The effects of Radiation can cause damage to tissue and/or organs depends on the dose of radiation received. Or the absorbed dose which is expressed in a unit called the gray (Gy). The potential damage from an absorbed dose depends on the type of radiation and the sensitivity of different tissues and organs.
Nuclear radiation, unlike the radiation from a light bulb or a microwave, is energetic enough to ionize atoms by knocking off their electrons. This ionizing radiation can damage DNA molecules directly. By breaking the bonds between atoms. Or it can ionize water molecules and form free radicals. Which are highly reactive and also disrupt the bonds of surrounding molecules, including DNA.
What is Ionizing Radiation
Ionizing radiation is a type of energy which atoms emit in the form of electromagnetic waves or particles.
Ionizing radiation happens when the atomic nucleus of an unstable atom decays and starts releasing ionizing particles.
When these particles come into contact with organic material, such as human tissue. They will damage them if levels are high enough, in a short period of time. This can lead to burns, problems with the blood, gastrointestinal system, cardiovascular and central nervous system, cancer, and sometimes death.
People are expose to natural sources of ionizing radiation, such as in soil, water, and vegetation, as well as in human-made sources, such as x-rays and medical devices
Applications of radiation
Radiation is all around us and it applies safely in many applications. Effects of radiation should always be noted.
Ionizing radiation has many beneficial applications, including uses in medicine, industry, agriculture and research. Sometimes, it applies to low-level laser therapy.
In medicine, X-rays and other forms of radiation also have a variety of therapeutic uses. When used in this way, they are most often intended to kill cancerous tissue, reduce the size of a tumor, or reduce pain. For example, radioactive iodine (specifically iodine-131) is frequently used to treat thyroid cancer.
Some geologist uses some form of radioactive substances to determine the ages of fossils and other objects through a process called carbon dating. This process have been very helpful in determining ages and compositions of rocks and so many mineral resources.
The agricultural industry makes use of radiation to improve food production and packaging. Plant seeds, for example, have been exposed to radiation to bring about new and better types of plants. Besides making plants stronger, radiation can be used to control insect populations, thereby decreasing the use of dangerous pesticides.
Exposure to very high levels of radiation, such as being close to an atomic blast, can cause acute health effects such as skin burns and acute radiation syndrome (“radiation sickness”). It can also result in long-term health effects such as cancer and cardiovascular disease. Exposure to low levels of radiation encountered in the environment does not cause immediate health effects, but is a minor contributor to our overall cancer risk.
What is Radiation Sickness
Radiation poisoning happens when a radioactive substance gives off particles that get into a person’s body and cause harm. Different radioactive substances have different characteristics. But the effects of radiation depend majorly on the dose of exposure. They can harm and help people in different ways, and some are more dangerous than others.
Normally, radiation occurs in a safe environment. Whether or not it becomes dangerous depends on:
- The use of the radiation
- how strong the radiation is
- how often the exposure occurs
- what type of exposure occurs
- how long exposure lasts
A dose of radiation from a single x-ray is not normally harmful.
Activity is a measure of the amount of a radionuclide present. It is expressed in a unit called the becquerel (Bq): one becquerel is one disintegration per second.
The half-life is the time required for the activity of a radionuclide to decrease by decay to half of its initial value. The half-life of a radioactive element is the time that it takes for one half of its atoms to disintegrate. This can range from a mere fraction of a second to millions of years (e.g. iodine-131 has a half-life of 8 days while carbon-14 has a half-life of 5730 years).
What Part of the Body Does Radiation Affect?
The risk of illness depends on the dose of radiation exposure. Very low doses of radiations are all around us all the time, and they do not have any effect. It also depends on the area of the body that is exposed.
The losing of hair quickly and in clumps occurs with radiations exposure at 200 rems or higher.
Since brain cells do not reproduce, they won’t be damaged directly unless the exposure is 5,000 rems or greater. Like the heart, radiations kills nerve cells and small blood vessels and can cause seizures and immediate death.
The thyroid gland is sensitive to radioactive iodine. Insufficient amounts, radioactive iodine can destroy all or part of the thyroid. By taking potassium iodide, one can reduce the effects of exposure.
- Blood System
When exposure of about 100 rems occurs, the blood’s lymphocyte cell count will reduce, leaving the victim more vulnerable to infection. This is often referred to as mild radiations sickness. Early symptoms of radiation sickness mimic those of “flu” and may go unnoticed unless a blood count is done.
- The Heart
Intense exposure to radioactive material at 1,000 to 5,000 rems would do immediate damage to small blood vessels and probably cause heart failure and death directly.
- Gastrointestinal Tract
Radiation damage to the intestinal tract lining will cause nausea, bloody vomiting, and diarrhea. This occurs when the victim’s exposure is 200 rems or more.
- Reproductive Tract Though reproductive tract cells divide rapidly. These areas of the body can damage at rem levels as low as 200. Long-term, some radiation sickness victims will become sterile.
Though these radiations affects our body system most often but that’s not a panic. The fatality of radiation depends on the dose of which u are exposed to.
What Radiation Dose is Dangerous?
Radiations dosage can be measured in various ways. Some of the units used are Grays, Sieverts, rems, and rads. They are used in a similar way, but 1 rad is equivalent to 0.01 Gray.
Below 30 rads: Mild symptoms will occur in the blood
From 30 to 200 rads: The person may become ill.
From 200 to 1,000 rads: The person may become seriously ill.
Over 1,000 rads: This will be fatal.
According to the Centers for Disease Control and Prevention (CDC), radiation sickness, or acute radiations syndrome (ARS) is diagnosed when:
A person receives over 70 rads from a source outside their body
The dose affects the whole body, or most of it, and is able to penetrate to the internal organs
The dose is received in a short time, usually within minutes.
The effective dose is used to measure ionizing radiation in terms of the potential for causing harm.
What Age Does Radiation Affect More?
Children and fetuses are especially sensitive to radiation exposure. The cells in children and fetuses divide rapidly, providing more opportunity for radiations to disrupt the process and cause cell damage. The effects of radiations on children are high. EPA considers differences in sensitivity due to age and sex when revising radiations protection standards.
If the radiations dose is low and/or it occurs over a long period of time (low dose rate), the risk is substantially lower because there is a greater likelihood of repairing the damage. There is still a risk of long-term effects such as cancer, however, that may appear years or even decades later. The effects of this type will not always occur, but their likelihood is proportional to the radiation dose. This risk is higher for children and adolescents, as they are significantly more sensitive to radiation exposure than adults.
Epidemiological studies on populations exposed to radiation, such as atomic bomb survivors or radiotherapy patients, showed a significant increase of cancer risk at doses above 100 mSv. More recently, some epidemiological studies in individuals exposed to medical exposures during childhood (paediatric CT) suggested that cancer risk may increase even at lower doses (between 50-100 mSv).
Prenatal exposure to ionizing radiations may induce brain damage in fetuses following an acute dose exceeding 100 mSv between weeks 8-15 of pregnancy and 200 mSv between weeks 16-25 of pregnancy. Before week 8 or after week 25 of pregnancy human studies have not shown radiation risk to fetal brain development. Epidemiological studies indicate that the cancer risk after fetal exposure to radiations is similar to the risk after exposure in early childhood.
Unit of measurement of radiations
The sievert (Sv) is the unit of effective dose that takes into account the type of radiation and sensitivity of tissues and organs. It is a way to measure ionizing radiation in terms of the potential for causing harm. The Sv takes into account the type of radiation and sensitivity of tissues and organs.
The Sv is a very large unit so it is more practical to use smaller units such as millisieverts (mSv) or microsieverts (μSv). There are one thousand μSv in one mSv, and one thousand mSv in one Sv. In addition to the amount of radiation (dose), it is often useful to express the rate at which this dose is deliver (dose rate), such as microsieverts per hour (μSv/hour) or millisievert per year (mSv/year). Beyond certain thresholds, radiation can impair the functioning of tissues and/or organs and can produce acute effects such as skin redness, hair loss, radiation burns, or acute radiation syndrome. These effects are more severe at higher doses and higher dose rates. For instance, the dose threshold for acute radiation syndrome is about 1 Sv (1000 mSv).
What are the symptoms of radiation Exposure
Radiation sickness can be acute, happening soon after exposure, or chronic, where symptoms appear over time or
after some time, possibly years later.
The signs and symptoms of acute radiation poisoning are:
vomiting, diarrhea, and nausea
loss of appetite
malaise, or feeling unwell
Symptoms depend on the dose, and whether it is a single dose or repeated.
A dose of as low as 30 rads can lead to:
loss of white blood cells
nausea and vomiting
A dose of 300 rads dose may result in:
temporary hair loss
damage to nerve cells
damage to the cells that line the digestive tract
Stages of radiations sickness
Symptoms of severe radiations poisoning will normally go through four stages.
Prodomal stage: Nausea, vomiting, and diarrhea, lasting from a few minutes to several days
Latent stage: Symptoms seem to disappear, and the person appears to recover
Overt stage: Depending on the type of exposure, this can involve problems with the cardiovascular, gastrointestinal, hematopoietic, and central nervous system (CNS)
Source of Radiations
The many activities that can expose people to sources of radiations include:
flying in an airplane
passing through a security scanner
using a microwave or cell phone
Smokers have a higher exposure than non-smokers, as tobacco contains a substance that can decay to become polonium 210.
Astronauts have the highest exposure of anyone. They may be expose to 25 rads in one Space Shuttle mission.
Preventive Measures against Radiation Exposure
WHO has established a radiation program to protect patients, workers, and the public against the health risks of radiation exposure under planned, existing, and emergency exposure situations. Focusing on public health aspects of radiation protection, this program covers activities related to radiations risk assessment, management and communication.
Damage by radiations is irreversible. When a cell damages, it does not repair itself. Until now, there is no way for medicine to do this, so it is important for someone who is expose to seek medical help as soon as possible. Possible treatments include:
Removing all clothing and Rinsing with water and soap.
Use of potassium iodide (KI) to block thyroid uptake if a person inhales or swallows too much radioiodine
Exposure to radiations can also be treated with Prussian blue, given in capsules, can trap cesium and thallium in the intestines and prevent them from being absorbed. This allows them to move through the digestive system and leave the body in bowel movements.
Another method of treatment is with Filgrastim, or Neupogen stimulates the growth of white blood cells. This can help if radiation has affected the bone marrow.
Depending on exposure, radiations can affect the whole body. For cardiovascular, intestinal, and other problems, treatment will target the symptoms.