Downplaying Greenpeace India's recent report which said India overtook China's air pollution levels in 2015, the Centre today said the study was based on "extrapolated and constructed" data "without" field validation.

"Greenpeace India published a report titled 'Clean Air Action Plan: The Way Forward' in February 2016. The report... is on the basis of NASA satellite data which is based on extrapolated and constructed data without field validation," Environment Minister Prakash Javadekar said in a written reply in Lok Sabha.

Greenpeace's analysis said India had overtaken China's air pollution levels in 2015 and its average particulate matter exposure was higher for the first time in the 21st century. "China's strong measures to curb pollution have contributed to the biggest year-on-year air quality improvement on record while in contrast, India's pollution levels continued a decade-long increase to reach the highest level on record," it had said.

Javadekar said ambient air quality is monitored regularly in 254 cities and towns by the Central Pollution Control Board, Pollution Control Committees and others.Analysis of these data indicates fluctuating trends on the basis of individual pollutants in ambient air.