Environmental Health: NCK Exam Questions & Revision

The most reliable household method to make water safe to drink is:

• A. Adding sugar
• B. Boiling or chlorination
• C. Filtering through cloth only
• D. Letting it settle overnight

Why: Boiling or chlorinating water reliably inactivates disease-causing organisms; settling or cloth-filtering alone does not.

Malaria control through vector management mainly targets the:

• A. Tsetse fly
• B. Anopheles mosquito
• C. Housefly
• D. Cockroach

Why: Malaria is transmitted by the female Anopheles mosquito, so vector control (nets, indoor spraying, larval control) targets it.

In the 3 pot method of water purification, how long must the water sit before it is deemed safe for consumption?

• A. 24hrs
• B. 48hrs
• C. 36hrs
• D. 30hrs

Why: Option B is correct because the 3 pot method requires water to sit for 48 hours to ensure adequate sedimentation and purification, allowing harmful pathogens to settle and be removed. Option A (24hrs) is incorrect as it does not provide sufficient time for complete sedimentation. Option C (36hrs) and Option D (30hrs) are also incorrect as they fall short of the recommended 48-hour period needed for optimal purification.

What are the key strategies involved in the primary prevention of hazards in occupational health care?

• A. Emphasis on first aid to minimize complications.
• B. Dealing with substances inhaled or contracted because of employee's poor attitudes.
• C. General screening of non occupational illness before a person is hired.
• D. Screening of the working environment to check that recommended preventive measures are put in place.

Why: Primary prevention in occupational health focuses on eliminating or reducing hazards before they cause harm. Screening the working environment to ensure that recommended preventive measures are in place is a proactive approach to prevent exposure to potential hazards. Options a, b, and c do not address the primary prevention of hazards; they either focus on response after exposure or are unrelated to occupational hazards.

What occupational illness are individuals employed in the information technology sector at risk of developing?

• A. Lead poisoning.
• B. Radiation sickness.
• C. Carpal tunnel syndrome.
• D. Mesothelioma.

Why: Individuals employed in the information technology sector are at risk of developing carpal tunnel syndrome due to repetitive strain and prolonged use of computer keyboards and mice. Lead poisoning is typically associated with exposure to lead in industrial settings. Radiation sickness is related to exposure to high levels of ionizing radiation, which is not common in IT environments. Mesothelioma is linked to asbestos exposure, not typically found in IT workplaces.

Identify the microorganisms that are linked to foodborne illnesses:

• A. Staphylococcus aureus, campylobacter jenuni, vibrio cholerae.
• B. Streptococcus pyogenes, Klebsiela pneumoniae, staphylococcus epidermidis.
• C. Clostridium Welchi, salmonella pseudomonas aeruginosa.
• D. Staphylococcus aureus, salmonella Tymphimunum, camphlobacter, jejuni.

Why: Option d is correct because Staphylococcus aureus, Salmonella Typhimurium, and Campylobacter jejuni are well-known pathogens associated with foodborne illnesses. Staphylococcus aureus can produce toxins in food, leading to food poisoning. Salmonella Typhimurium is a common cause of salmonellosis, a type of foodborne illness. Campylobacter jejuni is a leading cause of bacterial gastroenteritis. Option a is incorrect because Vibrio cholerae is primarily associated with waterborne illnesses rather than foodborne. Option b includes microorganisms that are not typically linked to foodborne illnesses. Option c contains incorrect names and associations, such as Clostridium welchii, which is an outdated term for Clostridium perfringens, and Pseudomonas aeruginosa, which is not a common foodborne pathogen.