BEIJING - About 1.52 million Chinese households plagued by fluorine-rich smoke generated by old fashioned stoves, or 19 percent of the country's total, have had their stoves replaced in a government project over the past 31 months, a health official said on Tuesday.

Most of the households used to rely on arsenic and fluorine-rich coal as their major cooking fuel in traditional open top stoves.

Wang Bin, an official with the Ministry of Health, said the central and local financial departments had used or allocated 842 million yuan ($131 million) to aid 1.63 million households from 2009 to 2011 in six provinces in central and western China.

Under the project, residents will be given subsidies if they replace their open top stoves, most of which have no chimneys to vent the fluorine-rich smoke, with new, enclosed stoves with chimneys.

The project has significantly improved the local environment and reduced fluorosis incidences, Wang said.

Excessive consumption of fluorine can result in yellow teeth, twisted spines, aching joints and deformed leg bones.