Runners and cyclists on city streets could be putting themselves at risk of strokes and other health problems from exposure to pollution, a leading stroke researcher says.
New research, published in The Lancet Neurology, has found air pollution now contributes to a third of all strokes worldwide.
Between 1990 and 2013, healthy years of life lost to strokes associated with environmental and household air pollution increased by over 33 percent.
The study's lead author Valery Feigin, director of the National Institute for Stroke and Applied Neurosciences at Auckland University of Technology said urban joggers and cyclists could be increasing their risk of strokes, heart attacks, respiratory disease and even cancer along with their fitness.
"These people should realise that they are jogging towards serious health problems, not just strokes, because their exposure to pollution is much greater than for people just walking or sitting in their cars."
In New Zealand, environmental pollution only contributed to about 5 percent of strokes, but this was still five times greater than in Australia, Professor Feigin said.
The biggest risk factors for New Zealanders remained poor diet and smoking.
"The encouraging news is that over 90 percent of the stroke burden could be avoided if we take action now, not only as individuals but also health service providers in the messages they're giving people at risk of strokes and at population level by the government."
The risk from sugary drinks alone had increased more than 60 percent in the last 20 years.
Professor Feigin said he would like to see taxes on sugar, salt and saturated fat - and the cash put back into "much needed" preventative programmes and research.
"All it takes is recognition of the urgent need to improve primary prevention, and the good will of the government to act."