NEW DELHI: THERE’s another reason why you shouldn't step out on Diwali night. Apart from loud crackers, scientists say the amount of carbon monoxide (CO) ill the atmosphere triples compared to other days.

Scientists who have monitored air quality on Diwali over the past three years say that along with CO, suspended particulate matter (SPM) also rises one-and-half times.

CO is harmful because it inhibits oxygen absorption in blood resulting in the vital organs’ falling short of oxygen supply. SPM is a proven carcinogen.

Other gases like nitrogen oxide and sulphur dioxide, harmful for asthma patients, also rise by more than 100 per cent. Even without firecrackers, the level of pollutants in Delhi is way beyond permissible limits for humans beings, say scientists.

On Diwali night breathing Delhi’s air is like living in a gas chamber and the only way to escape it is by driving away from civilisation, say scientists. They add that it could take over a week for pollutant levels to return to normal.

Scientists have monitored pollutant levels before and after the period when firecrackers are used so that the difference made by crackers is distinct. The monitoring has been done in over 10 areas of the city for the last three years and the result has been the same at all the places. Scientist say if the temperature is lower on Diwali night, air pollution is severe as inversion sets in by November. Low temperatures inhibit the pollutants from spreading. Instead of dispersing, pollutants stay close to the ground with humans inhaling them. Scientists mostly ascribe the meteoric rise in the level of pollutants to the chemical composition of crackers which has a lot of carbon. Gunpowder is an essential ingredient of all crackers and the louder or higher a cracker, more gunpowder is used to manufacture it.

On the noise pollution front the din caused by crackers increases noise by almost 25 decibel in most part of the city. Says a scientist from the Central Pollution Control Board (CPCB): "A rise of 25 decibel means a rise in sound energy by almost 250 times."

This because most crackers in the city violate the standard set by the Ministry of Environment. According to the standards, no fire crackers are supposed to emit noise beyond 125 decibel. A recent CPCB survey had shown that only three out of 23 crackers examined stuck to the norms.