Where is Wood Smoke a Problem?
Science: Where is Wood Smoke a Problem?

Where is wood smoke a problem? 2002 with a brief 2007 update.

Wood smoke is a problem all over the world. Wood smoke is a problem everywhere in the United States and Canada. We will concentrate on the San Francisco Bay Area as an example.

There are one and one half million fireplaces across the Bay Area but the percentage of people who burn on a given night is extremely small. It may require careful observation, to see the smoking plumes of the few active fireplaces, but you can always smell the smoke. In one area community where a survey was done, the highest percentage of burning homes on any evening of the year was 7%. That was Christmas day, when there was very little vehicle traffic but the highest fine particle concentrations of the year. Most people use their fireplaces only a few times per year but some, around 3%, burn nearly every night of the year (Ott, 2001). At any time 50% of the public will experience health problems from the wood smoke soup that fills the air. Our government agencies regard the pollution of this 3% as a given right. This societal illness costs $1.1 billion in health loses in the SF Bay Area (Hall, 1994).

US wood stove sales expansion began during the Oil Embargo and the subsequent oil shortages that caused crises in the 1970s. With the resultant high prices of oil and gas, some consumers began to heat their homes with wood. The newly established EPA (1970) encouraged wood stove sales. By 1989 the wood smoke pollution problem had become evident. Research indicated that only 3% of households used wood for heat but were producing over 50% of the fine particulate pollution (US EPA, 1989). Many airsheds in the country were fouled by wood smoke emissions. (Air sheds are natural basins like watersheds.)

By 1988 EPA enacted mandatory emissions certification of new stoves. EPA required states to form plans to cut wood smoke pollution emissions. These State Implementation Plans (SIPS) amounted to campaigns to sell new wood stoves, as they recommended replacing older stoves with newer designs. New designs incorporated baffles and secondary combustion chambers, or added a catalytic device in the waste gas stream. The word 'technology' has been oddly associated with these home incinerators, as if they performed some kind of computerized magic of making solid substances disappear. The EPA has done a good deal of research on stove design. There has been no improvement in the stoves since 1994. To date there is no technology to clean up the 0.1 micron and smaller particulate that these stoves generate. (Air cleaners remove particles 0.3 microns and larger.) Nor are there adequate face masks for use in wood smoke. With the push to cut debris in landfills more of it has ended up being burned illegally in the home. Wood-burning fireplaces, once an amenity in only the most expensive houses, are now usually standard even in multi-unit condominiums and there are as many as five or more fireplaces in some homes. Indeed fireplaces and wood stoves are a marketing feature used by the real estate industry. It is especially surprising to read ads such for San Francisco, Los Angeles, and New York City as those are very high density population areas. Smoke from fireplaces and wood stoves affects the house, neighboring houses (Larson, 1993), and apartments because of smoke is heavier than air and it settles rather than disperses under calm weather conditions. As population densities increase, solid-fuel burning becomes even more inappropriate because smoke toxins cannot be prevented from crossing property lines. In fact smoke incursions occur in the country side as well as the city.

It is a deception to promote certified wood stoves and pellet stoves and certified fireplaces to clean up our air. They won't solve our pollution problem. The failure of the EPA wood stove improvement efforts, can be seen in the PM10 emissions trends in California.

California has fifteen air districts and a super agency called the California Air Resources Board (CARB). The districts and the Board have superseded the Department of Public Health in matters of air quality. In the ten-year period from 1985 to 1995 vehicle emissions dropped by 40% (while vehicle miles traveled increased dramatically) but the area wide pollutant sources (wood burning is buried in the data) rose over 30%. Overall PM10 pollution rose 20% (CARB, 1999). (During this period California air districts promoted the sale of new wood stoves in their public relations, in recorded phone messages, in printed matter and to the press. This increase is not surprising with the increase in population during this period.) What the numbers on 1999 chart do not tell us is that the three highest PM pollution months are in mid winter and on high pollution days wood smoke can be as much as 80% of the PM. Looking at San Francisco Counties under PM10, we see a maximum (24-hour) daily concentration of 78 mg/m3 for the county, with an annual mean of 22.6 mg/m3 per day. For Santa Clara County (where some of SF county pollution ends up), we see a daily max of 114 mg/m3 annualized to 25.4 mg/m3 per day. For 30 days of the year in Santa Clara County the air is above the State 24-hour PM10 standard. Wood smoke will constitute up to 90% of the pollutant on those days.

Using the mortality chart, we can calculate the increased mortality on a daily max of 114 mg/m3 and 78 mg/m3.

 Ambient levels of PM10 mg/m3  Increase in human death  Hospitalization for heart disease  Hospitalization for Pneumonia and COPD
 114 mg/m3 (Santa Clara County)  5.5%  11.4%  22.8%
 78 mg/m3 (San Francisco County)  3.9%   7.8%  15.6%
Based on Information from The Health Effects Institute, 2000, BI/Clean Air Revival, Inc. 2001


"Currently, over 99 percent of Californians breathe air that violates the State PM10 standards during at least part of the year "(CARB, 1999). On 2001 Emission Trends table, there appear to be discrepancies between charts in 1999 and 2001 for the same years. It is unclear why there is a change between the two tables in the tons per day. What is extremely important is the expected growth in tons per day. The predictions show that the air is expected to get dirtier and dirtier, especially in the Area-wide Sources category, this is where wood burning is included. 'Area-wide sources' in the 2001 chart are broken down into "paved and unpaved road dust' and "Other." Wood burning is included but not identified in the "Other" section. Predictions for 2010 show that wood burning would be nearly half of the total of Area-wide sources. In this report health outcome predictions are stated for criteria pollutants and diesel PM10 but none for wood smoke.

For more than fifteen years the CARB and the California air districts have deliberately promoted wood burning and hidden the catastrophic and growing smoke that covers thousands of square miles of the most densely populated residential areas. Rational people wait for the next study and then the next. In the 1990's NASA flew planes over the SF Bay area to read the infra red heat spots of the burning! The air districts never intend to solve the problem. The consumer will spend thousands on the gadget wood stove rather than insulate, put in new windows, or buy a better furnace. No mention is made that it will probably cost the consumer more to heat with wood. It acknowledges that 50% of polyorganic matter and as much as 80% of over all pollution is from wood burning yet does not alert those who choose to burn of the health threat to themselves or to the their neighbors nor the added cost to all of society for the pollution they cause. Who wrote this page? Surprising as it may seem many air district and EPA employees, including top officials love to burn wood. It looks like the foxes run the districts and we the public are just a chicken dinner to them. We are not eaten alive but smoked to death instead. As you see from this CARB page wood burning is presented as a rational idea. To drive through the SF Bay area after 5:30 PM during the months of November to March is a stinking experience. The acrid, bitter, heavy wood smoke fills the car even with the vents closed just as it fills the millions of all homes. There is no safe house or clean room safe from the smoke, the CARB and the air districts insist on total control of all air regulation. They insist on not being responsible for public health. They insist that it is important to keep stove sellers and the timber industry happy and they consult with this industry. They force Burning Issues to exist to publish the facts. The people of the State of California have no voice on this regulators website, The Board is appointed by the governor. The deadly truth has no place on this regulators website. The CARB and its' air districts fill your hearts and lungs with deadly wood smoke. Medical bills and deep seated fear of this societal illness effect all of our lives. Democracy and human rights are ignored by the current regulatory regime.

Mary J. Rozenberg, 2002

Update: 2007 California Report from the Contra Costa Times: "Air Quality trumps cozy hearth" by Denis Cuff. "The BAAQMD commissioned poll showed 77% of the population reached were in favor of a mandatory no-burn rule. People are fed up with the smoke! About 17.6% of houses with fireplaces or stoves chose to not burn at all last winter due to air quality concerns. ( They reported only 2.4% from the previous winter.)

Air Districts offer rebates to change to gas fireplaces. About 30 no-burn nights were called in winter  2006-2007.

San Joaquin Valley Air Pollution District has a no wood fire rule on the bad air days with a $50 fine. The South Coast Management District is considering a no-burn rule."

 © 2007 Clean Air Revival   Home page at  http://BurningIssues.org