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Rem
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- 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.
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Iodine – 131
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- 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.
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Lead
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- 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 in 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.
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Mercury
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- 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 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.
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Fluorine
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- It occurs in nature as fluoride, in air, soil and water.
- Fluorosis is a common problem in several states of the country due to intake of high fluoride content water.
- Fluorides cause dental fluorosis, 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.
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DDT
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- Toxic pesticides such 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.
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Lead In Paints
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- 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.
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Trans Fat
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- Trans Fats 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,
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High Caffeine In Energy
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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, glucuronolactone, 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.
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Pesticide In Human Blood
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- Pesticides are commonly used in India but this comes at great cost to human health. It found 15 different pesticides in the 20 blood samples tested from four villages in Punjab.
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Testing Of Pesticide Toxicity
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- 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. The 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” kill 50 percent 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
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