Pollution is contamination of land, air and water. Motor vehicles are in abundance in big cities as well as there are numerous factories and industries also. Motor vehicles emit carbon monoxide and hydrocarbons. The factories contaminate air by smoke. Noise of factories results in sound pollution and waste of factories pollutes water and land. Delhi is third most polluted city in the world. Pollution here is three times the permissible limit. It may be nine times in eight years if some efforts are not made. Plastic is another big nuisance causing pollution. It never decays. If we burn it. It pollutes air. If we dump it into river or sea it pollutes water. Chemical fertilizers used by farmers are another source of pollution to land and water. In order to check pollution the polluted water from factories should be treated before it is disposed of in rivers. Plastic and other material should be recycled. New techniques should be adopted in motor vehicles. These measures can solve the problem of pollution.