ZHENGZHOU - A Chinese environmental volunteer is suing the capital city of central China's Henan Province for his "suffering" in smog, demanding compensation of the cost of masks he bought.

Sun Hongbin, 25, is accusing the government of Zhengzhou City of being slow to combat smog, forcing him and his colleagues to buy masks at a cost of 32 yuan (4.65 U.S. dollars) each during a trip to the city in late November.

The Intermediate People's Court of Xinxiang in Henan has accepted the case, as the law stipulates that administrative cases must be handled elsewhere. The court has given notification of the lawsuit to the Zhengzhou government.

"The air smelt bad, but many citizens were not wearing masks," said Sun, an employee of "Clean air guardian", an environmental protection NGO, as he recalled his Nov. 20 visit.

The air quality index in the city that day was 253 -- "serious" pollution -- so he and his colleagues bought masks.

Sun said his appeal is based on environmental laws that make the local government responsible for air quality. "If Zhengzhou had not been so inactive in dealing with the smog, we would not have had to buy the masks and would not suffered damage to our health," he said.

He said while other smoggy parts of China have made progress in cleaning the air, the situation in Henan in general and Zhengzhou in particular remains severe.

In the first half of 2016, Henan ranked second highest in densities of both PM10 and PM2.5. During the same period, the air quality of Zhengzhou was the third worst of 74 major Chinese cities. It was 10th worst in 2013.

Sun said he lodged the lawsuit to prompt Zhengzhou to address the issue in the hope it will compensate citizens.