China's disease control authority will carry out a study to find out how PM 2.5, or particles smaller than 2.5 micrometers in diameter, affect people's health in 10 cities that recently saw the worst pollution of that kind.

PM 2.5 is considered extremely hazardous to health as the particles go deeper into the lungs than larger particles in the air.

The Chinese Center for Disease Control and Prevention will conduct an indoor PM 2.5 study — through observations of subjects and the collection of environmental and meteorological information — to further understand the damage done by PM 2.5.

The study, which is expected to cost less than 60 million yuan ($9.6 million), will take three years to complete, said Wang Yu, director of the center.

The country is considering setting up a health-warning platform based on the results of the research project, he said.

Despite the fact that PM 2.5 has a negative effect on people's health, there has not been a detailed study on it, he added.

"The PM 2.5 composition is different in different regions and its effect on people's health also varies," he said.