Essay on the Distribution of Toxic Material in the Environment

Toxic material released in the environment may remain at the point of their discharge or' be transported to other place. The distance up to which they are transported depends mainly on the mobility of the agent carrying them. Moving waters and air currents are effective media for transfer and transport of toxic substances. The mobility of a toxic material is however, not confined to their dispersion within a single medium.
Materials released into water may get distributed in soil and air as well. Toxic material released into atmosphere may contaminate soil as well as water. Wastes discarded on the soil may contaminate the water which seeps through it or the air may get contaminated when it carries the vapours or small particles of the toxic material.
Pollutants can enter a biological system from any of the three media, such as water, soil on which carry them. In lower plants and animals, plasma membrane is the main barrier between outside environment and the biological system inside the cell.
In higher plants and animals we possess much better protective devices such as coating of wax, cuticles, multilayered epidermis pollutants have to take other routes. These routes may be through the roots, root-hairs, rhizoid stomata etc. in plants and through nasal mucosa and mucosal lining of mouth, respiratory track and gastro-intestinal track in animals. In many cases, the epidermis is pervious to certain types of pollutants.
Nature has provided higher animals including man with an efficient device which helps them to guard against pollutants which regularly enter through intestinal track. Materials absorbed from intestines are routed through hepatic portal system to the liver wherein harmful constituents are reacted upon by liver's enzymatic machinery.
A number of harmful materials absorbed intestines are degraded or converted to harmless state before reaching the blood circulation However, this is not so in the case of pollutants entering the system through respiratory track. The air in alveoli of lungs is in direct contact with blood in capillaries across a thin membrane. The material absorbed enters straight into the blood circulation. This becomes more significant in to light of the fact that we breathe in by weight about 16 times more air than total foodstuff and water consumed orally.
The plasma membrane through which all substances entering a cell must pass is lipoprotein membrane being made up of a thin layer of lipid or lipid like substance covered on both sides by a layer of proteins. The basic structure of plasma membrane is strikingly uniform throughout the living world.
The rate of entry of the toxic material into a biological system is influenced by the size of its molecules, its concentration in the medium, the nature and solubility of the substance in water as well as in lipids and fats. Substances soluble in lipoid material (lipophilic ones) are carried across the plasma membrane simply by dissolution and diffusion through the lipid layer. Lipoid insoluble but water soluble toxic material (hydrophilic ones) may require an active transport mechanism. Smaller molecules such as those of water simply pass through pores in membrane.
Inside a biological system the toxic material may be either stored or is reacted upon by the enzyme system and excreted. The phenomenon of accumulation of toxic agent inside cells and tissues of living organisms at concentrations above those of immediate environment is known is Bio-accumulation.
The toxic material soluble in lipoid substances or capable of forming complex with macromolecules within the cell may be stored for long duration of time as they are excreted very slowly. By virtue of complex formation and dissolution is lipoid materials which are storage products of cellular metabolism, these substances stay away from the enzymatic reaction which act on then the toxic material once inside a living organism may be concentrated several thousand times the process of Bio-magnification which causes enhancement in the concentration of toxic along the food chain.
Toxic agents who enter a living organism at the level of primary producers get concentrated many thousand times as they move up along the food chain to higher trophic levels. Thus, it is not only air, water or soil which may carry the toxic material of persistant nature.
The toxic agent may accumulate and be biomagnified through the food chain thus contaminating the entire biotic component of the locality. If the food we eat comes from organisms growing in contaminated environment, plants or animals, there is every possibility that it carries small amounts of toxic substance - the chances of getting higher concentration of toxic agent being higher and higher at higher trophic levels.

Essay on Girl Child Infanticide

Women are the receiving end in Indian society. They are will treated or tortured at every stage. A girl child is in bondage from her very childhood. She is under constant, vigil First by the parents, then her husband and finally her own children. Not only that, she is often condemned to death even before she is born. This is called female killing in the womb itself.
In ancient India the birth of a girl child was hailed as auspicious. An old Indian proverb lies down that a home without a daughter is like a body without soul. The coming of a daughter in the house was compared to the advent of Laxmi, the Goddess of wealth and Saraswati, the Goddess of fine arts. The usual blessing of a father at the time of his daughter’s marriage was: “May you excel in learning and public speaking”. No ceremony was considered complete without the presence of women. The belief was that “No home is complete without a woman.”
The situation, however drastically changed during the middle Ages when India was subjected to frequent foreign invasions. The invaders batty also comprised of women suffered badly, infanticide and ‘Purdah’ became prevalent. Sending a girl to school became risky. There was, therefore, sudden decline in female literacy and the position of women in society. This tradition lasting till today and the killing of a fetus has started with a boom.
The problem of female fetus is widespread in urban centres. With the help of new techniques it has become possible to determine the sex of the unborn baby or the fetus, and if it is found to be a girl child then, this is followed by abortion. Clinics offering such service have come up all over the country.
There are severing laws against the misuse of parental diagnostic techniques, which are meant only for detecting abnormalities in the unborn infant. The doctors, however, violate this law. Not a single case has been fielding so far under the law, which forbids such an unethical practice.
Today, the problem is quite widespread in the northern states of Bihar, Uttar Pradesh and Rajasthan. There are pockets of Tamilnadu where killing a girl child is practiced traditionally. The tribes, the Toda, The Kallar and the Gounder, earlier lived in war zones are facing torture of army soldier. They started to kill the girl child in order to keep the population of women down and thus save them from rape by invading armies. In Rajasthan also, a girl child is looked upon as a curse because her father has to lie low before the father of boy at the time of match finding.
Upon attaining puberty, a girl is considered to be a security risk, a likely source of trouble for the family’s honor and reputation. Then there are economic reasons for her killing. She is a liability for her parents from the cradle ceremony to the marriage. There has been not let up in the dowry system, which breaks the back of the parents. She is got rid of in order to save the family properly from partition. In some communities there is a dirty superstition that is a daughter is killed, the next child will be a son. In China also, the eldest male child inherits the property look upon the male child as their protector and supporter in old age. This gender-bias leads to the killing of girl child.
The greatest tragedy is that women themselves permit the death of their daughters as mercy killing. Unwanted baby girls are often left on the road or in the maternity homes at night. This is due to the unhealthy sex before marriage or due to the husband of may died, who is the only source to take of her and her baby. This unhealthy practice has caused a great imbalance in the ratio of boys and girls in several states and communities. To prevent this situation we must provide proper education and the laws, that are presently could not trap the criminal, should be strict. So those, all the people who engage in this child infanticide crime, think twice before doing it.