While it is known that burning solid fuels gives rise to harmful concentrations of fine particles (known as PM2.5), the direct evidence linking household air pollution to long-term risk of death, especially from cardiovascular causes, has been very limited.
Researchers from the University of Oxford in the UK, and Huazhong University of Science and Technology, the Chinese Academy of Medical Sciences, and Peking University in China have studied the association of the long-term use of solid fuels for cooking and heating with the risk of death from cardiovascular disease in a large study of 271,000 residents in five rural areas in China.
The researchers found that, compared with people who mainly used gas or electricity (‘clean fuels’), those who regularly cooked using coal or wood (‘solid fuels’) had a 20% higher mortality risk from cardiovascular disease, and people who heated their homes using solid fuels had a 29% increase in risk, after taking account of the effects of age, sex, socio-economic status, smoking, alcohol drinking, diet, physical activity, and adiposity. The study also showed clearly that the longer people used solid fuels, the higher the risk of death. Moreover, there were synergistic effects of household air pollution and tobacco smoking, with the risk of death from cardiovascular disease being 76% higher among smokers who used solid fuel than non-smokers who used clean fuels.
Professor Zhengming Chen, from the University of Oxford, UK, the co-lead Principal Investigator of the China Kadoorie Biobank, said “Air pollution has caused a lot of concern in China, but people have been focusing mainly on the outdoor air quality and overlooking the health consequences of pollution arising from domestic burning of coal and wood for cooking and heating, which may have a more profound impact on health”.
Read the full paper here.