Soil pollution MCQs With Answer

Soil pollution MCQs With Answer are essential for B. Pharm students to understand how soil contamination affects drug safety, public health, and environmental pharmacology. This concise, SEO-friendly introduction covers key concepts like sources of soil pollution, heavy metals, pesticides, pharmaceutical residues, antibiotic resistance, bioaccumulation, analytical detection (AAS, GC-MS, ICP-MS), and remediation strategies (bioremediation, phytoremediation). Mastery of soil chemistry, adsorption, mobility, and risk assessment helps future pharmacists appreciate environmental pathways that influence drug exposure and residue fate. These targeted MCQs reinforce theory and practical knowledge needed for coursework and competitive exams. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the primary definition of soil pollution?

• Deposition of organic matter improving fertility
• Presence of toxic chemicals or biological agents in soil in harmful concentrations
• Increase in soil moisture beyond field capacity
• Natural accumulation of clay minerals

Correct Answer: Presence of toxic chemicals or biological agents in soil in harmful concentrations

Q2. Which of the following is a common source of heavy metal contamination in soils?

• Organic farming practices
• Industrial effluents and metal processing
• Composting of vegetable waste
• Crop rotation

Correct Answer: Industrial effluents and metal processing

Q3. Which heavy metal is most commonly associated with neurotoxicity and is a concern in contaminated soils?

• Cadmium
• Arsenic
• Lead
• Mercury

Correct Answer: Lead

Q4. Persistent organic pollutants (POPs) in soil typically include which group?

• Simple sugars
• Polychlorinated biphenyls (PCBs) and dioxins
• Plant growth hormones
• Inorganic nitrates only

Correct Answer: Polychlorinated biphenyls (PCBs) and dioxins

Q5. Which analytical technique is commonly used for trace metal detection in soils?

• HPLC with UV detection
• Atomic absorption spectrometry (AAS)
• Paper chromatography
• pH titration

Correct Answer: Atomic absorption spectrometry (AAS)

Q6. How do antibiotics in soil contribute to public health risks?

• They increase soil pH permanently
• They promote antibiotic-resistant bacteria and resistance genes
• They enhance plant growth uniformly
• They neutralize heavy metals

Correct Answer: They promote antibiotic-resistant bacteria and resistance genes

Q7. What role does soil pH play in heavy metal mobility?

• Lower pH generally decreases metal solubility and mobility
• Lower pH generally increases metal solubility and mobility
• pH has no effect on metal mobility
• Higher pH always converts metals to gaseous form

Correct Answer: Lower pH generally increases metal solubility and mobility

Q8. Which of the following is a direct effect of pesticide accumulation in agricultural soils?

• Enhanced soil microbial diversity
• Decline in beneficial soil microorganisms
• Immediate increase in soil organic carbon
• Permanent sterilization of soil minerals

Correct Answer: Decline in beneficial soil microorganisms

Q9. Phytoremediation primarily uses what to remove contaminants from soil?

• Chemical oxidants
• Specific plants that uptake or stabilize pollutants
• High-temperature incineration
• Ion exchange resins

Correct Answer: Specific plants that uptake or stabilize pollutants

Q10. Which term describes the process where contaminants move downward through the soil profile with percolating water?

• Evaporation
• Leaching
• Adsorption
• Biotransformation

Correct Answer: Leaching

Q11. In soil chemistry, what does CEC stand for and why is it important?

• Carbon Emission Coefficient; it measures CO2 from soil
• Cation Exchange Capacity; it indicates soil’s ability to retain cationic pollutants
• Chloride Evaporation Constant; it predicts salt loss
• Contaminant Equilibrium Coefficient; it measures pollutant distribution only in water

Correct Answer: Cation Exchange Capacity; it indicates soil’s ability to retain cationic pollutants

Q12. Which pharmaceutical class is particularly concerning in soils due to persistence and endocrine disruption?

• Analgesics
• Synthetic estrogens and hormones
• Antacids
• Topical emollients

Correct Answer: Synthetic estrogens and hormones

Q13. What is biomagnification as it relates to soil pollution?

• Process where contaminants break down into harmless products
• Increase in contaminant concentration up the food chain
• Immediate dilution of pollutants in groundwater
• Removal of contaminants by soil microbes only

Correct Answer: Increase in contaminant concentration up the food chain

Q14. Which microorganism-based remediation strategy uses microbes to degrade organic pollutants?

• Phytostabilization
• Bioremediation (microbial degradation)
• Soil vapor extraction
• Electrokinetic remediation

Correct Answer: Bioremediation (microbial degradation)

Q15. Which soil property most directly affects adsorption of hydrophobic organic pollutants like PAHs?

• Soil texture only
• Organic matter content
• Soil color
• Macronutrient concentrations

Correct Answer: Organic matter content

Q16. What is the primary environmental concern associated with landfill leachate?

• Generation of ozone
• Contamination of soil and groundwater with complex mixtures of pollutants
• Decrease in atmospheric nitrogen
• Immediate neutralization of pesticides

Correct Answer: Contamination of soil and groundwater with complex mixtures of pollutants

Q17. Which regulatory parameter indicates acceptable concentrations of specific pollutants in soils for human health protection?

• Soil pH threshold only
• Soil screening levels or guideline values
• Crop yield limits
• Particle size distribution

Correct Answer: Soil screening levels or guideline values

Q18. Which analytical method is best suited for detecting organic pesticides in soil?

• Inductively coupled plasma mass spectrometry (ICP-MS)
• Gas chromatography-mass spectrometry (GC-MS)
• Conductivity measurement
• Gravimetric moisture analysis

Correct Answer: Gas chromatography-mass spectrometry (GC-MS)

Q19. What is the main mechanism by which activated carbon mitigates organic contaminants in soil?

• Chemical oxidation of organics
• Adsorption of organic molecules onto high-surface-area carbon
• Increasing soil temperature to volatilize pollutants
• Fixing metals through precipitation

Correct Answer: Adsorption of organic molecules onto high-surface-area carbon

Q20. Which heavy metal is particularly associated with kidney damage and is often mobile in acidic soils?

• Manganese
• Cadmium
• Calcium
• Silicon

Correct Answer: Cadmium

Q21. Which term best describes soil’s capacity to neutralize acids?

• Acidogenicity
• Buffering capacity
• Hydraulic conductivity
• Evapotranspiration

Correct Answer: Buffering capacity

Q22. How do crop uptake pathways influence human exposure to soil contaminants?

• They prevent contaminants from entering the food chain
• Contaminants accumulated in edible plant parts can lead to dietary exposure
• Plants detoxify all contaminants completely
• Crop uptake only affects fiber content, not contaminants

Correct Answer: Contaminants accumulated in edible plant parts can lead to dietary exposure

Q23. Which of the following is a hallmark of soil contamination by petroleum hydrocarbons?

• Increased soil alkalinity uniformly
• Presence of smells, hydrophobic coatings, and hydrocarbon fractions like BTEX
• Instant plant growth stimulation
• Formation of crystalline salts

Correct Answer: Presence of smells, hydrophobic coatings, and hydrocarbon fractions like BTEX

Q24. What is the role of sorption in controlling contaminant mobility in soil?

• Sorption increases contaminant volatility
• Sorption binds contaminants to soil particles, reducing mobility
• Sorption always degrades contaminants biologically
• Sorption enhances contaminant production

Correct Answer: Sorption binds contaminants to soil particles, reducing mobility

Q25. Which process describes chemical transformation of pollutants into less harmful forms in soil?

• Biomagnification
• Biotransformation/chemical transformation
• Leaching
• Dispersion without change

Correct Answer: Biotransformation/chemical transformation

Q26. Which soil amendment can immobilize heavy metals to reduce plant uptake?

• Adding soluble nitrates
• Adding lime or phosphates to increase pH and precipitate metals
• Adding synthetic surfactants
• Reducing organic matter content

Correct Answer: Adding lime or phosphates to increase pH and precipitate metals

Q27. For B. Pharm students, why is knowledge of soil pollution relevant to pharmacy practice?

• It is unrelated to drug therapy or safety
• Soil contaminants can enter food and water, affecting drug efficacy, toxicity, and exposure pathways
• Pharmacists only deal with tablets, not environmental issues
• Soil pollution solely affects geology exams

Correct Answer: Soil contaminants can enter food and water, affecting drug efficacy, toxicity, and exposure pathways

Q28. What is the best description of ‘organic contaminants’ in soils?

• Inorganic salts like sulfates and chlorides
• Carbon-containing chemicals such as pesticides, PAHs, and pharmaceuticals
• Only natural plant detritus
• Gaseous oxygen in the pore space

Correct Answer: Carbon-containing chemicals such as pesticides, PAHs, and pharmaceuticals

Q29. Which factor does NOT significantly affect degradation rate of organic pollutants in soil?

• Soil temperature
• Microbial activity
• Soil moisture
• Color of the laboratory coat used by researchers

Correct Answer: Color of the laboratory coat used by researchers

Q30. Which is an advantage of phytoremediation over excavation and disposal?

• Faster removal for all contaminant types
• Lower cost and less invasive, uses plants to stabilize or extract contaminants
• Guaranteed complete mineralization within days
• No need for site characterization

Correct Answer: Lower cost and less invasive, uses plants to stabilize or extract contaminants

Q31. Which organic pollutant class is a concern because of mutagenic and carcinogenic properties and persistence in soils?

• Polycyclic aromatic hydrocarbons (PAHs)
• Simple alcohols
• Volatile inorganic acids
• Natural sugars

Correct Answer: Polycyclic aromatic hydrocarbons (PAHs)

Q32. What is the significance of soil redox potential (Eh) in contaminant behavior?

• Eh controls solubility and speciation of redox-sensitive contaminants like arsenic and iron
• Eh only affects soil temperature
• Eh is unrelated to contaminant chemistry
• Eh measures only soil texture

Correct Answer: Eh controls solubility and speciation of redox-sensitive contaminants like arsenic and iron

Q33. Which of the following best reduces the spread of antibiotic resistance from soils to clinical settings?

• Increasing antibiotic inputs in agriculture
• Prudent antibiotic stewardship and reducing agricultural antibiotic use
• Using antibiotics as soil fertilizers
• Encouraging horizontal gene transfer

Correct Answer: Prudent antibiotic stewardship and reducing agricultural antibiotic use

Q34. What is a common indicator organism used to assess microbial contamination risk in soils and waters?

• Escherichia coli
• Pseudomonas aeruginosa only in sterile soils
• Streptococcus mutans exclusively
• Saccharomyces cerevisiae

Correct Answer: Escherichia coli

Q35. Which remediation technique uses electric fields to mobilize charged contaminants through the soil?

• Phytoremediation
• Electrokinetic remediation
• Thermal desorption
• Soil washing without any fluids

Correct Answer: Electrokinetic remediation

Q36. In context of soil pollution, what does ‘source-pathway-receptor’ refer to?

• A method for soil pH adjustment
• Framework describing origin of contaminant, how it moves, and who/what is affected
• A plant growth sequence
• Steps of composting

Correct Answer: Framework describing origin of contaminant, how it moves, and who/what is affected

Q37. Why is sample homogenization important during soil contaminant analysis?

• It makes soil taste better for lab personnel
• It reduces heterogeneity and ensures representative subsamples for reliable analysis
• It increases contaminant concentration artificially
• It only matters for soil color measurements

Correct Answer: It reduces heterogeneity and ensures representative subsamples for reliable analysis

Q38. Which of the following is a chemical indicator of long-term agricultural misuse leading to soil pollution?

• Elevated levels of residual herbicides and pesticide metabolites
• Increased earthworm populations
• Higher crop yields every season
• Enhanced natural vegetation diversity

Correct Answer: Elevated levels of residual herbicides and pesticide metabolites

Q39. What is the likely environmental fate of a highly water-soluble, low-Kow pesticide applied to soil?

• Strong adsorption to organic matter and no mobility
• High potential for leaching to groundwater due to low sorption
• Immediate biodegradation to harmless gases in all soils
• Permanent binding to clay particles only

Correct Answer: High potential for leaching to groundwater due to low sorption

Q40. Which international body provides guidelines relevant to soil contaminants and food safety?

• World Meteorological Organization (WMO)
• World Health Organization (WHO) and FAO joint guidelines
• International Olympic Committee
• World Trade Organization for soil only

Correct Answer: World Health Organization (WHO) and FAO joint guidelines

Q41. Which remediation method physically removes contaminated soil for treatment or disposal?

• In situ bioventing
• Excavation and off-site disposal or treatment
• Phytostabilization
• Monitored natural attenuation

Correct Answer: Excavation and off-site disposal or treatment

Q42. Which class of compounds in soil is most likely to persist due to chlorination and aromatic structure?

• Aliphatic alcohols
• Chlorinated aromatic compounds such as PCBs
• Simple inorganic nitrates
• Monosaccharides

Correct Answer: Chlorinated aromatic compounds such as PCBs

Q43. During risk assessment, what does ‘exposure pathway’ describe?

• Only the chemical structure of a pollutant
• The route by which humans or organisms come into contact with contaminants (ingestion, inhalation, dermal)
• The method of laboratory disposal
• The manufacturer’s supply chain

Correct Answer: The route by which humans or organisms come into contact with contaminants (ingestion, inhalation, dermal)

Q44. What is ‘soil washing’ as a remediation technique?

• Using water or solvents to extract contaminants from excavated soil
• Applying detergents to clean plant leaves
• Flushing soil with pure oxygen only
• Planting water-loving species

Correct Answer: Using water or solvents to extract contaminants from excavated soil

Q45. Which soil parameter would most directly indicate anaerobic conditions that favor certain contaminant transformations?

• High oxygen content in pore water
• Low redox potential (Eh) and presence of reduced species
• Maximum sunlight exposure during the day
• High clay content irrespective of moisture

Correct Answer: Low redox potential (Eh) and presence of reduced species

Q46. Which agricultural practice can inadvertently increase soil pesticide residues?

• Integrated pest management
• Over-application and improper timing of pesticide use
• Crop rotation with non-host plants
• Use of biological control agents only

Correct Answer: Over-application and improper timing of pesticide use

Q47. What property of a drug determines its sorption tendency to soil organic matter?

• Molecular color
• Octanol-water partition coefficient (Kow) indicating hydrophobicity
• Boiling point only
• Number of chiral centers regardless of polarity

Correct Answer: Octanol-water partition coefficient (Kow) indicating hydrophobicity

Q48. Which monitoring practice helps track long-term trends in soil contamination?

• One-off sampling every decade without records
• Periodic sampling at fixed locations with consistent methods
• Visual inspection of soil color only
• Relying on anecdotal farmer reports exclusively

Correct Answer: Periodic sampling at fixed locations with consistent methods

Q49. Which compound class often originates from incomplete combustion and is of concern in soils near industrial sites?

• Polycyclic aromatic hydrocarbons (PAHs)
• Simple inorganic phosphates
• Water-soluble vitamins
• Saturated fatty acids only

Correct Answer: Polycyclic aromatic hydrocarbons (PAHs)

Q50. Which preventive strategy is crucial to minimize pharmaceutical contamination of soils?

• Unregulated disposal of unused medicines
• Proper waste management, take-back programs, and reducing unnecessary prescriptions
• Increasing veterinary antibiotic use in agriculture
• Burying expired drugs in farmland

Correct Answer: Proper waste management, take-back programs, and reducing unnecessary prescriptions

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com