Unless you have an effective home air filter, the ambient (outside) level of pollution comes inside your house, office, church, store, daycare, or school. A growing body of scientific evidence shows that exposure to increased small particle pollution (PM 2.5) causes increased health consequences, short-term and long-term.
Following is a selection of health studies and reports on the consequences of fine particle pollution, called PM 2.5, in wood and coal smoke.
The American Lung Association has noted that “short-term exposure to particle pollution can kill.” This sobering statement puts our high PM 2.5 levels in context. From their 2010 State of the Air report:
Deaths can occur on the very day that particle levels are high, or within one to two months afterward. Particle pollution does not just make people die a few days earlier than they might otherwise—these are deaths that would not have occurred if the air were cleaner.
Particle pollution also diminishes lung function, causes greater use of asthma medications and increased rates of school absenteeism, emergency room visits and hospital admissions. Other adverse effects can be coughing, wheezing, cardiac arrhythmias and heart attacks. According to the findings from some of the latest studies, short-term increases in particle pollution have been linked to:
- death from respiratory and cardiovascular causes, including strokes;
- mortality in infants and young children;
- increased numbers of heart attacks, especially among the elderly and in people with heart conditions;
- inflammation of lung tissue in young, healthy adults;
- increased hospitalization for cardiovascular disease, including strokes and congestive heart failure;
- increased emergency room visits for patients suffering from acute respiratory ailments;
- increased hospitalization for asthma among children; and
- increased severity of asthma attacks in children.
Minnesota Pollution Control Agency “Health Effects of Wood Smoke” covers this topic clearly and with an excellent graphic. Fine particles, called PM 2.5, travel deep into the lungs and beyond into the body, carrying toxic contaminants on a deadly journey inside us.
Some of the smallest fine particles can go deep into the lungs and can even pass through the lungs into the bloodstream. They can trigger respiratory problems such as asthma attacks and even heart problems. Fine particles are considered especially dangerous for young children with developing lungs, and people of all ages who have asthma, bronchitis, other respiratory problems, and or cardiovascular disease.
“Woodsmoke health effects: a review” Naeher, et al (2007), recommends woodsmoke be regulated along with other ambient fine particle pollutants:
The sentiment that woodsmoke, being a natural substance, must be benign to humans is still sometimes heard. It is now well established, however, that wood-burning stoves and fireplaces as well as wildland and agricultural fires emit significant quantities of known health-damaging pollutants, including several carcinogenic compounds.
Critical Review of the Health Effects of Woodsmoke by Naeher PhD et al, 3/2005 provides a comprehensive coverage of its many health effects.
(T)here is a growing body of evidence from animal and human studies that exposure to wood smoke poses a risk to human health at environmentally relevant concentrations. These adverse health effects range from irritancy to serious respiratory diseases, including chronic obstructive airway disease and lung cancer.
Globally, the 1.4 million premature deaths from biomass fuels (indoor smoke from solid fuels) annually rivals those from malaria. Source: “Wood: The Fuel that Warms You Thrice” Kirk R. Smith, MPH, PhD (2008), Figure 5.1. Smith has a new take on the old New England expression, “Wood is the fuel that warms you twice. Once when chopping, and once when burning.” Smith writes that:
Wood seems to have the potential to generate heat a third time because the smoke from its burning is a major risk factor for respiratory infections and the fever that often accompanies them.
Other woodsmoke and PM 2.5 particulate studies are available on the National Institutes of Health PubMed publication search site.
The State of Alaska Epidemiology bulletin identified an association between PM 2.5 and Fairbanks hospital admissions 8/30/2010. See also the State of Alaska Department of Health and Human Services fact sheeton the 8/2010 bulletin. Also, see the FDNM article on the 8/2010 on the State of Alaska Epidemiology study.
Woodsmoke triggers asthma attacks. Read more on the Center for Disease Control, Asthma pages, and asthma trigger page. See also the NIH National Library of Medicine “Breath of Life” asthma publication to better understand this complex disease.
A Johns Hopkins study from 1998-2003 found a direct correlation in increased PM 2.5 levels in indoor air and asthma symptoms and medication use. According to the study, a rise in indoor PM 2.5 by 10 μg/m3 increases the number of days children were wheezing severely enough to limit their speech by 7% and the number of days children used rescue medication by 4%.
Jane Q. Koenig, PhD, MS Professor Emeritus of the University of Washington and Koenig’s faculty profile, has a number of relevant publications including: “Indoor- and Outdoor-Generated Particles” Koenig et al 2005 and “Effect of Particulate Air Pollution on Lung Function in Adult and Pediatric Subjects in a Seattle Panel Study” Carol A. Trenga, PhD, Koenig, et al 2005.
PM 2.5 air pollution has harmful cardiovascular effects according to a growing body of evidence, according to “Growing evidence linking air pollution with cardiovascular disease: AHA” by Michael O’Riordan on RD Brook, 2010:
PM2.5 generally has been associated with increased risks of myocardial infarction, stroke, arrhythmia, and heart-failure exacerbation within hours to days of exposure in susceptible individuals. Several new studies have also demonstrated that residing in locations with higher long-term average PM levels elevates the risk for cardiovascular morbidity and mortality.
Sunday newspaper insert Parade published an article “The Surprising Link Between Air Pollution & Diabetes” 11/7/2010. The article refers to a study published in Diabetes Care which found “a strong association between PM2.5 exposure and diabetes prevalence, suggesting that ambient air pollution may contribute to the increased prevalence of diabetes in the adult U.S. population.” This conclusion was published in “Association Between Fine Particulate Matter and Diabetes Prevalence in the U.S.” by John F. Pearson, BS, et al in Diabetes Care, 10/2010.
Given a hypothetical population of 1,000,000 people, our model suggests that for every 10 μg/cubic meter increase of PM2.5, there could be a resulting increase of ∼10,000 diagnosed cases of diabetes or an overall increase in diabetes prevalence of ∼1%/10 μg/cubic meter.
According to the 2009 US Census Bureau, the Fairbanks North Star Borough population estimate was 98,660, with 8.4% under the age of 5 and 26% under 18. In our community a 10 microgram increase in the annual average PM 2.5 level would be expected to result in an additional 900 to 1,000 individuals developing diabetes. Pearson’s article concludes:
…(E)vidence based on this study and others suggests that current limits [EPA annual limit of 15 μg/cubic meter] on particulate matter exposure may not adequately mitigate the public health consequences.
The Indo-US Collaboration on Environmental and Occupational Health, recommendations and abstracts, 2008 grimly portrays the effects of air pollution. One study, on page 32, lists the common short-term air pollution exposure effects [and symptom(s) associated with that effect]:
- mortality (cardio-respiratory)
- hospital admissions (cardio-respiratory)
- emergency room attendees (cardio-respiratory)
- primary care visits (upper and lower respiratory)
- respiratory symptoms (cough, phlegm, wheeze)
- use of medications (asthma drugs)
- lung function (restrictive and obstructive)
- blood (increased viscosity, fibrinogen)
- heart (increased heart rate variability, arrhythmia)
Another abstract in the Indo-US publication goes beyond the short-term effects, see page 53-54:
(The) WHO estimates 1.6 million premature deaths from indoor air pollution (twice that from outdoor air pollution) [800 thousand]…. Chronic exposure to biomass smoke causes genetic damage, cardiovascular disease and stroke.
Brains as well as bodies are put at risk. A recent US study found lower IQ in children of mothers exposed to higher levels of Polycyclic Aromatic Hydrocarbons (PAHs), the main toxins in woodsmoke. After controlling for variables, IQ was 5 points lower, about 4%, than children of mothers with lower PAH exposure. Study: Prenatal Airborne Polycyclic Aromatic Hydrocarbon Exposure and Child IQ at Age 5 Years published in Pediatrics7/2009.
A current study found an association between childhood autism and residence proximity, during pregnancy and near the time of delivery, to freeways and major roadways as a surrogate for air pollution exposure. The study was published in the journal Environmental Health Perspectives “Residential Proximity to Freeways and Autism in the CHARGE study” 12/16/2011 and also summarized in the LA Times “Proximity to freeways increases autism risk, study finds” 12/16/2011.
The New South Wales (Australia) Government’s “Action for Air” 2009 acknowledges PM 2.5 particles are particularly dangerous and that there is no safe exposure level:
Health research identifies particles of less than 2.5 micrograms (PM2.5) as a particular concern because their smaller size means they can be inhaled deeper into the lungs, and because there is no safe threshold level to use for setting standards.