Delhi, where air is already highly toxic, is witnessing a jump in benzene levels in the air and as it gets colder, the concentration of the carcinogen is expected to increase.
At Anand Vihar, around midnight on Tuesday, benzene levels in the air touched 43.7 micrograms per cubic metre (µg/m3), almost 9 times the prescribed standard of 5 µg/m3. At R K Puram, the benzene level at 7.30 pm on Tuesday was 37 µg/m3. At both places, the concentration of benzene did not go below 8 µg/m3 at any time during the past three days.
Watch What Else Is making News
According to scientists, benzene concentrations are higher in colder areas and if the temperature drops in the coming days — which is expected — the levels are bound to rise. The pollutant is highly toxic even at low concentrations and is known to cause leukemia in the long run. The biggest source of benzene in air is vehicular exhaust and fuel vapours.
Despite its toxicity, benzene is not part of the pollutants that comprise the National Air Quality Index. DPCC officials say they are aware of the high levels of benzene and have been ringing alarm bell for many months. In February, DPCC wrote to oil companies and asked them to install vapour recovery systems at petrol pumps to reduce pollution.
According to experts, while some benzene is produced when fuel is burnt, the major part is contributed as vapour from petrol pumps. In April, the National Green Tribunal also passed similar directions.
“We have again raised the issue in recent meetings with officials of the Environment Department. The levels are very high and benzene has a tendency to settle in colder areas. The coming days could see higher concentrations. Vapour recovery systems are crucial at this stage and we are insisting on them,” said Anil Kumar, director, Environment Department.
This is not the first time that high levels of benzene have been brought to the notice of officials. A study conducted by the Central Pollution Control Board (CPCB) in 2015 said that the average concentration of benzene in Delhi is 14 µg/m3 — almost three times the prescribed average. The average in Gurgaon was 0.22 µg/m3 and that in Rohtak was 0.18 µg/m3.
“Studies have found that benzene at lower levels is much more toxic than at higher concentrations. The levels we are seeing would fall into the category of low levels and can be very dangerous. The compound is typically linked to myloid leukemia — a form of blood cancer. On cold days, benzene concentration can reach up to 100 µg/m3 in Delhi. The situation is alarming and a vapour recovery system is crucial now,” said T K Joshi, director, Centre for Occupational and Environmental Health.