NEET-PG 2013 - Community Medicine Practice Questions

Q: Which of the following is a key criterion for a prudent diet?

Saturated fats < 10% of total energy. ***Saturated fats < 10% of total energy*** - Limiting **saturated fat intake** to less than 10% of total energy is a key recommendation for a prudent diet to reduce the risk of **cardiovascular disease**. - High intake of saturated fats can increase **LDL cholesterol** ("bad" cholesterol), contributing to **atherosclerosis**. *Fat intake 35-40% of total energy* - This range is generally considered **too high** for a healthy diet, as excessive fat intake can lead to **obesity** and increased risk of chronic diseases. - A more prudent range for total fat intake is typically around **20-35% of total energy**. *Dietary cholesterol < 300 mg/1000Kcal per day* - While limiting dietary cholesterol was historically a key recommendation, current guidelines emphasize reducing **saturated and trans fats** more strongly than dietary cholesterol itself due to its limited impact on blood cholesterol for most people. - The limit of **300 mg/day** for dietary cholesterol is an older guideline; many newer recommendations do not specify an upper limit for dietary cholesterol for healthy individuals. *Salt intake <10 g/day* - This statement indicates a salt intake of less than 10 grams per day, which is still **higher** than the generally recommended upper limit for a prudent diet. - Current guidelines suggest limiting **sodium intake** to less than 2300 mg (approximately 5.8g of salt) per day, with an ideal limit of less than 1500 mg (approximately 3.8g of salt) for most adults to manage **blood pressure**.

Q: In rural areas, what is the recommended distance for cattle sheds to be placed away from houses?

25 feet. ***25 feet*** - A minimum distance of **25 feet (approximately 7.6 meters)** is recommended between cattle sheds and houses in rural areas. - This distance helps to mitigate **odors, flies, dust, and noise**, contributing to better hygiene and living conditions. *5 feet* - A distance of **5 feet** is generally considered too close and would not effectively prevent the transmission of **odors, pests, and potential pathogens** from cattle sheds to houses. - This proximity increases the risk of **nuisance and health hazards** to residents. *10 feet* - While better than 5 feet, a distance of **10 feet** may still be insufficient to adequately separate cattle sheds from houses to prevent issues like **strong odors and fly infestations**. - This proximity could still lead to **sanitation and comfort concerns** for residents. *20 feet* - A distance of **20 feet** offers a reasonable buffer; however, **25 feet** is the more commonly recommended minimum to ensure a greater margin of safety and comfort. - While 20 feet is better for ventilation and pest control than smaller distances, it might still allow some impact on **residential air quality**.

Q: What is a standard requirement for the design of a slaughterhouse?

All of the above are standard requirements.. ***All of the above are standard requirements.*** - Proper design and construction of a slaughterhouse are crucial for maintaining **hygiene**, preventing **contamination**, and ensuring **food safety**. - All three requirements work together to create a safe environment for meat processing and prevent the spread of pathogens. - These standards are mandated by public health regulations and food safety guidelines. **Why each requirement is essential:** **Adequate ventilation systems must be installed:** - Controls **temperature and humidity** in processing areas - Removes airborne contaminants and prevents condensation - Ensures worker comfort and reduces microbial growth - Helps in odor control and maintaining air quality **Floors and walls must be made of washable, non-absorbent materials:** - Enables **easy cleaning and sanitation** to prevent microbial growth - Non-absorbent surfaces (like tiles, stainless steel) prevent **contamination absorption** - Facilitates effective disinfection procedures - Prevents harboring of pathogens in porous materials **Separate areas for clean and dirty operations must be maintained:** - Prevents **cross-contamination** between raw and processed products - Clean areas include deboning, cutting, packaging - Dirty areas include stunning, bleeding, evisceration, hide removal - Physical separation is a fundamental principle of **HACCP** (Hazard Analysis Critical Control Point) systems

Q: What is a psychrometer used to measure?

Humidity level. ***Humidity level*** - A **psychrometer** measures **humidity**, specifically **relative humidity** and dew point. - It consists of two thermometers: a **dry-bulb** and a **wet-bulb** thermometer, which measure the cooling effect of evaporation. *Airflow rate* - **Airflow rate** is typically measured by devices such as **anemometers** or **flow meters**. - These instruments quantify the velocity or volume of air moving through a system. *Ambient temperature* - While a psychrometer includes dry-bulb thermometers that measure **ambient temperature**, its primary purpose is not just this, but rather to calculate **humidity** using the difference between wet and dry bulb readings. - A standard **thermometer** is a simpler and more direct tool for measuring only ambient temperature. *Surface temperature* - **Surface temperature** is usually measured using **infrared thermometers** or **thermocouples** placed in direct contact with a surface. - A psychrometer is designed to measure atmospheric conditions, not the temperature of a solid surface.

Q: Which of the following statements about slow sand filters is true?

Requires a longer duration for filtration. ***Requires a longer duration for filtration*** - **Slow sand filters** operate at a much lower filtration rate (0.1–0.4 m/h) compared to rapid sand filters, thus requiring a **longer duration** to process the same volume of water. - This low filtration rate allows for the formation of a biological layer, the **schmutzdecke**, which is responsible for much of the purification. *Is more expensive than other filters* - **Slow sand filters** are generally **less expensive to construct and operate** than rapid sand filters because they do not require extensive chemical coagulation, flocculation, or backwashing equipment. - Their primary cost is often land acquisition due to the **larger footprint** required. *Uses sand size of 0.4 - 0.7 mm* - **Slow sand filters** use **finer (smaller) sand**, typically with an **effective size of 0.15-0.30 mm**, which is smaller than the sand used in rapid sand filters (0.4-0.7 mm). - The smaller sand particle size contributes to the slower filtration rate and enhanced biological treatment. *Occupies less space than other filters* - **Slow sand filters** require **significantly more land area** than rapid sand filters for a given output because of their low filtration rate and large basin size. - This larger footprint can be a limiting factor in areas with high land costs.

Q: What is the minimum contact period required for effective chlorination of drinking water?

30 minutes. ***30 minutes*** - A minimum **contact period of 30 minutes** is generally recommended for effective chlorination to sufficiently inactivate most pathogenic microorganisms in drinking water. - This duration allows for adequate time for the **chlorine residual** to penetrate and destroy bacterial and viral structures. *1 hour* - While a longer contact time like 1 hour would be effective, it is not the **minimum required** for practical purposes and might lead to increased operational costs or complexity without significant additional benefit in typical scenarios. - Exceeding the minimum contact time can sometimes lead to the formation of **disinfection byproducts**, although this is more dependent on chlorine concentration and water composition. *2 hrs* - A contact time of 2 hours significantly exceeds the **minimum effective period** for most disinfection needs. - Such extended contact times are usually only considered in specific situations with highly resistant pathogens or particular water quality challenges, or when using **lower chlorine doses**. *4 hrs* - A 4-hour contact period is far beyond the **standard minimum** for effective chlorination of drinking water. - Such long contact times are typically impractical for municipal water treatment and could potentially increase the risk of forming **undesirable disinfection byproducts** if not carefully managed.

Q: Which of the following insects has shown the least widespread development of resistance to DDT?

Tsetse flies. ***Tsetse flies*** - **Tsetse flies** have shown the least widespread development of **resistance to DDT**, likely due to their specific life cycles and limited exposure in widespread application campaigns. - This has made DDT, or its successor compounds, remain effective in certain tsetse control programs where other insects have developed high resistance. *Mosquitoes* - **Mosquitoes** have developed **widespread resistance to DDT** globally, significantly impacting malaria control efforts. - Their rapid breeding cycles and extensive exposure to DDT over decades led to the selection and proliferation of resistant strains. *Fleas* - **Fleas** have also developed **significant resistance to DDT**, especially in regions where it was heavily used for pest control in homes and livestock. - This resistance is a major factor in the continued prevalence of flea-borne diseases in certain areas. *Ticks* - **Ticks** have shown considerable development of **resistance to DDT** and other acaricides due to widespread use in livestock and agricultural settings. - Their resistance has complicated efforts to control tick-borne diseases and protect animal health.

Q: Which of the following is a stomach poison?

Paris green. ***Paris green*** * **Paris green** (copper(II) acetoarsenite) is primarily used as a **stomach poison** for insects, meaning it needs to be ingested to be effective. * It is a **highly toxic inorganic compound** that disrupts cellular respiration. * *DDT* * **DDT (dichlorodiphenyltrichloroethane)** is a **contact poison** and neurotoxin, primarily absorbed through the insect's cuticle. * It primarily affects the insects' **nervous system**, causing uncontrolled firing of neurons. * *Malathion* * **Malathion** is an **organophosphate insecticide** that acts as a **contact and stomach poison**, but its primary mode of action is through contact and fumigant effects. * It inhibits **acetylcholinesterase**, leading to paralysis and death in insects. * *Pyrethrum* * **Pyrethrum** is a natural insecticide derived from **chrysanthemum flowers** that acts primarily as a **contact poison** and repellent. * It causes **rapid knockdown** of insects by affecting their nervous system, though many insects may recover if not exposed to high enough doses.

Q: According to WHO guidelines, what is the recommended minimum air change rate per hour in isolation rooms for airborne infection control?

More than 6 air changes per hour. ***More than 6 air changes per hour*** - The World Health Organization (WHO) recommends a **minimum of 6 air changes per hour (ACH)** for airborne precaution rooms, particularly for naturally ventilated settings. - For mechanical ventilation systems, **WHO recommends 12 ACH** for airborne infection isolation rooms to effectively dilute and remove airborne infectious particles. - This higher rate ensures adequate ventilation to reduce the concentration of airborne pathogens like tuberculosis, measles, and varicella. - The WHO guidelines on Natural Ventilation for Infection Control in Health-Care Settings (2009) specify these minimum rates for effective airborne infection control. *2-3 air changes per hour* - An air change rate of **2-3 ACH** may be acceptable for general patient rooms or outpatient areas with natural ventilation in resource-limited settings. - However, this rate is **insufficient for airborne infection isolation rooms** where higher-risk procedures are performed or patients with confirmed airborne infections are housed. - This low rate does not provide adequate dilution of infectious aerosols for airborne precautions. *4 air changes per hour* - While **4 air changes per hour** provides better ventilation than 2-3 ACH, it still falls **below the WHO minimum recommendation of 6 ACH** for airborne infection isolation. - This rate might be acceptable for general wards but is inadequate for dedicated isolation rooms requiring airborne precautions. *1 air change per hour* - An **air change rate of 1 per hour** is completely insufficient for any healthcare infection control measures. - This extremely low rate would lead to dangerous accumulation of infectious particles, significantly increasing transmission risk. - Such minimal ventilation is unacceptable even for general patient care areas.

Q: Which of the following gases is a significant contributor to the greenhouse effect?

All of the options. ***All of the options*** - All listed gases (CO2, Methane, and Sulfur hexafluoride) are recognized as significant **greenhouse gases**, contributing to the **greenhouse effect** and **climate change**. - While they differ in their **global warming potential** and atmospheric lifetimes, each plays a role in trapping heat in the Earth's atmosphere. *CO2* - **Carbon dioxide** is a major greenhouse gas, primarily from the burning of **fossil fuels** and deforestation. - It is often considered the most significant contributor due to its high atmospheric concentration and long-term effects. *Methane* - **Methane** is a potent greenhouse gas, with a much higher **global warming potential** per molecule than CO2 over a shorter timescale. - Its sources include agricultural activities (livestock, rice cultivation), natural gas leaks, and landfills. *Sulfur hexafluoride* - **Sulfur hexafluoride** is a synthetic greenhouse gas with an extremely high **global warming potential** and a very long atmospheric lifetime. - Although its atmospheric concentration is lower than CO2 or methane, its potency makes it a significant contributor in specialized industrial applications.

Question 1

Which of the following is a key criterion for a prudent diet?

Accepted Answer

Saturated fats < 10% of total energy

Answer

Fat intake 35-40% of total energy

Answer

Dietary cholesterol < 300 mg/1000Kcal per day

Answer

Salt intake <10 g/day

Question 2

In rural areas, what is the recommended distance for cattle sheds to be placed away from houses?

Accepted Answer

25 feet

Answer

5 feet

Answer

10 feet

Answer

20 feet

Question 3

What is a standard requirement for the design of a slaughterhouse?

Accepted Answer

All of the above are standard requirements.

Answer

Adequate ventilation systems must be installed.

Answer

Floors and walls must be made of washable, non-absorbent materials.

Answer

Separate areas for clean and dirty operations must be maintained.

Question 4

What is a psychrometer used to measure?

Accepted Answer

Humidity level

Answer

Airflow rate

Answer

Ambient temperature

Answer

Surface temperature

Question 5

Which of the following statements about slow sand filters is true?

Accepted Answer

Requires a longer duration for filtration

Answer

Is more expensive than other filters

Answer

Uses sand size of 0.4 - 0.7 mm

Answer

Occupies less space than other filters

Question 6

What is the minimum contact period required for effective chlorination of drinking water?

Accepted Answer

30 minutes

Answer

2 hrs

Answer

4 hrs

Answer

1 hour

Question 7

Which of the following insects has shown the least widespread development of resistance to DDT?

Accepted Answer

Tsetse flies

Answer

Mosquitoes

Answer

Fleas

Answer

Ticks

Question 8

Which of the following is a stomach poison?

Accepted Answer

Paris green

Answer

DDT

Answer

Malathion

Answer

Pyrethrum

Question 9

According to WHO guidelines, what is the recommended minimum air change rate per hour in isolation rooms for airborne infection control?

Accepted Answer

More than 6 air changes per hour

Answer

2-3 air changes per hour

Answer

4 air changes per hour

Answer

1 air change per hour

Question 10

Which of the following gases is a significant contributor to the greenhouse effect?

Accepted Answer

All of the options

Answer

CO2

Answer

Methane

Answer

Sulfur hexafluoride

NEET-PG 2013 — Community Medicine