efe-epaBy Eric San Juan Dalat, Vietnam

The sight of bicycles navigating the increasingly busy streets of Vietnam's growing towns and cities remains unusual, especially in a country where motorbikes are very much the vehicle of choice.

But their ever-growing number has presented a challenge for urban developers; the country's cities are on track to become some of the world's most polluted, unless appropriate measures are taken.

Having grown tired of breathing in toxic petrol fumes on their daily ride to and from Thang Long institute, three 17-year-old Vietnamese students have taken up the environmental challenge; as part of a school science project, they have invented a simple device as they bid to improve the air quality in cities both in Vietnam and across Asia.

Mounted to the front wheel of a push-bike, the device invented by Tung Bao Khanh, Cao Thi Khanh Hoa and Tran Hoang Phi Bao is a simple contraption, consisting of six rotating blades that filter and funnel the air the rider breathes while pedaling along even the busiest, most polluted streets.

"The idea was that instead of having to wear an anti-pollution mask, our bikes would protect us," Hoa told EFE at Thang Long in Dalat, in a mountainous region of southern Vietnam.

After six months of hard work and long deliberations, the three would-be scientists and their professor, Le Thanh Hai, proudly show the rudimentary mountain bike, to which they have attached six small fans on the front wheel that spin powered by the movement of the bike.

Khanh explained how the movement of the fans feeds the battery, which triggers the filter through which the air passes, which, once purified, is funneled towards the cyclist's face.

Costing around $13.4, the initial results of the first tests are exciting: the device filters 86 percent of dust particles and 63 percent of nitrogen dioxide, one of the major pollutants in big cities.

Although it remains no more than a prototype, and its three inventors are focused on completing high school and deciding their academic future, the media coverage of their invention in Vietnam has encouraged them to continue perfecting it in the hopes that, one day, bikes across the country and even the continent could be equipped with the device.

"The version we have made is for bicycles, but it can be adapted very easily to a motorbike or an electric bike. It would be even smaller because you can take advantage of the motorbike's battery. We hope to reach the largest number of vehicles and help clean the air," said Hoa.

The three students hope to export it to other countries as well, especially the big Asian cities, where air pollution has become a threat to the health of millions of people.

"We can help reduce toxic air in cities like Beijing or New Delhi. The bicycle is already a means of ecological transport, but we can add this device and protect the cyclist's health and contribute to a cleaner air. In addition, we raise awareness about the environment," said Bao.

Their professor, Le Thanh Hai, could not conceal his pride as he told EFE that they would try to work with companies to perfect the device and be able to market it, as they "don't have the necessary equipment," he said.

Hai is optimistic about the product's potential, because "in Southeast Asia the bicycle is used a lot, especially the motorbike and many drivers would be interested."

Vietnam's capital Hanoi and its largest city Ho Chi Minh are two of the most polluted cities in the region, due mostly to traffic and in part due to its excessive dependence on coal-fired power plants for energy.

Vietnam ranks 159th out of 180 in air quality index developed by Yale University.