The World Health Organization (WHO) warns that 92 percent of the world’s population lives in areas of high air pollution. Many cities in Europe have pledged to phase out diesel cars - and there’s hope that sales of electric vehicles could take over as battery life improves.The British capital is one of the most heavily polluted cities in Europe — with levels of toxic gases regularly exceeding European Union limits. Pedestrians often don’t realize how close they are to sources of ‘raw pollution’, says Martin Williams of Kings College London. “One of the difficulties of getting the message across to the public at large these days is that air pollution, although it’s a major public health problem, is actually invisible. Not like the smogs of the 1950s and 60s when not only could you see it, you could barely see anything else,” said Williams. So what exactly are we inhaling on traffic-clogged streets? “The main problem that you are breathing in are the particulates, the soot largely from diesel exhausts, which is the primary problem as far as public health is concerned. And that’s responsible for maybe up to around 30,000 premature deaths across Britain," said Williams. "The other pollutant that’s more recently become an issue is nitrogen dioxide, again largely from diesel.” Diesel cars are seen as the main culprit of urban air pollution. German carmaker Volkswagen’s attempt to fix emissions tests — known as ‘diesel-gate’ — has sharpened the focus on phasing out diesel engines, says Areeba Hamid of environmental campaign group Greenpeace. “It’s quite clear that the car industry is feeling the pressure of a public health crisis owing to air pollution in big cities in particular — and the aftermath of the ‘diesel-gate’ scandal. Which is the reason why it’s looking to produce new electric models,” said Hamid. At last month’s annual Paris Motor Show, electric cars dominated the stands. Volkswagen has announced it aims to sell 2 to 3 million electric vehicles a year by 2025. Experts say electric cars could offer the solution to urban air pollution — with the proviso that the electricity is generated using renewable energy.