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DNA : When it rains, it pours acid in Pune, Nagpur : sept 5, 2007
When it rains, it pours acid in Pune, Nagpur
Environmentalists warn that the trend, if not checked, may pose a grave risk
to public health
Jaideep Hardikar. Nagpur
Analysis of rainwater quality over the decade in Nagpur and Pune by the
Indian Meteorological Department (IMD) shows a disturbing rise in levels of
acid in rainwater.
A study by Dr Jayant Sarkar, Director, Air Pollution Unit, IMD, and VK Soni,
a meteorologist with IMD, Pune, shows a substantial rise in sulphate and
nitrate concentration in rainwater in almost all parts of the country.
Meteorologists say there is no need to panic yet, but environmentalists warn
that the trend, if not checked now, may pose a grave risk to public health.
The IMD has a network of 10 stations across the country to collect and
analyse rainwater samples. The centres are: Allahabad, Jodhpur, Kodaikanal,
Minicoy, Mohanbari, Port Blair, Pune, Nagpur, Srinagar and Vishakhapatnam.
The office of Additional Director General of Meteorological (Research), IMD,
Pune, supervises the programme and analyses the results of all rainwater
samples.
For the past 26 years, the centres have been monitoring and documenting
long-term changes in the chemical composition of rainwater, as part of a
world-wide survey under the aegis of the World Meteorological Organisation
(WMO).
Analysis of the samples reveals the mean sulphate concentration in rainwater
at Pune rose from 0.94 mgl in 1986-95 to 1.62 mgl in 1996-2005, while
nitrate levels went up from 2.43 mgl to 3.04 mgl. In Nagpur, for the same
timeframe, sulphate concentration saw a sharp increase from 1.06 mgl to 3.48
mgl, while nitrate levels went up marginally from 4.67 mgl to 4.73 mgl. The
study attributes this increase to rapid industrialisation and urbanisation
in and around the two cities. Though Nagpur recorded a slight recovery in
2007, rainwater samples from Pune largely remained in the 'safe range'.
The study also shows that except Kodaikanal, all other centres display a
two-fold rise in sulphate concentration in the decade ending 2005. In 2006,
only 5 of the 88 samples collected in Pune were found acidic, but all the
monthly samples in Nagpur the same year were acidic. Pune has not recorded
any acid rain in 2007 so far. However, at Nagpur, rainwater samples for the
months of March, May and June were found acidic.
What is also worrying is the increase in the sulphate and nitrate
concentration in rainwater at Minicoy and Portblair islands in the Arabian
Sea and Bay of Bengal respectively. Scientists at the National
Environmental Engineering Research Institute (NEERI), Nagpur, warn that the
low pH levels (acidity) in rainwater may affect human health, vegetation,
forests and aquatic life adversely. Research has shown a rise in the
frequency of chest colds, cough and allergies. High acid content in
rainwater may pollute ground water, impacting farm yield and quality of
produce.
On a positive note, compared to the worldwide figures, India is better off
than other countries as far as acid rain is concerned.
Kapil Sibal, the Union Minister for Science and Technology and Earth
Sciences, responding to high acid content found in rainwater in Nagpur and
Pune, on August 31 told the Parliament, "Introduction of regulations
regarding ultra-low sulphur emission norms for vehicles and automobiles,
which have been extended to cover the whole country, will considerably
arrest the identified acidification trend."
Publication : DNA; Section : mumbai; Pg : 9; Date : 5/9/07 |
