Among the substances metabolized by industrial activities, fossil fuels are most significant, both in quantity and by the variety of chemicals that are mobilized.
Industrial consumers take fuels as inputs and exhaust residue products to air, land, and water.
Sulfur and nitrogen compounds are major fossil fuel residues that are released primarily to air and subsequently deposited to land and water bodies. The elements redistributed by industrial metabolism of fossil fuels are carbon, sulfur, nitrogen, as well as crustal and trace metals. In fact, these are the main chemicals of which living matter is composed of. As such, they are the key nutrients for the plants on earth. However, these substances may be either beneficial or harmful to the receiving ecosystem depending on their quantity, rate, and their chemical form.