Introduction
“Wood smoke can affect everyone, but children, teenagers, older adults, individuals with lung disease, including asthma and COPD or individuals with heart diseases are the most at risk. Research indicates that obesity or diabetes may also increase risk. Studies indicate that new or expectant mothers may be at increased risk”
((https://www.epa.gov/burnwise/wood-smoke-and-your-health).
Health and environmental effects as a result of exposure to carcinogenic wood smoke air pollution manifest themselves in many ways as we summarize below. This summary encompasses the health and environmental effects of key wood smoke air pollutants:
- Particulate matter (PM) e.g., PM2.5 (PM 2.5 micrometers (um) in diameter or less)
- Carbon monoxide (CO)
- Sulfur dioxide (SO2)
- Nitrogen dioxide (NO2)
- Lead (Pb)
- Volatile organic compounds (VOCs)
- Dioxins
- Polycyclic aromatic hydrocarbons (PAHs)
- Carbon dioxide (CO2) and methane (CH4)
as well as the relationship of visible emissions from wood smoke and malodorous matter emissions from wood smoke as to health and environmental effects.
This page as to the serious health effects of wood smoke is a compelling lead-in to the Observation tab on this website. There we outline a process to monitor and quantify particle emissions from wood smoke, visible emissions from wood smoke and malodorous matter 
emissions from wood smoke. That observation process constitutes the foundation for wood smoke complaints and a determination of compliance to wood smoke related laws.
And, finally, this page introduces the EPA’s Air Quality Index (AQI). The AQI is a simple but powerful tool to track air quality e.g., PM2.5 concentrations as they relate to emission standards, air quality levels, health cautionary statements and health effects statements.
Credit https://woodsmokepollution.org/wood-smoke-is-pm.html for its wood smoke warning.
The Key Wood Smoke Air Pollutants
PM2.5 Emissions from Wood Smoke and Your Health
One of the wood smoke pollutants of most concern is particulate matter (PM). The potential for PM causing health issues is in direct relationship to particle size. Small particles (e.g.PM2.5) 2.5 micrometers (um) in diameter or less present the greatest health risks, because they can penetrate deeply into the lungs, and thence the bloodstream, the circulatory system and almost all organs. The International Agency for Research on Cancer (IARC) – part of the World Health Organization (WHO) – classifies air pollution and PM2.5 as carcinogens.
Scientific studies link particle pollution e.g., PM2.5 exposure – short and long term – to an array of very serious respiratory, cardiovascular, neurological and other health issues, including:
- Inflammation of lung cells and susceptibility to and severity of COVID-19
- premature death in people with heart or lung disease
- nonfatal heart attacks
- irregular heartbeat
- stroke
- heart failure
- aggravated asthma
- decreased lung function
- increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing, burning eyes, runny nose
- bronchitis
- emphysema
- lung cancer
- COPD
- Respiratory infections including pneumonia
- Reproductive issues
- Dementia
- Reduced cognitive function
- An increase in Alzheimer admissions
- Parkinson’s
- Reduced intellectual performance
- Autism
- Depression
- Neurological problems in growth and development
“Particle pollution can be harmful even if it is inhaled over just a few hours or days, even if the year-round averages are low. “Short-term levels” refers to just such spikes. These represent levels averaged over a 24-hour period. Those days or weeks of high levels can be dangerous, even deadly” (http://www.stateoftheair.org/key-findings/short-term-particle-pollution.html).
The evidence links PM2.5 to airborne transmission of organic chemicals as well as pathogens e.g. the SARS-COV-2 virus which causes COVID-19 disease https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7345938/#:~:text=According%20to%20this%20analysis%2C%20a,more%20severe%20COVID%2D19%20results. )
The following sites offer considerable data and insight as to the health effects of PM2.5 in wood smoke:
https://www.epa.gov/pm-pollution/health-and-environmental-effects-particulate-matter-pm
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5999109/
https://dec.alaska.gov/air/burnwise/vignette-health-effects/
https://dec.alaska.gov/air/burnwise/vignette-health-effects/
https://www.news-medical.net/health/Air-Pollution-damages-brains-as-well-as-hearts-and-lungs.aspx.
https://www.caaquebec.com/en/at-home/guides/your-healthy-home-guide/wood-smoke/
https://fortress.wa.gov/ecy/publications/publications/91br023.pdf
https://www3.epa.gov/airnow/particle/pm-color.pdfhttps://www.scientificamerican.com/article/fire-pit-environmental-dangers/
https://www.labroots.com/trending/neuroscience/7678/smoke-brain
Carbon Monoxide (CO) Emissions from Wood Smoke and Your Health
Carbon Monoxide (CO) is a potentially deadly, odorless, colorless gas, produced in large amounts by burning wood with insufficient air. “CO reduces the blood’s ability to supply oxygen to body tissues, and can cause stress on your heart and reduce your ability to exercise. Exposure to CO can cause long-term health problems, dizziness, confusion, severe headache, unconsciousness and even death. Those most at risk from CO poisoning are the unborn child, and people with anemia, heart, circulatory or lung disease” http://www.foresthillmessenger.com/news/regional/burning-wood-produces-wood-smoke-and-air-pollution/article_53f030a0-c7fe-11e6-9e77-ef0f33726edb.html.”
Nitrogen Dioxide (NO2) Emissions from Wood Smoke and Your Health
One of the “Oxides of Nitrogen (NOx) – NOx impairs the respiratory system and its ability to fight infection. NOx also combines with VOCs to make ozone and with water vapor to form acid rain or acid fog” (http://www.foresthillmessenger.com/news/regional/burning-wood-produces-wood-smoke-and-air-pollution/article_53f030a0-c7fe-11e6-9e77-ef0f33726edb.html). “Nitrogen dioxide causes a range of harmful effects on the lungs, including: increased inflammation of the airways; worsened cough and wheezing; reduced lung function; increased asthma attacks; and greater likelihood of emergency department and hospital admissions. New research warns that NO2 is likely to be a cause of asthma in children.” (https://www.lung.org/clean-air/outdoors/what-makes-air-unhealthy/nitrogen-dioxide)
Sulfur Dioxide (SO2) Emissions from Wood Smoke and Your Health
“Short-term exposures to SO2 can harm the human respiratory system and make breathing difficult. People with asthma, particularly children, are sensitive to these effects of SO2. SO2 emissions that lead to high concentrations of SO2 in the air generally also lead to the formation of other sulfur oxides (SOx). SOx can react with other compounds in the atmosphere to form small particles i.e. particulate matter (PM) pollution” (https://www.epa.gov/so2-pollution/sulfur-dioxide-basics).
Lead (Pb) Emissions from Wood Smoke and Your Health
Lead (Pb) is a “heavy metal that can cause mental retardation, and increase in the rate of infections and cancer by blunting body’s defense mechanisms (the immune system). Lead accumulates in blood, bones, and soft tissue and may result in damage to brain, central and peripheral nervous system, and kidneys. While its suggested threshold is 0.4 part-per-million (ppm) for adults and 0.3 ppm for children, people can exhibit lead poisoning symptoms at 0.2 ppm” (http://www.businessdictionary.com/definition/lead-Pb.html).
Volatile Organic Compounds (VOC) Emissions from Wood Smoke and Your Health
“VOCs are evaporated carbon compounds which react with NOx in sunlight to form ozone (photochemical smog). Ozone injures the lungs and makes breathing difficult, especially in children and exercising adults. NOx and VOCs also form particulate matter through reactions in the atmosphere. For example wood smoke contains VOCs which include toxic and/or cancer-causing substances, such as benzene, formaldehyde and benzo-a-pyrene, a polycyclic aromatic hydrocarbon (PAH)” (http://www.foresthillmessenger.com/news/regional/burning-wood-produces-wood-smoke-and-air-pollution/article_53f030a0-c7fe-11e6-9e77-ef0f33726edb.html).
“VOC exposure can cause heart disease and exacerbate respiratory diseases, such as asthma and emphysema” (https://www.post-gazette.com/news/environment/2020/05/13/Methane-leaks-much-worse-than-previously-thought/stories/202005120163).
Dioxin Emissions from Wood Smoke and Your Health
“Dioxins are highly toxic and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer” (https://www.who.int/news-room/fact-sheets/detail/dioxins-and-their-effects-on-human-health).
Polycyclic Aromatic Hydrocarbons (PAH) Emissions from Wood Smoke and Your Health
This class of organic compounds are a health concern because they can bind to or form small particles in the air and can cause cancer. https://www.canada.ca/en/health-canada/services/air-quality/indoor-air-contaminants/avoid-wood-smoke.html
Carbon Dioxide (CO2) and Methane (CH4) Emissions from Wood Smoke and Your Health
These two pollutants and greenhouse gases contribute significantly to global warming and climate change. “Symptoms of CO2 exposure may include headache and drowsiness. At higher CO2 exposure levels, rapid breathing, confusion, increased cardiac output, elevated blood pressure and increased arrhythmias” (https://www.fsis.usda.gov/wps/wcm/connect/bf97edac-77be-4442-aea4-9d2615f376e0/Carbon-Dioxide.pdf?MOD=AJPERES).
Methane can “increases risk of Lyme disease and West Nile virus. High airborne concentrations of methane …can cause a host of health impacts including headaches and dizziness, nausea and vomiting, loss of coordination and trouble breathing” (https://www.post-gazette.com/news/environment/2020/05/13/Methane-leaks-much-worse-than-previously-thought/stories/202005120163).
Visible Wood Smoke Emissions and Your Health
Visible emissions from wood smoke can be a warning sign of risks to human health. You can see wood smoke in the air before it rises to harmful levels at spaces in proximity to the source of the smoke.
Inhaling visible emissions engenders human health effects as to “breathing and respiratory functions, aggravation of existing respiratory and cardiovascular disease, alterations in the body’s defense systems against foreign materials, damage to lung tissue, carcinogenesis, and premature death” (http://www.deq.idaho.gov/media/60176914/measuring-visible-emissions-at-your-facility.pdf).
Odor Emissions from Wood Smoke and Your Health
Odor emissions from wood smoke can also be a warning sign of risks to human health. You can smell chemicals in the air before they are at harmful levels. Individuals can as a result of smelling odors in the air experience a “decrease in their quality of life and sense of wellbeing” (https://www.atsdr.cdc.gov/odors/air_pollution_odor_diaries.html).
You can experience chemical odor emissions that make you sick. Symptoms include: headaches, nausea, reflex nausea, G.I. distress, fatigue, eye irritation, throat irritation, nose irritation , shortness of breath, runny nose, sleep disturbance, inability to concentrate, classical stress response, nasal congestion, hoarseness, sore throat, cough, chest tightness, wheezing, heart palpitations, drowsiness, mental depression (https://www.atsdr.cdc.gov/odors/faqs.html , http://fivesenses.com/Documents/Library/23%20%20Gray%20Line%20Nusance%20Health.pdf).
The Air Quality Index (AQI) and Your Health
What is the Air Quality Index (AQI) and What Are the Two Versions of the AQI?
The EPA AQI is an easy-to-use tool for expressing the quality of the air we breathe. The AQI can represent either the daily air quality for a specific air pollutant known as the U.S. Air Quality Index – daily index or the so called NowCast AQI that represents current air quality for a specific air pollutant for the most recent available hour.
State and local authorities may also issue AQI forecasts to predict the AQI for the next day for ozone and particulate matter (PM).
In General, What Values Apply to the AQI and What do They Mean?
EPA’s AQI PM2.5 is an invaluable tool to visualize measured particulate levels i.e., PM2.5 levels in ug/m3 at a wood smoke affected site at or beyond the property line nearest the source. Those readings may be compared to the customary and ordinary ambient background particulate PM2.5 level at the same site as measured at or beyond the property line nearest the source at the corresponding time and location and/or to the ambient PM2.5 levels at an unaffected control site at the same time in terms of the AQI PM 2.5 and associated health concerns.
https://www.airnow.gov/aqi/aqi-basics/
What do Specific AQI Values and Colors Mean?
Specifically, an AQI value of 100 means an ambient air concentration for a pollutant equal to its short-term national ambient air quality standard level for protection of public health. There is not necessarily a “safe” level of any particular pollutant. AQI values at or below 100 indicate that public health may not be at risk save for sensitive or compromised individuals. AQI values over 100 imply that air quality is unhealthy to a varying extent for certain populations and for everyone as the AQI increases.
The AQI features six colors. Each color relates the pollutant standards to a different range of values or levels in the index and associated air quality and health concerns: Green (0-50) for “Good” air quality, Yellow (51-5100) for “Moderate” air quality, Orange (101-150) for “Unhealthy” air quality “for sensitive groups”, Red (151-200) for “Unhealthy” air quality, Purple (201-300) for “Very Unhealthy” air quality and Maroon (301-500) for “Hazardous” air quality.
https://cfpub.epa.gov/airnow/index.cfm?action=aqibasics.aqi
What Air Quality Air Pollutants Does the AQI Track?
The U.S. Air Quality Index – daily index portrays air quality on the basis of any one of five of the six major air pollutants or “criteria” pollutants (five of which excluding ozone are in wood smoke as per above). These are the pollutants that the Clean Air Act (CAA) regulates to protect public health under the National Ambient Air Quality Standards (NAAQS):
- Particle pollution/ particulate matter (PM), including PM2.5 (PM 2.5 microns or less in diameter) and PM10 (PM 10 microns or less in diameter)
- Carbon monoxide
- Sulfur dioxide
- Nitrogen dioxide
- Lead (the AQI does not record Lead)
- Ozone
The AQI for each pollutant is based on the specific health – based standard for that pollutant. The illustrations below denote the 24-hour average range in ug/m3 and its equivalent AQI values for PM2.5 the signature pollutant in wood smoke. Note that the PM2.5 24-hour average standard in ug/m3 is 35.4 ug/m3. That corresponds to an AQI value of 100.
The NowCast AQI covers just two pollutants – ozone and PM2.5. It’s a convenient barometer as to timing of outdoor activities. The NowCast AQI is the AQI you see as “current air quality” and on the AirNow website.
24-Hour PM2.5 Levels (ug/m3)
Source: U.S. Environmental Protection Agency
What Special Considerations does The AQI Address and What is The AQI Calculator?
EPA’s AQI PM2.5 is an invaluable tool to visualize measured particulate levels i.e., PM2.5 levels in ug/m3 at a wood smoke affected site at or beyond the property line nearest the source. Those readings may be compared to the customary and ordinary ambient background particulate PM2.5 level at the same site as measured at or beyond the property line nearest the source at the corresponding time and location and/or to the ambient PM2.5 levels at an unaffected control site at the same time in terms of the AQI PM 2.5 and associated health concerns.
The AirNow website (https://www.airnow.gov/aqi/aqi-calculator/) features an AQI Calculator to convert PM2.5 levels due to wood smoke in ug/m3 to the AQI numbers. And, it does not only Concentration to AQI conversions but also AQI to Concentration conversions.
Note: The WHO guideline for PM2.5 is 10 ug/m3 (annual average) and 25 ug/m3 (24-hour average). The EPA guideline for PM2.5 is far less conservative at 12 ug/m3 (annual average) and 35.4 ug/m3 (24-hour average).
What Other References Can I Find as to the AQI?
The following sites may be of interest as to the AQI:
https://www.epa.gov/sites/production/files/2014-05/documents/zell-aqi.pdf
https://www3.epa.gov/airnow/aqi_brochure_02_14.pdf
