Does rain clean the air?
The rainy season is here! It is cooler during this season and some feels the air is fresher. Is it true that the rain cleans the air?
Rain “cleans” the air because the rain gathers pollution particles as it falls to earth – effectively washing the air. It also appears to clear the air as well because rain clouds usually make it difficult for the correct amount of temperature and sunlight to be available for ozone formation. You’ve probably noticed how much cleaner and fresher the air is after a heavy downpour.
The rain is moving the dust and pollution from one place to another but it does not mean the air is cleaner and healthier. Rain can remove particulates and soluble gases from the atmosphere. It can also moisten soils so that not as much dust gets blown into the atmosphere and extinguish grass and forest fires to prevent smoke emissions.
Rain is just a temporal natural cleaning for air polluted places. As for how long before the pollution builds back up again – several factors come into play here. On a hot, calm day pollution builds up quickly. If there’s a breeze blowing the pollutants are more readily dispersed and carried away. If it’s colder the pollutants tend not to ‘hang’ in the air.