Environmental campaigners have renewed calls to reduce traffic after research revealed air pollution could cause more than 2500 deaths a year in Scotland.

A report published by the Royal College of Physicians and the Royal College of Paediatrics and Child Health on Tuesday claimed 40,000 deaths are attributable to outdoor air pollution each year across the UK.

The study revealed the cases were much higher than previous official estimates, which projected air pollution causes 29,000 early deaths UK-wide.

Friends of the Earth Scotland said on the basis of the UK figures the number of deaths in Scotland would range from 2500 to 3500.

Emilia Hanna, air pollution campaigner for Friends of the Earth Scotland said: "This new research shows that the previous official figure for how many people die early from air pollution underestimated the scale of the problem, and that air pollution is a much more serious public health crisis than previously understood.

"Based on this new research we can estimate that over 2500 people in Scotland are dying early from air pollution each year.

"Breathing in toxic fumes increases the risk of having a heart attack, stroke, or cancer. Children, especially those growing up in urban settings, are forced to breathe in tiny harmful chemicals."

She said reducing traffic on the roads would be a "simple solution" to the problem and called on the Scottish Government to invest more money in sustainable travel options such as walking and cycling.

Ms Hanna added: "It is shocking that despite the overwhelming evidence showing that air pollution is a top killer and that traffic is the key cause, the Scottish Government continues to pour millions of pounds into unnecessary road building."

A Scottish Government spokeswoman said: "Much progress has been made over recent years in improving air quality.

"However, areas of poorer air quality related to emissions from transport remain in many of our urban areas and the Scottish Government recognises that more needs to be done.

"Poor air quality can impact on health and those with existing heart or lung conditions are more susceptible to the increased health risk associated with air pollution.

"We continue to work closely with local authorities and other partners to improve air quality and the lives and well-being of communities and individuals across the country."