if this lockdown carries on for months on end.”

Map Ives, the director of Rhino Conservation Botswana, shares her fears.

“We can expect not only poaching of rhinoceros and elephant and other iconic animals, but we can also expect a spike in bushmeat poaching across the continent,” he said. “There are going to be a lot of people that are not earning a living and they will turn on the natural world and you cannot blame them. These are hungry people.”

In the hopes of alleviating the situation, the Nature Conservancy, a U.S.-based environmental organization, recently began raising money for cash-strapped parks, conservancies and private reserves in Africa that need help paying rangers and guards.

While the full impact of the coronavirus on Africa’s wildlife remains to be seen, the events of the past two weeks illustrate the risks of relying too heavily on tourism to support conservation.

Catherine Semcer, a research fellow with the Property and Environment Research Center in North Carolina, believes the only way to prevent this from happening again is to diversify the sources of revenue that support wildlife conservation.

“We don’t want to decouple conservation from tourism, but I think we need to expand the range of sectors that support it,” she said.

Until this happens, Africa’s wildlife will remain in jeopardy and conservationists like Mr. Jacobs will continue getting calls about orphaned baby rhinos.

“If I get called out 10 times a day, I’m going to fly 10 times a day. I’ll fly as long as the finances can hold it,” he said.



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