EDINBURGH was on smog alert today as environment campaigners warned of a “dangerous pollution event” affecting the Capital on what is expected to be the hottest day of the year.
High temperatures, sunny weather, home-grown pollution and ozone drifting up from continental Europe were set to combine and create a “chemical soup” and break air quality guidelines, said Friends of the Earth Scotland.
Dr Richard Dixon, the group’s director, said vulnerable groups – the old, the young and people with asthma or other breathing difficulties – could be affected.
He said the Edinburgh pollution haze would be a “more minor” version of a smog which hit London, Brighton, Yorkshire, Humberside and the West Midlands in April.
It will be the third air pollution episode of the year after earlier ones in April and March.
Dr Dixon said: “If you were at the east end of Princes Street looking along, the spires at the west end would look very hazy.
Ozone is an irritant so will affect anyone with asthma or any breathing problemDr Richard Dixon
“Or if you were up on Blackford Hill, you could look across the city and see a noticeable haze. Anywhere with a wide vista, you would see things quite hazy.
“Ozone is an irritant so it is going to affect people with asthma or any kind of breathing problem.”
The problem comes when sunlight reacts with contaminants that have built up in the air, creating ground-level ozone. The heat makes the chemical reaction go faster.
“Because it’s coming from the south-east, we can get pollution from cars and factories and power stations in Europe.”
The coloured map showing Scotland’s official air pollution forecast ranges from “low” greens to “moderate” yellows and oranges and “high” reds and purples. And even though today’s forecast is “moderate” Dr Dixon said such a rating was relatively unusual. “For Scotland the whole map is going to go yellow, which is pretty rare,” he said.
Level four, which is predicted for Edinburgh, means an ozone level of between 101-120 microgrammes per cubic metre. The World Health Organisation guideline is for ozone to stay under 100mcg per cubic metre.
Official advice when pollution reaches “moderate” is that adults and children with lung problems, and adults with heart problems, who experience symptoms should consider reducing strenuous physical activity, particularly outdoors.
Earlier this year, authorities in Paris introduced emergency measures to halve the number of vehicles on the city’s roads to curb dangerous smog levels.
City environment leader Lesley Hinds, said: “Tackling air pollution continues to be a key priority for the council as we work to create a cleaner, greener Edinburgh. We regularly review the city’s Air Quality Management areas to assess levels of pollution and identify any areas where specific action is required.”