"We will implement an emergency plan 48 hours in advance if the air quality deteriorates during the August from 8th to 24th Games," Li Xin, a senior engineer who has prepared the plan for the Beijing Environmental Protection Bureau, was quoted as saying by the state-run China Daily.
The Air Pollution Index (API) has remained above 100, the national standard for good air quality in the past four days.
More vehicles could go off the roads and all construction sites and more factories in Beijing and its neighbourhood could be closed temporarily if the air quality deteriorates during Olympics, state media said.
Special measures for the 8th to 24th August Games are likely to be announced soon, the state-run China Daily said quoting the citys environment authority.
An environmentalist Zhu Tong has proposed keeping up to 90 per cent of private vehicles off the streets during the Games and allowing only those whose licence plate ends with the last digit of the date, it said.
The Chinese capital was shrouded in smog on Sunday and the API was noted to be between 103 and 124.
Hot and sultry weather with occasional breeze and the still high emission level have triggered fresh concerns over weather during the Olympic Games.
"The smog was likely to have been caused by poor weather and emissions both," Du Shaozhong, Deputy Director of the Beijing Environmental Bureau, said on Sunday.
He also said tougher plans were ready to safeguard athletes health.
Athletes have began arriving in Beijing since Sunday and the numbers would swell this week ahead of the Games commencing on August eight.
Olympics is considered a national prestige by China which has been battling pollution in Beijing for the past few years through a series of measures.
In the latest and last-ditch effort, Beijing had launched a drastic plan on 20th July pulling off half of nearly 3.30 million vehicles from the roads.
The shutdown for a two-month period allows vehicles with even and odd plate numbers to run on alternate days, apart from shutting down several polluting factories.
Beijing had pledged on Saturday to maintain air quality at "good or moderate levels" during the Games.
"Keeping an eligible air condition for the Olympic Games is a promise made by the Chinese government and we will honour our commitment," Du said.
By DDNEWS
According to RIA Novosti "Vehicles are a major cause of pollution in Beijing, with around 1,000 new cars hitting the capital's roads each day until the restrictions kicked in. Under the current scheme, cars with even and odd number plates are permitted on the roads on alternate days.
"The China Daily quoted environmentalist Zhu Tong as saying the city needs a 90% vehicle cut for the games. Zhu proposed that only vehicles whose license plates end with the last digit of the date for any given day should be allowed on the capital's roads."
