Environmental hazards – air, water, soil, radioisotopes MCQs With Answer

Environmental hazards – air, water, soil, radioisotopes MCQs With Answer

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Environmental hazards – air, water, soil, radioisotopes MCQs With Answer is designed for M.Pharm students to reinforce key concepts in environmental safety and hazard management. This set of carefully curated multiple-choice questions covers pollutant types, monitoring and analytical techniques, health effects, remediation approaches, regulatory limits, and radiation safety principles. Each question reflects real-world scenarios and laboratory considerations relevant to pharmaceutical practice, research, and regulatory compliance. Use these MCQs for self-assessment or quick revision to strengthen your ability to identify risks, interpret data, and select appropriate control and mitigation strategies in academic and industrial settings.

Q1. Which constituent is the primary component of photochemical (summer) smog that causes respiratory irritation?

  • Nitrogen dioxide (NO2)
  • Sulfur dioxide (SO2)
  • Ground-level ozone (O3)
  • Carbon monoxide (CO)

Correct Answer: Ground-level ozone (O3)

Q2. Which particulate matter fraction is most associated with deep lung (alveolar) deposition and systemic health effects?

  • PM10 (particles ≤10 μm)
  • PM2.5 (particles ≤2.5 μm)
  • PM100 (particles ≤100 μm)
  • Coarse fraction (2.5–10 μm)

Correct Answer: PM2.5 (particles ≤2.5 μm)

Q3. Biochemical oxygen demand (BOD) is a measure of which of the following in water samples?

  • The concentration of dissolved oxygen present at sampling
  • The oxygen required for chemical oxidation of metals
  • The oxygen required by microorganisms to biodegrade organic matter
  • The oxygen produced by photosynthetic algae

Correct Answer: The oxygen required by microorganisms to biodegrade organic matter

Q4. How does chemical oxygen demand (COD) primarily differ from BOD in wastewater analysis?

  • COD measures only inorganic oxygen-consuming substances
  • COD quantifies total oxidizable organic matter chemically and is faster than BOD
  • COD is a biological test requiring 5 days of incubation
  • COD indicates only nutrient concentrations like nitrate and phosphate

Correct Answer: COD quantifies total oxidizable organic matter chemically and is faster than BOD

Q5. Exposure to which heavy metal is classically associated with Minamata disease and severe neurological effects?

  • Lead (Pb)
  • Cadmium (Cd)
  • Mercury (Hg)
  • Chromium (Cr)

Correct Answer: Mercury (Hg)

Q6. Which analytical technique provides the highest sensitivity for multi-element trace metal analysis in environmental water samples?

  • UV–Vis spectrophotometry
  • Gas chromatography with FID
  • Inductively coupled plasma mass spectrometry (ICP-MS)
  • Ion-selective electrodes

Correct Answer: Inductively coupled plasma mass spectrometry (ICP-MS)

Q7. Which of the following persistent organochlorine pesticides is known for long environmental persistence and bioaccumulation?

  • Malathion
  • DDT (dichlorodiphenyltrichloroethane)
  • Glyphosate
  • Carbaryl

Correct Answer: DDT (dichlorodiphenyltrichloroethane)

Q8. The half-life of a radioisotope is defined as:

  • The time it takes for the isotope to become non-radioactive
  • The time required for half the original number of radioactive nuclei to decay
  • The time needed for emitted radiation to travel one meter
  • The period until the activity doubles

Correct Answer: The time required for half the original number of radioactive nuclei to decay

Q9. Which SI unit describes the absorbed radiation dose in terms of energy deposited per unit mass?

  • Sievert (Sv)
  • Curie (Ci)
  • Gray (Gy)
  • Becquerel (Bq)

Correct Answer: Gray (Gy)

Q10. In radiation protection, the acronym ALARA stands for:

  • As Low As Reasonably Achievable
  • All Levels Are Radiologically Acceptable
  • Annual Limit for Absorbed Radiation Amount
  • Approved Limits and Regulatory Actions

Correct Answer: As Low As Reasonably Achievable

Q11. Which material is most effective as a compact shield against high-energy gamma radiation in laboratory settings?

  • Polyethylene
  • Aluminum
  • Lead
  • Wood

Correct Answer: Lead

Q12. Which type of ionizing radiation has the highest linear energy transfer (LET) but the shortest penetration in matter?

  • Gamma rays
  • Beta particles
  • Alpha particles
  • Neutrons

Correct Answer: Alpha particles

Q13. Which control technology is widely used to remove volatile organic compounds (VOCs) from contaminated air streams?

  • Membrane ultrafiltration
  • Activated carbon adsorption
  • Ion exchange resins
  • Flocculation

Correct Answer: Activated carbon adsorption

Q14. According to WHO drinking-water guidelines, what is the acceptable level of E. coli or thermotolerant coliforms in 100 mL of potable water?

  • 100 CFU per 100 mL
  • 10 CFU per 100 mL
  • 1 CFU per 100 mL
  • No detectable coliforms (0 per 100 mL)

Correct Answer: No detectable coliforms (0 per 100 mL)

Q15. If a small spill of a soluble radioisotope occurs on a laboratory bench, the immediate correct action is to:

  • Wipe it quickly with bare hands to remove contamination
  • Ignore it if readings on the instrument are low
  • Isolate the area, restrict access, and notify the Radiation Safety Officer
  • Evaporate the spill using a heat gun

Correct Answer: Isolate the area, restrict access, and notify the Radiation Safety Officer

Q16. Which of the following is least likely to be transmitted as a waterborne pathogen?

  • Vibrio cholerae
  • Giardia lamblia
  • Escherichia coli (enteric strains)
  • Influenza virus

Correct Answer: Influenza virus

Q17. Elevated concentrations of which nutrient in freshwater systems most strongly promote eutrophication and algal blooms?

  • Iron (Fe)
  • Phosphate (PO4^3−)
  • Sodium (Na+)
  • Chloride (Cl−)

Correct Answer: Phosphate (PO4^3−)

Q18. Which remediation technique uses plants to extract and accumulate heavy metals from contaminated soils?

  • Soil washing
  • Thermal desorption
  • Phytoremediation (phytoextraction)
  • Chemical oxidation

Correct Answer: Phytoremediation (phytoextraction)

Q19. For detecting alpha surface contamination in a laboratory, which detector type is most appropriate?

  • Geiger–Müller tube with thick window
  • ZnS(Ag) scintillation alpha probe
  • Infrared gas analyzer
  • Thermal conductivity detector

Correct Answer: ZnS(Ag) scintillation alpha probe

Q20. Which pollutant is most commonly associated with incomplete combustion and causes tissue hypoxia by binding to hemoglobin?

  • Sulfur dioxide (SO2)
  • Nitrogen dioxide (NO2)
  • Carbon monoxide (CO)
  • Ozone (O3)

Correct Answer: Carbon monoxide (CO)

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