BEIJING -- A study has shown that China's air pollution control measures may avert more than 270,000 hospital admissions linked to heart and psychiatric diseases within four years.

The research, led by medical scientists from Xi'an Jiaotong University, analyzed over 48 million hospitalization records across 292 Chinese cities between 2013 and 2017, offering a comprehensive quantification of health benefits from the country's Air Pollution Prevention and Control Action Plan (APPCAP) launched in 2013.

Fine particulate matter with a diameter of 2.5 microns or smaller (PM2.5) and black carbon have long been believed to be associated with infectious and chronic illnesses, such as respiratory and cardiovascular diseases.

Compared with 2013, the annual average concentrations of PM2.5 and black carbon in 2017 decreased by 28.61 percent and 20.35 percent, respectively, according to a study published in Nature Medicine last Friday.

The study has revealed that China's clean air policies have cut hospitalizations for nine major diseases by an average of 30 percent associated with PM2.5 and 21.14 percent associated with black carbon.

For mental health, depression-related admissions fell by 34.35 percent, the largest decline among all conditions surveyed, followed by schizophrenia (32.56 percent).

Admissions of cardiovascular diseases decreased by 32.52 percent for arrhythmia, followed by stroke (29.66 percent), coronary heart disease (29.74 percent), and heart failure (28.92 percent), according to the study.

Clean air is also found to be related to reduced admissions of lower respiratory infections, Parkinson's disease and chronic kidney disease.

The researchers said the study highlights the substantial wide-ranging health benefits of clean air following the nationwide implementation of the APPCAP in China.