AIR pollution on streets in Glasgow and Paisley has reached some of the highest levels in the country.
Official figures show that pollution "spikes" - when levels rise during rush hour - are breaching safely levels.
Environment group Friends of the Earth Scotland say that air pollution has been linked with asthma attacks, heart attacks, strokes, emphysema, and lung cancer.
At the worst site, Paisley Central Road experienced 10 times the number of safe pollution peaks, with 214 spikes in Nitrogen Dioxide in 2013.
Paisley's Gordon Street is the fourth highest with 46 peaks, closely followed by Anderston in Glasgow with 42 pollution spikes.
Emilia Hanna, campaigner for Friends of the Earth Scotland, said: "Even if you are exposed to air pollution for a short amount of time it can damage your health.
"The Friends of the Earth Scotland air pollution campaign is regularly contacted by people who say that on certain days, they cannot travel into their city centre because they fear that bad air pollution will cause them to suffer an asthma attack or worse.
"For the sake of saving lives, we are urging both government and local authorities to spend more money on making it safe to walk and cycle, on improving public transport and on rolling out ultra low emissions which place restrictions on the most polluting vehicles." The group say 2000 people die from exposure to air pollution in Scotland each year.