AIIMS director asked people to avoid visiting most polluted areas. (File)

As many cities battle air pollution, officials at the country's top medical institute AIIMS said poor air quality has increased the number of patients visiting hospitals with respiratory problems.

All India Institute Of Medical Sciences (AIIMS) Director Dr Randeep Guleria said there has been an increase in the number of patients visiting hospitals with complaints of respiratory problems and cardiac arrests.

Studies are being conducted to asses the impact of pollution on public health, he said at the sidelines of an event at the AIIMS.

Delhi's air quality remained in the 'severe' category for the fourth consecutive day today as meteorological conditions continued to be unfavourable for dispersion of pollutants. The city is facing its worst pollution crisis since Diwali.

While the Central Pollution Control Board (CPCB) data showed the overall air quality index (AQI) at 'severe' level of 416, the Centre-run System of Air Quality and Weather Forecasting (SAFAR) recorded an AQI of 423.

Mr Guleria asked people to avoid visiting most polluted areas and take preventive measures.