Oxygen began entering Earth's oceans around 2.32 billion years ago, and shallow seas followed within a few million years.

Slow orbital changes caused pulses in Earth's oxygen cycle 500 million years ago, which spurred explosions of animal life.

For roughly 2 billion years of Earth's early history, the atmosphere contained no oxygen, the essential ingredient required ...

An aerial view of a river surrounded by trees (Brian Beckwith/Unsplash via Courthouse News) (CN) — Inland waters like rivers, lakes, streams and reservoirs need oxygen to survive, just like we do, but ...

Oxygen levels in the Earth's atmosphere are likely to have 'fluctuated wildly' one billion years ago, creating conditions that could have accelerated?the development of early animal life, according to ...

A New Hampshire emergency room doctor says simple technology could save lives in the fight against the coronavirus. Dr. Richard Levitan, who has three decades of experience, volunteered last month at ...

Hypoxia refers to low oxygen levels in waters near the sea floor, making affected areas uninhabitable for fish and other ...

In hospitals around the world, doctors are shaking their heads in disbelief as they watch Covid-19 patients who should be comatose or "seizing" from hypoxia -- a lack of oxygen in the body's tissues - ...

A doctor has disproved the myth that face masks or coverings lower oxygen levels in a viral video posted to Twitter. Maitiu O Tuathail, a doctor in Dublin, posted the video and said: "Getting asked ...

Oxygen saturation is a measure of the amount of hemoglobin that is bound to molecular oxygen at a given time point. It is an important parameter for managing patients in a clinical setup. Oxygen ...

FILE - A health worker uses a pulse oximeter to check the oxygen saturation level of another after administering COVID-19 vaccine at a hospital in Gauhati, India, Jan. 21, 2021. (AP Photo/Anupam Nath, ...