China is likely to start monitoring ozone and particle pollution from next year to keep anti-pollution campaigns going strong after the Olympics, an environmental official said on Sunday.

Fan Yuansheng, of the Ministry of Environmental Protection (MEP), said the two pollutants had caused great concern, and the MEP was making technical preparations to monitor them.

"We should be able to start regular monitoring of ozone and PM2.5 (particle matter) next year, which would lead to measures to deal with them," Fan told a press conference.

He was speaking in response to reports that China's environmental authorities had failed to include fine particles and ozone into their pollution measurements, resulting in an ignorance of the health risks caused by the pollutants.

"Fine particles" are tiny solid particles no larger than 2.5 micrometers in diameter. Health experts believe they are unhealthy to breathe, and have been associated with fatal illnesses and other serious health problems.

Colorless ozone is also believed to cause respiratory problems and affect lungs.

There have been worries that the air in Beijing, which will host the summer Olympic Games in three days, may be unhealthy for some athletes.

China has taken drastic measures to curb pollution, such as closing factories around Beijing and ordering half of 3.3 million cars in Beijing off the roads, to try to clear the skies during the Olympics.

"These measures have been effective so far," said Fan, director of the MEP's department of pollution control.

Fan refuted allegations that China's air pollution standards were more lenient than World Health Organization (WHO) guidelines.

Standards that China had been using to control four major air pollutants - sulphur dioxide, nitrogen dioxide, carbon monoxide and particles - followed the WHO's "phase one" guideline issued in 2005, he said.

The WHO allows developing countries like China to begin from this guideline to eventually reach its stricter final goals, he said.

Fan said measures adopted to reduce pollution in Beijing for its hosting of the summer Olympics would stay in force after the event.

"Most of these measures are long-term ones and will remain in place after the Games. Not all the temporary measures will be retained after the Games, but they may provide models for our future work," he said.

Many Beijing residents are worried air pollution could worsen after the Olympics, with factories reopened, construction resumed and traffic no longer restricted.

Fan argued the Olympics would leave environmental legacies in Beijing and China, which has spent billions of yuan to clean its environment.

Xinhua