Pollutants are transient in air. The length of time before removal is dependent on the pollutant and the local conditions. They are removed by a number of processes:
well dust can stay up in the air fof a few months blocking certain objects.
from dj swarp
2 years tops
Until it settles
it started in 1931 and lasted for a decadeit was a storm
210 days
The dust bowls lasted 9 whole years
Although uncommon, it happens, and it can last anywhere from a few seconds to a few years. There is a storm on Jupiter has lasted 300 years. So, it can happen for unknown periods of time.
You can never tell how long a thunder storm will last but you can tell how far away it is by waiting for thunder the count till you see lightning.
1 to 2 hrs
it started in 1931 and lasted for a decadeit was a storm
can last a day
A dust storm is a strong and violent wind that carries silt, clay, dust, and other particles that can travel in the air for long distances.
In most cases, no. A tornado depends on its parent thunderstorm as a source of energy. If the storm weakens too much, the tornado will dissipate. A typical tornado lasts less than 5 minutes. A typical thunderstorm lasts 20 to 30 minutes. That said, the storms that produce tornadoes usually last longer than a typical thunderstorms, in some cases several hours. As a result, some long-lived tornadoes do last longer than a typical, non-tornadic storm.
it depends on the natural metrological forces in place at the time of the storm. They can last minutes to hours
a couple of days
210 days
40 weeks from the last period.
Accupuncture is a great alternative treatment. The typical session will last 45 minutes.
not yet answered
until you can hear it