Saturday, March 19, 2011

Radiation Protection ...Post Japan Nuclear Disaster, Earthquake and Tsunami.
The March 2011 earthquake and tsunami in Japan damaged the many nuclear power plants whose explosions have caused nuclear radiation to spread over Japan and may travel to other areas by wind and later by ocean currents and indirectly through food and goods chain even from China.The enormity of the challenges facing the international community and Japanese over public health issues are enormous. No single authority or country can face this massive challenge alone. There is a dire need for all people to understand the health risks involved in radiation spread and exposure.
Radiation or electromagnetic spectrum consists of alpha,beta and gamma rays of which the latter causes the maximum damage and harm.These particles when they enter our bodies produce ionizing reactions which disrupt cellular, chemistry, genetics, reproduction and growth. This is dependent on the amount of radiation exposure in terms of dose and time of exposure. Fastest growing cells such as that of skin, reproductive organs and bone marrow etc are most affected. These radiation particles are measured in RADS and are measured by hand held portable counter instruments which tell the total amount of exposure and help the health surveillance and treatment to be given to the victims.There maybe many stages of radiation exposure but in the case of nuclear exposure there are mainly two stages: Initial radiation and fall out.
Initial radiation takes place within a minute of the nuclear explosion.Neutron activity is maximum in this phase and because they are scattered from all directions any shield is not sufficient in protection and that is why Cobalt60 is used in nuclear weapons to cause maximum damage and penetration as its fission produces highest neutron activity. Gamma rays emitted are next in amount and because they travel in straight lines the shield against them maybe more effective as shield is usually used in one direction.They are extremely penetrating and cause maximum damage.
Fall out This occurs after a nuclear explosion as the nuclear fireball cools and the sucked up dust cools , radio active materials condense and contaminate its particles.The mushroom cloud reaches its ceiling about ten minutes after the explosion ( in case of a ten mega ton explosion the cloud extends over 2,600 square miles , with its top up to 20 miles above the earth's surface. the fission residue and grains of dust which it contains disperse with the cloud. depending on their weight and the weather the residue particles and the sand particles continue to rise, merely drift or start to descend.Those which rise to 6 or more miles above the earth enter the stratosphere in which the jet stream flows up to300 miles an hour . This rapidly distributes radioactive contamination over very wide areas.The surface winds take these radiation particles to other places. In case of rain or snow their concentration rises in the area it falls.The fall out can be several hundred miles and can continue over many years depending on the height of the cloud. The lethality of a fallout depends upon the strength of explosion. In a ten megaton fallout after an hour all exposed are killed within nine hundred square miles.The contamination from a fallout is most dangerous as it may pass into the food chain After initial measurement of radiation exposure, there is need for decontamination and this is done by thorough washing with soap and water.Detergent cleaning of all clothes, utensils and contaminated structures should be done. Food and water should be stored in air tight suitable containers.If food is stored in containers over which the radiation and dust particles do not fall, this can be eaten. But if food is actually contaminated if stored in semi-porous sacs it should not be eaten. Just like food does not pass radiation unless contaminated with radiation particles and dust , the human body does not become radioactive.Paper or plastic bags containing food should be properly sealed and the seal should be removed after brushing and air brushing to remove contamination particles.Shelters with safe food storage are an ideal.Condensed, evaporated or dried milk should be used instead of fresh milk. Tablets of calcium lactate can be used.The smooth surfaced vegetables and fruits can be shaken washed and peeled for consumption. Cereal crops should be thoroughly winnowed and all husks rejected.
Symptoms of radiation sickness may appear early as early as few hours to as late as few years depending on the dose , duration, distance from exposure. They are nausea, vomiting, redness of eyes, mouth and throat, loss of appetite and general weakness. Diarrhea may appear. the reddening of skin may increase with blistering and loss of hair.Convulsions, coma and death may finally occur.General ageing, shrinking and weakness of tissues in general due to inability of food absorption, shortening of bladder, bone fractures, thrombosis, cancers, aplastic anemia, bronco-pneumonia, inflammation of kidneys, liver, spinal chord, heart and lungs can occur.Recovery may take several months. genetically produced cancers may occur over generations. If sickness is severe disorientation and fits may result in death.
Precautions and Treatment : Some resistance in states of oxygen deprivation and hypothermia may occur.Complete rest, regular bowel movement, nutrition maintenance and hydration are all important Iodine tablets to reduce the radiation exposure as iodine absorbs the radioactive materials are to be taken to reduce thyroid hormones contaminated life cycle.
(References: The Nuclear Survival Handbook, Barry Popkess,Arrow Books Ltd., internet.)