Persistent smog blanketed Beijing and parts of China’s north-east at the start of the week, forcing cancellation of hundreds of flights and closure of motorways and focusing concern and public anger on high air-pollution levels, MSNBC reported. While China’s environmental monitoring centre said the air was slightly polluted, the US embassy – which conducts its own measurements – rated it “hazardous” and Xinhua said the thick smog was likely to reach “dangerous” levels.

Agence France-Presse noted that while the embassy measures fine particles – those smaller than 2.5 micrometres – official figures are based on larger particles; the government readings, therefore, often give a less severe assessment of air quality, leading to accusations that the authorities are downplaying the situation.

Photos taken from the same spot in Beijing over a two-week period – showing starkly visible differences in air quality – were widely published, including by ifeng and China Daily. Environment ministry officials said public feedback on amending air-quality standards shows support for checks that would include the smaller PM2.5 particles, according to Sohu and China Daily.

Experts are worried, China Daily said, that particulate matter in the air may lead to more cardiovascular and respiratory disease. Exposure to PM2.5 particles – which lodge deep in the lungs -- is a major health hazard and, without intervention, PM2.5 could replace smoking as the main risk factor for lung cancer.

Discoveries of major shale-gas reserves have been reported in western Sichuan province, potentially boosting China’s domestic supplies of natural gas and reducing demand for imports, the Associated Press reported. Reserves have been found in at least 20 locations, a China National Petroleum Corporation official confirmed. Good initial results in production from two exploratory wells also were noted.

China is an exception to the global slump in nuclear electricity generation, according to the Worldwatch Institute. The country accounted for 10 of the 16 reactor construction starts in 2010, and initiated the installation of nearly 10 gigawatts of capacity, representing 62% of capacity construction worldwide. The likelihood of significant reductions in nuclear-generation growth remains low, given China’s booming energy demand and ambitious carbon-reduction targets.

Microsoft co-founder Bill Gates confirmed he is in discussions with China to jointly develop a new kind of nuclear reactor that can run on depleted uranium, the Associated Press reported. Gates has largely funded TerraPower, a US company developing a fourth-generation reactor that would produce significantly smaller amounts of nuclear waste than conventional reactors.

Ninety volunteers from across China are to help clear traps set for endangered wild Siberian tigers in Heilongjiang province again this winter, Xinhua said. Wire ring traps are used by poachers to catch the animals.

Six Chinese fishermen from Hainan province were charged in a court in the Philippines with catching endangered sea turtles in that country’s coastal waters, the Associated Press reported. Their boat was intercepted off the western province of Palawan