Where There's Fire There's Smoke: Reducing Smoke in British Columbia

Environmental Quality Branch

PARTICULATES

Last Updated: February 2002

Introduction

The smell of wood smoke on a cold, clear night. It sparks feelings of coziness, the simple life and getting back to the good old ways. We British Columbians have a long, close bond with wood, fire and smoke. Both the Aboriginal people and the pioneers burned wood for warmth and to cook their meals, as well as using fire to modify the land's vegetation.

Today we burn organic material (called "biomass") for many reasons:

to heat our homes;
to dispose of debris from gardening, agriculture and land development;
to get rid of logging slash and prepare land for planting;
to dispose of sawmill wood residue;
to prevent wildfires;
to enhance wildlife habitat; and
to improve cattle range.

But times have changed. What was once considered a harmless practice is now recognized as a major source of air pollution. The expansion of our communities and industries means that too many of us are burning too much and too often. What's more, the province's weather conditions, mountainous landscape and settlement patterns often combine to trap smoke right where people live — and breathe.

The fact is that wood smoke is not the romantic remnant of bygone days. It's a threat to our health and well-being. In addition, the smoke is often unnecessary: the result of burning inefficiently or of burning biomass that could have been used as a valuable resource.

We need to cut down on the amount of smoke that goes into our atmosphere by unravelling our historic tie with biomass burning.

Changing our old beliefs and burning practices will take some work and foresight. But the effort will be well worth it, ensuring fresh, healthy air for the British Columbians of today and tomorrow.

What's Wrong with Smoke?

Smoke contains several pollutants that can trigger health problems. The effects run from irritation of the eyes and respiratory tract to more serious disorders, including asthma, bronchitis, reduced lung function and heart disease. Children, the elderly, and people with lung disease are particularly vulnerable. Some of the pollutants also pose a small, but significant, risk of cancer.

In addition, biomass burning can create a haze that covers entire communities or even whole regions for weeks at a time, reducing visibility (which can hamper land and air travel) and hiding scenic vistas.

Wood Residue Doesn't Have to be a Waste

Traditionally, we have treated leftover organic material as "wood waste" — an inconvenient pile of debris needing disposal by burning or burying. The truth is, though, that the wood scraps, sawdust, shavings, leaves and other organic materials left from such activities as logging, sawmill operations, land clearing and gardening are an important resource.

Rather than being dumped in a fire and producing more clouds of smoke, this residue can be put to good use as chips for pulp and fibreboard mills, feedstock to generate energy, or the material for compost and mulch.

The Sources of Smoke in B.C.

Prescribed Burning
Prescribed burning is a valuable and, in many cases, necessary tool. It is done mainly by the logging industry for silvicultural purposes (slash burning). As well, prescribed burning is used to increase habitat for certain wildlife, improve cattle range and reduce wildfire hazard.

Unfortunately, prescribed burning can also cause extended periods of haze during the fall, posing health risks and blotting out scenery.

From a resource-management perspective, eliminating all prescribed burning is probably not a reasonable option. The practice can be significantly reduced, though. For example, the amount of wood residue from logging can be decreased, thereby requiring less burning.

Land Clearing and Construction Fires
Using fire to get rid of land-clearing residue and construction debris causes special problems. Frequently, the woody material left from land clearing is burned with noncombustible and toxic waste. Even tires have been used as fire accelerants.

With these practices, very noxious emissions can be released, which are especially dangerous in urban areas. In the case of land clearing too, other options are available for making use of the leftovers from land-clearing and construction.

Residue Burning in the Forest Products Industry
Most B.C. sawmills burn the trim ends, slabs, bark, shavings and sawdust left after the logs have been cut. There are two problems with this practice:

First, the burning is often done inefficiently, releasing a lot of smoke. As a result, the emissions from sawmill residue burners (especially teepee / beehive burners) cause frequent episodes of air pollution for many small communities, limiting visibility and leading to health problems.
Second, about half of the sawmill wood residue in B.C. is being wasted, simply being disposed of by burning. This material could be used as a beneficial byproduct — for example, as a clean-burning and renewable fuel (to produce steam and electricity), or as chipping for pulp and fibreboard mills.

Agricultural Burning
Fire is used in agriculture to dispose of crop residue, and control pests and disease. In some cases, burning is the best option. However, the smoke impacts can be lessened by scheduling burning for periods of good atmospheric dispersion. In other cases, the leftover prunings and organic material don't need to be burned, and could be better used as compost and mulch.

Burning in Municipal Areas
Many of us have spent an afternoon raking the leaves and then burning them, savouring the smell of smoke in the crisp, autumn air. Little did we realize that this seemingly wholesome practice could be an environmental problem. The truth is that burning our yard residue (such as leaves, grass clippings, and prunings) and our household trash can create a health hazard.

Organic debris from municipal land development and construction is usually burned, too, adding to our smoke problem. Another source is the many small, municipally operated landfills, which periodically burn refuse.

The issue is not so much quantity — the emission is relatively small — as proximity. People and neighbourhoods are often right in the middle of the smoke plume. If the burning coincides with periods of stagnant air, the emissions can accumulate to unacceptable levels. In fact, they can be worse than those from a larger fire, such as a prescribed burn.

What's in the smoke is another hazard. Wet materials are often burned with dry ones, and the burning itself is often inefficient, releasing substantial amounts of particulates and products of incomplete combustion.

In addition, other refuse is often thrown in, such as plastics, rubber, insulation and coated wire. This adds a host of dangerous air toxics to the other pollutants in wood smoke.

Residential Wood Burning
Smoke curling out of chimneys may seem "natural," refreshingly old-fashioned and harmless. But the reality is that, in some communities, wood stoves and fireplaces are a major source of air pollution.

Burning wood can release significant emissions of particulates and products of incomplete combustion, many of which are well-known respiratory irritants.

The greatest impact from wood stoves and fireplaces frequently occurs near or inside people's homes. Wood smoke particles are so tiny that they seep into houses, even through closed doors and windows.

British Columbia's climate, geography and settlement patterns make it particularly susceptible to this kind of air pollution. Valley bottoms, where many Interior communities are located, tend to have frequent, long-lasting periods of cold, stable air during the winter. Pollutants from wood smoke can be trapped and concentrated near the ground, accumulating to very high concentrations during these "air stagnation" periods.

Inefficient wood stove operation has as much to do with the problem as meteorology and geography. In many cases, the stove design is inadequate (imprecise control, wrong size). Poor fuel conditioning (wet or "green" wood) and poor burning practices (oxygen starvation) are also to blame.

Wood burning tends to reach its peak on cold, clear and calm nights. That's the very time when the atmosphere's capacity to disperse emissions is at a minimum. To make matters worse, people often try to make their final charge last all night by damping the air supply as much as possible. The smoke from this smouldering fire has a high concentration of pollutants.

What's in Smoke and How It Can Hurt You

Acrolein: Irritation of the eyes and respiratory tract.

Carbon Monoxide: Angina in people with heart disease. Lethal at high concentrations.

Fine Particulates: Fine particulates are very small, solid or liquid particles. At their largest, they are 10 micrometres in diameter, about the size of bacteria. They can easily be inhaled into the deepest reaches of our lungs, collecting in the tiny air sacs (called "alveoli") where oxygen enters the bloodstream. As a result, they can cause breathing difficulties and sometimes permanent lung damage. They are also often composed of harmful substances— for example, toxic trace metals like lead and cadmium, and sulphate, which is acidic.

Exposure to high levels of fine particulates is associated with a significant rise in respiratory and heart disease, and premature deaths. The respiratory disease includes asthma, bronchitis, pneumonia and emphysema. Senior citizens, infants and people who are already ill are most at risk, but healthy younger adults and children can also be affected. At current levels, fine particulates are the most serious kind of local air pollution in British Columbia.

Formaldehyde: Headaches, respiratory tract irritation. Probably cancer-causing.

Nitrogen Oxides (NO_x): Bronchial congestion and scarring of the lungs.

Polycyclic Aromatic Hydrocarbons (PAHs): Some PAHs can cause cancer.

Volatile Organic Compounds (VOCs): Respiratory tract irritation and illness. Some VOCs (e.g. benzene) can cause cancer.

Reducing Smoke and Using Wood Residue

What's the Government Doing?
The Ministry of Environment has moved to control the sources of smoke in B.C., and encourage the use of wood and leafy residue as a resource. It has done so by setting regulations, along with taking nonregulatory actions — such as broad programs, technical support and public education. And because motor vehicles are a major source of fine particulates, the ministry has brought in measures to control their emissions, as well.

The B.C. Government has passed the following regulations:

Open Burning Smoke Control Regulation (April 1993, amended in 1998 and 2000)
The Open Burning Smoke Control Regulation is meant to encourage the reduction and reuse of vegetative debris from large outdoor fires which are usually set for land-clearing, construction or forestry operations.
Solid Fuel Burning Domestic Appliance Regulation (August 1994)
The Solid Fuel Burning Domestic Appliance Regulation specifies particulate emission limits, and labeling and testing requirements for new wood stoves, fireplace inserts and factory built fireplaces manufactured in B.C., or sold or imported for use in B.C..
Wood Residue Burner and Incinerator Regulation (December 1995, includes amendments up to 2004)
Under this regulation, wood residue (beehive and silo) burners in populated areas (Tier 1) are to be shut down by the end of 2007. Of the original 80 Tier 1 burners, 73 have now been shut down. Eliminating these inefficient burners, which frequently cast palls of smoke over many valleys, will lead to cleaner air in many regions.

To make it easier for municipalities to pass their own "anti-smoke" bylaw, the ministry created a model bylaw on (back)yard burning in December 1997. Municipalities can use this model to draft a specific bylaw to limit or prohibit backyard burning. See the Model Municipal Bylaw for Regulating Backyard Burning (PDF: 131 KB / 18 pages).

With respect to nonregulatory approaches, the ministry has given educational and technical support to municipalities and the public — on proper burning techniques, wood stoves, backyard burning restrictions or bans, and composting.

The Ministry of Environment took part in developing the Canada-wide Standards for Particulate Matter and Ozone in July 2000. By setting targets for acceptable air quality, and agreeing to a set of joint initial actions, B.C. and the rest of Canada are taking an important step towards reducing the risk that fine particulates (and ground-level ozone) pose to human health.

Along with smoke, vehicle exhaust is a major source of fine particulates. In fact, scientists have recently found that fine particulate air pollution in cities causes more illness and death than smog does.

To reduce fine particulate pollution in the Lower Fraser Valley, the B.C. Government launched the AirCare ON ROAD (ACOR) testing program in 1999. ACOR targets heavy-duty, diesel trucks and buses — key culprits when it comes to fine particulates and other air pollution. Two mobile teams test the emissions of heavy-duty, commercial diesel vehicles. Vehicles that fail the emissions test must be repaired and re-inspected before they can qualify for insurance renewal.

B.C.'s tailpipe standards for new vehicles (see the regulations on our Vehicle Emissions website), the AirCare vehicle-emission testing program, and the older-vehicle "Scrap-It" program are all working to stop the production of secondary particulates. Secondary particulates are formed due to a chemical reaction involving gases emitted into the air. In this case, sulphur dioxide, nitrogen oxides and hydrocarbons released by vehicles are transformed into sulphates, nitrates and organic carbon compounds, respectively.

What Are You Doing?

Just about everyone who lights a fire contributes to smoke-caused air pollution. Here are some important ways you can help clear the air:

Be aware that allowable burn times are planned months in advance — long before anyone knows what the weather conditions will be like. If an allowable burn time occurs when the air is stagnant, and smoke will be trapped in the neighbourhood, it is a good idea to avoid burning. If you must burn, check the Ventilation Index" first, to see if the local air conditions are appropriate for burning.
Instead of burning your leaves and clippings, start a backyard compost. Both the air and your garden will benefit! Or, if your town has a community compost, take your organic leftovers there.
Don't burn your garbage, such as plastics, paper and cardboard. Reduce waste at its source by avoiding overpackaging. And recycle everything you can! Use your community recycling depots!
When using a wood stove or fireplace, make sure the combustion is efficient so that it releases the least possible amount of smoke. Here are some tips:
- Don't burn your garbage, such as plastics, paper and cardboard. Reduce waste at its source by avoiding overpackaging. And recycle everything you can! Use your community recycling depots!
- Make sure your wood is properly seasoned in a dry place for at least six months. Wet or green wood produces lots of smoke.
- Don't burn wood that's treated, painted, or laden with saltwater.
- Don't overload your stove with too much wood or starve the fire of air.
- Don't burn when the smoke won't dissipate from the area, such as on cold, clear and calm nights (nocturnal inversion). Be aware of the "no-burn" periods in your community, and follow the rules!

Spread the news! Tell your friends and neighbours how they can reduce their burning and make their fires more efficient — for the sake of everyone's health and comfort.
Support government efforts to cut down on smoke in our province. As well, contact your elected representatives to express your concerns and ideas about smoke management and air quality.

For More Information:

Environmental Quality Branch
Ministry of Environment
Government of British Columbia

PO Box 9341
Stn Prov Govt
Victoria, British Columbia
Canada V8W 9M1
http://www.env.gov.bc.ca/air/