Chemical agents: Epidemiology and clinical characteristics Flashcards
objectives
- what is a chemical attack
- how do attacks occur
what is chemical attack
-the purposeful use of chemical substance to harm people, cause economic or property damage or instill fear or panic
geneva protocol
- banning the use of chemical
- treaty
why the use of chemical weapons
- materials accessible
- easy to breach security barriers
- simple delivery systems
- greater psychological impact
- status “WMD” -poor mans nuclear weapon -> anyone can do
disadvantages of chemical weapons
- requires large quantities
- production and deployment hazardous to terrorist too
- easier to prepare for
how chemical could be used
- the severity of an attack is related to the toxicity of the chemical and its concentration when it reaches people
- during the day -> heat convection currents make the gases disperse
- during the night -> more concentrated in one area
- concentration variable include:
- wind
- volatility
- closed or open spaces
methods of disseminating chemical weapons
- ventilation systems
- misting, aerosolizing devices, or sprayers
- passive release (container of chemical left open)
- bombs, mines, or other explosive devices
- sabotage of plants or vehicles containing chemicals
- introduction of toxins in the food and water supply
- improvised chemical devices that combine readily available chemicals to produce a dangerous chemcial
detection
-many chemicals at high concentration can be readily detected with hand held detection equipment carried by many emergency responders
responding to exposures
- response can be confusing
- require rapid response
- protect staff from secondary exposure*
- differentiate between significant trivial exposures
- decontaminate (based on agent involved)
- notify appropriate agencies (poison control, public health and safety)
- removing clothing - 80% of contamination
warning signs
- abandoned containers
- devices containing suspect items
- strong chemical odors
- incident preceded by a written or verbal threat
- multiple patients exhibiting similar signs and symptoms
ways of contracting
- inhalation
- ingestion
- absorption (touch)
- injection
personal protection
- tactical withdrawal from contaminated area
- time
- distance
- shielding
- blot- blot off the agent
- strip- strip off all clothing (80%)
- flush- flush affected area with large amount of water
- cover- cover the affected area
chlorine gas
- choking agent
- severe coughing
- frothing sputum
- convulsions
- pulmonary edema
mustard gas / odor of garlic
blister agents
- effects:
- eyes
- lungs
- skin
- 2-24 hours onset
blood agents
- interferes with hemoglobin and o2
- hypoxia leading to:
- AMS
- seizures
- respiratory arrest
- cardiac arrest
- can spread through fire
- hydrogen cyanide
- oder: bitter almonds
nerve agents
- nerve agents affect the nervous system
- do not occur naturally
- the first know nerve agent was created in the 1930s- tabun (GA)
- new agents known as g-agents were stockpile by Germany during WW2- sarin (GB) and Soman (GD)
- 1960s- more focus on creating their potency and environmental persistence
- creation of the v-agents
- VX more potent than Sarin
physiological effects chemical warfare (CW)
- acts on the central nervous system
- seizures
- respiratory arrest
- cardiac arrest
signs and symptoms of nerve agents
- pinpoint pupils
- runny nose
- difficulty breathing
- loss of consciousness
- convulsions/seizures
- sweating
- nausea/vomiting
routes of exposure for nerve agents
- inhalation
- skin absorption
- ingestion
- injection
SLUDGEM
- salivation
- lacrimation (secretion of tears)
- urination
- defecation
- gastroenteritis (GI irritation)
- emesis
- miosis (pupil constriction)
- everything comes out at once
pathophysiology of nerve agents
- the NA binds with acetylcholinesterase
- allowing acetylcholine to overstimulate the nerve pathway located in the nervous system
Tabun (GA)
- persistent
- evaporates in 1-2 days
Soman (GD)
- non persistent
- evaporates rapidly
Sarin (GB)
- non persistent
- evaporates rapidly
V agent (VX)
- persistent
- remains for weeks or longer
Tokyo Subway attack
- march 20, 1995
- morning rush hour
- container of Sarin nerve gas
- 5 cars in 3 underground lines
- 3 cult members
- delivery- plastic bags punctured with sharpened umbrellas
- dispersion- liquid which turned into gas, concentration
riot-control agents
- tear gas (CS)
- mace (CN)
- pepper spray (OC)
herbicide agents
- main purpose is to disrupt agriculture food production and/or to destroy plants which provides cover or concealment to the enemy
- vietnam war- agent orange
- not banned by the CWC unless they are used as a method of warefare
- the used of agent orange still a lingering issue in the US vietnam relations
- in 2003, survivors sued the US corporation for damages
