At what oxygen concentration do people generally experience impaired judgment and coordination?

At what oxygen concentration do people generally experience impaired judgment and coordination?

• A. 12%
• B. 21%
• C. 17%
• D. 15%

Answer: (C)

When oxygen levels fall from normal atmospheric air, brain function begins to suffer and judgment and coordination become noticeably impaired. Normal air is about 21% oxygen, so at around 17% oxygen the brain starts to show measurable declines in thinking clearly and coordinating movements. That mid-teens range is where the impairment first becomes evident, which is why it’s the best choice. Lower levels, like 15% or 12%, lead to more severe effects, while 21% is normal and shows no impairment.

When oxygen levels fall from normal atmospheric air, brain function begins to suffer and judgment and coordination become noticeably impaired. Normal air is about 21% oxygen, so at around 17% oxygen the brain starts to show measurable declines in thinking clearly and coordinating movements. That mid-teens range is where the impairment first becomes evident, which is why it’s the best choice. Lower levels, like 15% or 12%, lead to more severe effects, while 21% is normal and shows no impairment.