Despite progress in many areas of the world, Asia, Europe, and the Middle East are still plagued by bad air pollution.
Scientists from Lancaster University measured how much pollution enters homes in the Lancaster area. They used dust monitoring devices and swiped surfaces and then analyzed the collected samples with magnetic romance.
The scientists placed a screen of 30 silver birch trees in planters in front of four of the homes, including one of the control houses, for 13 days. Samples from all eight houses showed that ones with the tree screens had between 52 to 65% lower concentrations of metallic particles.
A dust monitoring data comparison from the two original control houses confirmed that drop, showing a 50% reduction in PM1, PM2.5, and PM10 in the house with trees in the front yard.
The hairy surfaces of the birch leaves trapped metallic particles, which were most likely the result of brake wear and combustion from passing vehicles.
There is a strong association between the amount of material identified by magnetic remanence and benzo(a)pyrene, a carcinogenic polycyclic aromatic hydrocarbon found in particulates.