A new weapon in the fight against environmental pollution is literally a breath of fresh air. Dutch inventors have built an enormous outdoor ‘vacuum cleaner,' which pulls toxic particles from the air.

About 6.5 million people die every year due to air pollution according to the UN and 92 percent of people in the world are exposed to air quality so poor, it poses a major health risk.

The World Health Organization says air pollution is the "single greatest environmental threat we all face."

The air purification system has the ability to filter air 300 metres around and up to seven kilometres above it. It is intended to help reduce air pollution and the amount of cancer-causing chemicals in the environment.

The device is "placed basically on top of buildings and it works like a big vacuum cleaner," said Henk Boersen, a spokesman for the Envinity Group, which unveiled the system in Amsterdam on Tuesday.

Tests were carried out by the Energy Research Centre of the Netherlands on the prototype. "A large column of air will pass through the filter and come out clear," Boersen said, speaking on the sidelines of a major two-day offshore energy conference in Amsterdam.

It boasts the ability to treat some 800,000 cubic metres of air an hour compared to 30,000 cubic metres an hour filtered by the Smog Free Tower, another air purifying system. The tower was installed in Beijing by Dutch artist Daan Roosegaarde last month.

Governments, businesses and airports have already expressed interest in the project, Boersen said.