Environmental Protection Agency (EPA) MVAC Certification

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Prepare for the EPA MVAC Certification Exam. Study using comprehensive quizzes with multiple choice questions, hints, and explanations. Boost your knowledge and confidence for success!

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Approximately what percentage of the available ozone is found in the stratosphere?

50%
70%
90%
100%

The correct answer is: 90%

The stratosphere contains approximately 90% of the Earth's ozone. This layer of ozone, commonly referred to as the ozone layer, is crucial for life on Earth because it absorbs the majority of the sun's harmful ultraviolet (UV) radiation. The concentration of ozone in the stratosphere is significantly higher than in other parts of the atmosphere, such as the troposphere where most weather occurs and where only a small fraction of the total atmospheric ozone is found. The existence of such a high concentration of ozone in the stratosphere is essential for protecting living organisms. Without this protective layer, increased levels of UV radiation would penetrate the Earth's surface, potentially leading to higher rates of skin cancer, cataracts, and other detrimental effects on both human health and the environment. Therefore, it's important to recognize the significant role that the stratospheric ozone plays in maintaining ecological balance and protecting life on our planet.