Damages Caused to a Biological System by Radiations

Most of the damages caused by radio-active pollutants stem from their capacity to produce high energy radiations which are very harmful to a living system. There are two main modes in which radio-active pollution can be dangerous to a biological system:

1. Damages caused by radiations from outside sources.

2. Damages caused by radiations from sources inside the body.

Radiation is a phenomenon in which energy or particles carrying high energy traverse the environment. Those radiations which cause ionization are high energy radiations capable of removing electrons from an atom and attaching them to others there by producing positive and negatively charged ions. These are known as ionizing radiations and include X-rays and gamma-rays, emission of alpha and beta particles etc.

In contrast to these there are some radiations which do not cause any ionization. They have a shorter wavelength. Due to their high energy content, they are capable of causing harms to micro-organisms and damage only the surface tissue of man, plant and animal bodies. A familiar example of such type of radiations is that of Ultra-violet rays.

As the chemical properties of radio-active isotopes of an element are similar to those of its non-radioactive isotopes a biological system is unable to distinguish between the two. Many radio­active isotopes are taken up by biological systems used, accumulated and passed on to the higher tropic levels in the food chain.

Thus the radio-active source is lodged within the body, often in concentration many times higher than the original medium in which organism concerned lives. An internal source of radio-activity is much more dangerous than an external source and may cause galls, tumors, degenerative changes and other malfunctions in the tissues of the body.

Transmutation of the radio-active isotopes incorporated in the structural component of the body of the organisms -abuses complete chaos in the system as the very basis of internal structure may crumble down. Moreover, such an individual who is loaded with radio-active material is a moving source of radio- activity and a health hazard for others who come in contact with him.

Damages caused by radiations at deterrent levels in a Dialogical organization may be summed up as follows:

(1) Damages at Molecular Level:

Damages to macromolecules such as enzymes. DNA, RNA etc. through ionization, cross-linkages within and between the two affected mol­ecules.

(2) Damages at Sub-cellular Level:

Damages to cell membranes, nuclei, chromosomes such as fragmentation, mitochondria, lysozymes etc.

(3) Damages at Cellular Level:

Inhibition of cell division, death, decay and transformation to malignant state etc.

(4) Damages to Tissues and Organs:

Disruption of such systems as Central Nervous Sys­tem, loss of sight, inactivation of bone marrow activity resulting into blood cancer, ma­lignancy and ulceration of intestinal tract etc.

(5) Damages to an Individual and Whole Population:

Death or shortening of life due to radiations. Changes in characteristics due to mutations etc.

In human beings acute exposure to radiations results in little visible effects in early stages. But after 12-24 hours injury symptoms manifest themselves. These include erythematic of skin (reddening of skin), anemia, anorexia (loss of appetite), vomiting aiarrnoea Ana with high heavy doses, blister formation, pigmentation of skin, burning sensation all over the body, loss of sight, paraplegia caused by disruption of central nervous system etc.

A single whole body dose of over 500 rams could result in death within four or five days, Delayed effects which may take as much as twenty years to appear are blood cancer or leukemia, carcinogenesis, fetal developmental anomalies, radiation shortening of life etc. It must be pointed out at this stage that for all this there is no remedy available -once a person is exposed to radiations he has to endure its consequences. Medical aid can do little for it.

There are some sculpture compounds such as Cystaemines, Amino-ethylisothiouronium, Betamercaptoethylguanidine etc. which are able to perform some reparative treatment but these too are not effective at higher doses of radiations.