Chinese health authorities are trying to figure out the reason for the rapid rise in a form of lung cancer that develops deep in the lungs and is not associated with smoking. China has seen a sharp increase in the disease over the past 10 to 15 years, hitting groups traditionally not susceptible, such as women and non-smokers, said Xue Qi, Deputy Director of thoracic surgery at the Cancer Hospital of the Chinese Academy of Medical Sciences. “It might be related to the longterm exposure to air pollution, particularly PM2.5,” he said. China’s top health authority has been watching people’s health in relation to air pollution since 2013, said Mao Qun’an, Spokesman for the National Health and Family Planning Commission. “We need more research over a longer time to figure out the longterm health effects of air pollution,” he said. “Cancer is developed over a long period, not overnight.” Latest cancer statistics from the government showed China recorded nearly 4.3 million new cancer patients in 2015, and more than 730,000 of them had lung cancer, accounting for nearly 36% of the world’s total, the China Daily reports.