Toxic gases 2 Flashcards
what gas poisoning is also known as “Silo filler’s disease”?
Nitrogen oxide
what color is nitrogen dioxide?
reddish brown (NO2) - major pollutant
mixture of NO2 and N2O4 = yellow brown
Where does NO2 often settle?
it’s heavier then air - forms layers on top of silage and settles down the chute
What does NO2 in water form?
Nitric acid and nitric oxide
NO2 has a low water solubility
at what levels does Nitrogen oxide cause moderate irritation of the eyes and upper respiratory mucosa?
50 - 150 ppm
What is more toxic - acute exposure to high concentrations of NO2 or chronic exposure to low concentrations of NO2?
Acute high concentrations
What is the MOA of nitrogen oxide gases?
Direct irritation to MM by forming nitric acid
Damage to the lungs (bronchi/alveoli)
death is from hypoxia
What lesions can be seen with NO2 poisoning?
Pulm edema, hemorrhage, emphysema and inflammation of the bronchioles, cyanosis, methemoglobinemia
*methemoglobin is a form of hemoglobin where ferric (Re+3) iron has a lower binding affinity for O2 than ferrous (Fe+2) iron
What is the prognosis in animals with NO2 poisoning?
Low in acute high concentration exposures
better in animals chronically exposed to lower concentrations
Sulfur dioxide and sulfur trioxide are what type of pollutants?
Industrial
come from fossil fuel combustion at power plants primarily and from other industrial facilities
what is formed when sulfur oxide gases come into contact with moist mm?
Sulfuric acid - irritant
the odors can also cause coughing, choking, and suffocation
What are the ranges of toxic dose of SO2 for cats, herbivores, and pigs?
Cats - SO2 at 500ppm for 30 mins = fatal
Grazing animals - SO2 at 500ppm for 1 hour = dangerous
Pigs - SO2 at 5-40 ppm for 8 days = poisoning
What is the MOA of SO2 poisoning?
Direct irritation of the mm and reflex bronchoconstriction
Lung damage
Death due to hypoxia
