Indoor Air Pollution: A Tale of Two Problems

 

Wired technology reviewer Lisa Wood Shapiro is worried that just walking across a carpet will adversely affect her health.  At least she says she's worried, because she wrote a whole column about how just walking across a carpet can cause "resuspension" and raise up detectible amounts of "PM 2.5," which are particulates under 2.5 millionths of a meter in diameter.  That's pretty small, and not anything you can see with the naked eye.  One type of technology she reviews is particulate detectors, and that's how she knows that just walking across even a nominally clean carpet kicks up all this micro-dust. 

 

Being a reporter, she dug up dirt (so to speak) on how PM 2.5 particles can affect your health.  Living in a space with air purifiers that cut down such stuff can lower one's blood pressure slightly.  And the air purifiers, especially if they use HEPA (high efficiency particulate air) filters, can also get rid of something called PFAS, an array of fluorine-containing compounds that can come in solid, liquid, or gaseous form.  PFAS has been linked to cancer and other adverse health outcomes, so anything you can do to reduce your exposure to those chemicals will, in principle, benefit your health.

 

The rest of her column describes various pricey solutions to the carpet-dust problem, such as throwing out your old throw rugs and replacing them with pure-wool ones, buying battery-powered HEPA-filter-equipped vacuum cleaners, and taking off your shoes when you come into the house.  That last one isn't pricey, but on a cold day it's not that comfortable either. 

 

Indoor air pollution caused by my carpets is not high on my worry list, but I'm older than Ms. Shapiro, and some things that don't bother me at all seem to perturb folks under 40.  Solid body soap, for instance.  The attitude I sense of the younger set toward solid body soap, the kind you have to pick up with your hands and rub under running water to get suds from, resembles the attitude I have toward the "public brush and comb" provided by 19th-century railways in public bathrooms:  "Ecch!  Somebody else has touched it!"  Hence the under-40 set's preference for liquid body soap, untouched by human hands until it touches only yours.  I don't know how many germs can make a living off of solid body soap, but maybe some can.  It's probably not the actual statistics of germ-spreading from soap as it is just the ideas involved.

 

And that may be the case for Ms. Shapiro's indoor air pollution issue.  It may be partly real, or partly trumped up to give her an excuse to review a bunch of HEPA-filter vacuum cleaners.  But all of the above issues are what a friend of mine calls "first-world problems."  That is, they arise only when the basics of your existence—what you'll eat tomorrow, where you'll sleep, what clothes you will wear—are taken care of.

 

Indoor air pollution is a real and deadly problem, but not for journalists living in Maine or Brooklyn.  The United Nations Environment Programme estimates that household air pollution worldwide led to the deaths of over three million people in 2021, including 237,000 children under five. 

 

We're not talking about PM 2.5 dust raised by walking over carpets.  We're talking wood fires built on dirt in a poorly ventilated hut, or maybe a smoky kerosene fire in an old tin can.  Cutting wood for fuel is one of the leading causes of global deforestation.  If you've ever gone camping and found yourself on the wrong side of the campfire, you know how your eyes sting and you breathe in enough smoke to cause a coughing fit sometimes.  Well, what if you have to go through that every time you want a hot meal?  That is the situation for many millions of people in Africa and other underdeveloped parts of the world.

 

Dying is a lot more serious than having your blood pressure go up a few points.  What does the UN propose as a solution for household air pollution?  They pose a range of answers, but as the answers get better, the cost increases.

 

Certain kinds of charcoal briquettes make almost no indoor air pollution, but they have to be manufactured somewhere and somebody has to pay for them.  Even better than that is an LPG cookstove (liquefied petroleum gas).  And even better than that is an electric stove, but the residence has to be wired for electricity. 

 

You will notice that each step away from the pollution problem involves increasingly complicated infrastructure:  manufacturing and distribution of charcoal, transportation and storage of LPG, or an entire electric grid powered by something or other.  The anti-fossil-fuel contingent would have the electric grid powered by renewable energy.  And yes, that would be ideal.  But in a place where there is no electric infrastructure at all, and you want to get the most power to the most people for the least money, you may end up doing what China did to bring the bulk of its population out of poverty:  build a lot of fossil-fuel-powered generating plants. 

 

I'm no systems engineer, but natural gas, which we have so much of in this country we burn it off rather than ship it somewhere, would be an ideal way for people in Africa to get rid of their wood-fired cookery and use LPG stoves instead.  LPG tankers and shipping facilities will be needed, but the current U. S. administration did its best to stop such developments, because of the simplistic reason that it involves fossil fuels.  I won't go so far as to hang the indoor-air-pollution deaths of millions of people on this decision, but the connection is clear.

 

I hope Ms. Shapiro sells some vacuum cleaners.  But even more, I hope a few million people suffering through smoky suppers get to enjoy the benefits of clean cooking, even if it does contribute to global warming.

 

Sources:  Lisa Wood Shapiro's article "Your Indoor Air's Dirty Secret is Under Your Feet" appeared in Wired at https://www.wired.com/story/your-airs-dirty-secret-is-under-your-feet/.  The UN Environment Programme has an article on indoor air pollution I referred to at https://www.unep.org/news-and-stories/story/cooking-smoke-kills-millions-every-year-heres-what-world-can-do-about#:~:text=The%20problem%3A%20much%20of%20this,climate%20change%20and%20biodiversity%20loss.

 

Cooking with Gas No More: Natural Gas Bans

 

When I was growing up in Texas in the 1960s, natural gas was cheap, abundant, and generally regarded as one of the boons of modern life.  For a time, my father even worked for Lone Star Gas, the local franchisee in Fort Worth.  We had a gas stove, gas floor heaters and space heaters, a gas water heater, and many people we knew even had decorative gas lanterns that looked like miniature street lamps standing on their front lawns, emitting a greenish-white glow from a gas mantle while consuming gas 24 hours a day, which was why the gas company promoted them so much. 

 

So when I read recently that New York City, Los Angeles, and even some entire states are moving to ban the installation of natural gas in new construction, I understood their reasoning, which is that fossil fuels need to be phased out in favor of renewable-energy-produced electricity.  But at the same time, I couldn't help but wonder what they're going to be missing.

 

Switching from gas to electric heating and cooking is climate-change-friendly only if that electricity is produced from renewable sources.  As of February of this year, about 60% of electricity in the U. S. comes from fossil fuels, 20% from nuclear energy, and only 20% from renewables (primarily wind, hydropower, and solar).  So even if we shut off every gas valve in the country (except those at power plants) and used electricity instead, we'd end up producing more greenhouse gases under present circumstances.

 

Why?  Because if you start with a given amount of heat energy from natural gas, it's more efficient to burn it right where you use it—in a stove or a heating furnace—than it is to burn it in a power plant, make steam with the heat, turn a generator with the steam, and transmit the electricity to the place you're going to use it.  So-called Carnot-cycle heat engines, of which a fossil-fuel-fired power plant is an example, inevitably have efficiencies less than 100%, so it will take more gas to make electricity that is then turned into heat, than it would simply to burn the gas where you need the heat in the first place.

 

Of course, as the electric grid moves away from fossil fuels, this argument will gradually lose force, but right now it's still valid to the degree that places banning new natural gas installations still derive some of their electric power from fossil fuels. 

 

A recent article in National Review pointed out that certain types of restaurants depend on gas stoves for cooking particular kinds of food.  Asian food cooked in woks and certain types of Latin-American food really need gas, according to some Los Angeles chefs who are facing costly conversions if the city cuts off their gas supplies.  I have cooked Chinese dishes in a wok on an electric stove, and it can be done, but it takes longer than it would with a gas stove, and I can see why Chinese restaurants favor gas flames for cooking everything except rice. 

 

Representatives of the American Gas Association oppose such bans, saying that it drives up costs for new construction while not yielding a clear benefit with regard to greenhouse-gas emissions. 

 

This is a more complicated problem than it looks like at first glance.  For one thing, some bans are set to phase in over a schedule that extends several years in the future.  And a ban only on new construction using gas means that the total mix of housing using gas will gradually decline rather than falling off a cliff.  At the same time, the fraction of electric energy made from renewables will probably rise.  So the benefits in terms of greenhouse-gas emissions are hard to calculate and lie mostly in the future.

 

On the other hand, people living in places that have enacted bans or propose retroactive laws that don't exempt existing gas users are going to be put at a severe disadvantage pretty soon.  Fortunately, exemptions are being considered for such cases, and there don't seem to be any Carry Nations of the anti-gas lobby going around shutting off gas lines without permission. 

 

This is an example of how difficult it is to factor what economists call an externality (such as air pollution or greenhouse gas emissions) into local regulations that affect the lives of individual people differently. 

 

Something similar happened when automakers began adding anti-pollution equipment such as catalytic converters to cars.  Only in that case, most of the rules applied nationwide, although California tended to take the lead, using its large car market to impose regulations on the rest of the country almost by default. 

 

However it happened, everybody who buys a car now pays a certain extra amount for the anti-pollution gear in order that everybody in a region (or the country as a whole) can enjoy clean air.  After a good amount of tussling, we worked that problem out, and are well down the road toward the ultimate goal of zero-emission vehicles, which electric cars achieve if you don't pay attention to where the electricity comes from (see the above discussion about sources of electric energy).

 

It's not possible to make gas stoves or furnaces that burn a lot less gas for the same amount of heat, or burn it in a way that doesn't contribute to global warming.  In other words, there's no such thing as a catalytic converter for a wok.  So in order to reduce the greenhouse-gas contributions of residential and commercial gas users, they just have to be eliminated, or at least banned from new construction.  And that is intrinsically a geographically-bound issue.

 

Not surprisingly, some states such as Utah have put a ban on gas bans—the state is acting to prohibit localities from banning gas appliances.  Here in Texas, I haven't heard anybody promoting bans on natural gas, not even in the bluest part of Austin.  It's just too much a part of our regional DNA to turn our backs on something that was foundational to the prosperity of the state, and to a large degree still is. 

 

But that's the beauty of federalism—we don't all have to do things the same way.  Berkeley and New York City can make do with electric-range kung-pao chicken (it is possible), and Texans can still say good-by to their evening guests by the light of a gas-mantle yard lamp.  Only in America.

 

Sources:  The article "Gas Stove Bans Are Starting to Look Racist" appeared on the National Review website at https://www.nationalreview.com/the-weekend-jolt/gas-stove-bans-are-starting-to-look-racist/.  I also referred to an article in the Stateline blog section of the Pew Trust website at https://www.pewtrusts.org/en/research-and-analysis/blogs/stateline/2022/01/06/natural-gas-bans-are-new-front-in-effort-to-curb-emissions.  The percentages of electric energy sources are from https://www.eia.gov/tools/faqs/faq.php?id=427&t=3.