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THE EFFECTS OF CHEMİCAL WARFARE AGENTS (CWA) ON HEALTH

Konuyu Hazırlayan: Bio. İpek Niksarlı

What is a CWA?

Chemical warfare agents are chemical materials that have a high toxicity potential that are used for terror and to cause panic among civilian personnel. These materials can: kill, wound and weaken, have an incapacitating effect and disable, destroy food and animal resources, contaminate food stock and impair economically important goals, inhibit the ability of military and civilian personnel to move by forcing them to wear protective clothing and vehicles.

Why are CWA’s used?

There are two main reasons for their use:

  1. Direct effect and destruction
  2. Indirect destruction (through the long term wearing of protective masks and clothing)

What forms do they come in?

In solids, liquids, gases and aerosol forms; spread and dispersed through: spray containers, spray tanks carried on helicopters and airplanes, canons, rockets, missiles, mines, hand grenades or airplane bombs.

Classification of CWA’s:

CWA’s are classified according to their toxic characteristics as follows:

  1. Nerve agents
  2. Vesicants
  3. Pulmonary Irritants
  4. Incapacitating Agents
  5. Riot Control Agents
  6. Vegetation Destruction Agents

Entry into the organism

The effects of CWA’s can be seen systemically or locally. Many are absorbed in more than one way through the skin, the eyes, the mouth or the airways.

Penetration Strengths

Many CWA’s have an extremely high penetration strength through various materials. Surgical gloves are permeable. Such synthetic materials as butyl rubber and polyester are impermeable.

What should be done when in contact with CWA’s

  1. Detection and warning: The qualitative and quantitative detection of CWA’s.
  2. Protective measures: Gas masks, protective and secure clothing and shelters should be used on time and when necessary.
  3. Preliminary treatment, first aid and self -treatment :This information has been given for every substance.
  4. Decontamination: Difficult, time consuming but an obligatory procedure.

The goals of decontamination methods:

Chemically to destroy, remove, limit the physical blocks and damage of the toxic agent.

To wash, rinse, dry, absorb with absorbent material, dry the chemical agents with decontaminating agents to remove and clean them.

Personal Decontamination

  • Skin contamination: Speed is of the utmost importance. The contamination must take place in less than two minutes. Rubbing the skin during washing procedures can increase the absorption of the toxic agent.
  • Eye contamination: Rinsing with plenty of water and sterilized saline solution is recommended.

Area Decontamination

The surface of the earth should be removed and lime or a layer of lime should be spread over the area.

Belongings, Supplies, Equipment Decontamination

Hypocloride and DS2 substances are used. Physical decontamination (cleaning belongings through heating, hot air and boiling)

Food Decontamination

All contaminated food and liquids should be destroyed. As a protective measure all food should be placed in tightly closed aluminum, tin, or glass containers.

5. Specific and Supportive Measures

Substances used in CWA’s

  1. Nerve gases Developed as an acetyl cholinesterase inhibitor. These lethal agents are Tabun, Sarin, Soman and VX and possess immediate and life threatening effects.

Symptoms

  1. Elevation of muscarinic activity
  2. Nicotinic effects
  3. Central Nervous System symptoms

The first observable symptoms are:

  1. Running eyes
  2. Deep pain under the eyes
  3. Feeling of chest pressure, coughing
  4. Running nose

Treatment: In treating nerve agents, a specific antidote called atropine and an enzyme reactivator is used.

  1. Atropine: Adults: 2-5 mg. atropine sulfate (i.v.) / Children: 0.05 mg/kg atropine sulphate(i.v.)
  2. Oxime: Pralidoxime: Adults: 1-2g (i.v.) / Children: 25-50 mg/kg

OR Obidoxime: 250 mg (i.v.) (i.m.)

*Diapezem implementation: The last step of antidotal treatment.

Adults: 5-10 mg (i.v.) / Children: 0.25-0.4-mg/kg doses

2. Vesicants: General tissue irritants with systemic effects. These are mustard gases, nitrogen mustard gases and lewisite, which have lethal effects and incapacitate.

Mustard gas: This group of agents is the most important. Two minutes after coming in contact with the tissue there is damage to the tissue and later no matter what is done this damage is permanent. For this reason the decontamination must take place within two minutes.

Symptoms develop in this order:

  • On first contact there is no effect.
  • After 30 minutes to 3 hours, distinct symptoms begin in the eyes.
  • After 4 to 16 hours the symptoms become more pronounced with painful tearing of the eyes, nausea and vomiting.

Treatment: There is no specific antidote.

  1. Quick decontamination and symptomatic treatment.
  2. Burn treatment for blisters.

Decontamination: A %2.5 solution of sodium thiosulphate is recommended as specific decontamination agent for contact through skin, eyes and inhalation.

3.Pulmonary Irritants

Substances that cause physical irritation to the pulmonary system tissues.

Phosgene has lethal effects.

The first observable effects are the irritation of the eyes and the mucous membranes of the pulmonary area. The characteristic smell is of rotten weeds, corn silk and newly cut hay.

Treatment: There is no antidote. Decontamination is conducted through plenty of soap and water.

4.Blood poisons

This is a lethal CWA, which interfere with cell breathing. These are cyanides and hydrogen sulphur, which have sudden life threatening effects.

Cyanides

The most important ones are: hydrogen cyanide, cyanogenic chloride that is dispersed in gas form. They have a bitter almond smell. An overdose of cyanide can kill in 6-8 minutes.

Treatment:

  1. Immediately administer %100 O2
  2. Start antidotal treatment.
  3. Decontamination: As long as there is a heartbeat, antidote treatment is effective.
  1. Amyl Nitrite + Sodium Nitrite+ Sodium Thiosulphate antidote.
  2. Dimethylaminophenol Adults: 250mg (i.v.) / Children: 3mg/kg (i.v.)
  3. Dicobalt Edetate Administer: 600 mg (i.v.)

*Do not cause vomiting. Do stomach pumping.

*Do not attempt mouth-to-mouth resuscitation!

Hydrogen Sulphur

It has the characteristic small of rotten eggs. It is highly toxic and has direct effects on devastating the SSS cells.

Treatment:

Same as cyanide treatment but do not use sodium thiosulphate.

5.Incapacitating Agents

Substances, which cause disturbances that, resemble serious mental illnesses known as psychoses. The most frequently used substances are BZ (3-quinuclidinylbenzilate) and LSD (Lysergic Acid Diethyl amide).

BZ

Blocks the impulse control of the role that acetylcholine plays in the central and peripheral nervous systems.

Treatment

In case of inhalation:

  1. Remove the patient from the contaminated area.
  2. Control the patient’s pulmonary functions.
  3. Put the patient in a quiet and secure area for observation.
  4. Administer physostimin salycilate. Adults: 2 mg (i.v.) (10 ml %5 dextrose) / Children: 0.02 mg/kg (i.v.)
  5. Symptomatic treatment.

Tachyarrhythma’s that do not respond to physostigmine may respond to propranolel (i.v.)

In case of oral contact:

  1. Produce vomiting.
  2. Active coal.
  3. Cathartics
  4. Antidotes (physostimin salycilate)
  5. Symptomatic treatment

LSD

Symptoms

  1. Somatic
  2. Sensory
  3. Psychic

Treatment

In case of oral contact:

  1. Assess pulmonary and cardiovascular functions.
  2. Gastric washing and inducing vomiting are not important.
  3. Active coal.
  4. Cathartics
  5. Symptomatic treatment.

In case of inhalation:

Follow instructions in # 1 and 5 of oral contact.

6.Riot control agents

Cause quick but temporary loss of capacity.

The differences between psychochemical agents:

  1. The psychochemical effects start later but last longer after contact.
  2. The psychochemical affect the centers while riot control agents are sensory irritants.

a.Tear agents

The conjunctiva is especially sensitive to certain irritants, which increase tear secretions.

The effects of these agents usually rapidly disappear through escape from the contaminated area. The main chemicals are: chloroacetophenone (codename CN), orto-chlorobenzylidene-malononitrile (codename CS) and dibenz (b,f)-1,4-oxazepine (codename CR).

b.Vomiting agents

These agents irritate the nose and the mucosa of the upper respiratory tract. The chemical most used is diphenylaminearsine (DM)

General protective measures and treatment. The best preventive measure is to use a mask. Decontamination must take place. There is no specific antidote.

6.Vegetation Killing Agents

  1. These agents destroy vegetation, the enemy’s power to resist and food stocks.
  2. In areas with trees, the agent causes leaves to fall thus limiting the possibility for the enemy to hide.

There are two groups:

  1. Herbicides
  2. Agents that sterilize the earth

Treatment:

Decontamination and symptomatic treatment.

Table ( Characteristics Of Some CWA' S )

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