The chances of long-term health effects because of exposure to styrene vapour, which leaked from the chemical plant in Visakhapatnam, are small, AIIMS director Randeep Guleria said on Thursday, citing available data.

The illnesses caused by the gas are not universally fatal, Dr Guleria added.

As far as treatment is concerned, there is no specific antidote or a definite medicine for reversing the effect of this compound. The therapy remains mainly supportive, he said.

A large number of people have been admitted to hospital. Most of them are stable and hopefully will make a good recovery, Guleria told reporters here.

Asked whether the impact of the exposure can be long-term as was the case in the Bhopal gas tragedy, Guleria said: “The gas doesn’t stay for a very long time. The chances of long-term impact is less as the compound metabolises and leaves the body quickly.”

He added: “This is an acute exposure rather than a chronic exposure. But we will have to follow up and see. As of now, the data doesn’t suggest any significant long-term effect.”

Those who have had a very close exposure are the ones with a higher chance of experiencing severe effects, he said, adding that a house-to-house visit in the surrounding areas have been initiated to see if anyone has developed medical problems.

Eyes need to be washed with water. Tissues or towel can be used to clean the deposition in the skin, Guleria said.

Absorption of this compound can affect the central nervous system causing headache, nausea, vomiting and fatigue. People become unsteady, have difficulty in walking and sometimes also can fall over. High exposure can lead to coma, pulmonary edema and irregular heart beat, he said, adding the syndrome is known as styrene sickness.

The effect on skin is usually mild in the form of irritation, itching and some degree of dermatitis. It causes irritation in the airways and depending on the degree of the exposure, the effect can be much higher, the AIIMS director said.