Stages of Development of Chemical Intoxication

These include:

· primary decompensation

· physiological adaptation

· latent pathology

· decompensated pathology (poisoning)

Types of Poison Cumulation in Organism

· Material - accumulation of poison or its metabolites in organism;

· Functional - accumulation of only toxic effects of poison in organism;

· Mixed - accumulation of metabolites or poison and pathological effects in organism

Table 41

Classification of Toxic Substances according to Degree of Cumulation

Level of cumulation	Coefficient of cumulation Ccum	Time of response, (in days)
Supercumulation	< 1	< 20
Expressed cumulation	1 - 3	20 - 60
Moderate cumulation	3 - 5	60 - 100
Slight cumulation	> 5	> 100

 

Combined Effect of Poisons

As a rule, in real industrial conditions the isolated effect of poisons on organism is practically not encountered, more often the combined effect takes place (the effect of many substances at the same time), which can considerably change toxic effects in comparison with separate effect.

Types of Combined Effect

Theyare as follows:

· Antagonism (less than additive action),

· Summation (additive action),

· Potentiation (more than additive action).

Hygienic Estimation of the Industrial Environment Taking into Account Type of Combined Effect of Poisons

· In case of antagonism the estimation is carried out in respect of separate maximum permissible concentration for every found poison C < MPC;

· At summation the estimation is made according to the formula of summary toxicity by Averianov:

where

C – concentration of the found substance

MPC1 MPC2 MPC i MPC – maximum permissible concentration

· At potentiation the estimation is made according to the formula:

where C – concentration of the found substance

MPC1 MPC2 MPC i MPC – maximum permissible concentration

K - coefficient of potentiation

The Basic Methods of Detoxication of Industrial Poisons in organism

They include the following:

· Change of chemical structure of poison - hydroxylation (formation of OH-groups), oxidation, restoration, methylation (binding СН3-groups), connection with glucuronic acid and amino acids resulting in formation of less toxic metabolites.

· Depositing in organs and tissues (material cumulation) – a temporary decrease of concentration of poison in blood (for example, heavy metals are deposited in bones, liver and kidneys). It is a defective way of neutralization as under unfavorable conditions the exit of poisons from depot may take place resulting in aggravation of chronic poisonings.

· Elimination from organism - through lungs, kidneys, intestines, skin.

Detoxication System of Organism and Parameters of Its Functioning

This complex system can be presented as a 5-component protection:

· Microsome oxidation by microsome monooxygenases (MOGS). Indicators are cytochromes R-450, b 5, etc. The accumulation of oxide radicals, etc. is possible.

· Reaction of conjugation (connection) with proteins. Indicators - restored glutathione, etc.

· Bioenergy processes for detoxication - oxidizing phosphorylation, etc.

· Processes of peroxidation of lipides. Indicatiors – level of malonic dialdehyde, diene conjugates.

· Antiradical and antiperoxidation protection (activity of enzymes: catalase, peroxidase, superoxide dismutase, vitamin C, etc.)

According to the state and interrelation of these 5 components it is possible to differentiate adaptation and compensation: at activation of the 1st and 4th links the others links should be activated (it is adaptation): if at activation of the 1st and 4th links the others links are not activated, it is toxicogenic dishomeostasis, i.e. latent decompensation.

Ways of Entry of Industrial Poisons into Organism

· Inhalation is the most frequent and dangerous way (the area of the lungs with blood capillaries is 100–120 m2; there is no barrier function of the liver). This way is characteristic of volatile poisons – the higher their solubility in blood, the more dangerous they are.

· Through skin and mucous membranes - lipotropic poisons (soluble in fats) get into organism through injured skin, hair follicles, sudoriferous and sebaceous glands.

· Per os - through mouth and mucous membranes of stomach and intestines – this way in professional conditions is very rare; it is encountered at non-observance of rules of personal hygiene, casually with foods.

Adsorption of Poisons in Organism

After absorption poisons can accumulate in the liver, blood, bones, lymph, hair, nails.

Ways of Elimination of Industrial Poisons from Organism

We can distinguish the following ways of eliminatingindustrial poisonsfrom organism:

· Through kidneys - it is the most frequent way for many substances.

· Through intestines – it is for badly soluble poisons, such as lead, mercury.

· Through lungs – it is for volatile substances, e.g. sebaceous aromatic hydrocarbons.

· Through skin and endocrine glands (fat-soluble substances - through sebaceous, mammary glands, heavy metals - through sudoriferous, salivary glands).

Biosubstances, in which the content of poisons or their metabolites is determined to confirm the diagnosis of poisoning are as follows: blood, urine, faeces, exhaled air, secretion of glands.