Environmental Health Practice Questions

Q: Waste disposal of placenta after delivery is done by

Incineration. ***Incineration*** - **Incineration** is the recommended method for disposing of anatomical waste like the placenta due to its effectiveness in destroying pathogens and reducing waste volume. - This method ensures **safe and complete destruction** of potentially infectious material, preventing environmental contamination. *Disposing it in blue bags* - Blue bags are typically used for **general non-hazardous waste** or specific categories of non-anatomical biomedical waste, not for anatomical waste like the placenta. - Disposing of anatomical waste in blue bags would violate **biomedical waste management guidelines** and pose a risk of infection. *Autoclaving* - **Autoclaving** is a sterilization method that uses steam under pressure, primarily for medical instruments and some types of infectious waste. - While it sterilizes, it does not physically destroy or reduce the volume of anatomical waste like incineration does, making it less suitable for placenta disposal. *Microwaving* - **Microwaving** is not a recognized or safe method for the disposal of anatomical waste due to its inability to reliably sterilize or destroy biological material. - It would not achieve the necessary level of **pathogen destruction** required for waste like the placenta and poses safety risks.

Q: As per biomedical waste management rule 2016 the metallic body implants should be discarded in which of the following?

Separate collection system. ***Separate collection system*** - Metallic body implants, due to their nature and potential for **recycling or specific disposal methods**, are to be segregated into a **separate collection system** as per BMW Rule 2016. - This ensures they do not contaminate other biomedical waste streams and can be handled appropriately, often involving **recovery of precious metals**. *Red colored non-chlorinated plastic bag* - This category is typically for **reusable contaminated waste** such as tubing, catheters, IV sets, and urine bags, which are often plastic. - Metallic implants are not typically suitable for disposal in red bags because they are not meant for incineration or autoclaving in the same manner as these plastic items. *Yellow colored non-chlorinated plastic bag* - Yellow bags are used for **human anatomical waste**, animal anatomical waste, soiled waste, expired or discarded medicines, and **chemical waste**. - Metallic implants do not fall into any of these categories and require a different disposal method due to their material composition and potential for recycling. *Card board box with blue colored marking* - Blue or white translucent boxes/containers are designated for **sharps**, including needles, syringes with fixed needles, and blades, as well as broken or contaminated glass. - While metallic, body implants are not considered "sharps" in the same context, nor are they typically discarded in cardboard, which is unsuitable for their weight and specific disposal requirements.

Q: Orthotolidine (OT) test is done for determining residual free chlorine quantitatively and qualitatively. What is the colour of the solution after adding OT which indicates presence of free chlorine?

Yellow. ***Yellow*** - The **Orthotolidine (OT) test** historically was used to detect and quantify residual **free chlorine** in water. - When Orthotolidine reagent is added to water containing free chlorine, it produces a **yellow color**, with the intensity of the yellow directly proportional to the amount of free chlorine present. - **Important Note:** The OT test has been **discontinued and is no longer recommended** due to orthotolidine being a **suspected carcinogen**. It has been replaced by safer methods like the **DPD (N,N-diethyl-p-phenylenediamine) test**, which also detects free chlorine but uses a safer reagent. *Blue* - A blue color is not associated with the Orthotolidine test for free chlorine. - Other water quality tests or reagents might yield a blue color for different parameters. *Green* - A green color does not indicate the presence of free chlorine in the Orthotolidine test. - It may suggest interference from other substances or mixed reactions. *Red* - A red color is not the characteristic indicator for free chlorine in the Orthotolidine test. - Red or pink colors are associated with the **DPD method** (the current standard test), which produces a pink/red color in the presence of free chlorine.

Q: A vital layer, also known as "Schmutzdecke" is seen in which one of the following ?

Slow sand filter. ***Slow sand filter*** - A vital biological layer known as **"Schmutzdecke"** or **"filter skin"** forms on the surface of slow sand filters. - This layer, composed of **algae, bacteria, fungi**, and protozoa, is crucial for effective water purification by trapping and breaking down organic matter and pathogens. *Air filter* - Air filters primarily remove particulate matter from air, not water, and do not develop a biological layer like **Schmutzdecke**. - Their mechanism involves mechanical filtration, not biological degradation. *Reverse osmosis filter* - Reverse osmosis filters use a **semi-permeable membrane** to remove dissolved solids and contaminants from water under pressure. - They operate on a physical process and do not rely on the formation of a biological "Schmutzdecke" layer for filtration. *Rapid sand filter* - Rapid sand filters primarily rely on **physical straining** and **coagulation/flocculation** for clarification, followed by backwashing to clean the filter media. - While some biological activity may occur, they do not form a distinct, vital **"Schmutzdecke"** layer as seen in slow sand filters, and their primary mechanism is different.

Q: Consider the following stages of modern sewage treatment plants : 1. Use of Grit chamber 2. Use of Primary sedimentation tank 3. Screening 4. Use of Sludge digester What would be the correct sequence of the above stages ?

3→1→2→4. ***3→1→2→4*** - The correct sequence for modern sewage treatment begins with **screening** (3) to remove large debris, followed by **grit chambers** (1) for sand and gravel, then **primary sedimentation tanks** (2) to settle organic solids. Finally, the collected sludge is processed in a **sludge digester** (4). - This order ensures progressive removal of contaminants, from large physical objects to settled organic matter, optimizing the efficiency of each treatment stage. *2→3→4→1* - This sequence incorrectly places the **primary sedimentation tank** (2) as the first step, which would be inefficient as large debris and grit would interfere with its operation. - It also reverses the order of screening and grit removal, which are crucial initial physical processes. *3→2→1→4* - While starting with **screening** (3) is correct, this sequence incorrectly places the **primary sedimentation tank** (2) before the **grit chamber** (1). - Grit removal should precede primary sedimentation to prevent abrasive materials from damaging equipment and accumulating in sedimentation tanks. *4→2→1→3* - This sequence is entirely incorrect, as it begins with the **sludge digester** (4), which is a final step in sludge processing, not the initial treatment of raw sewage. - It also drastically misorders the preliminary physical treatment stages.

Q: Iodine can be used for the disinfection of which of the following? 1. Water 2. Faeces 3. Urine 4. Skin Select the correct answer using the code given below:

1 and 4 only. ***1 and 4 only*** - **Iodine is highly effective for water disinfection**, particularly in emergency and travel situations, killing bacteria, viruses, and protozoa - **Povidone-iodine is a standard antiseptic for skin disinfection** used pre-operatively, for wound care, and before injections due to its broad-spectrum antimicrobial activity - These are the two established and recommended uses of iodine for disinfection in medical and public health practice *1, 3 and 4* - While iodine effectively disinfects water and skin, it is **not used for urine disinfection** - Urine from healthy individuals is typically sterile and does not require routine disinfection - If disinfection of contaminated urine is needed (rare situations), other chemical agents would be preferred *1, 2 and 3* - Iodine is effective for water disinfection but **not suitable for faecal matter disinfection** - Faeces requires stronger disinfection methods: **chlorine-based compounds (sodium hypochlorite/bleach)**, heat treatment, or proper sewage treatment systems - Iodine is impractical and ineffective for the high pathogen load in faecal waste *1 only* - This option incorrectly excludes skin disinfection, which is **one of the most common applications of iodine** in medical practice - Povidone-iodine solutions (Betadine) are standard antiseptics used worldwide for skin preparation before surgical procedures

Q: Which of the following insecticides is not used as a larvicide?

Fenthion. ***Fenthion*** - **Fenthion** is an **organophosphate insecticide** primarily used as an **adulticide** for **mosquitoes** and other flying insects. - While it can target adult mosquitoes, it is **not commonly used or recommended as a larvicide** due to its higher toxicity profile and environmental concerns compared to other dedicated larvicides. *Dichlorvos* - **Dichlorvos** (DDVP) is an organophosphate insecticide that has been used as a **larvicide**, particularly in situations where rapid knockdown of larvae is required. - It is known for its **quick action** and **fumigant properties**, making it effective against early mosquito stages. *Paris green* - **Paris green** (copper(II) acetoarsenite) is historically one of the **earliest larvicides** used to control mosquito larvae. - It acts as a **stomach poison** when ingested by mosquito larvae. *Abate* - **Abate** (temephos) is a widely used **organophosphate larvicide** known for its **low toxicity to mammals** and aquatic organisms at recommended doses. - It is effective against mosquito larvae in various breeding sites, including drinking water, making it a **preferred choice for public health programs**.

Q: Excessive nitrates in drinking water can produce:

Methaemoglobinaemia. ***Methaemoglobinaemia*** - Nitrates are converted to **nitrites** in the gastrointestinal tract, especially in infants. Nitrites then oxidize the **ferrous iron (Fe2+)** in hemoglobin to **ferric iron (Fe3+)**, forming **methemoglobin**. - **Methemoglobin** cannot bind oxygen, leading to **cyanosis** and **tissue hypoxia**, often referred to as "blue baby syndrome" in infants. *Polycythemia vera* - This is a **myeloproliferative neoplasm** characterized by the overproduction of red blood cells, white blood cells, and platelets. - It is not caused by nitrate exposure but is rather a bone marrow disorder that can lead to symptoms like headaches, dizziness, and a ruddy complexion due to increased blood viscosity. *Hypochromic microcytic anemia* - This type of anemia is typically caused by **iron deficiency**, leading to smaller (microcytic) red blood cells with less hemoglobin (hypochromic). - It is not directly linked to excessive nitrate consumption; instead, nitrate toxicity primarily affects oxygen transport by converting hemoglobin to methemoglobin. *Hemophilia* - Hemophilia is a **genetic bleeding disorder** caused by a deficiency in specific blood clotting factors, most commonly Factor VIII or Factor IX. - It is an inherited condition and has no association with environmental factors such as nitrate levels in drinking water.

Q: Consider the following: 1. Skin 2. Water 3. Faeces 4. Urine Bleaching powder can be used for disinfection of which of the above?

2, 3 and 4. ***2, 3 and 4*** - **Bleaching powder** (calcium hypochlorite) is a strong oxidizing agent widely used for **disinfection** in public health. - It is highly effective for **water purification** (chlorination of drinking water and wells), **faeces disinfection** (in latrines and for controlling fecal-oral disease transmission), and **urine disinfection** (in urinals and public sanitation facilities). - These are the **standard applications** of bleaching powder in community medicine and environmental health. *1, 2 and 3* - While bleaching powder is effective for **water** and **faeces** disinfection, it is **NOT recommended for skin disinfection**. - Bleaching powder is a **strong irritant** that can cause chemical burns and skin damage. - **Skin antisepsis** requires gentler agents like alcohol, chlorhexidine, or povidone-iodine—not bleaching powder. *2 and 3 only* - This option correctly includes **water** and **faeces** disinfection. - However, it incorrectly omits **urine**, which is also routinely disinfected with bleaching powder in latrines, urinals, and sanitation systems for **odor control** and **pathogen elimination**. *1 and 2 only* - This option incorrectly includes **skin**, which should not be disinfected with bleaching powder due to its caustic nature. - It also omits both **faeces** and **urine**, which are major applications of bleaching powder in environmental health and sanitation.

Q: Association between hardness of drinking water and death rate from cardiovascular diseases is:

Inverse. ***Inverse*** * Studies have often shown an **inverse relationship** between water hardness and cardiovascular disease mortality. * This means that areas with **harder drinking water**, which contains more minerals like calcium and magnesium, tend to have **lower rates of cardiovascular disease deaths**. *Direct* * A direct association would imply that **harder water leads to higher death rates**, which is generally not supported by epidemiological evidence. * If the relationship were direct, promoting soft water consumption might be a public health goal for cardiovascular health, which is not the case. *No association* * While the association isn't universally strong or consistently replicated in all studies, many large-scale epidemiological studies suggest a **protective effect** of hard water components. * Therefore, stating no association completely would ignore a significant body of research suggesting a benefit. *Association is obtained in presence of confounders* * While **confounders** (such as diet, lifestyle, socioeconomic status, and other geographical factors) are always a consideration in epidemiological studies, many analyses have attempted to control for these variables. * The observed inverse association often persists even after adjusting for known confounders, suggesting it's not solely due to them.

Question 1

Waste disposal of placenta after delivery is done by

Accepted Answer

Incineration

Answer

Disposal in blue bags

Answer

Autoclaving

Answer

Microwaving

Question 2

As per biomedical waste management rule 2016 the metallic body implants should be discarded in which of the following?

Accepted Answer

Separate collection system

Answer

Red colored non-chlorinated plastic bag

Answer

Yellow colored non-chlorinated plastic bag

Answer

Card board box with blue colored marking

Question 3

Orthotolidine (OT) test is done for determining residual free chlorine quantitatively and qualitatively. What is the colour of the solution after adding OT which indicates presence of free chlorine?

Accepted Answer

Yellow

Answer

Blue

Answer

Green

Answer

Red

Question 4

A vital layer, also known as "Schmutzdecke" is seen in which one of the following ?

Accepted Answer

Slow sand filter

Answer

Air filter

Answer

Reverse osmosis filter

Answer

Rapid sand filter

Question 5

Consider the following stages of modern sewage treatment plants :

1. Use of Grit chamber
2. Use of Primary sedimentation tank
3. Screening
4. Use of Sludge digester
What would be the correct sequence of the above stages ?

Accepted Answer

3→1→2→4

Answer

2→3→4→1

Answer

3→2→1→4

Answer

4→2→1→3

Question 6

Iodine can be used for the disinfection of which of the following?

1. Water
2. Faeces
3. Urine
4. Skin
Select the correct answer using the code given below:

Accepted Answer

1 and 4 only

Answer

1, 3 and 4

Answer

1, 2 and 3

Answer

1 only

Question 7

Which of the following insecticides is not used as a larvicide?

Accepted Answer

Fenthion

Answer

Dichlorvos

Answer

Paris green

Answer

Abate

Question 8

Excessive nitrates in drinking water can produce:

Accepted Answer

Methaemoglobinaemia

Answer

Polycythemia vera

Answer

Hypochromic microcytic anemia

Answer

Hemophilia

Question 9

Consider the following:

1. Skin

2. Water

3. Faeces

4. Urine
Bleaching powder can be used for disinfection of which of the above?

Accepted Answer

2, 3 and 4

Answer

1, 2 and 3

Answer

2 and 3 only

Answer

1 and 2 only

Question 10

Association between hardness of drinking water and death rate from cardiovascular diseases is:

Accepted Answer

Inverse

Answer

Direct

Answer

No association

Answer

Association is obtained in presence of confounders

Environmental Health — MCQs

Environmental Health — MCQs

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