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18.1 Air Pollution. We can survive for some time without food, but we cannot survive even for a few minutes without air. This simple fact tells us how important clean air is to us. You already know that air consists of a mixture of gases. By volume, about 78% of this mixture is nitrogen and about 21% is oxygen.
Air pollution is the contamination of air by various hazardous substances that have a harmful impact on the environment. Explore its causes, types of pollutants, effects and control measures.
Air pollutants cause injury to all living organisms. They reduce growth and yield of crops and cause premature death of plants. Air pollutants also deleteriously affect the respiratory system of humans and of animals. Harmful effects depend on the concentration of pollutants, duration of exposure and the organism.
•••• define atmospheric pollution, list reasons for global warming. green house effect and acid rain; ••• identify causes for ozone layer depletion and its effects; ••• give reasons for water pollution and know about international standards for drinking water; ••• describe causes of soil pollution;
Class 9 Environmental Studies NCERT Book Pdf. We have provided below the latest CBSE NCERT Book for Class 9 Environmental Studies which can be downloaded by you for free. These free subject-wise NCERT textbook have been designed based on the latest CBSE Syllabus issued for current academic year.
National Council of Educational Research and Training (NCERT) has now decided to bring out project books for students of Classes VI to X. The books comprising this series attempt to build capacity for critical and multi-disciplinary thinking and a positive and problem-solving attitude. They aim at exposing students to the real-life
5 ημέρες πριν · Air pollution - Air pollution is the contamination of the air with chemicals, smoke, dust particles, and disease-causing agents. When fossil fuels are burned, distinct nitrogen and sulphur oxides are produced, which dissolve in rain and cause acid rain.
