Ranchi is one of the 100
cities chosen as part of India’s smart cities program.
by
Dr. Nitish Priyadarshi
Assistant Professor,
Department of Geology,
Ranchi University,
Ranchi
India.
emaiil: nitish.priyadarshi@gmail.com
Urbanization
and migration of people from rural areas to the Ranchi city has badly affected
the environment of the city which was earlier known as summer capital of Bihar/
Jharkhand united due to its healthy climate and less pollution. Ranchi is the capital of the
Jharkhand, formed in 2000, along with Chhattisgarh, and is one of the 100
cities chosen as part of India’s smart cities program. From the time the
state was formed in 2000, the number of vehicles in the city has increased 20
times, contributing to the increase in air pollution. With an increase in population
– this erstwhile hill station is now dealing with haphazard construction,
insufficient systems for solid waste management leading to open burning and an
increase in emissions from transport. Other sources include ones such as the burning of firewood
and other organic material for heating and cooking, as well as the open burning
of garbage and refuse. The main types of
pollutants found in the air in Ranchi would be ones that arise from the number
of different combustion sources. These would include materials such as black
carbon and volatile organic compounds (VOC's), both of which find origin in the
incomplete combustion of both fossil fuels as well as organic material, and as
such will be emitted from sources ranging from car engines, factory processes
to even the burning of firewood or other raw materials. Some examples of VOC's
include chemicals such as benzene, toluene, xylene, methylene chloride and
formaldehyde.
Other pollutants would be ones such as nitrogen dioxide
(NO2), sulfur dioxide (SO2) alongside polynuclear
aromatic hydrocarbons, polychlorinated biphenyls, dioxins, furans and even
heavy metals such as lead, mercury and cadmium.
Nowadays, more than half of the human population
live in urban areas and this number is increasing. This huge and often
unregulated phenomenon has changed dramatically the environmental conditions of
previous rural and natural areas, causing atmospheric and acoustic pollution,
loss of biodiversity and climatic alterations, with harmful consequences for ecosystem
functioning and human health.
Photographs posted here are from different areas
near to Ranchi city. From Ranchi city lichens are mostly absent. In forest
areas lichens are still found on the rocks, and trees indicating good air
quality.
The earliest accounts of the high sensitivities
of lichens to atmospheric pollution appeared around the peak of the
Industrial Revolution in western Europe. Grindon (1859) in Manchester and
Nylander (1866) in Paris both associated the disappearance of lichens from
their respective cities with the grossly polluted town air , smoke and sulphur dioxide
then being major components of the pollution.
Fresh, clean air is wonderful to breathe in. Without
the health risks of air pollution, fresh air feels great for our lungs. Lichens love clean air too- infact their
sensitivity to air pollution means they make great air quality indicators.
Basically, lichens
depend on atmospheric moisture: rain, fog and dew for growth. There are slow in
growth and very sensitive towards the changing environmental conditions. Since,
they absorb water and essential nutrients from atmosphere instead of from soil,
hence they respond in altered manner to increased concentrations of pollutants
in air. Comparison of lichens growth in polluted and healthy environment, a
clear cut change in growth as well as addition or reduced growth can be
observed.
Like small signposts, these curious organisms can
tell us a lot about the air we are breathing. Butterflies, nematodes, frogs,
and toads are very good indicators of environmental pollutants, but lichens are
easier to study and are quicker to respond to environmental change.
Next time you are on a walk, you can look around for
the types of lichens that grow in your area. As a rule of thumb, the smaller
the size and less variety of lichens in an area, the more polluted is the
environment. Main air pollutants that
affect lichen growth are nitrogen, sulphur dioxide, fluorides, ozone, hydrocarbons, and
metals such as copper, lead, and zinc.
Lichens look like
spots or clumps of colour, like someone has splashed paint onto a branch of a
tree. Their colours range from green to brown to white to russet red. Even in
these colours, lichens can be understated additions to tree trunks and rocks.
Because lichens have no roots or protective surface, they cannot filter what
they absorb, so whatever is in the air is taken straight inside. If there are
pollutants, it can accumulate in the lichen and can become toxic very quickly.
We breathe
in harmless nitrogen gas all the time - in fact it makes up a large part of
Earth's atmosphere. But when nitrogren is heated and combined with oxygen (as
it is in a car engine), nitrogen oxides are created.
Nitrogen
dioxide in the air can be a powerful polluter and becomes harmful for human
health in high concentrations.
In high
concentrations, sulphur dioxide can irritate the mucus lining of the eyes,
nose, throat and lungs. Exposure to sulphur dioxide may cause coughing and
tightness in your chest. People with asthma are more sensitive to sulphur
dioxide pollution.
Throughout history,
people have used lichens for food, clothing, dyes, perfume
additives, medicines, poisons, tanning agents, bandaging, and absorbent
materials. Compounds unique to lichens are used in
perfumes, fiber dyes, and in medicines for their antibacterial and antiviral
properties.
Lichens have been used in the treatment of
diverse diseases like arthritis, alopecia, constipation, kidney diseases,
leprosy, pharyngitis rabies, infection, worm and infestation. The medicinal utility
of lichens is regarded to presence of secondary compounds like
of usnic acid and atranorin. It is also used in treating wounds, skin
disorders, respiratory and digestive issues, and obstetric and gynecological
concerns.
References:
Bell, J.N.B. and
Treshow, M. (2002). Air pollution and plant life. John Wiley & Sons, Ltd.
309-342.
Grindon, L.H. (1859).
The Manchester flora. London: W. White.
Nylander,W. (1866).
Les lichens du Jardin du Luxembourg. Bulletin de la Societe Botanique de France
13,364-372
https://www.nhm.ac.uk/discover/nature-and-pollution-what-lichens-tell-us-about-toxic-air.html
https://www.iqair.com/india/jharkhand/ranchi
