0647126_DA545_nadeina_l_v_radioekologiya

2.3Some of the statements are not true, correct them.

a)The body fluids (blood, sweat, urine) of an externally contaminated person can contain radioactive materials.

b)People who are externally contaminated can’t spread the contamination by touching surfaces, sitting in a chair, or even walking through a house.

c)Radioactive contamination and radiation exposure could occur if

radioactive materials are released into the environment as the result of only an accident, and not an event in nature.

d)People who are externally contaminated can expose people near them to radiation from the radioactive material inside their bodies.

e)Since radiation can be seen, smelled, felt, or tasted, people at the site of an incident will know whether radioactive materials were involved.

f)An contaminated person can be exposed by not being too close to radioactive material or a contaminated person, place, or thing.

g)Radioactive materials give off a form of energy that travels in protons or neutrons.

2.4Read the following word formations and remember their pronunciation. controlled – uncontrolled

type – typical – typically stable – unstable evitable – inevitable

contaminated – contamination – contaminant radioactive – radioactivity – radiation environment – environmental

nature – natural – naturally biology – biological – biologically toxic – toxicity

treat – treatment

protect – protective – protection

2.5Choose between the alternatives to complete these sentences.

1.There are three types of radiation/ radioactive/radioactivity.

2.Gamma rays come from the nucleus of the atom of a radiation/ radioactive/radioactivity isotope.

3.They are the most energetic and most penetrating of all radiation/ radioactive/radioactivity.

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4. Contaminated/contamination/contaminant may occur from radioactive gases, liquids or particles.

5.On the other hand, radiation/ radioactive/radioactivity iodine is used in the diagnosis and treatment/treat of many diseases of the thyroid precisely because of the thyroid's selective uptake of iodine.

6.The hazards to people and the environment/environmental from radioactive contaminated/contamination/contaminant depend on the nature of the radioactive contaminated/contamination/contaminant, the level of contaminated/contamination/contaminant, and the extent of the contaminated/contamination/contaminant.

3.Read the text and do the tasks.

Sources and measurement of contamination

Radioactive contamination is the uncontrolled distribution of radioactive material in a given environment. The amount of radioactive material released in an accident is called the source term.

Radioactive contamination is typically the result of a spill or accident during the production or use of radionuclides, an unstable nucleus which has excessive energy. Contamination may occur from radioactive gases, liquids or particles. For example, if a radionuclide used in nuclear medicine is accidentally spilled, the material could be spread by people as they walk around. Radioactive contamination may also be an inevitable result of certain processes, such as the release of radioactive xenon in nuclear fuel reprocessing. In cases that radioactive material cannot be contained, it may be diluted to safe concentrations. Nuclear fallout is the distribution of radioactive contamination by a nuclear explosion.

Radioactive contamination may exist on surfaces or in volumes of material or air. In a nuclear power plant, detection and measurement of radioactivity and contamination is often. Surface contamination is usually expressed in units of radioactivity per unit of area. For SI, this is becquerels per square meter.

Hazards: low level contamination and high level contamination

In practice there is no such thing as zero radioactivity. Not only is the entire world constantly bombarded by cosmic rays, but every living creature on earth contains significant quantities of carbon-14 and most (including humans) contains significant quantities of potassium-40. These tiny levels of radiation are not any more harmful than sunlight, but just as excessive quantities of sunlight can be dangerous, so too can excessive levels of radiation.

The hazards to people and the environment from radioactive contamination depend on the nature of the radioactive contaminant, the level of con-

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tamination, and the extent of the contamination. Low levels of radioactive contamination pose little risk, but can still be detected by radiation instrumentation. In the case of low-level contamination by isotopes with a short half-life, the best course of action may be to simply allow the material to naturally decay. Longer-lived isotopes should be cleaned up and properly disposed of, because even a very low level of radiation can be lifethreatening when in long exposure to it. Therefore, whenever there's any radiation in an area, many people take extreme caution when approaching.

High levels of contamination may pose major risks to people and the environment. People can be exposed to potentially lethal radiation levels, both externally and internally, from the spread of contamination following an accident (or a deliberate initiation) involving large quantities of radioactive material. The biological effects of external exposure to radioactive contamination are generally the same as those from an external radiation source not involving radioactive materials, such as x-ray machines, and are dependent on the absorbed dose.

Biological effects

The biological effects of internally deposited radionuclides depend greatly on the activity and the biodistribution and removal rates of the radionuclide, which in turn depends on its chemical form. The biological effects may also depend on the chemical toxicity of the deposited material, independent of its radioactivity. Some radionuclides may be generally distributed throughout the body and rapidly removed, as is the case with tritiated water. Some radionuclides may target specific organs and have much lower removal rates. For instance, the thyroid gland takes up a large percentage of any iodine that enters the body. If large quantities of radioactive iodine are inhaled or ingested, the thyroid may be impaired or destroyed, while other tissues are affected to a lesser extent. Radioactive iodine is a common fission product; it was a major component of the radiation released from the Chernobyl disaster, leading to many cases of pediatric thyroid cancer and hypothyroidism. On the other hand, radioactive iodine is used in the diagnosis and treatment of many diseases of the thyroid precisely because of the thyroid's selective uptake of iodine.

Means of contamination

Radioactive contamination can enter the body through ingestion, inhalation, absorption, or injection. For this reason, it is important to use personal protective equipment when working with radioactive materials. Radioactive contamination may also be ingested as the result of eating contaminated plants and animals or drinking contaminated water or milk from exposed

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animals. Following a major contamination incident, all potential pathways of internal exposure should be considered.

3.1Are the following statements true (T) or false (F)?

1)Radioactive contamination is the uncontrolled distribution of radioactive material in a given environment.

2)Radioactive contamination may also be an inevitable result of certain processes, such as the release of radioactive xenon in nuclear fuel reprocessing.

3)In practice there is no such thing as zero radioactivity.

4)The hazards to people and the environment from radioactive contamination depend on the nature of the radioactive contaminant, the level of contamination, and the extent of the contamination.

5)Some radionuclides may be generally distributed throughout the body and rapidly removed, as is the case with tritiated water.

6)If large quantities of radioactive iodine are inhaled or ingested, the thyroid may be impaired or destroyed, while other tissues are affected to a lesser extent.

3.2Fill in the correct word from the list then make up sentences using them.

contaminated, personal protective, pediatric thyroid, chemical, x-ray, biological, longer-lived, tiny, every living, cosmic, zero, power, inevitable, uncontrolled, radioactive, nuclear

1………………………medicine

2……………………...contamination

3………………………distribution

4……………………… result

5……………………… plant

6……………………… radioactivity

7……………………… rays

8……………………… creature

9……………………… levels

10………………………isotopes

11………………………effects

12…………………….. .machines

13………………………toxicity

14……………………… cancer

15……………………….equipment

16……………………….plants and animals

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3.3Put words in order, form sentences and translate them.

1.Risk, pose, radioactive, of, contamination, levels, but, low, little,

still, can, by, detected, instrumentation, radiation, be.

2.Contamination, enter, body, ingestion, absorption, injection, radioactive, can, the, through, inhalation, or.

3.May, on, volumes, or, material, or, radioactive, of, contamination, exist, air, surfaces, in.

4.Occur, contamination, radioactive, may, gases, from, or, liquids, par-

ticles.

5. Term, source, the, called, accident, is, an, released, in, material, of, amount, the, radioactive.

6.Body, the, instance, for, enters, the, gland, thyroid, up, a, any, of, that, iodine, takes, percentage, large.

7.Radioactivity, in, is, zero, as, no, thing, such, practice, there.

8.Concentrations, safe, to, be, it, cannot, be, material, cases, that, diluted, contained, may, in, radioactive.

9.Sunlight, than, any, not, more, of, harmful, these, levels, tiny, are, ra-

diation.

10.Contamination, usually, in, of, per, of, surface, is, expressed, units, radioactivity, unit, area.

4.Translate these sentences into English.

1.Радиоактивное загрязнение почвы и атмосферы значительно изменяет параметры атмосферного электрического поля (АПЭ), искажая при этом естественный электромагнитный фон. 2. Аномалии АПЭ, возникающие в зонах радиоактивного загрязнения, могут быть тем дополнительным нерадиационным фактором, который вызывает наблюдаемое несоответствие между заболеваемостью людей и реальной радиоэкологической ситуацией. 3. Радиоактивное загрязнение окружающей среды и связанные с ним аномалии АЭП будут воздействовать на организм человека одновременно. 4. Даже если биологические эффекты от каждого из этих воздействий будут небольшими (или неощутимыми), то эффекты от их суммарного воздействия могут быть весьма значительными. 5. Есть основания полагать, что результат комбинированного воздействия малых доз радиации и аномальных электрических полей может превосходить сумму эффектов от каждого фактора в отдельности, т.е. может иметь место так называемый «синергизм». 6. У детей, проживающих вблизи радиоактивных зон, отмечена резко повышенная частота заболе-

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ваемости лейкозами, хотя и сами дети, и их родители не получали опасных доз радиации, а также такие явления как раннее старение, ослабление зрения, угнетение реактивности иммунной системы, чрезмерная психологическая возбудимость, изменение в составе крови и др. 7. По мнению исследователей, они могут быть связаны с дополнительным воздействием аномалий АЭП, возникающих в результате радиоактивного загрязнения окружающей среды, которое само по себе не вызывает наблюдаемых эффектов. 8. Действие малых доз радиации может быть также усилено присутствием тех или иных химических элементов и их соединений, синергизмом действия факторов ионизирующей радиации и химического загрязнения.

(Л.П. Рихванов «Радиоактивные элементы в окружающей среде и проблемы радиоэкологии», Томск, 2009)

5. Mind the pronunciation and the meaning of the following words.

Word	Pronunciation		Meaning
poisoning	[´pɔiz(ǝ)niŋ]		отравление, заражение
tissue	[´tiʃu:]		ткань
acute	[ǝ´kju:t]		крайний, критический
syndrome	[´sindrəum]		синдром, совокупность симптомов
disease	[di´zi:z]		болезнь
chronic	[´krɔnik]		хронический, затяжной (о болез-
			ни)
cancer	[´kæn(t)sə]		рак
tumor	[´tju:mə]		опухоль, новообразование
stochastic	[stɒ´kæstik]		случайный, стохастический
joule	[ʤu:l]		джоуль
sievert	[´si:vət]		зиверт (единица СИ эквивалент-
			ной дозы излучения)
gray	[grei]		грей ( единица СИ поглощенной
			дозы излучения)
radium	[´reidiəm]		радий
genetic	[ʤi´netik]		генетический
dosage	[´dəusiʤ]		дозировка, дозирование
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excessive	[ik´sesiv]	непомерный, избыточный
deliberate	[di´lib(ə)rit]	взвешенный, тщательно спланиро-
		ванный

6. Read the text and do the tasks.

Radiation poisoning

Radiation poisoning, also called «radiation sickness» or a «creeping dose», is a form of damage to organ tissue due to excessive exposure to ionizing radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period, though this also has occurred with long term exposure. The clinical name for «radiation sickness» is acute radiation syndrome (ARS) as described by the CDC. A chronic radiation syndrome does exist but is very uncommon; this has been observed among workers in early radium source production sites and in the early days of the nuclear program. A short exposure can result in acute radiation syndrome; chronic radiation syndrome requires a prolonged high level of exposure.

Radiation exposure can also increase the probability of contracting some other diseases, mainly cancer, tumors, and genetic damage. These are referred to as the stochastic effects of radiation, and are not included in the term radiation sickness.

The use of radionuclides in science and industry is strictly regulated in most countries. In the event of an accidental or deliberate release of radioactive material, either evacuation or sheltering in place will be the recommended measures.

Measuring radiation dosage

The rad is a unit of absorbed radiation dose defined in terms of the energy actually deposited in the tissue. One rad is an absorbed dose of 0.01 joules of energy per kilogram of tissue (or 100 ergs per gram). The more recent SI unit is the gray, which is defined as 1 joule of deposited energy per kilogram of tissue. Thus one gray is equal to 100 rad.

To accurately assess the risk of radiation, the absorbed dose energy in rad is multiplied by the relative biological effectiveness of the radiation to get the biological dose equivalent in rems. Rem stands for «Rontgen equivalent in man». In SI units, the absorbed dose energy in grays is multiplied by the same RBE to get a biological dose equivalent in sieverts (Sv). The sievert is equal to 100 rem.

The RBE is a «quality factor», often denoted by the letter Q, which assesses the damage to tissue caused by a particular type and energy of radiation. For alpha particles Q may be as high as 20, so that one rad of alpha radiation is equivalent to 20 rem. The Q of neutron radiation depends on their

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energy. However, for beta particles, x-rays, and gamma rays, Q is taken as one, so that the rad and rem are equivalent for those radiation sources, as are the gray and sievert.

Table of exposure levels and symptoms

Annual limit on intake is the derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. ALI is the smaller value of intake of a given radionuclide in a year by the reference man that would result in a committed effective dose equivalent of 5 rems (0.05 Sievert) or a committed dose equivalent of 50 rems (0.5 Sievert) to any individual organ or tissue. Dose-equivalents are presently stated in sieverts (Sv):

Exposure level	Symptoms
0.05–0.2 Sv	No symptoms. A few researchers contend that low
(5–20 REM)	dose radiation may be beneficial. 50 mSv is the yearly
	federal limit for radiation workers in the United States.
	In the UK the yearly limit for a classified radiation
	worker is 20 mSv. In Canada and Brazil, the single-year
	maximum is 50 mSv, but the maximum 5-year dose is
	only 100 mSv. Company limits are usually stricter so as
	not to violate federal limits.
0.2–0.5 Sv	No noticeable symptoms. White blood cell count
(20–50 REM)	decreases temporarily.
0.5–1 Sv	Mild radiation sickness with headache and in-
(50–100 REM)	creased risk of infection due to disruption of immunity
	cells. Temporary male sterility is possible.
1–2 Sv	Light radiation poisoning, 10% fatality after 30
(100–200 REM)	days (LD 10/30). Typical symptoms include mild to
	moderate nausea (50% probability at 2 Sv), with occa-
	sional vomiting, beginning 3 to 6 hours after irradiation
	and lasting for up to one day. This is followed by a 10 to
	14 day latent phase, after which light symptoms like
	general illness and fatigue appear (50% probability at 2
	Sv). The immune system is depressed, with convales-
	cence extended and increased risk of infection. Tempo-
	rary male sterility is common. Spontaneous abortion or
	stillbirth will occur in pregnant women.
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2–3 Sv	Moderate radiation poisoning, 35% fatality after 30
(200–300 REM)	days (LD 35/30). Nausea is common (100% at 3 Sv),
	with 50% risk of vomiting at 2.8 Sv. Symptoms onset at
	1 to 6 hours after irradiation and last for 1 to 2 days. Af-
	ter that, there is a 7 to 14 day latent phase, after which
	the following symptoms appear: loss of hair all over the
	body (50% probability at 3 Sv), fatigue and general ill-
	ness. There is a massive loss of leukocytes (white blood
	cells), greatly increasing the risk of infection. Perma-
	nent female sterility is possible. Convalescence takes
	one to several months.
3–4 Sv	Severe radiation poisoning, 50% fatality after 30
(300–400 REM)	days (LD 50/30). Other symptoms are similar to the 2–3
	Sv dose, with uncontrollable bleeding in the mouth, un-
	der the skin and in the kidneys (50% probability at 4 Sv)
	after the latent phase.
4–6 Sv	Acute radiation poisoning, 60% fatality after 30
(400–600 REM)	days (LD 60/30). Fatality increases from 60% at 4.5 Sv
	to 90% at 6 Sv (unless there is intense medical care).
	Symptoms start half an hour to two hours after irradia-
	tion and last for up to 2 days. After that, there is a 7 to
	14 day latent phase, after which generally the same
	symptoms appear as with 3-4 Sv irradiation, with in-
	creased intensity. Female sterility is common at this
	point. Convalescence takes several months to a year.
	The primary causes of death (in general 2 to 12 weeks
	after irradiation) are infections and internal bleeding.
6–10 Sv (600–	Acute radiation poisoning, near 100% fatality after
1,000 REM)	14 days (LD 100/14). Survival depends on intense med-
	ical care. Bone marrow is nearly or completely de-
	stroyed, so a bone marrow transplant is required. Gastric
	and intestinal tissue are severely damaged. Symptoms
	start 15 to 30 minutes after irradiation and last for up to
	2 days. Subsequently, there is a 5 to 10 day latent phase,
	after which the person dies of infection or internal
	bleeding. Recovery would take several years and proba-
	bly would never be complete.
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10–50 Sv	Acute radiation poisoning, 100% fatality after 7
(1,000–5,000	days (LD 100/7). An exposure this high leads to sponta-
REM)	neous symptoms after 5 to 30 minutes. After powerful
	fatigue and immediate nausea caused by direct activa-
	tion of chemical receptors in the brain by the irradiation,
	there is a period of several days of comparative well-
	being, called the latent (or «walking ghost») phase. Af-
	ter that, cell death in the gastric and intestinal tissue,
	causing massive diarrhea, intestinal bleeding and loss of
	water, leads to water-electrolyte imbalance. Death sets
	in with delirium and coma due to breakdown of circula-
	tion. Death is currently inevitable; the only treatment
	that can be offered is pain management.
More than 50	A worker receiving 100 Sv (10,000 REM) in an
Sv (>5,000	accident at Wood River, Rhode Island, USA on 24 July
REM)	1964 survived for 49 hours after exposure, and an op-
	erator named Cecil Kelley who received between 60 and
	180 Sv (18,000 REM) to his upper body in an accident
	at Los Alamos, New Mexico, USA on 30 December
	1958 survived for 36 hours; details of this accident can
	be found in the journal «Los Alamos Science», Number
	23 (1995).

6.1 Translate these phrases into English.

Зараженный человек; в виде пыли, порошка; вдыхать радиоактивные материалы; через открытую рану; осаждаться на разных органах тела человека; всасываться через кожу; проникать в тело человека; для того, чтобы человек подвергся заражению; удаляться из тела человека через кровь, пот, мочу и испражнения; находясь слишком близко к радиоактивным материалам; могут попадать в окружающую среду следующими способами; авария на атомной станции; испытание ядерного оружия; радиоактивная пыль; содержать радиоактивные материалы; предотвращать заражение; другими словами; так как радиацию нельзя увидеть или почувствовать; ограничение загрязнения; снизить риск внутреннего заражения; сократить время воздействия; избегать распространения заражения; принимать лекарственные препараты.

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