Weathering release occurs of Ca and other ions into surface waters. Rainfall is acidic because atmospheric carbon dioxide dissolves in the rainwater producing weak carbonic acid. In unpolluted environments, the rainfall pH is around 5.6. Acid rain occurs when gases such as sulfur dioxide and nitrogen oxides are present in the atmosphere. These oxides react in the rain water to produce stronger acids and can lower the pH to 4.5 or even 3.0. Sulfur dioxide, SO, comes from volcanic eruptions or from fossil fuels, can become sulfuric acid within rainwater, which can cause solution weathering to the rocks on which it
Nitrogen dioxide poisoning glutathione reductase, an enzyme that catalyzes the reduction of glutathione disulfide (GSSG) to the sulfhydryl form glutathione (GSH), which is a critical molecule in resisting "oxidative stress" and maintaining the reducing environment of the cell. Exposure to nitrogen dioxide has a significant effect on the male reproductive system by inhibiting the production of Sertoli cell, a "nurse" cell of the testicles that is part of a seminiferous tubule and helps in the process of spermatogenesis. These effects consequently retard the production of sperm cell. The effects of nitrogen dioxide poisoning of female reproduction may be linked with the effects of