Pollution of the Realms

Pollution of the Realms, abbreviated PotR, is a mod in Elysia: A World Reshapen which adds pollutant gasses (carbon dioxide and sulphur) which are emitted from machines from other mods, such as Immersive Engineering. It is advised that you install a filter on top of a machine to reduce the pollution generated.
If there is too much pollution in the sky, you will feel side effects like hunger, weakness, and mining fatigue, and, if too much is in a confined space, it will explode. You will also experience the effects if you walk directly into a carbon dioxide or sulphur block. You can temporarily avert the pollution with a Gas Mask or remove it with a filter and a pump.

Pollution generation

Pollution is generated by the use of Immersive Engineering (and add-on) machines or the Tinkers' Construct smeltery (forging tools does not pollute).
When used in the open, pollution naturally floats upwards.
Emissions come in two types: carbon dioxide and sulphur. Both are partially transparent, however, carbon dioxide is dark grey, whereas sulphur is yellow. Although the effects of sulphur are more severe, it is less common than carbon dioxide emissions.
Emissions can be reduced by installing a filter directly above production.

Removing pollution

Pollution can be removed from confined spaces with vents, pumps, and chimneys.

            Up to sky   
                c        v - Vent
                c        P - Pump
vvvvvvvvvvvvvvvvPr       c - Chimney
                         x - Machine
xxxxxxxxxxxxxxxxx        r - Active redstone input     

Using the layout above, you can remove pollutant gasses from indoor spaces.

To destroy pollution, you need a filter. There are different filter levels, being, in order from worst to best, iron, gold, diamond, and infinite, with each being able to filter more.
To filter carbon dioxide, you need vanilla Minecraft leaves (of any type), and to filter sulphur, you need wool (of any colour).
Pollution from the air can be sucked up with a pump and filtered at ground level.
Filters only work if pollution directly goes into it. It does not "suck up" pollution.