An unidentified 8-year-old girl in China has become the country’s youngest lung cancer patient, according to China’s Xinhua News Agency. Doctors from the Jiangsu Cancer Hospital say toxic air pollution, known as smog, is the primary cause of the young girl’s life-threatening condition.

Dr. Jie Fengdong from the hospital located in Nanjing told the Xinhua agency that the girl has lived along a busy road in the eastern province of Jiangsu for most of her life. During this time, she most likely inhaled a hazardous amount of particles including dust and coal smoke, Agence France-Presse reports.

The environmental impact of air pollutants in China came to a head last month when the city of Harbin, the capital of northeast Heilongjiang province, was shut down due to dangerous smog levels. Schools were closed, highways were clogged, and airports were shut down in a city that’s home to 11 million people.

According to a recent World Health Organization (WHO) report, outdoor air pollution has been classified as a carcinogen that can cause cancer, among other major health risks. The WHO attributed a significant rise in smog exposure levels to industrialized countries with large populations. Sources of air pollution include transportation, stationary power generation, industrial and agricultural emissions, and residential heating and cooking.

“There are effective ways to reduce air pollution,” said Dr. Christopher Wild, director of the WHO’s International Agency for Research on Cancer. “And, given the scale of the exposure affecting people worldwide, this report should send a strong signal to the international community to take action without further delay.”

Out of the 7.6 million cancer-related deaths in 2008, according to the WHO, 1.37 million were attributed to lung cancer. The amount of lung cancer deaths in China is four times higher than what it was 30 years ago, China’s Ministry of Health announced in a 2008 report. Lung cancer surpassed liver cancer with the most deaths linked to malignant tumors after an increase of 465 percent.