Science

A UCLA doctor is on a quest to free modern medicine from a Nazi-tainted anatomy book

Published

8 months ago

May 20, 2024

A UCLA doctor is on a quest to free modern medicine from a Nazi-tainted anatomy book

As Dr. Kalyanam Shivkumar pondered how to fix the human heart, he was given a gift laced with horror.

Shivkumar, a cardiac electrophysiologist known as “Shiv” to friends and co-workers at UCLA, was trying to better understand the intricate details of nerves in the chest. He hoped doing so might help him improve treatments for cardiac arrhythmias — aberrant rhythms of the heart — that can prove dangerous and even deadly.

A Canadian colleague sent him a set of anatomy books renowned for the beauty and detail of their drawings, but tipped him off that the “atlas” had an appalling history.

Shivkumar was aghast to learn it was the work of an ardent Nazi whose Vienna institute had dissected the bodies of prisoners, many executed for political reasons after Austria was annexed to Nazi Germany in 1938.

“Every time I open up that book,” he said, “my sense is revulsion.”

Shivkumar is a big thinker, an erudite physician quick with an apt quotation, whose Westwood office is stacked with Sanskrit volumes of the Mahabharata alongside books about late Bruins basketball coach John Wooden.

Dr. Shumpei Mori sets up a donated heart to be photographed at UCLA as part of the Amara Yad project to create new, ethically made anatomical images.

(Allen J. Schaben / Los Angeles Times)

As he waded into the scholarly debate over using the tainted atlas, the doctor bristled at hearing others praise its illustrations as “unsurpassable.” Much of the soul searching among physicians had revolved around when and how to use it. Shivkumar wanted to put those questions to bed.

“Could we be better?” he asked. “Could we not be making something that’s completely untainted?”

That question would launch Shivkumar on a quest that has lasted more than a decade and is expected to endure for years. He wants to surpass the anatomical atlas created by Dr. Eduard Pernkopf, a fervent supporter of the Nazi regime whose work was fueled by the dead bodies of its victims.

His passion project at the UCLA Cardiac Arrhythmia Center is called Amara Yad, a mashup of Sanskrit and Hebrew meaning “immortal hand.” The work has relied on the generosity of people who have willed their bodies for use at UCLA, as well as hearts that were donated but could not be used for transplant.

So far, Amara Yad has completed two volumes focused on the anatomy of the heart and is enlisting teams at other universities for more. The plan is to draft a freely available, ethically sourced road map to the entire body that eclipses the weathered volumes of watercolors from Pernkopf and honors the Nazis’ victims.

Anatomists have told him, “‘You’re crazy. It’s impossible. How could you ever surpass it?’” Shivkumar said of the Pernkopf atlas in a speech last year before members of the Heart Rhythm Society.

But “can it be beaten? The answer is yes.”

For decades, the origins of the Pernkopf Atlas were unknown to many who turned to its pages for guidance. Swastikas tucked into signatures of an illustrator were airbrushed out in later editions. Its history began to trickle out in journals in the 1980s.

When Dr. Howard Israel finally learned of its roots, he was horrified. Israel, an oral surgeon at Columbia University and self-described “very ordinary American Jew,” told the New York Times he had been relying on the book since he was a medical student.

‘’I felt stupid at using the book,” he told the newspaper, “that I could possibly have benefited from something that sounded so evil.” He and another physician enlisted the Holocaust remembrance group Yad Vashem and publicly pushed for the University of Vienna to investigate whose bodies were depicted in its pages.

The resulting probe found no evidence that the anatomy department under Pernkopf — who had ascended to become dean of the medical faculty at the University of Vienna in 1938 — had received bodies from the Mauthausen concentration camp, as some had wondered.

But the institute had been given at least 1,377 bodies of executed people, most of them sentenced to death for political reasons. Among the charges that led to their executions: “crimes of resistance” and “high treason.”

Using the bodies of executed people was “a centuries-old practice in anatomy,” preferred because anatomists could time their work swiftly after a scheduled death, said Dr. Sabine Hildebrandt, an anatomy educator at Harvard Medical School. What was new under the Nazis, she said, was the sheer number of executions.

The institute “was drowned in bodies,” and “the source for these bodies was mostly connected with the apparatus of repression of the Nazi regime,” said historian Herwig Czech, a member of the Lancet Commission on Medicine, Nazism, and the Holocaust, at a recent forum.

By the time those findings emerged, the publisher of the anatomy book had stopped printing it.

2 A close-up image of a corner of an illustration in a Pernkopf atlas volume. The artist added a swastika to his signature.

1. A stack of volumes of the Pernkopf atlas on a shelf in Dr. Kalyanam Shivkumar’s UCLA office. 2. Erich Lepier, one of the Pernkopf atlas illustrators, repeatedly included a swastika after the cursive R in his signature. (Allen J. Schaben / Los Angeles Times)

Yet use of the atlas persisted. Hildebrandt said that a decade ago, dental students in her classes “were basically giving each other thumb drives with bootlegged copies of the head and neck.”

Other anatomical atlases exist, but these illustrations had especially fine details, including of the nerves extending beyond the brain and spiral cord. One survey of nerve surgeons found that 13% of respondents were using the atlas. Among those who have publicly grappled with it is Dr. Susan Mackinnon, a surgery professor at Washington University School of Medicine in St. Louis known as a pioneer in nerve regeneration.

“I used this textbook for years before I knew the history of it,” she said. “My brain is contaminated with that. I can’t undo that.”

Mackinnon sought ethical guidance. Rabbi Joseph Polak, a Boston University assistant adjunct professor of health law who survived the concentration camps as a child, said one dilemma involved a patient in excruciating pain.

Polak recalled that the patient had told Mackinnon that “if you can’t find the nerve to stop the pain, then I want my leg amputated.” The rabbi walked through Jewish teachings that applied to the ethical quandary and conferred with other experts, penning a set of recommendations called the Vienna Protocol.

Among his urgings to doctors: If you use these drawings, make it clear to patients where they came from.

The Third Reich wanted “to extinguish them and to extinguish eventually all memory of them,” the rabbi said of Holocaust victims, speaking at a recent forum about the atlas. But when a doctor tells patients about what happened to the people depicted in the drawings, he said, “they’re being called out of that darkness.”

Mackinnon now keeps the atlas locked away. In the rare cases she feels she needs to consult it to operate, she tells patients and co-workers about the man behind it. His firings of Jewish doctors. The grim details in its pages — shorn hair, emaciated bodies — that began to raise suspicions about its terrible origins.

The only reason to use it, she said, is to save someone from misery — and only if “nothing else will help you.”

Dr. Kalyanam Shivkumar, wearing a lab coat and sitting behind an open laptop computer, gestures as he speaks.

Shivkumar said his goal is to eliminate the need to consult those pages at all. Inside UCLA’s Center for the Health Sciences in Westwood, he showed off a donated heart, prepped and ready for its close-up in a corner of the lab outfitted with a black backdrop and brilliant lights.

A spent heart normally wilts like a deflated balloon, but this one had been pumped with chemicals to imitate the fullness of life. The team first puts the organs to use in research, then carefully dissects them for imaging.

Bringing out a bisected piece of a heart, Dr. Shumpei Mori displayed how its inner architecture could be captured on camera, threading a catheter through the organ as a co-worker snaked in an endoscope.

“The internal structure is really fine and delicate,” said Mori, a specialist in cardiac anatomy who had jumped at the chance to do something new in the field.

“Even Pernkopf simplified the anatomy” in its drawings, Mori said. “What we are doing is more complicated.”

Dr. Shumpei Mori holds a bisected model of a heart.

The camera is far from their only tool: The team has generated 3-D images to illustrate the dimensions of the inner structures of the heart; done CT scans to produce hand-held models; and used sophisticated imaging from a microscope to reveal the lattice of nerves connecting to the organ — part of the signaling system that Shivkumar calls “the internet of the human body.”

In another lab, Mori carefully unzipped a bag on a metal gurney to reveal the stripped-down interior of a cadaver diligently dissected over a year and a half, its rib cage cracked open like a weighty book. Shivkumar pointed out the pale web of nerves stretching up through the neck. Mori had painted them yellow by hand.

The human body might seem like well-traveled territory, but as physicians work to find less invasive ways of healing, such as attacking a cancer with ultrasound, Shivkumar said there is “a volcanic desire for this kind of information.” Snip the right nerve, he said, and you can avert the need for a heart transplant.

“Pernkopf never did nerves like this,” he said with pride.

Amara Yad is also an act of “moral repair” meant to honor the victims, said Dr. Barbara Natterson-Horowitz, a UCLA cardiologist and evolutionary biologist who helped support the project. The Nazi atlases “were like documents of death. The atlases that Shiv is creating are really living, interactive tools to support life.”

When Shivkumar decided to launch the project, he had been inspired by the words of USC emeritus professor of rheumatology Dr. Richard Panush, who had pushed to set the atlas aside in the library of the New Jersey medical center where he had worked, moving it to a display case that explained its history.

Panush said the old atlas should be preserved only as “a symbol of what we should not do, and how we should not behave, and the kind of people that we cannot respect.”

Doctors need to know that history to understand their own moral fallibility, Hildebrandt said. Physicians in Nazi Germany “still thought they were doing the right thing,” she said, even as they failed to see some people as human.

Rabbi Polak stressed that doctors at the time “had the deepest, most profound respect of the masses.”

Yet when the Nazis took power, “it turned out that a vast proportion of them were moral sleazeballs,” Polak said. “They were the first to join when they saw that it could promote their careers.”

Model hearts in different forms and views line a bookshelf at UCLA.

Shivkumar said that beyond making new tools for physicians, the Amara Yad project is working with Oxford University to develop an accompanying curriculum that will explore ethical failures in medicine. Pernkopf’s anatomy book is only one example.

The history of the atlas “invites the contemplation of how doctors and medical scientists and anatomists are related to a regime,” said Sari J. Siegel, who heads the Center for Medicine, Holocaust and Genocide Studies at Cedars-Sinai. Thinking about it underscores that “medicine is political.”

“It can’t be divorced from the larger contexts in which it exists.”

Shivkumar, born to a Hindu family in the southernmost state of India, is used to people wondering why he became “possessed” with this project. He recalls first learning about the Holocaust from a photographer friend of his grandfather, a former newspaper editor once imprisoned for sedition against the British Empire.

He was 11 when the photographer showed him images dating to World War II, and it chilled him “to see that human beings could be so brutal to other humans.” As a child, his parents had told him they owed the world because their part of India was lucky to be long spared from such conflict.

In Amara Yad, we “get a rare opportunity in history to correct an unbelievably depressing stain that was placed in our field,” he told the Heart Rhythm Society.

It irritates him to think of the abundant resources that a Nazi had at hand to do this sort of work. “Imagine having five Shumpeis!” he exclaimed at one point, gesturing at his colleague who hand painted the nerves. At UCLA, the project has piggybacked on ongoing research and relied on donations. He is hoping to garner $500,000 annually to continue and expand the work.

But Shivkumar likes to quote the Emperor Ashoka on that point: “To do good is difficult. One who does good first does something hard to do. … Truly, it is easy to do evil.”

Science

2024 Brought the World to a Dangerous Warming Threshold. Now What?

Published

5 hours ago

January 10, 2025

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2024 Brought the World to a Dangerous Warming Threshold. Now What?

Source: Copernicus/ECMWF

Note: Temperature anomalies relative to 1850-1900 averages.

At the stroke of midnight on Dec. 31, Earth finished up its hottest year in recorded history, scientists said on Friday. The previous hottest year was 2023. And the next one will be upon us before long: By continuing to burn huge amounts of coal, oil and gas, humankind has all but guaranteed it.

The planet’s record-high average temperature last year reflected the weekslong, 104-degree-Fahrenheit spring heat waves that shuttered schools in Bangladesh and India. It reflected the effects of the bathtub-warm ocean waters that supercharged hurricanes in the Gulf of Mexico and cyclones in the Philippines. And it reflected the roasting summer and fall conditions that primed Los Angeles this week for the most destructive wildfires in its history.

“We are facing a very new climate and new challenges, challenges that our society is not prepared for,” said Carlo Buontempo, director of the Copernicus Climate Change Service, the European Union monitoring agency.

But even within this progression of warmer years and ever-intensifying risks to homes, communities and the environment, 2024 stood out in another unwelcome way. According to Copernicus, it was the first year in which global temperatures averaged more than 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, above those the planet experienced at the start of the industrial age.

For the past decade, the world has sought to avoid crossing this dangerous threshold. Nations enshrined the goal in the 2015 Paris agreement to fight climate change. “Keep 1.5 alive” was the mantra at United Nations summits.

Yet here we are. Global temperatures will fluctuate somewhat, as they always do, which is why scientists often look at warming averaged over longer periods, not just a single year.

But even by that standard, staying below 1.5 degrees looks increasingly unattainable, according to researchers who have run the numbers. Globally, despite hundreds of billions of dollars invested in clean-energy technologies, carbon dioxide emissions hit a record in 2024 and show no signs of dropping.

One recent study published in the journal Nature concluded that the absolute best humanity can now hope for is around 1.6 degrees of warming. To achieve it, nations would need to start slashing emissions at a pace that would strain political, social and economic feasibility.

But what if we’d started earlier?

By spewing heat-trapping gases into the atmosphere, humankind has lifted global temperatures to record highs.

If nations had started reducing emissions in 2005, they could have made gradual cuts to limit warming to 1.5 degrees.

Starting in 2015, when the Paris agreement was adopted, would have required steeper cuts.

Starting today would require cuts so drastic as to appear essentially impossible.

“It was guaranteed we’d get to this point where the gap between reality and the trajectory we needed for 1.5 degrees was so big it was ridiculous,” said David Victor, a professor of public policy at the University of California, San Diego.

The question now is what, if anything, should replace 1.5 as a lodestar for nations’ climate aspirations.

“These top-level goals are at best a compass,” Dr. Victor said. “They’re a reminder that if we don’t do more, we’re in for significant climate impacts.”

The 1.5-degree threshold was never the difference between safety and ruin, between hope and despair. It was a number negotiated by governments trying to answer a big question: What’s the highest global temperature increase — and the associated level of dangers, whether heat waves or wildfires or melting glaciers — that our societies should strive to avoid?

The result, as codified in the Paris agreement, was that nations would aspire to hold warming to “well below” 2 degrees Celsius while “pursuing efforts” to limit it to 1.5 degrees.

Even at the time, some experts called the latter goal unrealistic, because it required such deep and rapid emissions cuts. Still, the United States, the European Union and other governments adopted it as a guidepost for climate policy.

Christoph Bertram, an associate research professor at the University of Maryland’s Center for Global Sustainability, said the urgency of the 1.5 target spurred companies of all kinds — automakers, cement manufacturers, electric utilities — to start thinking hard about what it would mean to zero out their emissions by midcentury. “I do think that has led to some serious action,” Dr. Bertram said.

But the high aspiration of the 1.5 target also exposed deep fault lines among nations.

China and India never backed the goal, since it required them to curb their use of coal, gas and oil at a pace they said would hamstring their development. Rich countries that were struggling to cut their own emissions began choking off funding in the developing world for fossil-fuel projects that were economically beneficial. Some low-income countries felt it was deeply unfair to ask them to sacrifice for the climate given that it was wealthy nations — and not them — that had produced most of the greenhouse gases now warming the world.

“The 1.5-degree target has created a lot of tension between rich and poor countries,” said Vijaya Ramachandran, director for energy and development at the Breakthrough Institute, an environmental research organization.

Costa Samaras, an environmental-engineering professor at Carnegie Mellon University, compared the warming goals to health officials’ guidelines on, say, cholesterol. “We don’t set health targets on what’s realistic or what’s possible,” Dr. Samaras said. “We say, ‘This is what’s good for you. This is how you’re going to not get sick.’”

“If we were going to say, ‘Well, 1.5 is likely out of the question, let’s put it to 1.75,’ it gives people a false sense of assurance that 1.5 was not that important,” said Dr. Samaras, who helped shape U.S. climate policy from 2021 to 2024 in the White House Office of Science and Technology Policy. “It’s hugely important.”

Scientists convened by the United Nations have concluded that restricting warming to 1.5 degrees instead of 2 would spare tens of millions of people from being exposed to life-threatening heat waves, water shortages and coastal flooding. It might mean the difference between a world that has coral reefs and Arctic sea ice in the summer, and one that doesn’t.

Each tiny increment of additional warming, whether it’s 1.6 degrees versus 1.5, or 1.7 versus 1.6, increases the risks. “Even if the world overshoots 1.5 degrees, and the chances of this happening are increasing every day, we must keep striving” to bring emissions to zero as soon as possible, said Inger Anderson, the executive director of the United Nations Environment Program.

Officially, the sun has not yet set on the 1.5 target. The Paris agreement remains in force, even as President-elect Donald J. Trump vows to withdraw the United States from it for a second time. At U.N. climate negotiations, talk of 1.5 has become more muted compared with years past. But it has hardly gone away.

“With appropriate measures, 1.5 Celsius is still achievable,” Cedric Schuster, the minister of natural resources and environment for the Pacific island nation of Samoa, said at last year’s summit in Azerbaijan. Countries should “rise to the occasion with new, highly ambitious” policies, he said.

To Dr. Victor of U.C. San Diego, it is strange but all too predictable that governments keep speaking this way about what appears to be an unachievable aim. “No major political leader who wants to be taken seriously on climate wants to stick their neck out and say, ‘1.5 degrees isn’t feasible. Let’s talk about more realistic goals,’” he said.

Still, the world will eventually need to have that discussion, Dr. Victor said. And it’s unclear how it will go.

“It could be constructive, where we start asking, ‘How much warming are we really in for? And how do we deal with that?’” he said. “Or it could look very toxic, with a bunch of political finger pointing.”

Methodology

The second chart shows pathways for reducing carbon emissions that would have a 66 percent chance of limiting global warming this century to 1.5 degrees Celsius above the preindustrial average.

Science

U.S. Efforts to Cut Emissions Stalled in 2024 as Power Demand Surged

Published

13 hours ago

January 9, 2025

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U.S. Efforts to Cut Emissions Stalled in 2024 as Power Demand Surged

America’s efforts to cut its climate change pollution stalled in 2024, with greenhouse gas emissions dropping just a fraction, 0.2 percent, compared to the year before, according to estimates published Thursday by the Rhodium Group, a research firm.

Despite continued rapid growth in solar and wind power, emissions levels stayed relatively flat last year because demand for electricity surged nationwide, which led to a spike in the amount of natural gas burned by power plants.

The fact that emissions didn’t decline much means the United States is even further off-track from hitting President Biden’s goal of slashing greenhouse gases 50 percent below 2005 levels by 2030. Scientists say all major economies would have to cut their emissions deeply this decade to keep global warming at relatively low levels.

Since 2005, United States emissions have fallen roughly 20 percent, a significant drop at a time when the economy has also expanded. But to meet its climate goals, U.S. emissions would need to decline nearly 10 times as fast each year as they’ve fallen over the past decade. That seems increasingly unlikely, experts say, especially since President-elect Donald J. Trump has promised to dismantle Mr. Biden’s climate policies and promote the production of fossil fuels, the burning of which generates greenhouse gases.

“On the one hand, it is notable that we’ve now seen two years in a row where the U.S. economy grew but emissions went down,” said Ben King, an associate director at the Rhodium Group. “But it’s far from enough to achieve our climate targets.”

The biggest reason that U.S. emissions have fallen in recent years is that electric utilities have been retiring their older, dirtier coal-fired power plants and replacing them with cheaper and less-polluting natural gas, wind and solar power. That trend mostly continued last year, with a few unexpected ups and downs.

The nation’s demand for electricity, which has stayed more or less flat for two decades, suddenly jumped by roughly 3 percent in 2024, in large part because scorching heat during the summer caused many Americans to crank up their air-conditioners. A smaller factor was that tech companies have been building more energy-hungry data centers in states like Virginia and Texas.

While power companies installed large numbers of wind turbines, solar panels and batteries last year to meet rising demand, natural gas use also rose to record highs, while coal use declined only slightly. The net result was that emissions from the power sector increased an estimated 0.2 percent, according to the Rhodium Group.

At the same time, transportation, the nation’s largest source of greenhouse gases, saw an 0.8 percent rise in emissions last year. Gasoline and jet fuel consumption both increased as Americans continued to drive and fly more after the pandemic. Nearly 10 percent of new car sales in 2024 were less-polluting electric vehicles, but those models still make up a small fraction of total cars on the road and have yet to put a major dent in transportation emissions.

On the flip side, emissions from America’s industrial sector — which includes steel, cement and chemicals — fell by 1.8 percent in 2024. Some of that may have been the result of lost output, as two hurricanes and a strike at the nation’s ports disrupted some factory activity in the fall, Mr. King said.

“It’s a reminder that there’s always some bumpiness in emissions,” Mr. King said. “It’s not just a question of how many electric vehicles are on the road or how much solar we’ve installed. A big portion of our economy still relies on fossil fuels.”

One of the most striking findings in this year’s data was that emissions from oil and gas operations dropped roughly 3.7 percent in 2024. Even though the United States produced record amounts of oil and near-record amounts of natural gas last year, many companies appear to have curbed leaks of methane, which is the main ingredient in natural gas and which can seep into the atmosphere and contribute significantly to global warming.

Over the past few years, the Biden administration and several states have adopted new regulations that require oil and gas producers to detect and fix methane leaks. Many companies also have financial incentives to capture methane to sell rather than vent it into the air.

Between 2014 and 2024, U.S. companies appear to have reduced the amount of methane that escaped, per each cubic feet of gas they produced, by 40 percent, according to the Rhodium Group.

Several experts have estimated that greenhouse gases generated in the United States could start dropping sharply in the years ahead if many clean energy policies stay in place, particularly the 2022 Inflation Reduction Act that pumped hundreds of billions of dollars into low-carbon energy technologies such as electric vehicles, wind turbines, solar panels, nuclear reactors, green hydrogen and batteries.

While Mr. Trump has pledged to scrap many of Mr. Biden’s subsidies and tax credits for electric vehicles and low-carbon energy, it remains to be seen whether Congress will agree.

That law has not yet had a major impact on the country’s emissions, said Mr. King, since it takes time for new factories to open and power plants to get built. But, he said, data shows that low-carbon energy and transportation now make up fully 5 percent of total U.S. private investment.

“That’s a leading indicator that things are changing quickly,” he said.

Science

How to protect yourself from the smoke caused by L.A. wildfires

Published

1 day ago

January 9, 2025

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How to protect yourself from the smoke caused by L.A. wildfires

You don’t have to live close to a wildfire to be affected by its smoke. With severe winds fanning the fires in and around Pacific Palisades, the Pasadena foothills and Simi Valley, huge swaths of the Southland are contending with dangerous air quality.

Wildfire smoke can irritate your eyes, nose, throat and lungs. The soot may contain all kinds of dangerous pollutants, including some that may cause cancer. The tiniest particles in smoke can travel deep into your lungs or even enter your bloodstream.

Conditions like these aren’t good for anyone, but they’re particularly bad for people in vulnerable groups, including children, those with asthma or other respiratory conditions, people with heart disease and those who are pregnant.

Here’s what you should know to keep yourself safe.

Stay indoors

Minimize your exposure to unhealthy air by staying inside and keeping your doors and windows shut.

If you have a central heating and air conditioning system, you can keep your indoor air clean by turning it on and keeping it running. Make sure the fresh-air intake is closed so that you’re not drawing in outdoor air.

Keep your pets inside

They shouldn’t breathe the unhealthy air either.

Check your air filters

Clean filters work better than dirty ones, and high-efficiency filters work better than regular ones. The California Air Resources Board and the South Coast Air Quality Management District recommend filters with a MERV rating of 13 or higher.

You might consider using portable high-efficiency air cleaner in a room where you spend the most time. The U.S. Environmental Protection Agency has information about them here, and CARB has a list of certified cleaning devices here.

Don’t pollute your indoor air

That means no burning candles or incense. If your power is out and you need to see in the dark, you’re much better off with a flashlight or headlamp.

If you’re cold, bundle up. This is not the time to start a cozy fire in the fireplace. Don’t use a gas stove or wood-fired appliances, since these will make your indoor air quality worse, not better, the AQMD says.

The CDC also advises against vacuuming, since it can stir up dust and release fine particles into the air.

Take care when cleaning up

You don’t want your skin to come into contact with wildfire ash. That means you should wear long sleeves, pants, gloves, socks and shoes. The AQMD even wants you to wear goggles.

If you’re sweeping up ash outdoors, get a hose and mist it with water first. That will keep it from flying up in the air as you move it around. Once the ash is wet, sweep it up gently with a broom or mop. Bag it up in a plastic bag and throw it away.

It’s a good idea to wash your vehicles and outdoor toys if they’re covered in ash. Try not to send ashy water into storm drains. Direct the dirty water into ground areas instead, the AQMD advises.

Those with lung or heart problems should avoid clean-up activities.

Discard spoiled food…

If you lost power for a significant length of time, the food in your refrigerator or freezer may be spoiled.

Food kept in a fridge should stay safe for up to four hours if you’ve kept the door closed. If you’ve been without power for longer than that, you’ll need to toss all perishable items, including meat, poultry, fish, eggs, milk and cut fruits and vegetables. Anything with “an unusual smell, color, or texture” should be thrown out as well, according to the U.S. Centers for Disease and Control Prevention.

Refrigerated medicines should be OK unless the power was out for more than a day. Check the label to make sure.

…even if it was in the freezer

Your freezer may be in better shape, especially if it’s well-stocked. Items in a full freezer may be safe for up to 48 hours if it’s been kept shut, and a half-full freezer may be OK for up to 24 hours. (The frozen items help keep each other cold, so the more the better.)

If items have remained below 40 degrees Fahrenheit (4 degrees Celsius) or you can still see ice crystals in them, they may be OK to use or refreeze, according to the federal government’s food safety website.

Ice cream and frozen yogurt should be thrown out if the power goes out for any amount of time. Meat, poultry, seafood, eggs, milk and most other dairy products need to go if they were exposed to temperatures above 40 degrees F for two hours or longer. The same goes for frozen meals, casseroles, soups, stews and cakes, pies and pastries with custard or cheese fillings.

Fruit and fruit juices that have started to thaw can be refrozen unless they’ve started to get moldy, slimy or smell like yeast. Vegetables and vegetable juices should be discarded if they’ve been above 40 degrees F for six hours or more, even if they look and smell fine.

Breakfast items like waffles and bagels can be refrozen, as can breads, rolls, muffins and other baked goods without custard fillings.

Consider alternative shelter

If you’ve done everything you can but your eyes are still watering, you can’t stop coughing, or you just don’t feel well, seek alternative shelter where the air quality is better.

Hold off on vigorous exercise

Doing anything that would cause you to breathe in more deeply is a bad idea right now.

Mask up outdoors

If you need to be outside for an extended time, be sure to wear a high-quality mask. A surgical mask or cloth mask won’t cut it — health authorities agree that you should reach for an N95 or P-100 respirator with a tight seal.

Are young children at greater risk of wildfire smoke?

Very young children are especially vulnerable to the effects of wildfire smoke because their lungs are still rapidly developing. And because they breathe much faster than adults, they are taking in more toxic particulate matter relative to their tiny bodies, which can trigger inflammation, coughing and wheezing.

Any kind of air pollution can be dangerous to young children, but wildfire smoke is about 10 times as toxic for children compared to air pollution from burning fossil fuels, said Dr. Lisa Patel, clinical associate professor of pediatrics at Stanford Children’s Health. Young children with preexisting respiratory problems like asthma are at even greater risk.

Patel advises parents to keep their young children indoors as much as possible, create a safe room in their home with an air purifier, and try to avoid using gas stoves to avoid polluting the indoor air.

Children over the age of 2 should also wear a well-fitting KN95 mask if they will be outdoors for a long period of time. Infants and toddlers younger than that don’t need to mask up because it can be a suffocation risk, Patel said.

What are the risks for pregnant people?

Pregnant people should also take extra precautions around wildfire smoke, which can cross the placenta and affect a developing fetus. Studies have found that exposure to wildfire smoke during pregnancy can increase the risk of premature birth and low birth weight. Researchers have also linked the toxic chemicals in smoke with maternal health complications including hypertension and preeclampsia.

What about other high-risk populations?

Certain chronic diseases including asthma, chronic obstructive pulmonary disease or other respiratory conditions can also make you particularly vulnerable to wildfire smoke. People with heart disease, diabetes and chronic kidney disease should take extra care to breathe clean air, the CDC says. The tiny particles in wildfire smoke can aggravate existing health problems, and may make heart attacks or strokes more likely, CARB warns.

Get ready for the next emergency

Living in Southern California means another wildfire is coming sooner or later. To prepare for the bad air, you can:

Stock up on disposable respirators, like N95 or P-100s.
Have clean filters ready for your A/C system and change them out when things get smoky.
Know how to check the air quality where you live and work. The AQMD has an interactive map that’s updated hourly. Just type in an address and it will zoom in on the location. You can also sign up to get air quality alerts by email or on your smartphone.
Know where your fire extinguisher is and keep it handy.
If you have a heart or lung condition, keep at least five days’ worth of medication on hand.

Times staff writer Karen Garcia contributed to this report.