#Module 5: Environment Health-I

Spotter 1

1. Write the name of this diagram. (0.5)
Slow Sand Filter

2. Write two advantages and one disadvantage of the above method. (1.5)

Advantages:

1. Simple to construct and operate

2. Cheaper construction cost

3. Produces high-quality water (physical, biological, and bacteriological)

Disadvantage:

• Requires a large area to set up; considered an old-fashioned/outdated method

Spotter 2

1. Enlist 4 points to differentiate Slow Sand Filter (SSF) and Rapid Sand Filter (RSF). (1.5)

2. What is the heart of slow sand filter? (0.5)
Sand bed – vital layer responsible for biological and physical purification

Spotter 3

1. Enlist the methods of small-scale water purification. (1)

1. Boiling

2. Chlorination (chlorine tablets)

3. Chemical disinfection (iodine tablets)

4. Filtration

5. Ultraviolet (UV) irradiation

6. Reverse osmosis (RO) / multi-stage purification

2. Enlist the methods of large-scale water purification. (1)

1. Sedimentation / Coagulation-Flocculation

2. Filtration – slow sand filter or rapid sand filter

3. Disinfection – chlorination, ozonation, or UV treatment

4. Softening (if required)

5. Fluoridation (optional)

Spotter 4

1. Identify the specimen. (0.5)

Chlorination

2. Write the phases of chlorination. (1)

1. Adding chlorine to water – initial addition of chlorine

2. Break point chlorination – point at which chlorine demand is satisfied and free chlorine begins to appear

3. Superchlorination – addition of chlorine beyond the breakpoint to ensure disinfection

4. Orthotolidine test – used to detect residual chlorine in water

3. How is chlorine demand estimated? (0.5)
Chlorine demand is the difference between the amount of chlorine added to water and the residual chlorine remaining at the end of a specified contact period, under a given temperature and pH.

Spotter 5

1. Identify the specimen. (0.5)
Chlorination

2. How many grams of bleaching powder is required to disinfect 1500 liters of water, where the 4th cup is the 1st cup to show color change? (1.5)
2 grams of bleaching powder are required.

Explanation:

• The orthotolidine test determines the first cup to show color change, which indicates the amount of chlorine needed to satisfy chlorine demand and achieve safe disinfection.

• Based on the test, for 1500 liters of water, 2 g of bleaching powder is sufficient.

Spotter 6

1. Identify the figure. (0.5)
Modern Sewage Treatment Plant

2. Write the components of primary treatment of sewage. (1)

1. Screening – removal of large debris

2. Grit chamber – settling of sand and grit

3. Primary sedimentation – settling of suspended solids

4. Skimming / Scum removal – removal of floating materials

3. What is dry weather flow? (0.5)
Dry weather flow is the flow of sewage in sewers during dry weather conditions (i.e., without rain or stormwater).

Spotter 7

1. Identify the figure. (0.5)
Activated Sludge Process

2. Write the components of primary and secondary treatment of sewage. (1)

Primary Treatment:

1. Screening

2. Grit chamber

3. Primary sedimentation

4. Skimming / Scum removal

Secondary Treatment:

1. Activated sludge process

2. Biofilters / Trickling filters

3. Rotating biological contactors

4. Secondary clarifiers

3. What is zoogleal layer? (0.5)
Zoogleal layer is a biological slime layer of microorganisms that develops on the surface of a slow sand filter during water purification. It is also called Schmutzdecke and is crucial for biological purification.

Spotter 8

1. Name of the instrument: (0.5)

• Stevenson Screen / Thermometer Screen

2. Uses: (1.5)

• Acts as a storehouse for thermometers, hygrometers, and barometers

• White color reflects heat; slatted sides and double roof ensure air circulation and reduce solar heat absorption

• Provides a standard environment for accurate measurement of temperature, humidity, dew point, and atmospheric pressure

3. What is zoogleal layer? (0.5)
Zoogleal layer is a biological slime layer of microorganisms that develops on the surface of a slow sand filter during water purification. It is also called Schmutzdecke and is crucial for biological purification.

Spotter 9

1. Name of the instrument: (0.5)

• Kata Thermometer

2. Uses: (1.5)

• Ventilation & HVAC: assess air circulation

• Industrial Safety (Mining): evaluate airflow in mines

• Meteorology: measure low wind speeds and air currents, complementing anemometers

• Occupational Health: gauge thermal comfort and heat stress in workplaces

• Radiant Heat: estimate radiant heat effects

Spotter 10

1. Name of the instrument: (0.5)

• Globe Thermometer

2. Uses: (1.5)

• Heat Stress Assessment: indicates heat risk in outdoor work, sports, and military operations

• Thermal Comfort: measures combined effect of radiation and convection on people

• Building Design: evaluates solar heat gain and loss

• Environmental Monitoring: measures Mean Radiant Temperature (MRT) to understand thermal environments, from urban heat islands to industrial settings

Spotter 11

1. Name of the instrument: (0.5)

• Anemometer

2. Uses: (1.5)

• Meteorology & Climatology: used in weather stations for predicting storms, understanding climate patterns, and tracking atmospheric conditions

• Aviation: pilots use it for safe takeoffs, landings, and flight planning

• Renewable Energy: measures wind resources to optimize wind turbine placement and operation

• Aerospace: used in wind tunnels to test vehicle aerodynamics (cars, planes, spacecraft) for better design

Spotter 12

1. Which type of ventilation is shown in the picture? (0.5)
Mechanical Ventilation

2. List types of ventilation. (1)
Natural ventilation

Mechanical ventilation

Mixed / Hybrid ventilation

3. Mention any two effects of inadequate ventilation. (0.5)
Accumulation of airborne pathogens

Accumulation of carbon dioxide (CO₂)

Spotter 13

1. Mention at least two daylight factors in these areas: (1)

• Living Room:

  1. Adequate daylight factor for general activities

  2. Proper distribution of sunlight to avoid glare

• Kitchen:

  1. Sufficient direct sunlight for cooking and cleaning tasks

  2. Even illumination to reduce shadows on work surfaces

2. Mention the biological effects of daylight. (1)
Vitamin D synthesis in the skin

Reduces eye strain

Boosts mood and reduces stress

Helps in natural disinfection of living spaces

Spotter 14

1. Write the name of the given spotter. (0.5)
Siphon Flush Toilet

2. Mention the importance of this item. (1.5)
Efficient removal of waste with minimal water usage

Maintains hygiene and odor-free environment due to water seal

Simple and reliable for household use

Spotter 15

1. Write the name of the given instrument. (0.5)
Incinerator

2. What is the ideal temperature for processing by this method? (0.5)
800–1200 °C

3. Enlist 2 drawbacks of this method. (1)
Requires high energy/fuel

Produces air pollutants if not properly controlled

Costly equipment and maintenance

Spotter 16

1. Write the name of the given instrument. (0.5)
Incinerator

2. What is the ideal temperature for processing by this method? (0.5)
800–1200 °C

3. Enlist 2 uses of it. (1)
Medical waste disposal – used bandages, syringes, anatomical waste

Municipal solid waste management

Hazardous or chemical waste disposal

Spotter 17

1. List 3R’s of Health Care Waste Management. (0.5)

Reduce, Reuse, Recycle

2. What is the amount of estimated health care waste generated in Nepal (kg/person/day)? (0.5)
1 to 1.7 kg/bed/day

3. Mention latest and best technique of waste management for new hospital settings. (1)
Autoclaving

https://global.noharm.org/news/working-hospitals-sustainable-health-care-waste-management-kathmandu?utm_source=chatgpt.com

Spotter 18

1. Enlist the type of waste that is stored in this bin/bag as per latest guidelines for segregation of bio-medical waste. (1)
Infected waste: contaminated dressings, bandages, swabs

Pathological and anatomical waste: body parts, tissues, organs

2. What is the full form of 3R’s in healthcare waste management? (1)

Reduce, Reuse, Recycle

Note:

Spotter 19

1. Mention methods for management of Health Care Waste according to guidelines of Nepal 2071. (1)

1. Waste minimization – reduce the amount of waste generated

2. Waste segregation – separate waste at the point of generation by type and hazard

3. Waste collection and storage – use appropriate bins and store safely

4. Waste transportation – move waste safely to treatment or disposal areas

5. Waste treatment and disposal – disinfect, recycle, or safely dispose according to type

2. Enlist the type of waste that goes in red bin. (1)
Contaminated but sharpless recyclable wastes: IV tubes & sets, catheters, gloves, syringes, contaminated plastics

Spotter 20

1. Identify this picture. (0.5)
Incinerator

2. Mention the type of wastes that are treated by this instrument. (1.5)

• Human anatomical waste

• Animal waste

• Soiled waste

• Expired/discarded medicines

• Sharps

3. Write treatment method of infected waste. (0.5)
Autoclaving, incineration, chemical disinfection, or burial

Spotter 21

1. Identify this picture. (0.5)
Inertization

2. Which type of waste is treated by this instrument? (1)

1. Chemical wastes: acids, alkalis, and toxic chemicals

2. Pharmaceutical waste: hazardous but non-infectious

3. Radioactive or heavy metals

4. Sharps after disinfection

3. Comment on the mixing of this type of waste with others before treatment. (1)

• Typical inertization mixture:

  • 65% pharmaceutical waste

  • 15% lime

  • 15% cement

  • 5% water

• This mixture stabilizes and neutralizes the waste before safe disposal