BEIJING, May 19 -- Air pollution is still public enemy number one in China's fight for green living, according to the country's environmental watchdog.

Among 1,463 complaints received by the Ministry of Environmental Protection in 2014, 78 percent were related to air quality, a 5-percent year-on-year increase, according to a ministry statement on Tuesday.

All the complaints were lodged through the telephone hotline "12369." Other major reasons for complaints were water and noise pollution.

The ministry said they handled all complaints and discovered 78 percent involved illegal activities.

Violators responsible received punishment ranging from warnings to suspension, closure, fines or were handled by law enforcement.

Central and eastern China regions still drew the highest number of complaints, with Henan, Shandong, Jiangsu, Hubei and Guangdong accounting for 43 percent of the total.

The ministry noted that complaints from Hebei, a major steel producer in north China, registered a 72 percent decline thanks in part to coordinated pollution control measures in the Beijing-Tianjin-Hebei region.