China saw an overall sharp reduction in emissions of heavy metals in 2014, but levels are still high due to the rapid growth of heavy metal industries, the national environmental watchdog said on Thursday.

Total emissions of five major heavy metal pollutants fell by 20.8 percent between 2007 and 2014, said the Ministry of Environmental Protection, which released the annual assessment on the governments' performance. In 2013, the ministry reported a 10 percent emissions reduction over 2007.

The five major heavy metal pollutants are lead, mercury, cadmium, chromium and arsenic metal.

Tianjin and Zhejiang province ranked the best in the annual assessment. Five cities were financially penalized for ineffective emission controls.

Among the major pollution-control projects identified in the 12th Five-Year Plan period (2011-2015), nearly three-quarters of them have been completed, the ministry said.

But it said heavy metal contamination of soil and underground water has remained a thorny problem, and the growth in the heavy metal industry poses an ongoing contaminations risk.

Regions that have experienced increases in emissions include the cities of Chenzhou, Loudi, Yueyag city in Hunan province, Yantai city of Shandong province and Liangzhou city in Gansu province. The ministry will cut special funds allocated to support those cities' efforts to control heavy metals pollution. The central government had allocated 2.8 billion yuan ($439 million) overall for such efforts in 2015.

Some regions, including Hebei, Fujian, Sichuan, Shaanxi provinces and Inner Mongolia autonomous region, also have faced difficulties in controlling new industrial projects that emit heavy metals, the ministry said.

The ministry said any provinces lagging behind their pollution goals will be pushed to conduct a thorough assessment next year and take the necessary steps to reduce heavy metal emissions.