Latest statistics show the concentration of nitrogen dioxide in the air in St John's Road in Edinburgh has the worse air quality in Scotland due to traffic congestion and is now almost double the legal limit.
Average nitrogen dioxide levels for the first half of 2015 rose from an average 59 micrograms per cubic metre to 72, compared with the legal limit of 40. NO2 levels have exceeded 200 micrograms on 35 occasions this year. The "safety standard" allows the N02 levels to go over the limit only 16 times a year.
Friends of the Earth said the figures were "appalling" and they reinforced the case for refusing plans for a new supermarket in the street.
Thousands of Scottish people are dying prematurely because of poor air quality.