Environmental controls aimed at curbing vast swathes of toxic smog that choke northern China each winter are failing, official media reported, amid warnings of heavy smog that were issued on Friday.
Environmental protection officials are warning cities in the region to prepare for "unfavorable" weather conditions that could lead to worse-than-usual toxic air pollution.
The meteorological bureau issued severe smog warnings on Friday for Beijing, Tianjin, and southern Hebei and central Henan, as well as the southwestern province of Sichuan.
Northern Shanxi province and Heilongjiang in the northeast were issued with moderate smog warnings, with severe smog in some areas.
A resident of Heilongjiang told RFA on Friday that the air pollution was thick enough to burn people's throats.
"Looking outside, I can see curls and clouds of smoke and fog, and my throat hurts, probably from the air pollution," the resident said. "There's not much I can do about that."
"I reckon visibility is down to five or six meters; beyond that you can't see much. You can see that there's a person, but not who it is," the resident said.
"It's very thick smog. It happens every year when there's low pressure."
The U.S. embassy in Beijing, which issues unofficial air pollution readings via Twitter, said pollution levels in the city were at "Hazardous" levels on Friday, with PM2.5 particulates at 259 per cubic meter, more than 10 times World Health Organization (WHO) guidelines.
Environmental activist Wu Lihong said enforcement is always the biggest obstacle to tackling the problem in China.
"The main problem is that heavy industry isn't switching off some of its high-energy, high-polluting equipment, which is also low in efficiency," Wu said.
"Why not? Because we still have so many steel plants and coal mines."
"Also, if they can't get hold of good quality fuels, the vehicle exhaust emissions are already very high, as well as very serious emissions from various waste-incinerators," he said.
"If the government doesn't really take these industries in hand, we are going to see this phenomenon come back year after year," Wu added.
Wu said he has reported heavy-polluting industries to the authorities three times in the past year in accordance with environmental protection legislation.
But local environmental protection bureaus had failed each time to respond, in spite of pledging a response within 15 working days, he added.
'Named and shamed'
Several northern cities have failed to implement effective smog control measures and have failed to crack down hard enough on polluting firms, state news agency Xinhua reported.
The report comes after the environmental protection ministry sent out inspection teams to eight of the cities worst-hit by the country's "airpocalypse" smog events.
Among those authorities named and shamed was Qianan in the northern province of Hebei, which borders Beijing, where emergency emission cutting measures were "unreasonable" and not strict enough on local enterprises, Xinhua said.
Last month, authorities in the northwestern Chinese city of Xian detained five environmental protection officials after they were found to have tampered with air-quality monitoring equipment and to have falsified data.
They were accused of tampering with a real-time pollution monitoring system set up by the ruling Chinese Communist Party in the face of widespread falsification of data.
Falsification of data was included as an offense in environmental legislation that went into effect at the start of the year.
The officials stand accused of stuffing sensors with cotton to lower emission readings and removing surveillance camera recordings to eliminate evidence of malpractice.
Reported by Yang Fan for RFA's Mandarin Service. Translated and written in English by Luisetta Mudie.