Melvin Prueitt, a scientist with the Los Alamos National Laboratory in California, has filed patents for a process which could literally suck pollution from the skies.
Prueitt describes a hollow convection tower 600ft high. His system works by using spray guns to cast a fine mist of water over the mouth of the tower. The electrically charged mist attracts particles of pollution. On hitting the air, the water droplets evaporate rapidly causing a drop in temperature of 10-20iC. The droplets fall to the bottom of the tower with the pollution particles attached because the electrical charge is still present.
The process, repeated on a large scale, sucks more air into the tower and creates a downward rush of air.
Pollution particles can be removed from the air in two ways. One is to have a second bank of spray guns inside the base of the tower causing a precipation of pollution particles in water which can be discharged to sea via the sewage system. The other is to use electrically charged plates to capture the polluted particles, discharging clean air from the bottom of the tower as a constant breeze.
To halve the air pollution in a city the size of Los Angeles it would take 95 towers, each costing between £6.5m and £13m.