Using an indoor wood stove or fireplace increases women's risk of developing lung cancer by 43% compared with those who do not use wood heating, according to a US study involving 50,000 women. The research, part of the Sister Study, tracked participants for an average of 11 years and found that more frequent use led to greater risk. Those who used a wood burner on more than 30 days a year had a 68% increased risk.
The study accounted for factors such as income and tobacco use. Among the 347 women diagnosed with lung cancer during the study, 289 were current or former smokers and 58 had never smoked. The elevated risk from wood burning was observed in both groups, suggesting that wood smoke poses a danger independent of smoking.
Dr Suril Mehta, from the US National Institute of Environmental Health Sciences and lead author, said: 'Our study provides evidence that even occasional indoor wood burning from stoves and fireplaces can contribute to lung cancer in populations where indoor wood burning is not the predominant fuel source.' Wood smoke contains carcinogens such as benzene and polycyclic aromatic hydrocarbons.
Prof Fay Johnston from the Menzies Institute for Medical Research, Tasmania, who was not involved in the research, commented: 'The new results from the Sister Study provide strong evidence of the risk of living in homes heated by wood combustion. Even relatively low usage was associated with an increased risk of lung cancer.' She added that 'wood heater smoke is not safe' and called for interventions to reduce exposure.
In the UK, only 4% of homes using solid fuel rely on it as their sole heating source, with wood often used as a secondary option. The study adds to existing evidence; the International Agency for Research on Cancer classified wood smoke as probably carcinogenic to humans in 2006.
