India's capital, Delhi, may have surpassed Beijing to become the city with the worst air pollution in the world.
In "Delhi world's most polluted city: Study" published Jan. 29, Hindustan Times, one of India's highest circulated daily newspapers, cited the latest Environmental Performance Index (EPI) report by U.S.-based Yale and Columbia universities to substantiate claims of India overtaking China in the hierarchal list of cities with the worst air pollution. Delhi and Beijing were followed by Cairo, Santiago and Mexico City.
"The study described India's air pollution as the worst in the world, tying with China in terms of the proportion of population exposed to average air pollution levels exceeding World Health Organisation (WHO) thresholds," the article read.
EPI project director Angel Hsu of the Yale Center for Environmental Law and Policy, however, said that the EPI research does not compare cities and focuses only on nationwide pollution.
"The EPI does not rank cities, nor do the data in the EPI provide any information on city-level performance," Hsu said. "Beijing reports [pollution] data on an hourly basis over a publicly accessible platform. Delhi's reporting is not as consistent or transparent, making direct comparison impossible. Delhi may or may not have dirtier air than Beijing, but it is clearly behind in how it makes air quality information available to its citizens."
Although the air quality comparison between Beijing and Delhi is speculative, it is undeniable that Delhi has pollution problems. Research from India's Center for Science and Environment (CSE) showed that Delhi's PM 2.5, which refers to the toxic pollutants that can enter a person's lungs and cause severe health problems such as lung cancer, has hit 575 micrograms per cubic meter while the permissible limit is only 60 m/cum.
"While it is true that a comparison doesn't take into account the unique issues facing the two cities, it also remains true that Delhi has been very lackadaisical in its attitude towards air pollution," Anumita Roychowdhury of CSE said. "China has been much more stringent and it shows, their air pollution levels are lowering while ours are rising."
