Low level pollution well within UK guidelines causes changes to the heart similar to those seen in the early stages of heart failure, a new study warned.
The shocking findings were based on British volunteers who did not live in large cities but near loud, busy roads.
Road transport accounts for 20 to 30 per cent of outdoor air pollution in the UK.
Being exposed to levels of soot and harmful fumes at levels well within UK legal limits damages the heart and the more a person was exposed, the larger their hearts became.
Scientists are now urging the UK had to adopt stricter limits to air pollution as it is now the largest environmental risk factor linked to deaths in England.
The study was based on around 4,000 participants in the UK Biobank study who did not have underlying heart problems, or had recently moved.