Pollution - Case study
Pesticide pollution in India
One of the most terrifying effects of pesticide contamination
of groundwater came to light when pesticide residues were
found in bottled water. Between July and December 2002, the
Pollution Monitoring Laboratory of the New Delhi-based Center
for Science and Environment (CSE) analyzed 17 brands of bottled
water, both packaged drinking water and packaged natural mineral
water, commonly sold in areas that fall within the national
capital region of Delhi. Pesticide residues of organochlorine
and organophosphorus pesticides, which are most commonly used
in India, were found in all the samples. Among the organochlorines,
gamma-hexachlorocyclohexane (lindane) and DDT were prevalent,
while among organophosphorus pesticides, Malathion and Chlorpyrifos
were the most common. All these were present above the permissible
limits specified by the European Economic Community (EEC),
which is the norm, used all over Europe.
One may wonder as to how these pesticide residues get into
bottled water that is manufactured by several big companies.
This can be traced to several facts. There is no regulation
that the bottled water industry must be located in 'clean'
zones. Currently, the manufacturing plants of most brands
are situated in the dirtiest industrial estates or in the
midst of agricultural fields. Most companies use bore-wells
to pump out water from the ground from depths varying from
24-152 m below the ground. The raw water samples collected
from the plants also revealed the presence of pesticide residues.
This clearly indicated that the sources of pesticide residues
in the polluted groundwater are used to manufacture the bottled
water. This is despite the fact that all bottled water plants
use a range of purification methods. Thus, the fault obviously
lies in the treatment methods used.
These plants use membrane technology, where the water is filtered
using membranes with ultra-small pores to remove fine suspended
solids and all bacteria and protozoa and even viruses. While
nanofiltration can remove insecticides and herbicides, it
is expensive and thus rarely used. Most industries also use
an activated charcoal adsorption process, which is effective
in removing organic pesticides but not heavy metals. To remove
pesticides, the plants use reverse osmosis and granular activated
charcoal methods. So even though the manufacturers claim to
use these processes, the presence of pesticide residues points
to the fact that either the manufacturers do not use the treatment
process effectively or only treat a part of the raw water.
The low concentrations of pesticide residues in bottled water
do not cause acute or immediate effects. However, repeated
exposure even to extremely miniscule amounts can result in
chronic effects like cancer, liver and kidney damage, disorders
of the nervous system, damage to the immune system and birth
Similarly, six months after CSE reported pesticide residues
in bottled water it also found these pesticides in popular
cold drink brands sold across the country. This is because
the main ingredient in a cold drink or a carbonated non-alcoholic
beverage is water and there are no standards specified for
water to be used in these beverages in India.
There were no standards for bottled water in India till September
29, 2000, when the Union Ministry of Health and Family Welfare
issued a notification (no. 759(E)) amending the Prevention
of Food Adulteration Rules, 1954. The BIS (Bureau of Indian
Standards) certification mark became mandatory for bottled
water from March 29, 2001. However, the parameters for pesticide
residues remained ambiguous. Following the report published
by CSE in Down to Earth (Vol 11, no. 18), a series of Committees
were established and eventually on 18th July 2003, amendments
were made in the Prevention of Food Adulteration Rules stating
that pesticide residues considered individually should not
exceed 0.0001 mg/l and that the total pesticide residues should
not be more than 0.0005 mg/l and that the analysis shall be
conducted by using internationally established test methods
meeting the residue limits specified herein. This notification
came into force from January 1, 2004.
River pollution in India
Almost all the rivers in India are polluted. The causes of
pollution may also be more or less similar. This is a case
study of the River Damodar as reported in Down to Earth. The
563-km long Damodar River originates near Chandwa village
in the Chhotanagpur hills in Bihar's Palamau district. It
flows through one of the richest mineral belts in the world
before draining into the Hooghly, about 50 km south of Kolkota.
Indian industry depends heavily on this region as 60% of the
coal consumed in our country comes from the Chhotanagpur belt.
Coal-based industries of all types dot the area because of
locational advantages and the easy availability of water and
power. In addition, various industries such as steel, cement,
fertilizer and explosive plants are also located here. The
River Damodar is polluted with minerals, mine rejects and
toxic effluents. Both its water and its sand are infested
by coal dust and waste from these industries. There are seven
thermal power plants in the Damodar valley. The states of
Bihar and West Bengal depend almost entirely on this area
for their power requirements. These power plants not only
consume a lot of water but also dump ash in the valley.
As underground mines cannot keep pace with the rising demand,
60% of the coal extracted from the area comes from open-cast
mines, which are responsible for serious land degradation.
The disposal of rock and soil extracted along with the coal
only adds to the problem.
The industries in the area do not have proper effluent treatment
plants. Among the big coal-based industries, the washeries
account for the bulk of the pollution in terms of the total
suspended solids (TSS), oil and grease. About 20% of the coal
handled goes out in the form of slurry, which is deposited
in the ponds outside. After the slurry settles, coalfine (the
sediment) is collected manually. Due to inadequate retrieval
methods very often the water discharges into the river from
the pond carries high amounts of fine coal particles and oil,
thus polluting the river. The other major coal-based polluters
are the coke oven plants that heat co?1 to temperatures as
high as 1100°C in the absence of oxygen to prepare it
for use in blast furnaces and foundries. The volatile components
in the coal are removed, leaving hot, non-volatile coke in
the oven, which is washed with huge quantities of water. This
water that contains oil and suspended particles is then discharged
into the river.
Fly-ash from the thermal power plants
Only one of the thermal power plants has an electrostatic
precipitator to collect the fly-ash, while the other just
make do with mechanical dust collectors. As most of these
plants are located on the banks of the river, the fly-ash
eventually finds its way into the river. The bottom-ash from
the boilers is mixed with water to form a slurry, which is
then drained into ash ponds. Most of the ponds are full and
in several cases the drainage pipes are choked. The slurry
is, therefore, directly discharged into the river.
The river and its tributaries are the largest source of drinking
water for the huge population that lives in the valley. On
April 2, 1990, about 200,000 litres of furnace oil spilled
into the river from the Bokaro Steel Plant. This oil traveled
150 km downstream to Durgapur. For a week after the incident,
five million people drank contaminated water in which the
oil levels were 40 to 80 times higher than the permissible
value of 0.03 mg/l.
The Damodar Action Plan, an end-of-the pipe pollution treatment
scheme, seeks to tackle effluents. One viable option could
be to switch to less polluting industries and cleaner technology.
This would need strong Government initiative and also a mass
movement by people.