d. Absorption of Blood Agents. Blood agents are primarily absorbed into the
body through the respiratory system. They quickly enter the blood circulatory system
where they interfere with oxygen exchange. In high concentration, AC may cause death
after a few breaths.
e. Physiological Effects. Once the agent enters the circulatory system, it
reacts rapidly with enzymes that are vital in the absorption and release of oxygen. The
first organ to be impaired from the decrease in oxygen is the brain. These agents can
cause unconsciousness, coma, and death. Death from AC leaves the blood
well-oxygenated and the casualty's skin has a pinkish look similar to that of carbon
monoxide poisoning. In addition to interfering with oxygen exchange, CK also attacks
the respiratory system and causes eye irritation.
LUNG-DAMAGING (CHOKING) AGENTS
Lung-damaging (choking) agents attack lung tissue and cause irritation of the
respiratory system. Damage can also result in secondary infection.
a. Types of Choking Agents. Lung-damaging agents include phosgene (CG),
diphosgene (DP), chlorine (Cl), and chloropicrin (PS). Phosgene is the lung-damaging
agent most likely to be used.
b. Methods of Dissemination. Lung-damaging agents can be delivered by
artillery shell, mortar shell, rocket, aircraft bomb or bomblet, or missile. Lung-damaging
agents are usually disseminated as gasses. Phosgene can be in liquid form when the
temperature is below 46oF (7.8oC).
c. Characteristics of Lung-Damaging Agents. Phosgene is colorless both as
a gas and as a liquid. Phosgene has an odor that resembles the smell of newly mowed
hay, grass, or green corn. Chlorine has a characteristic odor and produces immediate
irritation of the respiratory system. Lung-damaging agents are classified as
d. Absorption of Lung-Damaging Agents. Lung-damaging agents are
absorbed through the respiratory system. If the casualty has been exposed to a lethal
concentration of CG, death usually results within 24 to 48 hours. Exposure to very high
concentrations of CG can result in death within 5 hours.
e. Physiological Effects. Phosgene attacks the lungs by damaging the alveoli
(air sacs) and capillaries and by scarring the lungs. Damage to lung tissue can cause
blood plasma to seep into the lungs and result in pulmonary edema. This condition,
sometimes called "dry land drowning," interferes with the exchange of oxygen and
waste products between the air in the lungs and the red blood cells of the circulatory
system. The trachea, bronchi, and other parts of the respiratory tract are irritated, but
not significantly damaged.