China's top legislature called on Monday for strengthened air pollution control measures in key sectors as it concluded inspections on the implementation of the Air Pollution Control Law and found the law is not adequately applied in some areas.

The legislature's inspections in eight provincial regions, including Henan, Shandong and Jiangsu provinces, found many local governments failed to implement measures as required by the law to control air pollutants from bulk coal consumption, straw burning, construction sites, mines and motor vehicles, top legislator Li Zhanshu told a session of the Standing Committee of the National People's Congress on Monday.

Bulk coal is a major contributor to smog in northern China during the winter. Li said more than 200 million metric tons of bulk coal is consumed in the region as a heating source each winter. Calculations by authorities show that air pollutants from a ton of bulk coal used for heating equals that of 10 to 15 tons of coal used in power generation.

The Air Pollution Control Law stipulates that governments of all levels should take measures to strengthen bulk coal management. Some local governments in Shanxi and Shaanxi provinces, however, were found to have made slow progress in replacing the polluting energy with clean ones, Li said.

More than 20 million tons of bulk coal is consumed every year in the Guanzhong region of Shaanxi, home to five cities including the province's capital Xi'an. Bulk coal is still widely used in old communities in urban areas, shantytowns and rural areas in the region. Local governments fail to carry out control measures "effectively", the legislator said.

Another major problem legislators found is that some local governments haven't made sufficient efforts in supervising fuel quality and controlling pollution from motor vehicles. Motor vehicles have taken a larger share as a source of pollution as many areas have shifted to cleaner fuels for energy and heating.

There are special clauses on pollution control with motor vehicles and fuel quality supervision, but it's common to see diesel trucks with substandard pollution control measures or even no such measures at all, Li told the session.

Some of the local authorities have inadequate capability in vehicle supervision and some fail to fulfill their duties in the supervision work. Vehicle testing institutes in some areas falsify testing results, noted Li.

There also are gaps in the supervision of fuel manufacturing and circulation in some regions. While there are unlicensed enterprises manufacturing fuel illegally, no government departments in these regions is in charge of supervising the diesel in the market, Li said.

Some enterprises are also blamed for failure in implementing pollution control measures as required by the law.

The law stipulates that enterprises in steel, construction materials, petroleum and chemical industries should resort to clean technologies in production and equip pollution control facilities.