HEALTH EFFECTS OF FIREWOOD SMOKE

Firewood smoke in the urban environment is clandestinely a major source of aggravation and ill health for many people, especially those with allergy or chemical sensitivity. The toxicity of wood smoke is well known, as mentioned in the last publication) contains many carcinogenic substances such as aldehydes, dioxin, polycyclic aromatic hydrocarbons (PAH), carbon monoxide and ultrafine particulate matter i.e. particles that are less than 2.5 microns in diameter (PM2.5). The problem with these ultrafine particles is that when they are less than 2.5 microns in diameter they are retained in the human lungs and have been shown to cause increases in morbidity and mortality. 

In developing countries, firewood smoke has had a serious effect on human health as most fire wood usage (either in cooking or other uses) emit smoke to indoor air.

Scientific studies have shown that such emissions of firewood smoke indoors,  cause exposures that reduces lung function, especially in children, and in fact was responsible for a large proportion of obstructive airway disease. 

Studies have shown, In Mexico City, where there is also a huge motor exhaust pollution problem, women exposed to firewood smoke were shown to have a higher risk of contracting chronic bronchitis and obstructive airway disease than those who were not exposed to firewood smoke. In Africa, cooking with firewood greatly increased the risk of stillbirth, while indoor air in homes with fire wood smoke was found to have higher levels of mutagenic material.

In developed countries studies have also found significant health effects in people who use woodstoves. In the USA, children living in homes with wood stoves tended to have higher levels of respiratory symptoms, increased incidence and severity of wheeze, more coughing and a decline in lung function.

Forest firefighters in the USA had decreased lung function after fighting fires and the use of firewood for cooking and other domestic uses by these firefighters also affected their lung function. Eight out of twelve homes were also shown to have an increase in indoor mutagenicity. 

In New York, for example, woodstoves were associated with middle ear problems while other studies in the USA also showed illnesses attributable to fumes from firewood cooking.

In areas where airtight woodstoves are used and these are vented outside, neighbours downwind of the woodstoves probably have a high level of exposure than those indoors at the source of the smoke. In the USA, whole neighbourhoods have been found to suffer, while in some counties, a higher incidence of asthma admission to hospitals were reported - particularly on days of high woodsmoke pollution.

In Sydney, another independent study by the NSW EPA found that most of the particulate pollution in winter came from 13% of households using wood heaters. Studies also showed that death rates are generally higher in winter on days of high pollution, or days following high particle pollution.

‘Woodsmoke is estimated to be 12 times more carcinogenic than an equal concentration of cigarette smoke'.....

In a laboratory study, mice were subjected to either Firewood smoke, oil furnace fumes or clean air for 6 hours. They were then challenged with a streptococcus bacterium and within two weeks, 21% of the mice exposed to woodsmoke were dead compared with the 5% of the mice exposed to the oil furnace fumes or clean air.

Autopsies then showed that particles less than 2.5 microns in diameter (PM 2.5) are retained in human lungs. 

Larger particles are not retained.

The following can be caused by firewood smoke:

1.)  Obstructive airway disease

2.)  Reduced lung function

3.)  Asthma, 

4.)  wheezing, 

5.)  Cough

6.)  Higher incidence of bacterial infections

7.)  Cataract

8.)  Eye lens opacification

9.)  Bronchiolitis

10.) Otitis media (ear inflammation)

11.)  Methemoglobinaemia (reduced oxygen in blood)

12.) Cancer sore throat 

13.) Migraine

14.) neumonitisfibrosis of the lungs 

15.) Unnecessary /avoidable deaths, Etc. 

Our thanks to Dorothy Robinson of the Armidale Air