The special report on 'global exposure to air pollution and its disease burden', released on Tuesday, noted that the number of premature deaths in China caused by dangerous fine particulate matter, known as PM2.5, has stabilised in recent years but has risen sharply in India.

It also said that both the countries together were responsible for over half of the total global attributable deaths while India had registered an alarming increase of nearly 50% in premature deaths from particulate matter between 1990 and 2015.

Besides data analysis on air pollution, the report also carries an interactive website on the issue highlighting that 92% of the world's population lives in the areas with unhealthy air.

"We are seeing increasing air pollution problems worldwide, and this new report and website details why that air pollution is a major contributor to early death," said Dan Greenbaum, President of the Health Effects Institute (HEI), the global research institute that designed and implemented the study.

He said, "The trends we report show that we have seen progress in some parts of the world - but serious challenges remain."

The State of Global Air 2017 is the first of a new series of annual reports and accompanying interactive website, designed and implemented by the Health Effects Institute in cooperation with the Institute of Health Metrics and Evaluation (IHME) at the University of Washington and the University of British Columbia.

The IHME is an independent population health research center that publishes the annual Global Burden of Diseases -- a systematic scientific effort to quantify the magnitude of health loss from all major diseases, injuries, and risk factors in populations across the world. Its results are published every year in The Lancet medical journal.

"Although there are many parts of the world where air pollution has grown worse, there has also been improvement in the US and Europe. The US Clean Air Act and actions by the European Commission have made substantial progress in reducing people exposed to PM pollution since 1990," said a statement issued by the HEI.

Referring to the study, it said, "The US has experienced a reduction of about 27% in average annual population exposures to fine particulate matter with smaller declines in Europe. Yet some 88,000 Americans and 258,000 Europeans still face increased risks of dying early due to PM levels today".

The report noted that the highest concentrations of combustion-related fine particulate matter were in South and Southeast Asia, China and Central and Western Sub-Saharan Africa in 2015 where household solid fuel use, coal-fired power plants, transportation, and open burning of agricultural and other wastes were among the most important contributors to outdoor air pollution.

"The Global Burden of Disease leads a growing worldwide consensus - among the WHO, World Bank, International Energy Agency and others - that air pollution poses a major global public health challenges," said Bob O'Keefe, Vice President of HEI and Chair of Clean Air Asia.

He said, "Nowhere is that risk more evident than in the rapidly growing economies of Asia."

The study finds that increasing exposure and a growing and aging population have meant that India now rivals China for among the highest air pollution health burdens in the world, with both countries facing some 1.1 million early deaths from air pollution in 2015.

It said the long-term exposure to fine particulate matter -- the most significant element of air pollution -- contributed to 4.2 million premature deaths and to a loss of 103 million healthy years of life in 2015, making air pollution the 5th highest cause of death among all health risks, including smoking, diet, and high blood pressure.

India has, however, always been sceptical of such reports. Though the government here did never deny the negative impact of air pollution on human healths, it preferred not to speak about numbers.

Even recently during Budget session of the Parliament, the government had on February 6 said that there was no conclusive data to link deaths exclusively with air pollution. It, however, admitted that the air pollution could be one of the triggering factors for respiratory ailments and diseases.

"There is no conclusive data available in the country to establish direct co-relationship of death exclusively with air pollution. Health effects of air pollution are synergistic manifestation of factors which include food habits, occupational habits, socio-economic status, medical history, immunity, heredity etc. of the individuals," said the country's environment minister Anil Madhav Dave.

Dave, in his written response to a Parliament question in Rajya Sabha, had said, "Air pollution could be one of the triggering factors for respiratory associated ailments and diseases."