Health and Environment Flashcards
What are examples of diseases with the largest absolute burden attributable to modifiable environmental factors?
diarrhoea; lower respiratory infections; ‘other’ unintentional injuries; and malaria.
What different attributes that the six basic effects include?
- Acute toxicity
- Chronic toxicity
- Developmental and reproductive toxicity
- Mutagenicity
- Ecotoxicity
- Environmental fate
What are the 5 parts to an exposure pathway?
A source of contamination (such as an abandoned business)
An environmental media transport mechanism (such as
movement through groundwater)
A point of exposure (such as a private well)
A route of exposure (eating, drinking, breathing, or touching)
A receptor population (people potentially or actually exposed).
What are the different types of environmental hazards?
Outdoor pollutants
Indoor Pollutants
Water pollutants
Land and soil pollutants
What is the largest single course of outdoor pollution?
Transportation
What are the principles of environmental control?
Prevention
Substitution
Isolation (separation by distance or barriers)
Ventilation
Treatment (destruction, conversion, removal & inhibition)
Administrative
Where is the main asbestos waste site located?
Succabba /Old Harbour – (St. Catherine)
What are the elements of Green Housing?
Materials : obtained from natural, renewable sources; managed and harvested in a sustainable
way
Energy : Natural lighting, energy efficiency, renewable energy
Water : Minimising water use, rainwater harvesting, recycle grey water, low flow shower heads, low-flow flush toilets, waterless/composting toilets
Health : Use of non-toxic materials, low or no VOCs, moisture resistant materials, controlled humidity, temperature & ventilation.
What are sources of infection in daycare centres?
Workers
Water
Vectors
Fomites
Children
Food
What type of diseases can ingesting contaminated water cause?
Diarrhoea
Cholera
Dysentery
Typhoid
Polio
How many deaths per year did drinking contaminated water cause?
502 000 diarrhoeal deaths each year.
What are the 5 processes of the Hydrologic cycle?
- Evapotranspiration
- Condensation
- Precipitation
- Infiltration (percolation)
- Runoff
Which of the 5 hydrologic cycle processes does not occur continuously?
Precipitation
What is a Watershed?
The term watershed refers to the geographic boundaries of a particularwater body, its ecosystem and the land that drains to it.
What are large watersheds often referred to as?
River basins
What are examples of Watersheds?
Groundwater aquifers
What is the major source for public water supply systems?
Surface Water
Where does Surface water sources come from?
1.Precipitation
2. Ground water
What are the factors that control surface water runoff ?
Veronica - Vegetation covering the ground
Must - Man-made influences
Run- Rainfall intensity
Down - Duration of rainfall
Some - Soil composition
Slippery - Soil moisture
Slopes - Slope of the ground
What is the water table?
The water table is the upper surface of the zone of SATURATION closest to the ground surface.
Fill in the blanks.” The water in the saturated zone is called ______”
Ground Water
Fill in the blanks. “ The soil that holds the ground water is called _____”
Acquifer
What structure makes up 97.5% of earth’s water?
Oceans
What percentage of the water on the earth’s surface is considered fresh?
3%
Where is majority of the Earth’s freshwater found?
Glaciers and ice caps - 68.6 %
What is Water Stress?
Countries/regions undergo water stress when annual supplies drop below 1,700 cubic meters per person.
What is Water scarcity?
Defined as annual per capita supplies less than 1,000 cubic meters.
What is Potable Water?
Water that is free from pathogenic microorganisms, harmful chemicals/radiation and which is pleasing to the sight and palatable to the taste.
What is Safe Water?
Water that does not contain harmful microorganisms, toxic chemicals or materials and is considered safe for drinking even though it may have taste, odor, color and certain mineral problems.
How does Water acquire its characteristics?
- From the soils, rocks and minerals
- From the air that the water contacts
- From the animals and people that contact and influence the water
What are Physical Water Characteristics?
Temperature
Turbidity
Colour
Taste
Odour
What are Chemical Water Characteristics?
Inorganic
Organic
What are the four general sources that Organic water chemicals have?
- Plant and animal decomposition
- Waste water discharges yield synthetic organics found in municipal wastes, industrial and chemical wastes
- Agricultural run-off yields synthetic organics – pesticides, herbicides
- Water treatment operations yield complex organics - trihalomethanes
Which substance is the most dangerous water contaminant and what is its maximum contaminant level (mg/L)?
Nitrate (as N) - 10.0 (mg/L)
What are Biological Water Characteristics?
Algae
Bacteria
Viruses
Protozoa
Which inorganic chemical can cause red staining of fingers, teeth, and hair; general weakness; depression; irritation of the nose and throat and has a maximum contaminant level of 0.01?
Selenium
Which inorganic chemical can cause permanent gray discoloration of skin; eyes, and mucus members?
Silver
True or False? Arsenic can cause Increased blood pressure & nerve block?
FALSE!! Barium causes increased blood pressure & nerve block while Arsenic causes small sores on hands & feet, possibly leading to cancer.
What type of water- sanitation infections is guinea worm, schistosomiasis?
Water-related diseases ( infectious agent is transmitted with water contact )
What are water-washed diseases and what are examples of the?
Infectious agents harbored by persons without hand washing/body washing, e.g. Shigella, diarrhoeal diseases
True or False? Cholera is a water- washed disease?
FALSE!! It is a water-borne disease - infectious agents ingested from unclean water- cholera , typhoid etc.,
Fill in the blanks. ___________ diseases are often due to failure to dispose of stool result in direct contact - hookworm.
Sanitation - related diseases
What is the causative organism for Dysentry?
Shigella (bacteria)
Which two water-borne diseases are caused by the causative organism Shigella?
Gastroenteritis
Typhoid- Salmonella typhosa (bacteria)
Which disease is caused by a virus founding shell fish grown in polluted waters and causes yellowed skin, enlarged liver, abdominal pain, low mortality, lasts up to 4 months?
Infectious hepatitis
(Hepatitis A)
What is Potable Water?
Potable water that is free of contaminants that can cause disease or be toxic to the consumer.
What is Palatable Water?
Palatable water that is free, of unpleasant characteristics such as colour turbidity, taste and odour.
What are methods for disinfecting water?
- Heat treatment - Boiling
- Radiation treatment – UV light
- Chemical Treatment – Chlorine, Bromine, Iodine, Ozone
- Microfiltration
- Reverse osmosis
How long should water be boiled for after it was brought to a boil?
For 2-5 minutes
True or False? Sunlight is a natural means of disinfection .
TRUE!!
At what concentration is Ozone considered hazardous to health at a concentration in air ?
0.25mg/L
What is the most common form of disinfection of water practiced globally?
Chlorination
What process of the Preliminary Treatment involves
removing algae, aquatic plants, and small debris that can clog or foul other processes?
Micro-straining
What is Screening in the Preliminary Treatment
Process?
Removes large debris that can foul or damage plant equipment.
Which preliminary treatment process measures the amount of water being treated?
Flow Measurement
True or False? Chemical pre-treatment is apart of the Main Plant Processes?
FALSE!! It is apart Preliminary Treatment process. Conditions the water for the eventual removal of algae and other aquatic nuisances that case taste, odour, and colour
What are the processes in Main plant processes?
As- Aeration
Camryn - Coagulation/flocculation
Said - Sedimentation
Something - Softening
Fadiil - Filtration
Also - Adsorption
Stabbed- Stabilization
Florence - Fluoridation
Deep - Disinfection
Which main plant process in water treatment removes hardness-causing chemical from water?
Softening
Which main plant processes in water treatment removes odours and dissolved gases, adds oxygen to improve taste?
Aeration
What is the purpose of Stabilization in the main plant process in water treatment ?
It prevents scaling and corrosion
What is the Chemistry of Chlorination?
Chlorine + Water → Hypochlorous acid + Hydrochloric acid
Cl2 + H2O → HOCl + HCl
Fill in the blanks. “ As additional chlorine is added, the amount of chloramine reaches a minimum value
Beyond this point, a point is reached where further addition of chlorine produces free residual chlorine. This point is known as __________.”
Breakpoint
What is known as the concentration of chlorine available for disinfection?
Free Chlorine
When is breakpoint of chlorine achievable?
- No chlorine residual is affected
2.The strong chlorine taste at the plant is not found in the distribution system
3.The ammonia level in water decreases - A chlorine dose increase results in an individual release of chlorine residual.
What is the recommended chlorine dosage for normal domestic use?
0.2 and 0.5 mg/l (0.2 -0.5 ppm).
From what reaction is Trihalomethanes (THMs) formed?
Humic acid and Fulvic acid