Human role in pollution control, Environment and human health; Effects of pollutants on animals and plants; urbanisation and industrial development.
Human role in pollution control
The enhanced pace of developmental activities and rapid urbanization have resulted in stress on natural resources and quality of life. The trend of increasing pollution in various environmental media is evident from the deteriorating air and water quality, higher noise levels, increasing vehicular emission etc. Realising the urgent need for arresting the trend, Both Central and State Governments have adopted policy for Abatement of Pollution which provides for several mechanisms in the form of regulations, legislation, agreements, fiscal incentives and other measures to prevent and abate pollution. Further, realizing that conventional pollution control approach by treatment at the end of the pipe is not delivering the desired benefits in terms of resource conservation, the thrust has been shifted to pollution prevention and control through promotion of clean and low waste technology, re-use and recycling, natural resource accounting, Environmental Audit and Institutional and Human Resource Development.
Various techniques to control Air Pollution are:-
- Combustion:- is used for controlling those air pollutants that are in the form of organic gases or vapours. In this technique, the organic air pollutants are subjected to flame combustion technique (also known as catalytic combustion). In this technique, organic pollutants are converted into less harmful products and water vapour.
- Absorption:-is the most commonly used methods, especially for controlling emissions from small sources. It can be physical adsorption or chemisorptions.
- Fabric filters, or baghouses, remove dust from a gas stream by passing the stream through a porous fabric. The fabric filter is efficient at removing fine particles and can exceed efficiencies of 99 percent in most applications.
- Mechanical devices:-There are many mechanical devices that clean the air of pollutants either due to (i) gravity in which the particles settle down by gravitational force; or by (ii) sudden change in the direction of gas flow in which particles separate out due to greater momentum.
- Electrostatic precipitators:-is a particle control device that uses electrical forces to move the particles out of the flowing gas stream and onto collector plates.
Environment and human health; Effects of pollutants on animals and plants
Human beings are exposed to a variety of chemicals including industrial chemicals, pesticides, air pollutants, natural and man made toxicants etc in the environment through the skin, respiratory system and gastrointestinal tract that can affect vital body systems such as pulmonary, reproductive and nervous and immune system. Dysfunction of these systems could have far-reaching consequences, which affect individuals and even their progeny from serious health ailments.
Air pollutants can be in the form of particulate matter which can be very harmful to our health. The level of effect usually depends on the length of time of exposure, as well the kind and concentration of chemicals and particles exposed to. Short-term effects include irritation to the eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia. Others include headaches, nausea, and allergic reactions. Short-term air pollution can aggravate the medical conditions of individuals with asthma and emphysema. Long-term health effects can include chronic respiratory disease, lung cancer, heart disease, and even damage to the brain, nerves, liver, or kidneys. Continual exposure to air pollution affects the lungs of growing children and may aggravate or complicate medical conditions in the elderly.
Effects of Water Pollution
Waterborne diseases caused by polluted drinking water:
Waterborne diseases caused by polluted beach water:
- Rashes, ear ache, pink eye
- Respiratory infections
- Hepatitis, encephalitis, gastroenteritis, diarrhoea, vomiting, and stomach aches
Conditions related to water polluted by chemicals (such as pesticides, hydrocarbons, persistent organic pollutants, heavy metals etc):
- Cancer, incl. prostate cancer and non-Hodgkin’s lymphoma
- Hormonal problems that can disrupt reproductive and developmental processes
- Damage to the nervous system
- Liver and kidney damage
- Damage to the DNA
- Exposure to mercury
The impacts on human health from degradation of the environment affect society not only in terms of loss of quality of life, but also in terms of expenditure on health care, loss of productivity and loss of income.
Urbanisation and Industrial development
Major Environmental problems of unplanned urbanization are:-
1.High rent & land prices: More travel time and release of pollutants due to transport
2.Electricity crisis : Use of generators
4.Gardens & buildings