Scooters produce more pollution than lorries


Scientists have discovered that scooters, far from being the greener option many of us think they are, actually produce more pollution than larger vehicles – including lorries!

A study has shown that scooters are capable of producing volumes measuring thousands of times more of the smog causing pollutants called “organic aerosols” than that of larger vehicles, consequently the comparatively small number of scooters are contributing relatively more pollution in cities around the world. The most worrying aspect is that some of the pollutants given off by scooters are particularly dangerous to the health of anyone exposed to them, these include benzene – which can cause cancer and a range of toxic chemicals called “reactive oxygen species”, levels of these pollutants were found to be high by scientists who say that the risk is so high, even waiting behind a scooter at a junction “may be highly deleterious to health”.

The study was carried out by a number of scientists, including some from the Centre for Atmospheric Science at the University of Cambridge and the Paul Scherrer Institute in Switzerland, Markus Kalberer from the University of Cambridge said “We showed that, in contrast to the general belief, scooters can be a dominant source of air pollution, including soot and organic particles, in urban areas”, he added “We showed that the particles transformed the atmosphere from these scooter emissions are especially toxic.” It appears that the problem is scooters usually use two stroke engines which the scientists say are much less efficient at burning fuel, their exhaust systems do not have catalytic converters so they are far less effective in the removal of pollutants, meaning that exhaust emissions from scooters contain higher levels of the chemicals that are in the fuel and oil they use.

The scientists involved in the study tested the air pollution in various cities around the world, including those in Europe, United States of America and Asia and their findings were published in the journal “Nature Communications”. Their paper said that it is possible that scooters could be contributing up to two thirds of the roadside air pollution in some cities “Using average two stroke scooter emission factors… suggests that two stroke scooters contribute to around 60 per cent of roadside POA in Bangkok, where they account for 10 per cent of fuel consumption” the paper also said “Our data suggest that two stroke scooters are a significant, and in many cities, the largest source of vehicular particular matter and toxic secondary organic aerosols and aromatic hydrocarbons, despite being a relatively small fraction of the total fleet” adding “Therefore, given the alternative technologies available, restrictions on two stroke scooters, already implemented in China, could improve air quality in many cities around the globe.” Stephen Platt was the lead author of the paper and he said “Cars and trucks, particularly diesel vehicles, are thought to be the main vehicular pollution sources” adding “This needs re-thinking, as we show that elevated particulate matter levels can be a consequence of ‘asymmetric pollution’ from two-stroke scooters, vehicles that constitute a small fraction of the fleet, but can dominate urban vehicular pollution through organic aerosol and aromatic emission factors up to thousands of times higher than from other vehicle classes.”

Of course it is not only scooters that use two stroke engines, they are also found in lawn mowers, strimmers, chain saws, outboard motors, model airplanes and more.