A latest study has shown that Scotland has failed to meet European targets to curb air pollution.
WWF Scotland has analysed Scottish Air Quality data on nitrogen dioxide (NO2) levels in parts of Aberdeen, Dundee, Edinburgh, Glasgow and Perth.
According to the group, they were in breach of EU air pollution targets. This has exposed people living in the cities to dangerous gases.
The Scottish Government has been asked to take immediate measures to control the situation.
Dr Dan Barlow, head of policy at WWF Scotland, said: "It is totally unacceptable that Scotland has breached European air pollution targets for the second year in a row.
"As a result of a complacent approach thousands of people are exposed to dangerous levels of air pollution in Scotland's major cities.
Dr Barlow further said: "Scotland has had plenty of time to take preventative action, so it is shocking that we have failed to put in place the measures needed to meet air quality targets and protect human health."
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