Exercising in heavily polluted environments can damage the lungs and lead to heart failure, a study of more than 16,000 people has found.
Research conducted by the University Hospital Brussels, which found air pollutants narrow the blood vessels in lungs, is the first of its kind to report the impact of air pollution in this way.
Blood flow in the lungs (pulmonary haemodynamics) was measured in 16,295 patients 2009-2013, and correlated with average air pollution in Brussels on that day and in the last five and ten days. A separate individual, randomised crossover study then examined the effect of dilute diesel exhaust on ten healthy male volunteers in a controlled environment, with a drug, dobutamine, given to simulate exercise.
Levels of PM10 and PM2.5, fine particulates associated particularly with diesel emissions, were found to worsen the function of the right ventricle of the heart, the chamber responsible for pumping blood around the lungs.
Dr Jean-Francois Argacha, a cardiologist at the University Hospital (UZ) Brussels, Belgium, said: “This is a major public health issue for people living in polluted urban areas where exercise could damage the lungs and potentially lead to decompensated heart failure.”
Dr Argacha said: “Air pollution was associated with increased pulmonary vascular tone which makes it more difficult for blood to flow to the lungs."
Longer exposure to air pollution exposure seems necessary to impair the heart's ability to effectively pump blood to the lungs, he said.
Exposure to diesel exhaust did not affect volunteers’ pulmonary circulation (blood flow to the lungs) at rest, suggesting the effects of air pollution are more harmful when exercising.
On how to minimise the health risks, Dr Argacha said: “Our main advice is to limit physical activities during heavy air pollution. More studies are needed before specific recommendations on intensity and duration of exercise can be given.”
He said sources of pollution, such as engine crankcases, tyres and brake wear “are becoming important”, adding “no strong evidence exists on effectiveness of face masks to eliminate or reduce particle exposure.”
He added that EU legislation protecting the population from air pollution is weak.
“Diesel emission control has been associated with health outcomes5 but unfortunately the standards defined by the European Union differ from those of the World Health Organization,” he said.
The findings of the study were presented at EuroEcho-Imaging 2016, the annual meeting of the European Association of Cardiovascular Imaging (EACVI).