pollution kills. Fine particles produced by cars, industrial plants and
numerous other sources are particularly dangerous to human health. That is what
scientists across the world have convincingly established over the past quarter
of a century, and air regulations have been gradually tightened in most Western
countries as a result. Even so, the World Health Organization (WHO) estimates
that exposure to outdoor air pollution accounts for 4.2 million deaths each
year. And in recent years, something insidious has happened in some places: the
science linking air pollution to premature deaths has come under attack.
The problem is most acute in the United States, where the administration of President Donald Trump is bent on dismantling a variety of environmental and public-health regulations. At a meeting last month, a science panel that advises the US Environmental Protection Agency on air-quality standards was divided on the extent to which fine-particle pollution causes premature death. The panel was chaired by Tony Cox, a Trump appointee, statistician and consultant whose research has been funded by oil, gas and other industries, and who has long questioned evidence supporting the link.
Scepticism about air pollution’s health impacts has arisen in other countries, too, including France, Poland and India. And in Germany, 140 lung specialists signed a statement released in January that cast doubt on the health impacts of nitrogen oxides (NOx) and fine-particle emissions from vehicles. The statement acknowledged epidemiological evidence that people in areas with high levels of NOx and fine particulates tend to die slightly earlier than those elsewhere, but questioned whether pollution was the cause.
Earlier this month, the German national academy of sciences set the record straight. NOx, and particularly nitrogen dioxide, increase rates of respiratory illnesses such as asthma while also contributing to the formation of fine particulates. The particulates contribute to premature death by increasing the risk of respiratory and cardiovascular diseases, as well as of lung cancer.
A guest editorial