Diesel-engine Exhaust Filter Reduces Harmful Particles By 98 Percent

A commercially available particle trap can filter microscopic pollutants in diesel-engine exhaust and prevent about 98 percent of them from reaching the air, according to research reported in Circulation: Journal of the American Heart Association. Inhaling exhaust particles increases the risk of dying from heart and lung diseases. Air pollution, including diesel exhaust as a major contributor, causes 800,000 premature deaths annually in the world, according to the World Health Organization.

"This study focused on cardiovascular effects in men exposed in the laboratory to diesel fumes. Equipping diesel-powered vehicles with particle filters could significantly reduce heart disease," said David E. Newby, M.D., Ph.D., co-senior author of the study and the British Heart Foundation John Wheatley Chair of Cardiology at the University of Edinburgh in Scotland.

Newby and Anders Blomberg, M.D., Ph.D., of the Umea University in Sweden, led an international research team in the diesel-exhaust study that involved 19 healthy, non-smoking men with an average age of 25.

The study's primary endpoints include the ability of blood vessels to constrict and dilate and the formation and dissolution of blood clots.

The volunteers breathed filtered air, unfiltered dilute diesel-engine exhaust and dilute diesel-engine exhaust after it passed through a particle trap. Participants inhaled each gas for one hour in an exposure chamber during which they did two 15-minute periods of moderate exercise. At least one week separated each inhalation session. Researchers randomized the order in which each man breathed the three gases.

The particle trap oxidized nitric oxide (NO) into nitrogen dioxide (NO2), both important nitrogen-containing reactive gases in diesel exhaust.

"We have previously exposed people to nitrogen dioxide alone and seen no effect on the body," Newby said. Among the study's findings: