New Delhi: The city seems to be paying an increasingly heavy price for its deteriorating air quality. An average of 23 people die every day due to respiratory diseases in the capital, a number that has doubled in the past four years, data released by the Delhi government reveals. Doctors warn that worsening air quality, a major trigger for respiratory conditions such as chronic bronchitis, lung cancer and infections, may cause more fatalities in the coming years if appropriate measures are not taken. The latest statistical handbook, released by Delhi government on Tuesday, shows respiratory diseases to be the fastest growing killer in a city where fatalities from most other ailments were declining. The total number of deaths annually has also declined significantly, which is being attributed to better access to healthcare facilities and treatment.