Reduce Radiation Exposure

Introduction to reduce radiation exposure

The radiation dose limits indicate the maximum occupational dose (OD) allowed for radiation workers in a year. One should make considerable efforts to adopt strict protective measures for working with radiations in order to reduce the radiation exposure to as low as reasonably achievable ( ALARA). To minimize the radiation exposure must be critically evaluated and adopted concept, techniques, equipment and procedures. Action level 1 is when a radiation worker receives > 5 mSv per quarter ( 10 % of OD per year) and Action level 2 is when a radiation worker receives > 15 mSv ( 30% of OD per year ). If these limits are exceeded, corrective actions must be taken by the RSO or higher limit must be justified by the particular situation. Let us see the action to be taken to reduce radiation exposure


Remedial action to reduce radiation exposure

Natural background is excluded from the above limits and the circumstances in which natural background itself or more especially, natural radiation sources enhanced locally by man's operations for selected purposes, can give rise to annual exposures above the level of 1mSv.

Remedial action levels involve a balance of risk and many other socio-economic factors. In general, the aim of setting a remedial action level is to reduce the greatest risks from a given type of radiation sources. It is clear that once a remedial action level is established for given circumtances, action is recommended when a level above it is found. Actions to reduce exposure should not be limited by or to the remedial action. Several criteria relevant to the low level risk or triviality of risk were considered in which perspective that tend to minimize subjective aspects of judgement. Smallness of risk was considered in relation to :

magnitude of dose,

difficulty in detection and measurement of dose and health effects,

natural risk for the same health effects,

perception of and behavioral response to risk levels.

estimated risk for the mean and variance of natural background radiation exposure levels.

An annual limit of 1 mSv effective dose for continuous exposure  and an annual limit of 5 mSv effective dose for infrequent exposure.

Remedial action levels for the public of 5 mSv annual average effective dose for exposure from natural sources excluding radon and an annual average of 7 x 10 ^ -3 Jh m^ -3 for total exposure to radon and its decay products.

 Another important change is the introduction of the radiation weighing factor which range from 1 for all photon energies up to 20 for 1 MeV neutrons and alpha particles. Thus these are the measures taken to reduce radiation exposure

Types of Pollutants Air Quality

Introduction to types of pollutants air quality
Pollution is the addition of any such constituents to air, water or land, which adversely alter the natural quality of environment. The constituent thus added is called pollutant.  Check this awesome  Three Properties of Ionic Compounds i recently used.


Types of pollutants sir quality


Pollutants can be categorized in two ways:

    According to source – Based on the source the pollutants are of two types:
a) Wastes from the industries, etc., as well as wastes from human and animal bodies.

b) Deliberate additions in the environment in the form of application such as pesticides and insecticides on cultivated plants, stored grains etc.

   Based on the degradability the pollutants are of two kinds:
a) Biodegradable pollutants are such substances that can be broken down by organisms and dispersed.

b) Non – biodegradable pollutants are those that are virtually indestructible. For example DDT and various detergents move up in the food chain (producer to primary consumer to secondary consumer and so on) becoming more and more concentrated at each trophic level

 Certain substances are totally non-biodegradable, for example aluminum, glass and plastic are not acted upon by any organism and if felt in environment they remain as junk for all the time.  

Solve all your Common Chemical Formulas problem with me. Please comment on my blogs.

Pollutants and pollution


These types of pollutants leads to various types of pollution, such as air pollution, water pollution, soil pollution, thermal pollution and noise pollution.

Air pollution – The pollutant responsible for this type of pollution are of two types namely:

Particulate air pollutants – consists of unburnt particles of coal, coke etc.
Gaseous air pollutants – consists of sulphur dioxide, nitrogen dioxide, hydrogen sulphide, carbon monoxide, ammonia etc.
Water pollution – the pollutants responsible for this type of pollution are:

Organic pollutants – dissolved in water reduces aquatic life
Poisonous insecticides – this primarily consists of DDT, and some other industrial wastes.
Sewage – untreated sewage causes cholera, typhoid etc.
Oil from washings of automobiles and oil spilling.
Similar types of pollutants contribute to soil, thermal and noise pollution as well.

What are State Functions

Introduction to what are state functions

State function is a thermodynamic term in thermodynamics.  Thermodynamics is a branch of science that deals with the study of interconversion of heat with other forms of energy during physical and chemical processes.  In order to understand thermodynamics, the knowledge of the following terms is essential.  Those are system, surroundings and Boundary. Please express your views of this topic Thermodynamics Problems by commenting on blog.

System: A system is a specified portion of the universe which is under thermodynamic study and which is separated from the rest of the universe with a definite boundary.

Surroundings: The surroundings is the portion of the universe excluding the system and capable of exchanging matter and energy with the system.

Boundary: The real or imaginary surface that separates the system from the surroundings is called boundary.


State of a System:


The state of a system is the condition of the system expressed by giving definite values for its properties such as temperature, pressure, volume, enthalpy, Entropy, gibbs free energy etc. Looking out for more help on Formation of Ionic Compounds in chemistry by visiting listed websites.


State function:


The variables like temperature, pressure, volume, enthalpy, Entropy, gibbs free energy  etc which define the state of a system are called state functions or thermodynamic variables.

When the state of a system changes, the values of the state functions also change.  If any two state functions like pressure and temperature are known, the value of the third state function, volume is fixed automatically.  The two state functions like pressure and temperature are called independent state functions while volume is the dependent state function.

The values of state functions depend only on the state of the system and not upon the way in which the state is reached.

Work and heat are not state functions.( W and q)

Standard state: The state of a system at 298K and 101.3 kPa pressure is known as standard state of the system.

Enthalpy: It is the one of the state function which is defined as the total heat content of a system.  It is measured as the sum of its internal energy and the product of pressure and volume.  It is represented as H.

H=U+ (PV)

Where U is the internal energy, P is the pressure and V is the volume of the system.

Entropy: It is a measure of disorder or randomness of a system.  Substance in a highly disorded state have high values of entropy.  When the disorder increases, the value of entropy also increases.  Entropy is represented by S.

Gibbs free energy:  Gibbs energy is the capacity of a system to do non-mechanical work.  It is represented by G.

G=H-TS

Where H is Enthalpy, T is temperature and S is Entropy of the system.