He wedged himself into a dark cranny in the misshapen rocks, where at least none of the acidic rain could penetrate.

These pollutants are changed chemically when carried through the atmosphere and fall to earth as acidic rain, snow, fog or dust.

The lower the number, the more acidic the rain.

There is also a slightly acidic rain that falls at very regular intervals and the group is careful to not to get wet.

These oxides are changed chemically in the atmosphere and fall to earth as acidic rain, snow, fog or dust.

Such emissions change chemically and return to earth as acidic rain, snow or particles.

After becoming exposed on land, the limestone was dissolved by acidic rain and underground water.

Though acidic rain was discovered in 1853, it was not until the late 1960s that scientists began widely observing and studying the phenomenon.

In addition, humans would not require pressurized suits when outside, merely air to breathe and a protection from the acidic rain.

Once released into the atmosphere, the emissions are carried long distances by the wind and return to earth as acidic rain, snow, fog or dust.