[PM and Emergency Calls for Health with Respiratory Diseases in Chengdu in 2017].

Objective: To determine the association between daily particulate matter 2.5 (PM ) mass and emergency calls for help with respiratory diseases.

Methods: Semi-parametric generalized additive model was established to determine the association between daily PM and emergency calls for help with respiratory diseases in 2017 in Chengdu, after adjustments for time trend and variations in the days of the week and weather conditions.