Trees may be guilty for trapping pollution in cities, a new report says. The study was done in the UK and aimed to outline how government can reduce toxic fumes and reduce their effect on public health.
The scientists say that trees trap pollutants and keep them at the street level. However, a number of factors may influence the gas-trapping effects of trees, like “street design, number and siting of trees, species and canopy density, time of year and wind direction relative to the street.
These factors can all influence the air currents on the roads, slowing them down and trapping the polluted air at street level, while protecting those in buildings above the trees. The plants can also act as “sinks” for particulates, such as volatile organic compounds, that may have direct and indirect impacts on air quality.”
Air pollution is to be blamed for about 40,000 premature deaths per year just in the UK. In London, some sites surpassed the yearly safe limit on air pollution set by the EU within just eight days of the New Year. Other places like Mumbai and Beijing are even worse.
Speed bumps, frequent acceleration and deceleration of vehicles increases the level of emissions, so redesigning traffic rules could render even more useful than cutting the poor trees off the streets.
Now, a study is a study, it’s probably been made with scientific data, gathered and analyzed over a longer period of time. However, I guess anyone can relate to the fact that in winter, when trees have no leaves, you can barely breathe in highly congested areas, while the same thing doesn’t happen in spring or summer, when there’s plenty of leaves and green vegetation around.
I don’t really know how valid the conclusions of this study are, but wind plays a big part of this phenomenon. Wind doesn’t blow from one direction only, and doesn’t always have the same speed, so the debate can go on and on, before anyone can cut those trees with 100% certainty that they’re doing a good thing.
Meanwhile, instead of funding all sorts of studies and redesigning traffic and so on (this is all expensive stuff), governments could incentivize the use of electric cars, which don’t pollute the air at all.
[via iflscience]
