Queen Mary University researchers gave six children in London monitors which recorded black carbon over a 24-hour period during weekdays.
While the kids spent 7 per cent of the day travelling, they experienced 15 per cent of their daily exposure to black carbon during their journeys.
They discovered the children spent 32 per cent of the day at school, but got 44 per cent of their exposure to the pollution during that time.
Andy Lester, director A Rocha told Premier he wasn't surprised by the findings.
"The reality is that there have been a number of studies done and take London for example, right across the city, every primary school exceeds the World Health Organisations' recommendations," he said.
Explaining what could be done by individuals to reduce air pollution, he said: "It is all about finding alternatives, so the more people use public transport - the more people cycle, walk to work or to school - that helps.
"And if you think about schools, the biggest problem with pollution in and around schools are parents taking their kids into school and parking with their engines running, letting their kids off."
Meanwhile, three of the world's biggest car-makers are being investigated over claims they worked together to block anti-emissions technology.
An EU regulator says it's had information that BMW, Mercedes owner Daimler and Volkswagen had all held meetings on the matter.
The watchdog's looking into whether they agreed not to compete against each other on systems that limit dangerous pollution.
Listen to Andy Lester speaking with Premier's Eno Adeogun:
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