Most polluted city in the world, Delhi, a toxic pollutant punchbowl, says UK study - Delhi, the world's most polluted city, suffers from a toxic blend of geography, poor energy sources and unfavorable weather that boosts its high levels of air pollution, scientists, including one of Indian-origin, have found.

A team of scientists led by the University of Surrey, UK, evaluated how Delhi's growing urban population, landscape, energy consumption and weather combines to raise concentrations of air pollutants, including ultra-fine particles, the most harmful to human health.

According to the scientists, classified as the world's fifth 'megacity,' Delhi has a population of 25.8 million, which continues to grow. With this growth, the number of road vehicles would increase from 4.7 million in 2010 to nearly 26 million by 2030. Moreover, the total energy consumption in the national capital has risen 57 per cent from 2001 to 2011.

Delhi has limited sources to flush polluted air out of the city. Coastal megacities such as Mumbai have at least a chance to replace polluted air with relatively unpolluted sea breezes, whereas Delhi's surrounding areas are sometimes even more polluted than the city, according to the report.

Dr. Prashant Kumar of the University of Surrey said that Delhi's pollution problem is aggravated by some factors that are out of human control. Therefore, it is essential that the population is protected in whatever ways they can be from health-endangering pollutants.

The study has been published in the journal Atmospheric Environment.