'CPCB underestimating pollution from coal-fired thermal power plants'
Data released by NASA’s Aura
satellite calls into question the veracity of Central Pollution Control
Board’s (CPCB) claim made in 2012 that the mean sulphur dioxide (SO2)
emissions in India
decreased in 2010 as compared to 2001 level. A new
study led by Zifeng Lu of Decision and Information Sciences Division of
Argonne National Laboratory in Argonne, USA, based on images taken by
the Aura satellite between 2005 and 2012, says that SO2 emissions from
India’s thermal power plants has gone up by a whopping 71 per cent from
what it was in 2005. The rapid rise in demand for power and the absence
of regulations are seen as the reasons behind the drastic rise. The
study was published online on December 5, 2013, in
Environmental Science & Technology.
The study is based on a new technique for observing power plant
emissions using measurements captured by the Ozone Monitoring Instrument
(OMI) on the Aura satellite, developed by researchers two years ago.
The OMI measures ozone and other key air-quality components (including
sulfur dioxide and nitrogen dioxide) and collects data over the same
locations at the same time daily. OMI data was used by researchers in a
2011 study to show that SO2 emissions from coal-fired power plants in
the US had fallen in 2010 when compared to 2005 level. Images released
with the study show rising emissions from coal-fired power plants in
central India, especially the Vidarbha region of Maharashtra,
Chhattisgarh and Jharkhand.
Courtesy Environmental Science & Technology
CPCB's failure?
In a press note released by NASA, lead author of the study, Lu, has
said that the discrepancy between the figures in the study and those
released by CPCB arise from the fact that CPCB’s figures are based on
ground observation, and a large number of monitoring stations – 291 out
of 361 in the country – are based in urban areas away from power plants,
while just 70 stations collect measurements close to power plants. “We
should know the air quality not only in populated cities, but also in
industrial areas, where coal-fired power plants truly dominate national
sulfur dioxide emissions,” Lu is quoted as saying. “On the one hand,
local residents are influenced by these emissions, and on the other,
long, lifetime, sulfur-containing air pollutants such as sulfate can be
transported long distances to affect public health and the environment
at a regional scale,” he said.
Images of SO2 emission patterns released along with the press note
show that emission from smoke-stacks of power plants have risen between
2005 and 2012. In 2010, India surpassed the United States to become the
world’s second highest emitter of SO2, second only to China.
The press note says that SO2 in small quantities is produced by
volcanoes and other natural processes, but a substantial amount is
produced by human activities such as the combustion of fuels with
sulfur-containing impurities and the smelting of metals such as copper
and nickel. The gas contributes to the formation of acid rain and, in
high concentrations, can cause respiratory problems. It is also a
precursor for sulfate
aerosols,
a type of suspended particle that can affect the properties of
clouds—an effect that is difficult to measure and remains a large point
of uncertainty in climate models.
Vidarbha's bane
The most important reason for rising SO2 emissions in central India’s
power plants, says Suresh Chopane of the Chandrapur-based non-profit
Green Planet Society (GPS), is antiquated technology. Chopane, who is a
professor of environmental science at the Bhawanji Bhai Chavan College
in Chandrapur district, has been agitating for the scrapping of the first two units of the Chandrapur Super Thermal Power Plant (CSTPS) for the last several years.
“Many of the thermal power plants in Vidarbha, including CSTPS, and
Koradi and Khaparkheda thermal power stations near Nagpur, have
surpassed the 25-year limit of utility, and their pollution control
systems are not working any more,” said he. “Respiratory illnesses have
risen phenomenally in these areas. However, despite strong public
demand, government is not shutting down these old and highly polluting
units.”
He said that high SO2 and nitrogen dioxide emissions are causing acid
rain in Chandrapur almost every year now for almost a decade.
