Perilous Times
6 January 2012 Last updated at 08:10 ET
Pollution rise 'worsens' South Asia's smothering smog
By Navin Singh Khadka Environment reporter, BBC News
Experts say the smog problem is becoming increasingly serious
A rapid rise in air pollution from fossil fuels and biomass
burning has worsened winter smog and extended its duration in many
parts of South Asia, scientists and officials have said.
In Bangladesh, India and Nepal the temperature has plummeted and
clouds of fog and smoke hang in the sky blocking sunlight for
several days.
Normal lives have been affected with many flights diverted and
suspended and trains delayed because of low visibility.
Experts say they have noticed that the intensity of smog has grown
in the Indo-Gangetic plains in the last few years, leading to
increased impacts.
"Since 1990 onwards, there has been increase in the number of
[smog-affected] days in northern India," says BP Yadav, director
of the Indian Meteorological Department.
"It is not a linear trend showing an increase every year. There
are, of course, year-to-year fluctuations.
"But there are more years that have seen dense fogs."
Nepal's Department of Hydrology and Meteorology director-general
Keshav Prasad Sharma agrees the issue of smog is becoming
increasingly serious in the plains in southern Nepal bordering
India.
"Until 10 years ago, we did not have such dense fog for long
durations like we have these days," he says.
"Although the 10-year period is too short for statistical trends,
it is indeed being seen as a major issue now."
“At times, all means of transport come to a complete halt because
of zero visibility ” - Iqbal Habib, Bangladesh Environment
Movement
Some are also investigating whether the conditions can be linked
to health problems in parts of the region. Although widely
reported as the direct effect of a cold wave, medical
professionals say deaths and illnesses are often related to
respiratory diseases.
"None of our patients died of hypothermia," says senior consultant
physician Gaurang Mishra of a regional referral hospital in
south-eastern Nepal where dozens of people have been reported to
have died during the last three weeks that saw many smoggy days.
"They mostly suffer from chronic pulmonary obstructive disease
that is caused by burning of wood and cow-dung cake and pollution
from industries and vehicles, mainly during winter season."
The number of such patients, particularly children and elderly
people, is also in the rise in Bangladesh.
"But it is not just about people's health in our country," says
Iqbal Habib of the Bangladesh Environment Movement (BAPA). "At
times, all means of transport come to a complete halt because of
zero visibility and all walks of lives are affected.
"The working hours come down to as little as four hours a day."
Vehicles are regular sources of pollution, but there are many
others
Experts say besides regular sources like vehicles, industrial
factories, power plants and dust from gravelled roads, air
pollution in some areas in Bangladesh is getting worse because of
fast increasing numbers of brick kilns.
Some studies have shown that they account for around 40% of air
pollution in and around the capital Dhaka.
"Since we have a sustainable economic growth rate, we need more
bricks and the number of brick kilns is going up day by day,"
admits Monowar Islam, director general of Bangladesh's Department
of Environment.
"We know the situation is becoming serious but it is not alarming.
"We have been demolishing unauthorised brick kilns and have been
implementing the World Bank-supported clean air and sustainable
environment project through which we patronise new technologies
that reduce air pollution."
Just like in Bangladesh, India also sees lots of constructions
during winter as this is the dry season before the region gets
monsoon rainfall preventing such works.
"Construction works too are major contributors for the smog in
this season as they lead to more pollution in the air," says the
Indian Meteorological Department's BP Yadav.
That is in addition to pollutants from energy sources.
Energy demand
In its World Energy Outlook 2010, the International Energy Agency
said: "India is the second-largest contributor to the increase in
global energy demand to 2035, accounting for 18% of the rise."
Scientists say pollutants and aerosols in the air enhance
condensation of water in the atmosphere causing dense smog.
"The more pollutants in the air, the denser the smog," says Keshav
Prasad Sharma at Nepal's Department of Hydrology and Meteorology.
"In some Nepal-India bordering areas, smog blankets can be seen
from early evening."
When such blankets of smog block sunlight, sending temperatures
down, people make fire from wood, cow-dung cake and hay to warm
themselves and that creates more air pollution which leads to
denser smog.
Scientists say the real trouble is that smog during winter cannot
escape to the upper atmosphere as it can during other seasons,
because of meteorological conditions.
"During winter, the cold air that blows towards the southwest from
the northeast tends to push the boundary layer (the layer of
atmosphere closest to the Earth surface) low," William Lau, deputy
director for atmospheres at Nasa's Goddard Space Flight Center
told BBC News.
"As a result, all the pollutants get trapped in the boundary layer
that is pushed down to as low as one kilometre from the Earth's
surface while it is more than five kilometres away during other
seasons.
"The cold wave becomes severe because of this local trapping of
the aerosols and other pollution that block off the solar
radiation and create very unhealthy air in this part of the
world."