reply to post by searching4truth
Thanks for that! There is a latent period after exposure as well...where the person may seem ok
4.1.1. Acute Inhalation Exposure
The acute toxicity of phosgene inhalation has been well documented in humans (WHO, 1998, 1997; U.S. EPA, 1986c, 1984; Underhill, 1919).
Inhalation of phosgene at high concentrations results in a sequence of events, including an initial bioprotective phase, a symptom-free latent period,
and a terminal phase characterized by pulmonary edema (Schneider and Diller, 1989; Diller, 1985). In the initial phase, high concentrations (>3 ppm)
may result in a vagal reflex action that causes frequent, shallow respiration and decreased respiratory vital capacity and volume. This, in turn,
leads to a decreased arterial CO2 pressure increase and decreased blood pH. After cessation of exposure, the reflex syndrome shows a tendency to
regress.
In the second phase, which may last for several hours postexposure, clinical signs and symptoms are generally lacking (Schneider and Diller, 1989;
Diller, 1985). However, histologic examination reveals the beginnings of an edematous swelling, with blood plasma increasingly entering the pulmonary
interstitium and alveoli. This may result in damage to the alveolar type I cells and a rise in hematocrit. In exposed humans, the individual is
unaware of these processes; thus, this phase is termed the “clinical latent phase.” The length of this phase varies inversely with the inhaled
dose.
In the third clinical phase of phosgene toxicity (Schneider and Diller, 1989; Diller, 1985), the accumulating fluid in the lung results in the edema
becoming apparent both directly and indirectly. The severity of the edema increases, potentially resulting in decreased gas exchange as the fluid
gradually rises from the alveoli to the proximal segments of the respiratory tract. Agitated respiration may cause the protein-rich fluid to take on a
frothy consistency. A severe edema may result in an increased concentration of hemoglobin in the blood and congestion of the alveolar capillaries. At
sufficiently high exposure levels, the heart also may be affected,
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www.epa.gov... (WARNING...this is a PDF)