Thread: Local Environmental Issues [Urbanization hazards]

• Environmental problems in urban and rural areas
• Problem of congress-grass and other weeds
• Problems arising out of pesticides and weedicides and smoking etc.

Environmental problems of Urbanization

Urban people use the environment through consumption of food, energy, water, land and goods more than the level of replenishment / recycle / replacement, thus in turn, pollute it more. This adversely affects the lives of the urbanites. Let us now see as to how urban cities lead to environmental problems.

Habitat Loss:

The man-made cities have been carved on the land of wildlife (non-domesticated animals, uncultivated plants and micro-organisms). The habitat of wildlife (natural home of wildlife), it means has been destroyed for making the urban habitation, roads, offices, institutions and commercial areas etc.

Deforestation:

Urbanization leads to change of land use, primarily from natural ecosystem to cities. Imagine if man had not carved cities and towns, there would have been forests almost everywhere. In other words, the reservoirs of energy in terms of fuel and food/fodder, oxygen, fibre, fertilizer, water and climatic stability etc. gets lost to cities. This also leads to floods and consequential losses and unrest.

Soil erosion:

Since top fertile living part of earth’s crust i.e. soil in cities enjoys very thin vegetation cover, it remains naked for erosion to wind and storm rainwater. The soil surface is otherwise also relatively compact. Here, the rainwater percolates less leading to lesser groundwater recharge. Most of the rainwater flows away from cities as run-off, taking along lots of mineral ions, thereby making the area infertile.

Water loss:

Because of the reasons of (a) compactness of the soil in cities, (b) more of concrete city surface (because of roads and buildings) and (c) scarcity of ground cover by vegetation, the availability of surface area for seepage of rain water is reduced tremendously. Resultantly, the water table hardly gets recharged or replenished. Further, since the water falling on the ground gets quickly lost; the evaporation of water from the surface is also very short lived. This diminishes cooling effect. As if it is not enough, it also aggravates the problem of maintaining adequate vegetation for sustaining the environment for urban dwellers.

Biodiversity loss:

As already explained above, because of development of cities, the habitat of wildlife gets destroyed. As a result, the wildlife goes to the edges or outskirts of the urban areas and even the satellite towns. Consequently, weak species get lost/vanish leading to loss of diversity. This biodiversity (variation and in the types of plants, animals and microbes) loss is a matter of worry for the whole world.

Ecological disruption:

Nature has maintained a balanced interaction between different species. We call it ecological balance. However, if we remove or add something beyond a limit it gets disturbed. Let us try to understand this phenomenon with the help of an example. Let in a closed forest there are rats. The basic principle suggests that to eat these rats snakes will appear. Since the food is in plenty, the growth and reproduction of the rats will be good. Soon, with the increased number of snakes, the food (rats in this example) will go in short supply. Resultantly, the snakes will starve, will grow and reproduce slow. In other words their number will decrease. As a result, the rats will eaten less, they will grow and reproduce more leading to increase in their number. This way the natural balance in terms of oscillations between rats and snakes is maintained. In the similar way the balance between food-grains (food of rats) and the rats on one hand while between vultures and snakes on the other gets sustained in nature. By making urban cities, man results in disrupting the natural ecological balance.

Sewage:

Sewage system in every big city poses a great problem especially after a few decades. Cities mostly have a single sewage system. With increasing population, the demand of flow increases. In addition, with more constructions of the buildings, the runoff rain-water tunnels through the available path, especially in case the buildings are parallel to the slope. In case they are perpendicular, water stays and floods the cities. Because of flooding, the buildings, roads and other properties get damaged, the outbreak of epidemics/diseases and disruption of life, transport system, communication system adds to the catastrophe. The recent examples of instant floods during monsoons in Mumbai and Ludhiana exhibit good examples in this regards. In the case of tunneled run-off, in addition to the loss of water (which under ideal conditions should recharge the ground water-table), it leads to choking of the sewage drains, resulting in floods in the city. Further, since the storm water when reaches the sewage treatment plants it exceeds the tank capacity. It is too expensive to (a) build separate system for rain-water and (b) enhance by many times the capacity of the treatment tanks.
Congestion on the road : Transportation demand in urban areas continue to increase in spite of better communication (wired and wireless-cell-phone) systems have improved tremendously. Increase in transportation leads to excessive fuel consumption, more heat, more pollution (thereby loss to vegetation and dependent animals thus, biodiversity), more congestion, more accidents and therefore more miseries.

Air pollution:

Industrialization and urbanization has resulted into profound deterioration of urban air quality. In urban areas everything, including the pollutants get concentrated. People living there get exposed to more of pollutants in terms of quantity and types – more noise, heat, suspended particulate matter and gases. It is often said that the number of deaths due to cancer and heart failures are more in big cities than rural areas. This holds irrespective of race or gender. Air pollution being maximum in cities (especially the downtown or the centre of the city) is regarded as the cause of deaths or ailments there.

India’s efforts to improve the urban air quality have recently been focused on improving the vehicular quality and checking the pollution through enforcing the regulatory norms (accepting the standards of Europe (Euro-I and Euro-2). India has also realized the need to enforce the environmental laws which are adequate. In 1998, India’s Supreme Court issued a ruling by which by 31-3-2001, Delhi’s city busses to be run on compressed Natural Gas (CNG) which unlike petrol & diesel gets burnt completely and does not leave polluting gases like carbon monoxide and oxides of Sulphur and Nitrogen.
Urban cities affect the climate by making them relatively warm. The effect is primarily in two ways: Firstly, the tall and closely constructed buildings obstruct the flow of air and rather they channel it – sometimes resulting in fast wind tunnels. Because of general obstruction of the wind flow, the pollutants get accumulated in the area. These pollutants result in warming also. Secondly, because of reduced sunlight (again because of obstruction by the buildings), the city centers are relatively more warm than the periphery. Often the cities experience “Urban Heat Island” because the tall buildings trap the heat produced by the increased heat production by burning of petrol/diesel/LPG, electric appliances etc. The recent erections of mobile phone towers / repeater stations emitting e.m.f. (electro magnetic frequency) radiations installed in the walled cities add to the urban heat island.

Indoor Pollution:

Without deviating from the theme of the chapter, we find that most of these problems are on account of population density in the cities. However, many a times the environment inside the home (indoor environment) is worse than that outdoor. Quickly, let us also see as to how we pollute our selves in our homes or in doors, where we spend majority of our lives.
We prefer wall to wall carpets. These carpets being hygroscopic (hygro- stands for water, while scopic- for attraction; i.e. these carpets attract or are the storehouse of water molecules) become a very good place for micro-organisms to grow and reproduce. We treat Carpet as a symbol of status. These carpets are basically a good source of insulation in temperate climate (cold conditions) and not in our part of the world especially in summers and monsoons. The carpets in rooms especially in rainy season not only smell foul, but also become a source of biological pollution from the micro-organisms fungi etc. This leads to asthma.

Water-borne, water-washed (or water-scarce), airborne, food-borne, vector-borne, including some water-related vectors (e.g. Aedes mosquitoes breeding in water containers where households lack reliable piped supplied). The coloured food (pink, green, violet or such synthetic colours-added sweets), synthetic sweeteners like aspartame, saccharine used in sweets or drinks, face masks dissolved in organic solvents like benzene, cheep holi colours containing mica and lead, cheep hair dyes containing ammonia and lead, polished pulses, cheep cosmetics containing ethylene glycol (anti-freeze agent used as break-oil in vehicles) junk food are all injurious to our health.

There is no denying the fact that if we develop very fast (e.g. say increase motorized vehicular load, we will have to increase the road network, consume more of fuel, increase more of air pollution and thus pollution related health problems) pollution and other environmental problems will bother us. On the other hand if we do not develop or develop very slow we will have to face the problems of sanitation and consequential diseases.
Under either situation, when people complain of ‘environmental problems’ they mean damage to the physical environment and consequential human welfare for the present and the future. In other words, urban environmental problems result from the man-caused threats to present and the future human well-being,

Environmental Problems in Rural Areas

Pollution : In rural areas or villages it’s a common practice to use wood, cow-dung cakes and kerosene etc. as a fuel for cooking food. These sources are not environment friendly, they generate a lot of smoke, soot and hydrocarbons which goes into the environment and pollute it. When a fuel is burned completely Carbon dioxide is generated, this gas is not poisonous so does not pollute the air to a greater extent. But in the conventional Chulas used by village people the fuel doesn’t burn completely. As a result of the incomplete burning of the fuels carbon monoxide is generated, which is a poisonous gas and cause health hazards. The smoke of the chulas also contains harmful air pollutants like oxides of sulphur, nitrogen soot and ash. They cause irritation in eyes, many respiratory problems and prolonged exposure may even cause asthma and chronic health problems.

Public Hygiene :

Rural people are not adequately aware of personal as well as public hygiene. The various activities of people in rural areas that enhance the hygiene problems include:

-Non availability of clean drinking water: In most of the backward villages, people depend on a common well for drinking water and the village pond for bathing of cattle and washing of clothes etc. Such water is highly contaminated and cause large number of water-borne diseases like cholera, typhoid, dysentery, diarrhoea, amoebiasis.
-Improper disposal of sewage- In rural areas, the sewage drains are mostly open. These open drains are not only source of ugly sight, but cause foul smell, forma a breeding ground for malaria causing mosquitoes and other pests. Usually rural people defecate in open areas, agricultural fields and the sewage is not properly dispose off. In rare cases, temporary pit are dug for the decomposition of sewage. But this is not a hygienic or proper method for the disposal of sewage and may lead to spread of many communicable diseases among the inhabitants of the village.
-Dust and Particulate matter: In the absence of cemented or Pucca roads, the streets have loose surface. During rains the muddy water flows through the streets. Likewise with wind, the area contains high degree of suspended particulate matter. High speed vehicle moving through the street also leads to such pollution.
-Poor ventilated buildings: In rural areas, the building designs do not meet the architectural norms. These lack adequate source of natural light or ventilation for exchange of air and gases. Likewise, the floors in the houses also do not meet the approved designs.

4. Lack of Education:

Blind faiths and Superstitions: In rural people being simple and innocent blindly follow certain superstitions. Because of poor literacy, they remain unaware of their polluted surroundings. In the even of ailment they visit the doctor after exhausting the channels of quacks and other non-medical treatments. In the meantime many a times, the disease spreads beyond the level of control


5. Excessive use of Fertilizers and Pesticides:

India is mainly an agricultural country and the economy of the nation rests mainly on the agricultural produce. To increase the produce the rural people instead of adopting modern agricultural techniques, tend to use more of fertilizer and pesticide/weedicides.
No doubt, with the use of fertilizers and pesticides, rural people increase their agricultural produce. However, it leads to serious pollution of ground water. Mainly the fertilizers contain nitrogen in the form of nitrates. Excess nitrates when get into the body of animals are converted into nitrites by the microbial fauna in the intestine. These nitrites combine with haemoglobin of blood forming methane-haemoglobin and interfere with the oxygen carrying capacity of the blood. Also addition of excess nitrates and phosphates to the water bodies leads to depletion of oxygen due to the formation of algal blooms. This, in turn, affects the environment and organisms.

Problem of congress-grass and other weeds

Problems arising out of pesticides and weedicides and smoking etc.

Tobacco Smoking:

Whole PDF:

[HIDE]

Code:

http://cvs.puchd.ac.in/Local%20env.%20issues%20chapt.pdf

[/HIDE]

thanks very much