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Thus, at the upper thermosphere, where air density is very low and photon flux is high, oxygen photodissociation is fast while ozone creation is low, thus its concentration is low. Thus the most important reactions are oxygen photodissociation and oxygen recombination, with most of the oxygen molecules dissociated to oxygen atoms.
Tissue hypoxia refers to low levels of oxygen in the tissues of the body and the term hypoxia is a general term for low levels of oxygen. [2] Hypoxemia is usually caused by pulmonary disease whereas tissue oxygenation requires additionally adequate circulation of blood and perfusion of tissue to meet metabolic demands.
Ground-level ozone (O 3), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas.
A study of 450,000 people living in U.S. cities saw a significant correlation between ozone levels and respiratory illness over the 18-year follow-up period. The study revealed that people living in cities with high ozone levels, such as Houston or Los Angeles, had an over 30% increased risk of dying from lung disease. [107] [108]
Many organisms require hypoxic conditions. Oxygen is poisonous to anaerobic bacteria for example. [3] Oxygen depletion is typically expressed as a percentage of the oxygen that would dissolve in the water at the prevailing temperature and salinity. A system with low concentration—in the range between 1 and 30% saturation—is called hypoxic ...
In the oxygen-rich capillaries of the lung, this property causes the displacement of carbon dioxide to plasma as low-oxygen blood enters the alveolus and is vital for alveolar gas exchange. The general equation for the Haldane Effect is: H + + HbO 2 ⇌ H + Hb + O 2; However, this equation is confusing as it reflects primarily the Bohr effect.
The yield of ozone will therefore be greatest during the day, especially at noon and during the summer season. This relationship also demonstrates how high concentrations of both ozone and nitric oxide are unfeasible. [4] However, NO can react with peroxyl radicals to produce NO 2 without loss of ozone: RO 2 + NO → NO 2 + RO
The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal arterial blood oxygen saturation levels in humans are 96–100 percent. [1] If the level is below 90 percent, it is considered low and called hypoxemia. [2] Arterial blood oxygen levels below 80 percent may compromise organ function, such as ...