http://www.theguardian.com/commentisfree/2023/jun/19/wildfires-new-york-canada-toxicologist

How bad is wildfire smoke for your health? Here’s my view as a toxicologist

by Christopher T Migliaccio, published Mon 19 Jun 2023 06.05 EDT

Last week, smoke from more than 100 wildfires burning across Canada rolled into North American cities far from the flames. New York City and Detroit were listed among the five most polluted cities in the world because of the fires on 7 June. The smoke has triggered air quality alerts in several states in recent weeks.

We asked Chris Migliaccio, a toxicologist at the University of Montana who studies the effect of wildfire smoke on human health, about the health risks people can face when smoke blows in from distant wildfires.

What’s in wildfire smoke that’s a problem?

When we talk about air quality, we often talk about PM2.5. That’s particulate matter 2.5 microns or smaller – small enough that it can travel deep into the lungs.

Exposure to PM2.5 from smoke or other air pollution, such as vehicle emissions, can exacerbate health conditions like asthma and reduce lung function in ways that can worsen existing respiratory problems and even heart disease.

But the term PM2.5 only tells you about size, not composition – what is burning can make a significant difference in the chemistry.

In the northern Rockies, where I live, most fires are fueled by vegetation, but not all vegetation is the same. If the fire is in the wildland urban interface, manufactured fuels from homes and vehicles may also be burning, and that’s going to create its own toxic chemistry, as well. Chemists often talk about volatile organic compounds, (VOCs), carbon monoxide and PAHs, or polycyclic aromatic hydrocarbons produced when biomass and other matter burns having the potential to harm human health.

How does inhaling wildfire smoke harm human health?

If you have ever been around a campfire and got a blast of smoke in your face, you probably had some irritation. With exposure to wildfire smoke, you might get some irritation in the nose and throat and maybe some inflammation. If you’re healthy, your body for the most part will be able to handle it.

As with a lot of things, the dose makes the poison – almost anything can be harmful at a certain dose.

Generally, cells in the lungs called alveolar macrophages will pick up the particulates and clear them out – at reasonable doses. It’s when the system gets overwhelmed that you can have a problem.

One concern is that smoke can suppress macrophage function, altering it enough that you become more susceptible to respiratory infection. A colleague who looked at lag time in the effect of wildfire smoke exposure found an increase in influenza cases after a bad fire season. Studies in developing countries have also found increases in respiratory infections with people who are cooking on open fires in homes.

The stress of an inflammatory response can also exacerbate existing health problems. Being exposed to wood smoke won’t independently cause someone to have a heart attack, but if they have underlying risk factors, such as significant plaque buildup, the added stress can increase the risk.

Researchers are also studying potential effects on the brain and nervous system from inhaled particulate matter.

When smoke blows over long distances, does its toxicity change?

We know that the chemistry of wildfire smoke changes. The longer it’s in the atmosphere, the more the chemistry will be altered by ultraviolet light, but we still have a lot to learn.

Researchers have found that there seems to be a higher level of oxidation, so oxidants and free radicals are being generated the longer smoke is in the air. The specific health effects aren’t yet clear, but there’s some indication that more exposure leads to greater health effects.

The supposition is that more free radicals are generated the longer smoke is exposed to UV light, so there’s a greater potential for health harm. A lot of that, again, comes down to dose.

Chances are, if you’re a healthy individual, going for a bike ride or a hike in light haze won’t be a big deal, and your body will be able to recover.

If you’re doing that every day for a month in wildfire smoke, however, that raises more concerns. I’ve worked on studies with residents at Seeley Lake in Montana who were exposed to hazardous levels of PM2.5 from wildfire smoke for 49 days in 2017. We found a decrease in lung function a year later. No one was on oxygen, but there was a significant drop.

This is a relatively new area of research, and there’s still a lot we’re learning, especially with the increase in wildfire activity as the planet warms.

What precautions can people take to reduce their risk from wildfire smoke?

If there is smoke in the air, you want to decrease your exposure.

Can you completely avoid the smoke? Not unless you’re in a hermetically sealed home. The PM levels aren’t much different indoors and out unless you have a really good HVAC system, such as those with MERV 15 or better filters. But going inside decreases your activity, so your breathing rate is slower and the amount of smoke you’re inhaling is likely lower.

We also tend to advise people that if you’re in a susceptible group, such as those with asthma, create a safe space at home and in the office with a high-level stand-alone air filtration system to create a space with cleaner air.

Some masks can help. It doesn’t hurt to have a high-quality N95 mask. Just wearing a cloth mask won’t do much, though.

Most states have air quality monitors that can give you a sense of how bad the air quality is, so check those sites and act accordingly.

• Christopher T Migliaccio is a research associate professor of toxicology at the University of Montana
• This article is republished from the Conversation, a non-profit news organization dedicated to sharing ideas from academic experts

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https://www.theverge.com/23767216/pollution-gas-stoves-benzene-secondhand-smoke-stanford-study

Pollution from gas stoves can be worse than secondhand smoke

A Stanford professor decided to give up his gas stove after seeing how much indoor pollution it creates.

By Justine Calma, a science reporter covering the environment, climate, and energy with a decade of experience. She is also the host of the Hell or High Water podcast.

Jun 20, 2023, 4:32 PM EDT

Gas stoves release worrying amounts of benzene, a chemical linked to leukemia and other blood cell cancers, according to a new study from Stanford researchers. Benzene that gas-burning stoves release inside homes can reach concentrations even higher than what’s typical in secondhand smoke, according to the paper published last week in the journal Environmental Science & Technology.

The study adds ammunition to efforts to phase gas connections out of homes and buildings. There’s a growing body of evidence on the risks gas stoves pose to public health and the environment. The fossil fuel industry, however, has pushed back hard against policies to shift to clean energy by playing on people’s attachment to gas stoves.

“Seeing the concentrations of pollutants rise so quickly in my own home and thinking about that occurring day after day after day was a motivation to change,” Rob Jackson, Stanford professor and principal investigator for this research, said in a press briefing on the paper today. He said the research prompted him to get rid of his gas stove after testing the study’s methods in his own house.

“Seeing the concentrations of pollutants rise so quickly in my own home and thinking about that occurring day after day after day was a motivation to change.”

Benzene forms in flames, and people are often exposed to it from tobacco smoke, wildfires, and tailpipe emissions. “I really am hard-pressed to think of a more powerful chemical cause of leukemia than benzene,” hematologist / oncologist Jan Kirsch said in the press briefing (Kirsch is not one of the authors of the study but spoke to the health effects of benzene exposure). Benzene happens to be more potent than most other carcinogens at lower exposure levels, she noted. “The idea is not obviously to cause panic. The idea is that there are risks, and we want to reduce them,” Kirsch said.

This study is the first to calculate indoor pollution of benzene caused by gas stoves, according to its authors. They studied 87 homes in California and Colorado with gas and propane stoves in 2022. In about 30 percent of kitchens tested, they found that benzene emissions from a single gas burner set on high or a gas oven set to 350 degrees Fahrenheit created higher concentrations of benzene than the averages for secondhand tobacco smoke.

Benzene even wafted from kitchens all the way to bedrooms, the study found. In bedrooms, unhealthy concentrations of benzene lingered for hours, even after the stove was turned off. In one house, bedroom benzene levels were comparable to pollution events near schools in California and Colorado that triggered investigations in 2020.

The age or brand of the stove didn’t make a significant difference in how much benzene it produced. And while good ventilation makes a difference in how much benzene a household is exposed to, the researchers also found that range hoods weren’t always effective at curbing the pollution. Some hoods recirculate air instead of ventilating it outside.

By comparison, induction stoves didn’t produce any measurable amounts of benzene. Electric stoves can emit much smaller amounts of benzene — about 10 to 25 times less than gas and propane stoves — potentially because of any food scorched on red-hot surfaces.

https://volume.vox-cdn.com/embed/ab04c6075?autoplay=false&loop=true&placement=article&player_type=youtube&tracking=article:middleIs it time to say goodbye to the gas stove?

Climate change is the big reason places like Berkeley, New York City, and New York state have moved to phase out gas connections in new homes and buildings. After all, gas stoves run on methane, a greenhouse gas more potent than carbon dioxide that routinely escapes from gas infrastructure and kitchen appliances.

This isn’t the first time gas stoves have been linked to negative health effects, either. A 2022 study attributed close to 13 percent of childhood asthma in the US to gas stove use. And another analysis in 2013 found that kids living in homes with gas stoves had a 42 percent higher risk of having asthma symptoms than kids in homes without them.

In California, up to 20 percent of childhood asthma could potentially be prevented if people gave up gas stoves, according to the 2022 study. And yet, efforts to phase out their use have hit legal challenges. Berkeley, California, became the first city in the US to ban gas hookups in new construction back in 2019. Then in April, a federal court blocked the policy from being implemented.

A bill that would prevent a federal ban on gas stoves passed in the House earlier this month, even though there’s no federal legislation proposing such a ban. “Customers like natural gas—in fact, one new residential customer signs up for natural gas service every minute,” Karen Harbert, president and CEO of the American Gas Association, said in a statement after the bill was introduced.

The gas industry has spent decades promoting “cooking with gas” campaigns with everything from paid Instagram influencers to this cringey rap video from 1988. “It’s the only way to cook; that’s what I was taught,” it says.

“I grew up in a house with a gas stove; I didn’t think about it twice,” Stanford PhD student and lead author of the study Yannai Kashtan said during the press briefing. “I’m very glad that now I happen to be living somewhere with an electric stove.”

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news.yahoo.com/scientists-discovered-alarming-side-effect-100000446.html

Scientists have discovered an alarming new side effect of air pollution: ‘We had not thought about this before’

Eliot Engelmaier

Tue, June 20, 2023 at 6:00 AM EDT·2 min read

Air pollution is having an unbelievable effect on flies [and other insects we need to live], altering how they attract one another and mate.

What’s happening?

Insects typically find their mates by heavily relying on pheromones –– chemicals that allow males and females to locate each other and mate.

These pheromones are distinctive to males and females of a species, and in the case of flies, they are being disrupted and degraded by the pervasive increase of ozone in the air, which is a result of air pollution.

Scientists at the Max Planck Institute for Chemical Ecology in Germany discovered these effects by developing an experiment that mimicked ozone levels similar to what is measured during the summertime in cities.

Typically, male flies’ pheromones attract females while simultaneously repelling other males. But increased ozone levels caused a decrease in pheromones, which caused females to be less attracted to males and led to courtship between male flies.

“We could explain that males started courting each other after a short ozone exposure because they obviously could not distinguish ozonated males from females,” said researchers Nanji Jiang and Markus Knaden. “However, we had not thought about this before. Therefore, we were quite puzzled by the behavior of the ozone-exposed males, which lined up in long courtship chains.”

Why is this important?

The effects of this news are substantial. It is not just flies that are affected –– ozone is thought to affect the patterns of many insects.

Pheromone communication is not only used for mating. It also helps insects identify members of the same species and their communities, such as bee hives, wasp nests, and ant colonies. Nothing sounds more chaotic than a bunch of ants, bees, and wasps confused and out of place.

The chaos doesn’t stop there –– insects such as bees and butterflies are vital pollinators. A decrease in pheromones equals a decline in reproduction and population. The effects could be detrimental, as 80% of our crops require insect pollinators.

What can I do to help prevent this?

According to Bill Hansson, head of the Evolutionary Neuroethology Department and co-founder of the Max Planck Center Next Generation Insect Chemical Ecology, “the only solution to this dilemma is to immediately reduce pollutants in the atmosphere.”

Immediately reducing pollutants in the atmosphere will require efforts from large brands and corporations that release a significant amount of pollutants. Still, some steps can be taken on an individual level as well. Individuals can drive their cars less, use less energy, and opt for more sustainable shopping options, to name a few.