An estimated 280 million people are using unsafe drinking water, according to a report released by China's environment authorities Friday.

The report, issued by the Ministry of Environmental Protection (MEP), was based on a sampling survey conducted between 2011 and 2012 of 91,527 permanent residents aged 18 and above in 31 Chinese provincial-level regions to evaluate Chinese people's exposure to environmental risks.

The survey also found that 110 million Chinese people are living less than 1 kilometer away from at least one industrial site with pollution concerns, such as petrochemical, coking or thermal power plants, while 590 million people are cooking with solid fuels indoors.

Moreover, about 140 million people live within 50 meters of a main communication artery.

In particular, the report pointed out that the risk of Chinese people's exposure to unsafe drinking water is 2.4 times higher than for US residents, if pollutant densities are the same on the two sides, while urban residents in China are less likely to be affected by air pollution given the same pollutant density.

The report urged establishing a network for monitoring environmental health risks in the country's high-risk areas and intensifying risk evaluation measures and warnings.

A report on minors' exposure to environmental risks is expected to be published by the end of 2015, the ministry said.

Pan Xiaochuan, a professor with Peking University who also participated in the research work, said that the report mainly focused on the time of people's exposure to pollutants and future research would take the density of pollutants into consideration to study the impact of pollutants on humans, reported The Beijing News.

Chinese Premier Li Keqiang "declared war" on pollution earlier this month at the annual legislative session of the National People's Congress.

A total of 50,000 small coal-fired furnaces will be shut down this year and cleaning technologies will be introduced at power plants, while 6 million high-emission vehicles will be banned from the roads and cleaner diesel fuel will be provided nationwide.

The government will also implement a clean water action plan to strengthen the protection of drinking water, prevent and control water pollution.