The benefits of trees in the urban landscape
by Chris, 11 November, 2016, 3 comments
Each day, our cities are exposed to pollution from cars, power stations, industry etc. All of these release particulate matter (aka particulates) and various gases - such as carbon dioxide, carbon monoxide, sulphur dioxide, and nitrogen oxides. The pollutants in many of our city streets frequently exceed the World Health Organisation (WHO) guidelines.
Particulate matter is the sum of all solid and liquid particles suspended in air - it may include dust, pollen, soot, smoke and various liquid droplets. These particulates are often divided into
PM10 particles - that have a diameter of 10 micrometers or less, are inhalable and may pass into the lungs and then the bloodstream. And,
PM2.5 particles have a diameter of less than 2.5 micrometers - these are very fine and often contribute to the haze in the air.
Many particles form as a result of complex reactions between sulphur dioxide and nitrogen oxides.
Read more...
