More than 3 million people a year are killed prematurely by outdoor air pollution, according to a landmark new study, more than malaria and HIV/Aids combined.
Wood and coal burning for heating homes and cooking is the biggest cause, especially in Asia, but the research reveals a remarkably heavy toll from farming emissions in Europe and the US, where it is the leading cause of deaths.
But the research found that agricultural emissions of ammonia had a “remarkable” impact, according to Professor Jos Lelieveld, at the Max Planck Institute for Chemistry in Germany, who led the research. A fifth of all global deaths resulted from these emissions, which come mainly from cattle, chickens and pigs and from the over-use of fertiliser.
The ammonia reacts with fumes from traffic and industry to produce tiny particles and is the largest cause of air pollution deaths in the eastern US, Japan and in Europe. “For London, agriculture is the main source,” said Lelieveld. Across the UK, 48% of the premature deaths were ultimately the result of agricultural pollution.
Currently it is assumed that all particulates are equally toxic. But if those from fuel burning are more toxic, as some scientists suspect, the proportion of premature deaths attributable to farming emissions would be lower. Even so, Professor Michael Jerrett, environmental health expert at the University of California said “the finding is highly valuable … because agriculture has generally not been seen as a major source of air pollution or premature death, and because it suggests that much more attention needs to be paid to agricultural sources, by both scientists and policymakers.”
Source: The Guardian (abridged)