WMO - UV-B Levels In Mumbai, Other Indian Cities Comparable To Antarctica

[hatrack]

MUMBAI: Every time you step out into the open you are exposing yourself to another danger: ultraviolet radiation. The World Meteorological Organisation (WMO), which measures UV radiation across 50 global cities, has given Mumbai another cause for concern.

“Mumbai, Hyderabad, Chennai, Kolkata and Bangalore receive extreme amounts of UV radiation, while Delhi receives very high levels,” says the report released this month. Compare that to Australian cities like Canberra, Sydney and Brisbane, close to the Antarctic ozone hole, which are in the ‘veryhigh’ category. According to the US Environmental Protection Agency’s UV index, 9-10 is classified as ‘very high’ and 11 and above as ‘extreme’. Sustained exposure to UV rays can cause skin diseases, including skin cancer, and eye problems.

EDIT

An average Mumbaikar’s potential exposure to ultraviolet radiation is as much as a person in Antarctica, which is also in the extreme bracket, where a gaping hole in the ozone layer lets in UV rays unhindered. More than figuring out ways to fend off frost bite, scientists who land up in Antarctica go to extreme lengths to avoid being exposed to UV radiation. “I am not surprised. Mumbai is paying the price for not bothering about air pollution. With vehicles increasing by the day and industries spewing poisonous gases in the atmosphere nature has thrown in the towel. There is only so much abuse an ecosystem can take,” says environmentalist Debi Goenka

While there has been no systematic attempt to study the possible depletion of ozone layer over Mumbai, several environmental scientists suspect that unabated industrialisation has eroded nature’s shield. But there are few, like environmental scientist Rakesh Kumar of National Environmental Engineering Research Institute (NEERI), who have a different theory. “Air pollution has decreased in Mumbai and Suspended Particulate Matter (SPM) levels have come down due to the use of CNG and unleaded fuel. I suspect that UV levels have increased because SPM used to act as a shield against UV rays. Ironically, reduction in atmospheric pollution seems to have taken away one of the barriers to UV rays,” says Kumar What is alarming the scientists even more is the increasing use of HCFCs (hydrochlorofluorocarbons) by the average Mumbaikar, often without even being aware of it. HCFCs are used in aerosol cans to get the ‘spray effect’. So every time you use your deodorant or an insect repellent you are releasing HCFC, which thins the ozone layer.

EDIT

http://www.dnaindia.com/report.asp?NewsID=1059600

[phantom power]

1. Comparable to Antarctica? WTF?

And didn't they ban HCFCs?

[jpak]

2. The OP is a little misleading...

The intensity of UVB varies with latitude and season

It's always highest near the Equator (Mumbai is at ~18 degrees N latitude).

The UV index also takes into account UVB (which is not attenuated to a great extent by cloud cover) and UVA (which is attenuated by cloud cover).

Mumbai experiences naturally high UVB fluences and UV indices.

UVB fluences during extremely low total column ozone events in the Antarctic, however, (~1200 J/m2/day @ ~150 Dobson Units) are similar to UVB fluences measured in the Equatorial Pacific.

Smog (tropospheric ozone) should attenuate UVB and reduce the UV index - I think the writer is a little confused here (or wants to sensationalize this)...

[phantom power]

3. That adds up. We regularly get UV indexes of 11 here in AZ.

[hatrack]

4. I wondered about that - they're not that far from the Equator

And I don't think the HCFCs can deplete ozone at the point of release - low temps, high winds, UVB are all required for chlorine to break down O3.