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 value" is 40 μg /m. On March 2015, Brussels took the United Kingdom into court for breaching emissions limits of nitrogen dioxide at its coal-fired Aberthaw power stations in Wales. The plant operated under a permit allowing emissions of 0.0012 μg/m, which is more than twice the 0.000 5μg /m limit specified in the EU’s large combustion plant directive. Generally, long-term prognosis is helpful to survival of initial exposure to nitrogen dioxide. Some cases of nitrogen dioxide poisoning resolves with no observable symptoms and patient may be determined by pulmonary function testing. If chronic exposure causes lung damage, it could