Free SCFHS Public Health Technician mock test

Public Health Technician sample questions with answers

10 more original exam-style Public Health Technician questions, worked in full. They are not real or recalled exam questions, and none of them is in the mock above or on the bank page, so sit the mock first if you have not.

1. Question 1 · Environmental Health

   Which fraction of airborne particulate matter is most likely to penetrate deep into the lungs and reach the alveoli?

   1. APM2.5, particles of 2.5 micrometres or less
   2. BPM10, particles between 2.5 and 10 micrometres
   3. CTotal suspended particles larger than 10 micrometres
   4. DCoarse dust settling within a few metres of its source
   Show answer and explanation

   Correct answer: A. PM2.5, particles of 2.5 micrometres or less

   Fine particles of 2.5 micrometres or less pass the upper airway and reach the alveoli, which is why they carry the greatest health burden. Larger fractions are mostly trapped in the nose and throat or settle out of the air.

   Reference: WHO, Global Air Quality Guidelines (2021)

2. Question 2 · Epidemiology Concepts and Methods

   A study finds that people who carry matches have more lung cancer than those who do not. Smoking is linked to both match-carrying and lung cancer. What explains the association?

   1. ASelection bias from volunteer participation
   2. BLead-time bias from earlier detection
   3. CConfounding by smoking
   4. DRecall bias from the cases
   Show answer and explanation

   Correct answer: C. Confounding by smoking

   A third factor associated with both the exposure and the outcome, without being on the causal path, produces a false association, which is confounding. Selection, lead-time and recall bias arise from how participants are chosen, detected or questioned, not from a shared cause.

   Reference: Gordis, Epidemiology, 6th ed. (2019)

3. Question 3 · Food and Water Safety

   A factory prepares cooked chicken for sandwiches: receiving, chilled storage, cooking, cooling, slicing and packing. For the hazard of Salmonella, which step is the critical control point?

   1. AReceiving the raw chicken from the supplier with a temperature check on the vehicle
   2. BChilled storage of the raw chicken
   3. CSlicing the cooked chicken with clean knives and gloves before packing
   4. DCooking to a defined core temperature for a set time
   Show answer and explanation

   Correct answer: D. Cooking to a defined core temperature for a set time

   A critical control point is the step where the hazard can be eliminated or reduced to an acceptable level, and later steps cannot do this for Salmonella. Receiving and storage are prerequisite controls that only limit growth, and slicing could only add recontamination.

   Reference: Codex Alimentarius, General Principles of Food Hygiene, CXC 1-1969 (rev. 2020)

4. Question 4 · Epidemiology Concepts and Methods

   To compare mortality between two regions where one has an older population, which measure is most appropriate?

   1. AThe crude death rate
   2. BThe age-standardised mortality rate
   3. CThe proportionate mortality ratio for each age group
   4. DThe case fatality rate
   Show answer and explanation

   Correct answer: B. The age-standardised mortality rate

   Age standardisation removes the effect of different age structures so the regions can be compared fairly. The crude rate is confounded by age, and proportionate mortality and case fatality answer different questions.

   Reference: CDC, Principles of Epidemiology in Public Health Practice, 3rd ed. (2012)

5. Question 5 · Environmental Health

   Which indoor pollutant, released from soil and some building materials, is the second leading cause of lung cancer after smoking?

   1. ARadon
   2. BCarbon monoxide
   3. CFormaldehyde
   4. DNitrogen dioxide
   Show answer and explanation

   Correct answer: A. Radon

   Radon is a radioactive gas that seeps into buildings and is a recognised cause of lung cancer. Carbon monoxide causes poisoning, and formaldehyde and nitrogen dioxide are irritants rather than the second leading cause of lung cancer.

   Reference: WHO, WHO Handbook on Indoor Radon (2009)

6. Question 6 · Epidemiology Concepts and Methods

   A survey measures blood pressure and body weight in 2,000 adults during one week. Which study design is this?

   1. AA cohort study
   2. BA cross-sectional study
   3. CA case-control study
   4. DA randomised controlled trial
   Show answer and explanation

   Correct answer: B. A cross-sectional study

   A cross-sectional study measures exposure and outcome at one point in time and gives prevalence. A cohort follows people over time, a case-control starts from cases, and a trial assigns an intervention.

   Reference: Gordis, Epidemiology, 6th ed. (2019)

7. Question 7 · Insecticides and Pest Control

   What is the safest way to control cockroaches in a hospital kitchen?

   1. AFogging the room with insecticide while food is left uncovered on the benches
   2. BSpraying a residual insecticide on food preparation surfaces each week at closing time
   3. CLeaving open food waste out overnight to attract the insects to a trap
   4. DBetter sanitation and sealed cracks, with gel baits set by a licensed operator
   Show answer and explanation

   Correct answer: D. Better sanitation and sealed cracks, with gel baits set by a licensed operator

   Integrated control starts with removing food and shelter, then uses targeted baits placed away from food. Fogging or spraying food surfaces contaminates food, and open waste attracts more pests.

   Reference: WHO, Public Health Significance of Urban Pests (2008)

8. Question 8 · Public Health and Safety

   After a power cut, the vaccine refrigerator reads 12 degrees Celsius. What is the correct first action?

   1. AUse the vaccines first, because warmth does not affect their potency
   2. BLabel them do not use, keep them cold and ask the programme for advice
   3. CPlace them in the freezer to bring the temperature down quickly
   4. DDiscard them at once without recording the event
   Show answer and explanation

   Correct answer: B. Label them do not use, keep them cold and ask the programme for advice

   Vaccines exposed to a temperature excursion are quarantined while the programme judges their stability, with the event recorded. Using them, freezing them or throwing them away unrecorded risks ineffective vaccine or avoidable waste.

   Reference: WHO, Immunization in Practice, 2015 update

9. Question 9 · Public Health and Safety

   A health centre works with the local school, the municipality and the water authority to reduce diarrhoea in children. Which primary health care principle does this show?

   1. AAppropriate technology
   2. BEquitable distribution of services
   3. CIntersectoral collaboration
   4. DA curative focus in hospitals
   Show answer and explanation

   Correct answer: C. Intersectoral collaboration

   Working with other sectors such as education, local government and water reflects intersectoral action. Appropriate technology, equity and a curative focus describe other principles or are not primary health care principles.

   Reference: WHO and UNICEF, Declaration of Alma-Ata (1978)

10. Question 10 · Medical Waste Disposal

    Where should a used syringe with its needle attached be placed immediately after an injection?

    1. AIn a yellow clinical waste bag after the needle has been recapped
    2. BIn the general waste bin once the syringe is empty
    3. COn a tray for later collection by the cleaner
    4. DIn a puncture-resistant sharps container at the point of use
    Show answer and explanation

    Correct answer: D. In a puncture-resistant sharps container at the point of use

    Needles go straight into a sharps container at the point of use, with no recapping, to prevent injuries. Bags and general bins can be pierced, and trays leave sharps exposed to staff.

    Reference: WHO, Safe Management of Wastes from Health-Care Activities, 2nd ed. (2014)