``As it is, cases of asthma are 12 per cent above the national average in Delhi,'' said R K Goel, director, department of environment. The SPM which is the main culprit goes up as much as eight times in some cases on Diwali.

Nitrate will be released by the explosion of crackers, which will form more Ozone and more smog. ``With the inversion phenomenon already operating, Diwali just aggravates the situation by releasing hydrocarbons and nitrates which are a precursor to the formation of fog,'' said Professor A K Atri from the School of Environmental Sciences, Jawaharlal Nehru University.

According to sources in the meteorological department, theweather condition is not likely to change in the next few days and it is going to worsen around Diwali time. The only relief could have been strong winds or rain but none is likely to come the next day.

A study in All India Institute of Medical Sciences (AIIMS) has shown that there is a dramatic increase in the number of asthma cases a day after Diwali day. The emergency room figures regarding patients requiring nebulized broncho-dilator therapy goes up by three times just one day after Diwali. ``The morbidity continues for sometime as even the next week the cases keep pouring in,'' said Dr J N Pande from AIIMS.

In fact, in 1997 when the study was conducted, the smog had not made an appearance unlike this year when for the last 10 days, mornings and evenings have seen a thick black layer of smog.

Though the Delhi Pollution Control Committee had launched a successful campaign targeting children and making them aware of the harmful effects of crackers on an over-stressed city, there is much scope forimprovement.

Monitoring was done at 19 places in the city which showed the rise in pollution in 1997. In Tilak Nagar, the levels were 3,100 ppm in 1997 but came down to 1,429 ppm in 1998. In Rajpur Road, the level went up to 1,100 ppm in 1997 but came down to 185 ppm last year. The other places where it was bad was Shalimar Bagh, Meera Bagh and Janak Puri.

``This is hazardous considering the fact that the permissible limit for SPM is 100 ppm,'' said Goel.

With no immediate solution in sight, the only hope for the residents is that keeping the gravity of the situation in mind, they burst less crackers.