ENVIRONMENTAL POLLUTION

Dr VISHAL SHARMAAssoc. Prof.

Botany DepartmentPost Graduate College for Girls-11,

Chandigarh

AIR POLLUTION:

Air pollution is defined as any atmospheric condition in which certain substances are found in such cincentration that they can produce undesirable effects on living organisms.

Major types of pollutants are:

(1)Sulphur dioxide:

Humans chronically exposed to SO2have a higher incidence of coughs, shortness of breath, bronchitis, fatigue, ‘colds’ of lung duration.

Small particles can adsorb sulfur dioxide and with water form acid containing particles which irritate the respiratory system and damage the cells that line the system.

Effect of SO2 + Effect of small particles ----> worse effect than the sum of the individual effects.

(2)Photochemical smog:The word ‘smog’ means combination of smoke and fog.The characteristic symptoms of smog arebrown haze,eye irritation,respirators distress,reduce visibility and damage to plants.

Action Results

•acts as oxidizing agent and attacks cells cell break down and collapse

•modifies proteins, amino acids, unsaturated fatty acids, sulfhydryl residues

leakage of water and iron from cells

•produces ethylene damage in plants sensitive to ethylene

•reduces carbon dioxide fixation reduced plant vigor and reduction in new amount of cell material produced.

(3) Effect of Ozone on Plants

Suspended Particulate Matter- very small particles- solid or liquid- float in air/ settle slowly

Types of Suspended Particulates- Mist(>10 μm)- Fog- Dust(1μm)

- Fly ash -Smoke(o.1 μ to 1 μm) -Fumes(0.1 μm)

Effect of Toxicity is modified by- number of particles- size of particles

(4)Particulate matter:These are the atmospheric substances which are not gases and are in the form of suspended droplets or solid particles.

(5)Nitric oxides :

These are the major primary pollutants of seven oxides of nitrogen,only three N2O(nitrous oxide),NO(nitric oxide) and NO2(nitrogen dioxide)

The primary source of these oxides is automobileexhaust and combustion of fuels.These play an important role in formation of photochemical smog.

- It is not very toxic at ambient levels- is rapidly converted to nitrogen dioxide which is toxic- at concentrations far above those observed in cities, it can cause disturbance in the- central nervous system- circulatory system- enzyme system

Nitrogen Dioxide (NO2)- NO2 penetrates to the most remote portions of the respiratory tract, the alveoli because of its low solubility in water.

The effects of carbon monoxide are dependent upon both- concentration- duration

Oxygen transport cells usually replace carbon dioxide with oxygen. However, in the presence of carbon monoxide, they will replace oxygen and carbon dioxide with carbon monoxide. This reduces the supply of oxygen to the body.Carbon dioxide has a strong affinityu with haemoglobin and reduces its oxygen carrying capacity,thus affecting the respiratory activity and metabolism.It causes severe headache,blurred vision and onconciousness.

Under ambient conditions, carbon monoxide intoxication is likely to aggravate existing physical conditions. Under acute conditions, it may result in death.

(6)Carbon Monoxide(CO):

It is considered to be single largest pollutant in the urban atmosphere.This gas is produced by incomplete combustion of coal,charcoal,petrol and its products.

The source of atmospheric carbon monoxide is the oxidation of methane.Anaerobic decomposition of organic matter produces CH4 which gets oxidised to produce CO.

Concentration of CO (ppm) Effect

High concentration- greater than 100 ppm for 10 minutes.

Physiological stress on patients with heart disease

100 ppm-intermittently Impaired performance in psychomotor tests

50 ppm – for 90 min. Impaired time-interval discrimination for non-smokers

30 ppm – for up to 12 hours. Elevated carbon in hemoglobin levels- reduced oxygen transport

Effect of Carbon Monoxide

OZONE HOLE

Ozone is largely found in the stratosphere and the atmospheris ozone plays a very important role in biospheres.It absorbs all the solar ultraviolet radiations.

Recently ,satellite data has indicated that there is a reduction of the ozone layer over Antartica causing ozone hole.The gasese resposible for depletion is Cholorofluorocarbon(CFC),NO3 etc

CCl2F2----------------CClF2+ClCl+2O3--------------CL+3O2

A single atom of chlorine is sufficient to convert I Lakh molecules of Ozone into oxygen.In ozonosphere chlorine attacks ozone ,thus depleting 6.5% in the process

Ozone depletion(2006)

Effect of Global Warming on Earth Atmosphere

Melting glaciers

Effect of Acid Rain on Forest

SOURCES OF WATER POLLUTION

1) INDUSTRY

Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.

Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.

Pollutants from industrial sources include: Asbestos – This pollutant is a serious health hazard . Asbestos fibres can be inhaled and cause illnesses such as asbestosis, lung cancer, intestinal cancer and liver cancer. Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.

Mercury - irritation of respiratory system, lung, liver and kidney damage

Arsenic: - irritation of respiratory system, liver and kidney damage - weakness, loss of appetite, nausea and vomiting

Cadmium - lung, liver and kidney damage - irritation of respiratory system

Chromium - lung damage and Irritation of respiratory system

Nickel - lung, liver and kidney damage

Chemical and Metallic Pollutants:

Industries including textiles, pesticides,paints,dyes,soap ,drugs,cement, rubber,paper , pulp,sugar,steel and metal industries pou their pollutants which include Mercury,Arsenic,Cadmium,Chromium,Nickel etc in water.These chemicals have adverse effect on human beings and crop productivity

(2) OIL POLLUTION IN WATER

Oceans are polluted by oil on a daily basis from oil spills, routine shipping, run-offs and dumping.

Oil spills make up about 12% of the oil that enters the ocean. The rest come from shipping travel, drains and dumping.

An oil spill from a tanker is a severe problem because there is such a huge quantity of oil being spilt into one place.

Oil spills cause a very localised problem but can be catastrophic to local marine wildlife such as fish, birds and sea otters.

Oil cannot dissolve in water and forms a thick sludge in the water. This suffocates fish, gets caught in the feathers of marine birds stopping them from flying and blocks light from photosynthetic aquatic plants

3) RADIO ACTIVE WASTE

Nuclear waste is produced from industrial, medical and scientific processes that use radioactive material. Nuclear waste can have detrimental effects on marine habitats.

Nuclear waste comes from a number of sources:

Operations conducted by nuclear power stations produce radioactive waste. Nuclear-fuel reprocessing plants in northern Europe are the biggest sources of man-made nuclear waste in the surrounding ocean. Radioactive traces from these plants have been found as far away as Greenland.

Mining and refining of uranium and thorium are also causes of marine nuclear waste.

Ganga Action plan:An plan was setup to save river Ganga.The plan was launched in 1985.It was aimed to reduce the pollution levels in the ganga.But, the increasing population andindustrialization have already damagedthis mighty river beyond repair.

Yamuna action plan:

This plan was setup to save river Yamuna.It was launched in 1993.It had a plan to restore the river yamuna to its past glory.There were two plans setup named as YAP-I and YAP-II.