Wood burning stoves produce PM2.5 particles in amounts similar to traffic and increase global warmingBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h3738 (Published 14 July 2015) Cite this as: BMJ 2015;351:h3738
- Dorothy L Robinson, senior statistician and adjunct senior lecturer1
A comprehensive review identified the misguided nature of favourable taxation for diesel vehicles: “global warming has been negatively affected, and air pollution has become alarming in many European locations.”1 Policymakers did not adequately consider the serious health effects of particles less than 2.5 microns in size (PM2.5)—known since 1993 when the Six Cities study was published—and the additional global warming from nitric oxide and nitrogen dioxide, ozone, and black carbon emissions.1
Other equally misguided policies continue. Pollution from domestic wood burning is increasing (17% of UK PM2.5 emissions in 2013, similar to the 18% from road transport).2 A new log burning stove emits more PM2.5 each year than 1000 petrol cars.
The UN Environment Program/World Meteorological Organization recommended phasing out log burning stoves in developed countries to reduce global warming and dangerous air pollution.3 Even using sustainably sourced wood, methane and black carbon emissions from a log burning stove cause more global warming than those from a gas heater or electric heat pump.
Despite the concern about nitrogen dioxide, PM2.5 are thought to affect more people than any other pollutant—the estimate of 29 000 UK deaths from air pollution relates to PM2.5.4
Effective policies should aim for the greatest possible reduction in health damage with available resources. London’s PM2.5 average (15.5 μg/m3) is much higher than the WHO guideline of 10 μg/m3, now considered inadequate.
London’s annual mean PM10 from wood burning (1.1 μg/m3) far exceeds the predicted city-wide reduction of 0.17 μg/m3 from phases 1 and 2 of the Low Emission Zone to reduce traffic pollution.5 Solving the wood burning problem could generate more benefits for less cost than additional measures to reduce traffic emissions.
Health professionals must explain this to policymakers, so that—instead of repeating past mistakes—future policies use the best, most cost effective ways to minimise damage to public health from air pollution.
Cite this as: BMJ 2015;351:h3738
Competing interests: None declared.
Full response at: www.bmj.com/content/350/bmj.h2757/rr-0.