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. Classes. Class 1 - 3; Class 4 - 5; Class 6 - 10; Class 11 - 12; COMPETITIVE EXAMS. CBSE. NCERT Books. NCERT Books for Class 5; NCERT Books Class 6; NCERT Books for Class 7; NCERT Books for Class 8; NCERT.