Lelieveld et al., Nature 525, 367–371 (17 September 2015) doi:10.1038/nature15371: The contribution of outdoor air pollution sources to premature mortality on a global scale.
Here’s the abstract:
Assessment of the global burden of disease is based on epidemiological cohort studies that connect premature mortality to a wide range of causes1, 2, 3, 4, 5, including the long-term health impacts of ozone and fine particulate matter with a diameter smaller than 2.5 micrometres (PM2.5)3, 4, 5, 6, 7, 8, 9. It has proved difficult to quantify premature mortality related to air pollution, notably in regions where air quality is not monitored, and also because the toxicity of particles from various sources may vary10. Here we use a global atmospheric chemistry model to investigate the link between premature mortality and seven emission source categories in urban and rural environments. In accord with the global burden of disease for 2010 (ref. 5), we calculate that outdoor air pollution, mostly by PM2.5, leads to 3.3 (95 per cent confidence interval 1.61–4.81) million premature deaths per year worldwide, predominantly in Asia. We primarily assume that all particles are equally toxic5, but also include a sensitivity study that accounts for differential toxicity. We find that emissions from residential energy use such as heating and cooking, prevalent in India and China, have the largest impact on premature mortality globally, being even more dominant if carbonaceous particles are assumed to be most toxic. Whereas in much of the USA and in a few other countries emissions from traffic and power generation are important, in eastern USA, Europe, Russia and East Asia agricultural emissions make the largest relative contribution to PM2.5, with the estimate of overall health impact depending on assumptions regarding particle toxicity. Model projections based on a business-as-usual emission scenario indicate that the contribution of outdoor air pollution to premature mortality could double by 2050.
There’s also a press release: More deaths due to air pollution: Air pollution could claim 6.6 million lives by 2050. What I want to complain about1 is the last sentence of the abstact, and the subheading of the press release. Otherwise, it all seems fair enough. The press release sets the scene for the error with Surprisingly, the largest sources of air pollution are not industry and transport but small domestic fires and agriculture. That’s not a surprise to anyone who has been following such things; the high mortality from terrible indoor pollution from cooking fires is well known. I assume they’re talking about indoor cooking fires, but I don’t knowhow they reconcile that with the “outdoor” word in their title.
So the error is the obvious one: you don’t expect such deaths to scale with BAU emissions scenarios. Quite the reverse: as people get richer under BAU you expect less indoor cooking fires, and hence fewer deaths.
The finding noted in the press release, Vehicle emissions cause twice as many deaths as traffic accidents in Germany, is interesting too.
1. As long term readers will have realised some time ago, this blog is primarily for complaining about things.