Shankar IAS Summary: Environment Issues and Health Effects | Famous Books for UPSC Exam (Summary & Tests) PDF Download

TOXICOLOGY EFFECTS

• Eco-toxicology is “a study of the effects of released pollutants on the environment and on the biota that inhabit it.

Rem

• It gives an indication of biological damage. It is an estimate of the amount of radiation of any type, which produces the same biological injury in man as that resulting from the absorption of a given amount of X-ray radiation or gamma radiation.

Iodine - 131

• Iodine - 131 produced by nuclear tests is passed to vegetation and then appears in the milk of the cattle that consume the contaminated vegetation and is passed to humans.
• Iodine - 131 causes serious damage to thyroid gland, especially among children. About 99% of long-term radioactivity from either strontium or radium taken into the human body is found in the bones.

Lead

• Lead is highly toxic to plants and animals including man. Lead generally affects children more severely than adults.
• Lead poisoning causes a variety of symptoms. These include liver and kidney damage, reduction in haemoglobin formulation, mental retardation and abnormality in fertility and pregnancy. Symptoms of chronic lead-poisoning are of three general types.
  (i) Gastrointestinal troubles most common in industrial workers includes intestinal stress,
  (ii) Neuromuscular effects collectively called lead palsy, and impairment of muscle metabolism resulting into residual paralysis and muscular atrophy.
• Central nervous system effects CNS syndrome- a panoply of nervous system disorders, they may lead to delirium, convulsions coma and death.

Mercury

• This is the most common and most toxic in water bodies. It occurs, in water as monomethyl mercury.
• Methyl mercury vapours cause fatal poisoning.
• The recent popularity of energy efficient compact to fluorescent lamps or CFLs has added another dimension to the controversy.
• Toxicity of mercury is much greater than any other substance, about 1000 times more potent than colchicines.

Fluorine

• It occurs in nature as fluoride, in air, soil and water.
• Fluorisis is a common problem in several states of the country due to intake of high fluoride content water.
• Fluorides cause dental fluorisis, stiffness of joints (particularly spinal cord) causing humped back. Pain in bones and joint and outward bending of legs from the knees called Knock-Knee syndrome.
• In cattle, fluoride intake causes staining, mottling and abrasion of teeth, Lameness and decrease in milk production.

DDT

• Toxic pesticides as BHC, PCB, DDT etc., are not easily degraded and are long-lasting in the environment.
• Their concentration therefore goes on increasing in water and soil with successive applications.
• DDT was sprayed for many years on marshes to control mosquitoes,

The DDT has bio-magnified from water to fish eating birds and humans. DDT is known to depress the activity of estrogen, the female sex hormone and testosterone, male sex hormone.

LEAD IN PAINTS

• Present in paints.
• Though several countries have banned the use of this substance India is yet to: do so, Which is why paint makers use them.
• Inhaling lead dust like opening or closing windows is the most common source of lead poisoning.
• The human body is not designed to process lead. Young children are particularly
• Vulnerable to lead as it can damage the central nervous system and the brain. If lead is so poisonous why do paint makers continue to use it.
• Using lead, substitutes increases the cost and also reduces paint performance.

TRANSFAT

• Transfats are formed during the process of addition of hydrogen atoms to oils, a process which industry prefers as it keeps the oil from turning rancid and ensures a longer Shelf life ; E.g trans-fatty acid in vanaspati).
• Transfats are associated with a host of serious health problems ranging from diabetes to heart disease to cancer.
• The health ministry in 2008 came out with a notification for labelling food including transfats. Junk food high in transfats,

HIGH CAFFEIENE IN ENERGY
Energy drinks are in controversy because of its high caffeine content. Most of these brands

• Have upto 320 ppm of caffeine in them. These drinks are marketed as an instant source of energy.
• The manufacturers claim that it is the combination of caffeine, taurine, glucoronolactone, vitamins, herbal supplements, and sugar or sweeteners that gives the energy.
• According to study reports, it is the sugar that gives the energy rush, the caffeine only gives a 'feeling’ of energy. Energy drinks fall under the category of 'Proprietary foods’ in the Prevention of Food Adulteration (PFA) Act of 1954.
• An amendment in the PFA act 2009 ensured that caffeine in energy drinks should be capped at 145 ppm, the limit that was set for carbonated beverages.
• However, Red Bull managed to get a stay order on the amendment of the PFA act in2010 and since then the energy drink market is expanding unregulated.
• The Food Safety and Standards Authority of India (ESSAI) is currently making regulations on energy drinks.

PESTICIDE IN HUMAN BLOOD

• Pesticides are commonly used in India but this comes at great cost to human health. It found that 15 different pesticides in the 20 blood samples tested from four villages in Punjab.

TESTING OF PESTICIDE TOXICITY

• All pesticides are tested to establish toxicity- a dose necessary to produce a measurable harmful effect; it is usually established through tests on mice, rats, rabbits and dogs.
• Results are then extrapolated on humans, and safe exposure levels predicted. He value commonly used to measure acute toxicity is LD 50 (a lethal dose in the short term; the subscript 50 indicates the dose is toxic enough to" killl 50 per cent of lab animals exposed to the chemical).
• LD 50 values are measured zero onwards; the lower the LD 50 the more highly toxic the pesticide.
• Comparison of DDT most Used in India up to the early 1990s ,with monocrotophos, currently most used.
• DDT S LD 50 is 113 mg/kg; monocrotophos, 14 mg/kg. But never forget that lower LD 50 means higher acute toxicity

DISEASES CAUSED BY ENVIRONMENTAL DEGRADATION
1. Minamata disease

• First discovered in Minamata city in Kumamoto prefecture, Japan in 1956.
• Caused by the release of methyl mercury in the industrial wastewater from the Chisso Corporation's chemical factory, which continued from 1932 to 1968.
• Referred to as Chisso-Minamata diseas, is a neurological syndrome caused by severe mercury poisoning. 

2. Yokkaichi asthma

• Occurred in the city of Yokkaichi in Mie Prefecture, Japan between 1960 and 1972.
• The burning of petroleum and crude oil released large quantities of sulphur oxide that caused severe smog. 

3. Itai-itai disease

• Was the documefited case of mass cadmium poisoningin Toyama Prefecture, Japan, starting around 1912.
• The cadmium poisoning caused softening of the bones and kidney failure.
• The cadmium was released into rivers by mining companies in the mountains.

4. Blue baby syndrome

• Caused by high nitrate contamination in ground water resulting in decreased oxygen carrying capacity of haemoglobin in babies leading to death. 

5. Pneumoconiosis

• The coal miners are frequently caught by the black Lung disease, which is also called as Pneumoconiosis
• Caused due to the deposit of coal dust in the lungs of coal miners, leads to a serious lung disease called as Black Lung disease 

6. Asbestosis

• Workers working in the asbestos industry are caught by the serious lung Disease called as asbestosis. 

7. Silicosis

• Caused due to the deposit of silica in the lungs of workers working in silica industries or at the sand blasting sites 

8. Emphysema

• The breaking down of sensitive tissue of lungs due to air pollution and smoke of cigarette is called as Emphysema.
• Once this disease happens, the lungs cannot expand and contract properly 

9. Sick Building Syndrome (SBS)

• Sick building syndrome (SBS) is a combination of ailments (a syndrome; associated with an individual's place of work or residence.
• Most of the sick building syndrome is related to poor indoor air quality.

The National Wastelands Development Board (NWDB)

• The National Wastelands Development Board (NWDB) was set up under the. Ministry of Environment & Forests in 1985 with the objective of
  I. To increase tree and other green cover on wastelands,
  II. To prevent good land from becoming wasteland, and
  III. To formulate within the overall nodal policy, perspective plans and programmes for the management and development of the wastelands in the country.
• In 1992, the Board was transferred to the Ministry of Rural Development, Putting under a New Department of Wastelands Development under the charge of a Minister of State 

Bioassay

• A test in which organisms are used to detect the presence or the effects of any other physical factor, chemical factor, or any other type of ecological disturbance.
• Are very common in pollution studies. Can be conducted by using any type of organisms.
• The fish and insect bioassays are very common.
• The aim is to find out either lethal concentration or effective concentration causing mortality or other effects. Ultimately they are to be used for determination of safe concentration of a chemical or maximum acceptable toxicant concentration (MATC).