Capital still at orange alert as smog lingers

Beijing on Monday maintained its orange pollution alert, the second-highest alert level, as severe smog was forecast to linger in the Chinese capital for another three days.

The density of PM2.5, particles smaller than 2.5 microns in diameter, which have been a major contributor to the smog, climbed to 346 microgram per cubic meter on Sunday and remained at high levels, the city's office for severe air pollution emergency response said in a statement.

Beijing has a four-tier alert system, with blue, yellow, orange and red indicating the air pollution level in order of increasing severity.

Despite a spate of control measures, Beijing and neighboring cities, mainly in Hebei province, are prone to frequent air pollution.

The current smog, which started on Thursday, is also forecast to persist in neighboring Tianjin, Hebei province and parts of Shandong province for the next two days, according to the China Meteorological Administration.

Meanwhile, a team of Tsinghua University research fellows also recently identified more than 1,300 microorganisms in Beijing's smog.

Most of the microorganisms do not cause disease, but a small number of them may lead to lung diseases or allergies. The influence of the microorganisms on people's health still remains unknown, the Beijing-based Legal Mirror reported on Monday.

Beijing will see more heavy pollution on Tuesday, local environmental monitoring center said on Monday.

Environmental organizations have also started their investigation and research on air pollution.

The China indoor environment monitoring committee on Monday launched an investigation covering 100 families in 100 cities in China with an intelligent indoor environmental pollution monitoring system, in an effort to identify pollution caused by PM2.5 and formaldehyde in rural and urban families.

This campaign is the first of its kind in China, which will help form a regular indoor pollution monitoring system based on statistics on indoor environmental pollution, Song Guangsheng, the secretary-general with the committee, told China News Service (CNS).

The campaign, aimed at tackling heavy smoggy weather, will start in Beijing and then expand to other areas in the country, CNS reported on Monday.

City authorities on Friday ordered 36 companies to halt production and another 75 to reduce production as part of a response mechanism when the pollution alert was raised to orange from yellow.

The measures came after Beijing issued a yellow pollution alert on Thursday, the first since October, when the emergency response system in the city was put into place.