Wood Smoke: Environmental Pollution and Its Health Implications

It is wrong to assume that wood smoke is harmless. Smoke from wood stoves, fireplaces, burn fires and so on form a major part in air pollution problems. This is because wood smoke contains particles and gases that have the potential of causing serious health problems when they are breathed. These gases contain toxic chemicals that can irritate the respiratory track and may even cause cancer. In environments where wood is burned, they are bound to be higher levels of indoor smoke and more environmental pollutants in form of particles and gases. Also, smoke from wood stoves can seep into houses where wood stoves are not used.

What makes up wood smoke

Wood smoke contains a cocktail of solids, liquids and gases. These contain lots of air pollutants which can affect human health in ways similar to cigarette smoke, which may include severe respiratory diseases and cancer. One of these pollutants that is of most concern is fine particles. These are tiny bits of solids and liquids made of incomplete wood burning. These fine particles are inhaled deeply into the lungs when we breathe in air from wood smoke. Long term environmental exposure to wood smoke pollution may lead to toxic particles settling in the lungs which may lead to diseases. Most wood smoke particles implicated in most air pollution diseases are 2.5 µm or less in size – smaller in diameter than a human hair. Also known as PM2.5, these tiny particles are so small they are able to avoid the respiratory tract’s defenses to reach deepest areas of the lungs, the alveoli, where they enter the blood stream.

Residential wood burning, wood stove cooking and bush burning greatly increases the amount of fine particles in the air. Research studies show that fine particles, even at low levels, are harmful to human health just as many of the health effects caused by fine particles may be related to wood smoke.

Many organic chemicals in wood smoke contribute to environmental pollution that constitute serious health problems in the respiratory tract. Evidence exists that these organic compounds have also being shown to be transfered by these fine particles in wood smoke. Harmful organic chemicals carried by PM2.5 in wood smoke include: benzene, formaldehyde, acetaldehyde, and polycyclic aromatic hydrocarbons (PAHs).

Health Effects of wood smoke

Environmental pollution of PM2.5 from wood smoke has both short- and long-term effects.Short-term effects of wood smoke exposure includes eye, throat, sinuses, and lungs irritation, headaches, reduced lung function. In children, the effects could be severe. They include especially in lung inflammation or swelling, increased risk of lower respiratory diseases and more severe or frequent symptoms from existing lung diseases (such as asthma and pneumonia), and risk of heart attack and stroke. Long-term exposure to wood smoke can be chronic lung disease including bronchitis and emphysema, chemical and structural changes in lungs, and cancer.

Adults with normal health generally may have resistance to most effects of wood smoke although they may feel shortness of breath and other symptoms like irritated eyes, sore throats, phlegm, chest tightness, headaches, and allergy symptoms. Although anyone can have health effects from wood smoke, those most likely to be affected even at low levels are: infants and children, the elderly and adults with existing heart or lung conditions.

Children breathe more air in contrast to adults because of their developing lungs. This makes them more susceptible to the health implications from the environmental pollutants from wood smoke. Children who regularly breathe wood smoke are more likely to have shortness of breath, coughing, wheezing, asthma, disrupted sleep, inflamed respiratory tracts, and pneumonia. A research study conducted by the University of Washington have found more symptoms of respiratory disease in Seattle preschool children who live in residential areas with high levels of wood smoke than in children living in areas with lower wood smoke levels.

Further environmental pollution studies have revealed that the exposure to wood burning stoves increases the risk of lower respiratorytract infections likebronchitis and pneumonia in young children. It is also believed that children with lower respiratory tract infections may develop chronic lung disease in later life.

Studies have also revealed that the lower the heart is able to respond to changes in activity levels when people breathe, the more they are prone air pollution. This concept has been proven to be true in young people and older adults. Also, adults with existing heart conditions, as well as smokers and ex-smokers, are more susceptible to the effects of wood smoke. Older adults are at greater risk from wood smoke if they have common chronic health problems, which can be worsened by exposure to fine particles.