Chinese companies have offered up a fresh idea to help pollution-weary travellers while cashing in on public concerns over dirty air at the same time -- smog insurance.

The country's top online travel agency Ctrip.com and the leading insurer Ping An have "started to sell haze travel insurance", the state-run China Daily reported.

The fresh idea comes as popular frustration mounts over the dense smog that frequently cloaks wide swathes of the country, prompting national leaders to confront the issue after years of downplaying it.

In the insurance scheme, in exchange for premiums of 10 to 15 yuan ($1.60 to $2.40), Ctrip and Ping An have promised to cough up as much as 50 yuan a day to travellers subjected to hazardous skies.

Terms and conditions apply -- for example, the tourist must have booked a tour through Ctrip lasting three to seven days.

The insurance so far only covers six major cities, where standards vary.

In Beijing and Xian, a popular tourist site home to the ancient Terracotta Warriors, the air pollution index will have to top 200 on a specific mobile phone app.

In the northeastern city of Harbin and in Chengdu in the southwest the minimum index is 150, and for Shanghai and the southern city of Guangzhou, 100.

Air quality readings in those cities frequently exceed those figures.

But despite the seemingly favourable odds, a few frequent travellers were not holding their breath.

"The premium does not go directly to tackle the heavily polluted air. I would like the money to be put to better use," Tian Yiyi, a sales representative, told the China Daily.

Qian Yigang, a technician, told the paper no amount of compensation would suffice.

"People travel around for fun," he said. "If their mood is upset by poor atmospheric conditions, it cannot be rewound or fixed by money."

Public anger over pollution spiked in January this year when an "airpocalypse" shrouded the capital in thick smog, with particulate matter shooting 40 times past UN standards and horrifying images spreading worldwide.

Premier Li Keqiang vowed to "declare war" on pollution at the country's annual legislative gathering this month, and announced new measures to add to a raft of others issued over the past year.

China's pollution problem -- blamed on decades of no-holds-barred economic development -- has fuelled the capitalist spirit of other entrepreneurs too.

Chen Guangbiao, a billionaire recycling tycoon known for publicity stunts, drew attention following the "airpocalypse" by offering to sell so-called cans of fresh air.

In December last year a hospital in Chengdu opened a "smog clinic", the official news agency Xinhua reported.

Within 10 days it saw more than 100 patients "with sore throats, runny noses and coughs", the clinic's director was cited as saying.