Regulars and Shorts

When Smoke Gets in Your Eyes (and Lungs)

By Ashley Miller

It’s time to pay attention to “no burn” days.

Tis the season for relentless episodes of national-newsworthy air pollution in the Salt Lake Valley—air that reaches the unhealthy range and lingers for days without a storm to blow it away. Now is the time to think about our individual impacts and what we can do to lessen our contribution to smog.

One significant thing those of us with fireplaces and stoves (including EPA certified), pellet stoves, outdoor fireplaces, fire pits, burn barrels, charcoal grills, smokers and coal-burning stoves can do is to pay attention during the “no burn” period (November 1-March 1) and respect the “no burn” days, both voluntary and mandatory. (Natural gas and propane stoves are okay.)

Let’s take a look at wood.

The toxic truth about wood smoke

Isn’t wood a source of renewable energy? A natural substance? A heat source since prehistoric times, and an alternative to “dirty” fossil fuels? Sure. Unfortunately, natural doesn’t always mean harmless, and a growing number of studies are associating wood smoke with an array of illnesses like asthma, heart disease and other lung and respiratory illnesses—many of the same illnesses that are associated with smoking.

Wood consists largely of two relatively harmless ingredients: cellulose and a strengthening substance called lignin. The real problem is that wood isn’t burned completely. It instead forms what scientists call “products of incomplete combustion.” Green wood contains more than seasoned wood. Fire temperature matters, too.

Wood smoke contains over 200 chemicals and compounds, including carbon monoxide, benzene, formaldehyde, sulfur dioxide, nitrogen oxides (NOx), dioxins and polycyclic aromatic hydrocarbons (PAHs).

In fact, wood smoke is strikingly similar to cigarette smoke. The EPA estimates that a single fireplace operating for one hour burning 10 pounds of wood (just a couple logs) will generate 4,300 times more PAHs than 30 cigarettes. The EPA further estimates that the lifetime cancer risk from wood smoke is 12 times greater than that from an equal volume of second-hand tobacco smoke.

Burning impact on health

Aside from being so similar to cigarette smoke, wood smoke is especially unhealthy due to the size of the particles contained within. The serious pollution we experience during our wintertime inversions is PM 2.5— fine particulate matter that is 2.5 micrometers in diameter. Most wood smoke particles range from .2 to .05 micrometers.

Think about it like this. A grain of sand is roughly 90 micrometers. The width of a human hair is between 50-70 micrometers. Dust is considered 10 micrometers, or PM 10. Your body’s natural defense mechanisms are able to reject much of PM 10 exposure by coughing, sneezing or blowing your nose. But these ultrafine particles are too small to be filtered out by the upper respiratory system and travel deep inside our lungs, getting trapped in the tissue. This causes irritation and decreased lung function. Research suggests these particles can cross into the blood stream and induce inflammatory responses at a quicker rate than exposure to fine particles, leading to asthma attacks, acute bronchitis and increased susceptibility to respiratory infections.

People who already suffer from heart or lung disease may experience negative health effects earlier and at lower levels than healthy people. Children are more susceptible to smoke because their respiratory systems are still developing, they breathe more frequently than adults and they’re more likely to be active outdoors. During and following periods of elevated air pollution along the Wasatch Front, hospital admissions and emergency room visits increase.

The air shed impact

Wood burning impacts the overall regional air quality, and it particularly impacts local neighborhoods where the burning is taking place. During inversions the “lid” of warm air keeps wood smoke close to the ground where it easily enters buildings right at the level where we are breathing. Just a few hours of burning wood in one home can lead to seriously elevated concentrations of ultrafine particulate matter pollution within the home doing the burning as well as in dozens of homes throughout that neighborhood.

Because the particles are so small, there really is no effective way to prevent wood smoke pollution from traveling. In fact, 70% of the smoke leaving the chimney of a fireplace will re-enter nearby homes.

According the Utah Division of Air Quality, wood smoke accounts for more than 16% of the particulate matter in Utah’s air on the average winter day. In a study released last spring, scientists found that the total amount of wood smoke in the air remained about the same even on days when a burning restriction is in place—a sign that people were not complying with the “no burn” rule. The Division of Air Quality has since increased the fines for non-compliance from $25 to $150 for the first offense, and $299 for subsequent offenses.

Exemptions are available for people who rely on wood as a sole source of heat and for cooking, though they may do the bulk of the burning. With that in mind, UCAIR is offering a limited number of $1,000 vouchers toward the purchase of a gas appliance in exchange for decommissioning an active woodburning stove: Food-related businesses with pollution controls installed can get permits for their commercial-grade wood-fired ovens.

Yes, the fines target those of us who enjoy fire for the romance of it. But romance wanes when the inversion puts a lid on the valley and we realize that some people’s pleasure may be others’ actual physical difficulty.

According to the California Air Resources Board, the inhalable particle pollution from one woodstove is equivalent to the amount emitted from 3,000 gas furnaces producing the same amount of heat per unit. So-called “EPA certified” wood stoves may be cleaner than their alternative, but they are still far dirtier than natural gas. If you’re hooked on romance, think about replacing that wood burner with a gas insert.

Please consider the air this inversion season. It can be as simple as not starting that fire.

Ashley Miller, J.D., is CATALYST’s new air quality columnist. Miller is program and policy director for Breathe Utah. She is a member of the Utah Air Quality Policy Advisory Board and the SL County Health Department Environmental Quality Advisory Commission.


This article was originally published on January 1, 2018.