Eighty-seven Chinese cities will begin releasing hourly updates on air quality from New Year's Day, taking the total number doing so to 161, the Ministry of Environmental Protection announced.

Data will be collected from 449 monitoring stations across the Beijing-Tianjin-Hebei area, the Yangtze River Delta and the Pearl River Delta.

The stations have been upgraded to provide real-time updates on levels of sulfur dioxide, carbon monoxide and PM2.5 - particles smaller than 2.5 microns in diameter that can damage the lungs - in accordance with China's improved air quality standards.