🧪 Inhaled Toxins and Gases
Which gas binds hemoglobin with 240x the affinity of oxygen?
What is carbon monoxide?
Explanation: CO forms carboxyhemoglobin, impairing oxygen delivery and shifting the O₂ dissociation curve left.
Which heavy metal exposure is linked with hypertension and gout?
What is lead?
Explanation: Lead causes vascular and renal dysfunction with uric acid retention (“saturnine gout”).
What urinary metabolite best confirms benzene exposure?
What is trans,trans-Muconic acid?
Explanation: Sensitive biomarker for low-level benzene; more reliable than phenol.
Primary treatment for organophosphate poisoning?
What is Atropine followed by pralidoxime?
Explanation: Atropine treats muscarinic symptoms; pralidoxime reactivates cholinesterase.
What syndrome is linked with poor ventilation and VOC off-gassing in offices?
What is Sick Building Syndrome
Explanation: Nonspecific symptoms (headache, irritation) from VOCs, formaldehyde, mold.
A worker near sewage sludge collapses; what’s the likely agent?
What is Hydrogen sulfide?
Explanation: H₂S causes cytochrome oxidase inhibition → rapid CNS depression and respiratory arrest.
Which metal is not classifiable as carcinogenic (IARC Group 3)?
What is Mercury?
Explanation: Unlike cadmium, benzidine, and asbestos, mercury has insufficient evidence for carcinogenicity.
Which chlorinated solvent can cause ventricular arrhythmias from catecholamine sensitization?
What are Chlorofluorocarbons (CFCs)?
Explanation: CFCs sensitize myocardium to epinephrine; exposure can trigger fatal dysrhythmias.
Which test best reflects CNS effects of organophosphate poisoning?
What is Red blood cell cholinesterase
Explanation: RBC cholinesterase correlates with neuronal acetylcholinesterase inhibition.
Which occupational skin disorder is caused by halogenated hydrocarbons like dioxin?
What is Chloracne?
Explanation: Acneiform eruption due to exposure to halogenated aromatic hydrocarbons.
Which inhaled gas causes delayed pulmonary edema after 6–24 hours?
What is Phosgene?
Explanation: A low-water-solubility gas that damages alveoli; classic “delayed pulmonary distress.”
Which metal poisoning may follow ingestion of contaminated moonshine?
What is lead?
Explanation: Homemade distillation in lead-soldered coils leaches lead into alcohol.
What is the most important determinant of vapor exposure risk?
What is Vapor pressure?
Explanation: High vapor pressure → greater volatility → higher inhalation risk.
Which antidote is used for cyanide poisoning?
What is Hydroxocobalamin?
Explanation: Binds cyanide → forms cyanocobalamin (vitamin B₁₂), excreted safely.
What occupational condition results from chronic exposure to isocyanates?
What is Occupational asthma?
Explanation: Immunologic bronchial hyperreactivity from sensitization to isocyanate vapors.
What property predicts the site of airway injury for irritant gases?
What is water solubility?
Explanation: Highly soluble gases (e.g., NH₃) affect upper airways; poorly soluble (e.g., phosgene) affect alveoli.
What is the preferred antidote for arsenic poisoning?
What is Dimercaprol (BAL)?
Explanation: Chelates trivalent arsenic, promoting renal excretion.
Which aromatic hydrocarbon is most hematotoxic?
What is Benzene?
Explanation: Causes bone marrow suppression and leukemia with chronic exposure.
Which insecticides may trigger allergic dermatitis or asthma?
What is Pyrethrins / pyrethroids
Explanation: Usually low systemic toxicity; can cause allergic or irritant skin reactions.
Which psychosocial factor combination increases cardiovascular risk?
What is High job demand + low control
Explanation: The Karasek “job strain” model links these with hypertension and CAD.