24

2022

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04

What is environmental hypoxia, and what concentration does it take to achieve hypoxia

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Under normal conditions, the oxygen content in the ambient atmosphere is 20.9%. If you are in an environment with an oxygen content lower than 18%, the oxygen intake of the human body is insufficient, the partial pressure of oxygen in the blood is too low, and the hemoglobin is in an unsaturated state, and cells in various parts of the tissue will appear due to insufficient oxygen supply. changes, showing corresponding hypoxia symptoms.

When the oxygen concentration in the ambient atmosphere drops to 16-14% (oxygen partial pressure 122-106 mmHg), the breathing is deepened and accelerated, the pulse is strengthened and accelerated, the blood pressure rises, and the movement coordination function of the limbs becomes poor.

When the oxygen concentration in the ambient atmosphere drops to 14~10% (oxygen partial pressure I06~76mmHg), you will feel fatigue, mental movement disorder, loss of concentration, and disordered thinking, just like being drunk, and then you will lose your direction and lose consciousness. .

When the oxygen concentration in the ambient atmosphere drops to 10-6% (oxygen partial pressure 76-46 mmHg), headache, tinnitus, vertigo, nausea, vomiting and purple group appear, the whole body is feverish, and the ability to move and speak is lost, and soon loses Conscious, fell into a coma.

When the oxygen concentration in the ambient atmosphere drops below 6% (oxygen partial pressure below 46mmHs), the blood pressure drops, the heartbeat is weak, convulsions, mouth breathing, soon stops breathing, and enters a state of death.

However, there is considerable variation in how well individuals tolerate and respond to hypoxia. Especially people who are labor-intensive or suffering from diseases such as hyperthyroidism are more sensitive to hypoxia. In a severe hypoxic environment, sometimes there is no obvious aura symptoms and sudden coma. People who enter a severely hypoxic environment without preparation are often unable to escape or even die when they realize that they have difficulty breathing.

Patients with mild environmental hypoxia can quickly return to normal after being transferred to a normal oxygen supply environment in time or obtaining supplemental oxygen in time. If the hypoxia lasts for a long time, it may cause pathological changes such as cerebral edema, with varying degrees of headache, nausea, vomiting, hallucinations, apathy or excitement and other continuation symptoms. In severe cases, it may cause permanent lesions such as the cerebral cortex and basal ganglia, resulting in paralysis, memory loss or loss of consciousness.

Environmental hypoxia mostly occurs in dense spaces, such as cellars, basements, septic tanks, greenhouses, cold storages, culverts, pumping stations, culverts, underground pipes, storage tanks, reaction towers, ship cabins, etc. Hypoxia occurs in these places, mainly because the oxygen in the air is consumed without being replenished or renewed. Rusting of metal equipment placed in confined spaces will consume oxygen, and stored agricultural products will consume oxygen. In addition, the leakage of the gas pipeline and the generation of biogas will replace the original oxygen in the confined space.

There should be a clear awareness of environmental hypoxia. Be sure to test before entering a confined space. When it is necessary to enter an oxygen-deficient space, the necessary oxygen supply equipment or breathing apparatus directly connected to the outside fresh air should be provided. Filtering breathing masks will not solve the lack of oxygen, nor will covering the mouth and nose with a wet towel. (Shaanxi Feint Instrument Technology Co., Ltd., Li Jie: 13619214418)

Generally speaking, any environment with an oxygen content below 20.9% is an oxygen-deficient environment. Even in a mildly hypoxic environment, living and working in it for a long time will cause varying degrees of damage to lifelong health. For example, if you live and work in an air-conditioned room for a long time in the hot season, give birth and work in a poorly ventilated room for a long time in the cold season, and "confinement" in a densely wooded and ventilated room, the mother will appear pale, lose appetite, and have headaches. Symptoms of chronic environmental hypoxia such as dizziness, dizziness, memory loss, etc., if not corrected by supplementary oxygen supply measures, will have adverse effects on the whole body health, and will cause lesions to the heart, brain, kidney, liver and other organs over time.