Key Concepts in Environmental Health
The Water Cycle
Most of Earth’s water is in the oceans. The sun drives the water cycle by heating water, causing it to evaporate into the air. Ice and snow can also sublimate directly into water vapor. As air rises, it cools and condenses into clouds. Air currents move these clouds globally. Within clouds, tiny water particles collide, grow, and eventually fall as precipitation (rain, snow, etc.). Snow can accumulate as ice caps and glaciers, storing water for thousands of years. In warmer climates, snow packs thaw and melt in spring, with the melted water flowing overland as snowmelt. Finally, most precipitation returns to the oceans or land, and due to gravity, the precipitation on land flows over the ground as surface runoff.
Factors Affecting Environmental Health
Environmental health addresses all human-health-related aspects of the natural environment and the built environment. Environmental health is affected by factors like:
- Air quality, including both ambient outdoor air and indoor air quality, which also comprises concerns about environment
- Tobacco smoke
- Biosafety
- Climate change and its effects on health
- Disaster preparedness and response
- Food safety, including in agriculture, transportation, food processing, wholesale and retail distribution and sale
- Hazardous materials management, including hazardous waste management, contaminated site remediation, the prevention of leaks from underground storage tanks and the prevention of hazardous materials releases to the environment
- Housing, including substandard housing abatement and the inspection of jails and prisons
- Childhood lead poisoning prevention
- Land use planning, including smart growth
- Liquid waste disposal, including city wastewater treatment plants and on-site wastewater disposal systems, such as septic tank systems and chemical toilets
- Medical waste management and disposal
- Noise pollution control
- Occupational health and industrial hygiene
Sulabh Sauchalaya Leach Pit Latrines
The concept was introduced by Dr. Bindeshwar Pathak. He modified the standard hand flush latrine to suit the rural Indian community. It consists of a specially designed pan and a water seal trap. It is connected to a pit 3x3x3 feet. Minimal water is needed in the process. The excreta gets decomposed to manure in the pit. This provides clean and sanitary toilets to the users at a minimal cost. These are also maintained by the Sulabh International society.
Advantages of Leach Pit Toilets
- Hygienically and technically appropriate, and socio-culturally acceptable
- Affordable and easy to construct with locally available materials
- Design and specifications can be modified to suit householder’s needs and affordability
- No chance of mosquito, insect, and fly breeding
- Can be constructed in different physical, geological, and hydrogeological conditions
- Free from health hazards and does not pollute surface or ground water, if proper precautions and safeguards are taken during construction
- Can be located within the premises as it is free from foul smell and fly/mosquito nuisance etc.
- Can be constructed on upper floors of houses
- Pits are generally designed for 3-year desludging interval, but if desired, it can be designed for longer periods or it can be reduced even to two years
- Maintenance is easy, simple, and costs very little
- Needs only 1 to 1.5 litres of water for flushing, while conventional flush toilet needs 12 to 14 litres of water
- Needs less space than a septic tank toilet system
- Does not need scavengers for cleaning the pits or disposal of sludge. This can be done by the householder
- Makes available rich fertilizer and soil conditioner
- Can be easily connected to sewers when introduced in the area
Hospital Waste Disposal Coding System
“Universal Coding System” for hospital waste disposal, outlining different types of waste and their corresponding colored bags:
- Black Bag: Household & non-infectious waste (e.g., paper, packing material, paper napkins)
- Yellow Bag: Clinical infected waste for incineration (e.g., gloves, syringes, stained gauze, dressings, cotton, blood transfusion sets, urosac, ileostomy bag)
- Green Bag: Plastic items for recycling (e.g., IV sets, Ryles tubes, respiratory tubings, plastic wrappers)
- Red Bag: Infected Linen for Laundry (e.g., blood and body fluid stained bedsheets, clothes)
Methods for Controlling Air Pollution
- Substitution of technological processes: This involves shifting from coal and oil to cleaner energy sources like natural gas and electricity
- Containment: Preventing toxic gases from escaping into the atmosphere through methods like enclosure, local exhaust ventilation, and releasing treated air from high chimneys or towers
- Plantation of trees: Trees absorb CO2 and release oxygen, thus planting them widely helps purify the air
- Legal action: Implementing strict legal measures against industries and vehicles that exceed pollution emission standards, enforcing acts like the Prevention of Pollution Act and requiring PUC certificates
- International Cooperation: Establishing an international network of laboratories for monitoring and studying air pollution, issuing warnings, and collaborating on environmental engineering research, exemplified by NEERI in India
Radiation Protection Measures
“Protection against radiation” It outlines various measures under three main categories:
Health Promotion
- Health education regarding handling of x-ray machines and allied equipment
- Personal hygiene
- Good housekeeping – keeping everything clean, tidy, and neat
Specific Protection
- Using minimum effective dose
- Avoidance of indiscriminate use
- Use of lead aprons, goggles
- Decreasing time of exposure
- Using shield and keeping distance
- Enclosing procedure totally
Early Diagnosis and Treatment
Periodic health check-up by using:
- Film badge (known as dosimeter) on chest when at work. It records dose received
- Blood cell examination
Engineering Methods for Malaria Control
Anopheline mosquitoes, which are responsible for its spread. The core idea is to eliminate mosquito breeding grounds, primarily in stagnant clean water.
Here are the control measures outlined in the passage:
- Urban Water Tanks: Open overhead water tanks on terraces and lofts in urban areas are major mosquito breeding sites. These should be fitted with air-tight covers, and overflow pipes should have a wire mesh
- Filling Low-Lying Lands: Low-lying lands in residential areas should be filled up to prevent water stagnation
- Proper Drainage: Ensure proper drainage of rainwater without stagnation by leveling the land
- Civil Constructions: During major civil constructions like bridges, care must be taken not to obstruct the natural flow of rivers. Ditches created in riverbeds should also be properly maintained
- Railway and Highway Construction: During the construction of railways and highways, borrow pits (excavated areas) should be avoided. If necessary, they must be interconnected and the accumulated rainwater drained into nearby natural water courses. Water collection in places like bird’s pots, animal drinking troughs, or around faulty town water supply taps should also be managed
- Screening of Houses: Houses should be screened to prevent mosquitoes from entering
- Draining Open Nallas/Water Courses: Open drains (nallas) and natural water courses in urban areas should be properly drained, especially during low flow periods. Half-round pipes can be laid in the center of the bed to ensure water flows without stagnation
- Preventing Scattered Water Pools: No scattered water pools should be allowed to form in riverbeds and irrigation canals. Seepage around these areas must also be prevented