Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Toxicology > Toxic Gases > Flashcards

Toxic Gases Flashcards

1
Q

What are the local responses to toxic gases?

A
  • Iritation
  • inflammation
  • edema
  • necrosis
  • fibrosis
  • emphysema
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are farm sources of toxic gases?

A
  • Uncontrolled decomposition of feeds (eg - NO2 from silage)
  • Anaerobic decomposition of animal wastes inside confinement buildings
    • NH3, CO2, CH4, H2S
  • Incomplete combustion of fossil fuels (CO)
  • Accidental/intended release of anhydrous NH3
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the source of Nitrogen Dioxide?

A
  • Fermentation of corn/forages high in nitrate
  • NO2 is formed in the first 2 weeks after the ensiling.
    • Incomplete Reduction of NO3
    • Highest concentration in the first 48 hrs of ensiling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the characteristics of NO2

A
  • Brownish in color
  • Pungent irritating odor
  • Heavier than air - accumulates in low areas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to NO2 when exposed to H2O in the air?

A
  • forms nitric acid
  • direct toxicant and strong irritant to eyes, respiratory tract and lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Silo Fillers Disease?

A
  • Nitrogen Dioxide toxicosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the MOA of NO2

A
  • Direct irritant - forms HNO3
  • Oxidant ⇢ lipid peroxidation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the effects of NO2

A
  • Ocular and upper airway irritation, coughing, chocking at > 50 ppm
  • Pulmonary edema, tachycardia, fever, dyspnea, hypoxia are delayed effects
  • Chronic bronchitis or emphysema
    • “Silo Fillers disease”
  • Rapid progression, may be fatal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the clinical signs of NO2 exposure

A
  • Reddened mucous membranes
  • Lacrimation
  • Salivation
  • ⇣ Food and water intake
  • coughing, paning
  • Dyspnea - flyid sounds in chest
  • Hypoxia
  • Fever
  • Pneumonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What lung lesions are common to NO2 exposure?

A
  • Edema
  • Hyperemia + hemorrhage
  • Emphysema
  • Bronchiolar inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is NO2 exposure diagnosed and treated?

A
  • Dx - clinical signs, history, few tox tests
  • Rx - Move to ventilated places
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the characteristics of Methane gas?

A
  • Lighter than air
  • Odorless
  • Explosive at 5% in the atmosphere
  • Toxicity by displacing O2
    • very high levels (rare) ⇢ asphyxiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the sources of Methane gas?

A
  • Natural Gas:
    • 85% methane
    • 9% ethane
    • 3% propane
    • 2% nitrogen
    • 1% butane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the characteristics of CO2

A
  • Odorless
  • Heavier than air
  • 0.03% (300 ppm) in atmosphere
  • 1540 ppm - recommended maximal concentration in environmental air for swine
  • 10% distress, increased respiratory rate
  • 25% coma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the characteristics of Ammonia (NH3)

A
  • Lighter than air
  • Colorless
  • Sharp pungent odor
    • 5ppm very slight
    • 20pp, easily detected
    • 6-35ppm found in confinement units
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the sources for NH3

A
  • Fertilizers - NH3 rarely a problem
    • NH4NO3, NH42CO3, NH43PO4
  • Manure - slurry pits
    • chicken or horses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the effects of NH3 at 50 ppm?

A
  • Chronic stressor
    • Exacerbated respiratory disease
    • Reduces pulmonary bacterial clearance
    • Feed intake, growth rate decreased by ≥10%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the effects of NH3 at 100 ppm?

A
  • Strong odor
  • Eye and respiratory irritation
  • Salivation, lacrimation, corneal damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the effects of NH3 in poultry?

A
  • 20 ppm - decreased egg production
  • 50 ppm - increased incidence of respiratory disease
  • 60-75 ppm - corneal injury (keratoconjunctivitis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the clinical signs of NH3 exposure?

A
  • Reddened mucous membranes
  • Keratoconjunctival lesions
  • Lacrimation
  • Nasal discharge (⇡ pulmonary infection)
  • Sniffling, sneezing, coughing
  • Pulmonary edema, congestion
  • Dyspnea - fluid sounds
  • hypoxia
  • Electrolyte and A/B imbalance
  • Decreased egg production in birds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the Terminal signs of NH3 exposure?

A
  • Cyanosis
  • Violent struggling
  • Clonic convulsions
22
Q

How is NH3 exposure diagnosed?

A
  • Clinical signs
  • Odor
  • No reliable analytical tests for the field
23
Q

How is NH3 exposure treated?

A
  • Remove from the source
  • Ointment for eyes
  • Antibiotics
24
Q

What are the characteristics of Hydrogen sulfide (H2S)

A
  • Colorless
  • Heavier than air, collects in low places
  • Odor of rotten eggs
25
What are the sources for H2S?
* Formed by anaerobic decomposition of sulfur containing AA * Held as tiny bubbles deep within manure slurry in pit and released when the slurry is agitated prior to pumping * Also from oil drilling and industrial sources * Feed related - high sulfur diets
26
What are the toxic levels of H2S
* 0.1-0.2 ppm - odor threshold * 3-5 ppm - offensive odor * 50-100 ppm - irritating to eyes, respiratory tract * 200 ppm - olfactory paralysis * \> 500 ppm - pulmonary edema, potentially lethal * \>1000 ppm - respiratory paralysis, collapse * \> 3000ppm - death after a few violent gasps
27
What is the MOA of H2S
* Direct irritant to eyes and lungs * CNS effects - inhibition of respiratory center (??), seizures, unknown MOA * General metabolic: inhibition of cytochrome oxidase
28
What are the clinical signs of H2S exposure?
* Coughing, lacrimation, nasal discharge * Dyspnea * Depression * Fluid sounds in lungs * Terminal cyanosis, convulsions * Lesions: * Edema in lungs (intestine and brain) * Dark blood * Smell of H2S in tissues
29
How can H2S exposure be diagnosed?
* Difficult * Clinical signs * Odor * Hx of exposure * Gas detectors - $$$ * Necropsy and tests to eliminate other causes: * neurodegeneration in the brainstem * Humans: sulfide, thiosulfate in serum/urine
30
What is the treatment for H2S exposure?
* Remove from source * No antidotes * Experimental Tx: * Nitrites * Cobinamide * Hydroxycobolamine * Thiamine
31
What are the characteristics of Carbon Monoxide (CO)?
* Odorless * Colorless * Lighter than air
32
What are the sources of CO?
* Internal combustion engine exhaust: * automobile exhaust ( up to 9% CO) * Lethal CO in 10 minutes in enclosed spaces * Unvented or faulty heating equipment: * Furnaces, gas water heaters, gas or kerosene space heaters, charcoal grills * lethal in enclosed spaces * Fires: * CO may reach 10% in the atmosphere in burning building
33
What is the MOA of CO?
* Co absorbed from lung, combines with Hb to from COHb ⇢ Anoxia * Affinity of Hb for CO ~300x more than for O
34
What are the Acute signs of CO exposure?
* Drowsiness, lethargy, weakness, deafness, incoordination * Reduced heart excitability * Cherry red color to skin, mucous membranes * Dyspnea, coma, terminal clonic spasms, acute death
35
What are the clinical signs of CO exposure?
* Based on degree of anoxia: * Acute - * pregnant animals may abort * CO crosses placenta ⇢ Fetal hypoxia * fetal Hb even more susceptible to CO than maternal Hb * Chronic * low exercise tolerance * Abnormal posture and gait * ECG abnormalities consistent with anoxia and necrosis of heart muscle fibers
36
How is CO exposure diagnosed?
* Hx of exposure * Clinical signs * Necropsy shows bright red blood or pink mm * Anoxia causes necrosis of cerebral cortex and white matter, globus pallidus and brain stem * Measure CO in environments * Measure COHb in whole blood * \<5% normal * 10-20% headache, fatigue, irritability * 20-30% weakness, dizziness, mild symptoms * 30-60 % confusion, increased heart and respiratory rate, coma * \>60% usually fatal * COHb in fetal serosanguinous thoracic fluid (\>8% is significant)
37
What is the treatment for CO exposure?
* Main goal - restore adequate oxygen supply to the brain and heart * Move patient to fresh air to stop further CO exposure * Maintain patent airway and provide artificial respiration if necessay * Patients breathing hyperbaric or 100% O2 recover more quickly
38
How can CO exposure be prevented?
* Maintain properly functioning heaters, exhaust systems and adequate ventilation * Use CO detectors * Do Not operate automobile engines and other cources of CO in or near enclosed spaces
39
What are the sources of Anhydrous Ammonia?
* Agricultural fertilizer - injected into soil as source of N * Used as a commercial refrigerant * Used in meth labs
40
What is the MOA of Anhydrous Ammonia?
* Released gas seeks water * attacks moisture rich tissues - cornea, mm, respiratory epithelium * Gas NH3 + H2O = NH4OH * Produces strong alkali burns in the tissue
41
What are the clinical effects of Anhydrous Ammonia?
* Acute death from laryngospasm * Fluid accumulation in lungs * Sloughing epithelium or respiratory system * Corneal opacity, blindness * Secondary bacterial invasion
42
What pathological affects are common with Anhydrous Ammonia
* necrosis of superficial layers * dermis of muzzle * epithelium of trachea
43
What are the effects of ventilation failure on animals?
* Hyperthermia - from * Metabolic activity of large animals * thermal inpute from exterior (summer) * Inadequate building ventilation * Heat generation from manure stored in pits
44
What are the sources for Polytetrafluoroethylene (PTFE)
* Overheated Teflon or Silverstone coated cooking pans * Ironing board covers, electric irons, range top drip pans, self-cleaning ovens
45
What temperature do Pyrolysis products form from PTFE?
* at \>280-530C (535-985F) * Pyrolysis products = particulates + acidic volatile gases
46
What animal is the most sensitive to PTFE?
birds
47
What are the clinical signs of PTFE exposure?
* Acute respiratory distress * Audible respiration * Dyspnea * Rapidly fatal
48
What lesions are seen with PTFE exposure?
* Pulmonary hemorrhage and congestion * Particles my be seen on lung sections
49
How is PTFE exposure prevented?
* Do not use non stick cookware around pet birds * Have good ventilation * Remove birds from house when cooking
50
What is the treatment for PTFE exposure?
* Difficult unrewarding * Move immediately to fresh air * Corticosteroids to reduce shock, pulmonary edema * Fluids, broad spectrum antibbiotics

Toxicology (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions