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
What are examples of Trihalomethanes?
- Chloroform
- Bromoform
- Bromodichloromethane
- Dibromochloromethane
True or False? Surface water contains more organic acids than ground water and is more chlorinated.
TRUE!!
Which specific trihalomethanes have been linked to carcinogens in animal studies?
Chloroform
What is the usual indicator organisms tested for in the microbiological testing of water?
Coliforms
What is the methods for microbiological testing of water?
Multiple Tube Fermentation and Membrane Filtration
What is the reagent used in a Cooler Wheel Test Kit?
N,N diethyl-p-phenylene diamine (DPD)
What are the parameters analysed monthly by NWC?
▪ BOD
▪Suspended Solids
▪ Chloride
▪ Nitrates
▪ Nitrite
What are the different methods used to purify bottled water?
Chlorination
Ozonation
UV Radiation
Filtration
Reverse osmosis
What is the pH of bottled water?
5.5- 8.5
What is the pH of tap water?
6.5- 8.5
What is the Biochemical Oxygen Demand ( BOD)
It is a measure of the amount of free oxygen required by aerobic microorganisms to decompose the organic matter in a sample of water biologically, usually within 5 days at 200 C.
What is the unit of measurement for Biochemical Oxygen Demand ( BOD)?
In parts per million (ppm or mg/m3)
What can the Biochemical oxygen demand be used to determine?
It can be used to measure the degree of water pollution and the strength of the waste.
What is the Chemical Oxygen Demand ( COD) ?
A measure of the amount of oxygen chemically (rather than biologically) consumed under specific conditions in the oxidation of organic and oxidizable inorganic materials in wastewater.
True or False? The COD is usually measured in relation to chemical wastes.
FALSE!! COD usually measured in relation to industrial wastes
An over- enrichment of a water body with nutrients, resulting in excessive growth of organisms and the depletion of free oxygen is known as?
Eutrophication
Fill in the blanks. ‘ Suspended solids are those solids that are ________ and in ________ in water.
They are visible and in suspension ( duhh)
What is the order by which sewage treatment plants are designed to remove pollutants in the following order?
S - Suspended solids
D - Dissolved biodegradable
organic matter
I - inorganic nutrients
’ SDI not STI’
Which wastewater treatment process involves a detention time of 1-2 hrs?
Primary Treatment
True or False? In Tertiary treatment of wastewater treatment process sludge is produced!
FALSE!! Sludge is produced in secondary treatment
What is the purposes of the Gift chambers and comminutors used in the Preliminary treatment process?
Gift chamber - removes abrasive suspended materials such as sand, pebbles etch.
‘ gift chamber leaves gifts ‘
Comminutor - Shreds materials are not removed by screens.
What three instruments are used in the preliminary treatment process?
Bar screens ( 1-3 cm)
Gift Chambers
Comminutor
What percentage of suspended solids are removed in Primary treatment?
50-75%
What percentage of biodegradable pollutants are removed during Primary treatment ?
40- 50%
What happens during Secondary Treatment of the wastewater treatment process?
- Removes dissolved organic pollutants
- Controlled microbial biodegradation to remove
pollutants - Biodegradable pollutants serve as food for microorganisms
What process is typically followed at the end of the Secondary Treatment process?
Chlorination
What are the typical designs included in the secondary treatment process?
- Oxidation/Stabilization Ponds/Beds or Lagoons,
- Trickling Filters,
- Rotating Biological Contactors,
- Extended Aeration/Activated Sludge
systems.
What are the two types of trickling filter media that are there?
Stone filter media & Plastic filter media
What are the different zones that are apart of the Oxidation/Stabilization Systems in the Secondary treatment process?
Aerobic
Facultative
Anaerobic
What is the length of the Aerobic zone?
0.2- 0.6 m
What is the length of all three zones combined?
1.0 M ( min)
1.5 ( max)
True or False? Activated sludge systems can remove 90-99% of viruses, bacteria and cholera vibrio while trickling filters can remove 90-95% but neither can remove leptospires.
TRUE!!
What are the main nutrients involved in the tertiary treatment process?
Phosphorus and Nitrogen
How is phosphorus removed?
Microbiological removal by
heterotrophic or autotrophic organisms
How is Nitrogen removed?
- Nitrification - bio-oxidation of ammonia to nitrate.
- De-nitrification - Biological reduction of nitrate to nitrogen gas.
What is the effluent standard for the Biochemical oxygen demand?
20 mg/L
What is the effluent standard for chemical oxygen demand?
100 mg/L
What is the Effluent standard for total nitrogen?
10 mg/L
What is the effluent standard for total phosphates?
4 mg/L
Which treatment process of wastewater treatment processes involves the removal of nutrients?
Tertiary Treatment
Fill in the blanks, “ Waste generation is closely linked to _______ , _________ and __________.”
Population
Urbanization
Affluence
True or False? In solid waste management, waste from municipal sewage networks and treatment, as well as municipal construction and demolition is excluded from municipal wastes. (OECD)
TRUE!!
What are municipal solid wastes?
This is solid or semi-solid waste generated in population centers including domestic and, commercial wastes, as well as those originated by the small-scale industries and institutions (including hospital and clinics); market street sweeping, and from public cleansing.(PAHO).
What is solid waste?
Non-liquid waste materials arising from the domestic, municipal, trade/commercial industrial, agricultural, etc. activities but EXCLUDING the solids in wastewater.
What is refuse ( solid waste management wise) ?
It is used interchangeably with solid waste. (Includes all putrescible( liable to decay) and nonputrescible ( not susceptible to rapid decomposition - can be divided into combustible and non- combustible) solid wastes except human body waste.)
What is the name given to a special type of garbage, which is wholly or nearly edible and useable as food and having food value for animals. (Typically accumulating from animals, vegetable or other materials and is high in liquid content.) ?
Swill
Fill in the blanks.” Garbage consists of _______ waste while rubbish consist of _______ waste.”
Garbage - Putrescible waste (GP)
Rubbish - Non-putrescible (RN)
True or False? Ash is considered as rubbish.
FALSE!!
What is a leachate ?
Liquid resulting from precipitation percolating through landfills containing water, decomposed waste, and bacteria.
What is the equation to calculate Waste generation?
Waste generation = Materials recovered + Discards
What is known as the solid waste remaining after materials recovery?
Discards
What is known as the amount of materials & products that enter the wave stream?
Generation
What is the order of the waste management hierarchy?
Reduce
Reuse
Recycle
Recovery ( aka Scavenging)
Responsible disposal
Wastes that are considered industrial are coming from what sites?
Light and heavy manufacturing , fabrication , construction sites , power and chemical plants.
Wastes that are considered commercial are coming from what sources?
Stores, hotels, restaurants, markets, office buildings.
What is the solid waste generation for Jamaica?
0.44 tons of municipal waste/person/yr; 2.64 lbs./person/day
What is the solid waste generation for China?
2.5 pounds/person/day
What substance has the greater percentage of the overall composition of waste collected?
Compostable ( 62.22%)
What are the reasons for public health significance of solid waste management ?
◼ Potential risk to health : Disease transmission – direct and/or indirect.
◼ Environmental pollution (air, water, land)
◼ Aesthetics
◼ Land-use
◼ Others (eg. economic, social, etc.)
What are examples of health effects in solid waste management ?
◼ Fatal occupational injuries
◼ Non-fatal injuries are mainly musculoskeletal.
◼ Other common injuries are fractures, ocular trauma, and bites, and diseases include skin and gastrointestinal disorders.
◼ Workers at municipal solid waste incinerators are exposed to a variety of concerning substances, such as heavy metals, respirable quartz dust, dioxins, furans, and mutagens.
What are Indirect health risks?
B - Breeding of disease vectors
A - Air pollution due to inefficient burning of wastes.
S - Surface and ground water pollution by leachate.
S - Spontaneous combustion of waste at dump sites.
P - Production of greenhouse gases: CO2 & CH4
H - Heavy metals contamination by sludge in soil conditioners.
A - Aesthetics
T- Traffic accidents
T - Toxic waste spills
” Bass phatt”
What integrated waste management strategies ?
◼ Source reduction
◼ Recycling & composting
◼ Combustion (waste-to-energy facilities) ◼ Landfills
What is the components of the SWM system ?
◼ Storage (at or near the point of generation)
◼ Collection & transportation
◼ Street cleansing (behavioural, natural & road traffic waste)
◼ Treatment
◼ Disposal
How often is collection of bulky wastes recommended?
Every 3 months
How often is collection of domestic wastes recommended?
1-2 times/week for domestic wastes.
What is the name given to mass burn that is sourced by refuse- derived fuel?
Incineration
What are Type C landfills?
Isolated/Secure landfills
What are Type A landfills?
Uncontrolled landfills
What are Type B landfills?
Controlled landfills
What is toxicology?
The study of the interaction between chemicals and biological systems to determine quantitatively the potential for chemicals to produce toxicity.
What are examples of extremely toxic compounds and what’s their LD50 ?
Cyanide and Vitamin D
Nicotine and Caffeine can be classified as _________ on the toxicicity category scale of human poisons
Very toxic
What are the factors determining the movement and distribution of pollutants?
Localization
Persistence
Bioconcentration & Bioaccumulation
Bioavailability
Chemical interaction
What are the factors determining environmental toxicity?
Factors related to the Toxic agent
Factors related to the Exposure
Factors related to the Host
What are the different interactions between chemicals?
Independent effect
Additive effect
Antagonistic effect
Potentiating effect
Synergistic effect
What are examples of toxins that produce an antagonistic effect?
BAL (Dimercaprol or British anti-Lewisite or EDTA (Ethylenediaminetetraacetic acid) and lead
What happens to a toxin that has a potentiating effect?
Where one substance does not have a toxic effect on a certain organ but when combined with exposure to another chemical, it makes the latter much more toxic.
Which groups of people are largely impacted by air pollution?
Children
Women
Outdoor Workers
What are the different gaseous compositions of the atmosphere and what are their respective concentrations?
▪ Nitrogen (78.1%)
▪ Oxygen (20.9%)
▪ Noble gases (<0.1%)
▪ Hydrogen (0.5 ppm)
Which gas has the greatest variability in concentration?
Water Vapour
Which group of people are most affected by poor air quality?
People who have asthma , heart disease & COPD
What are primary air pollutants?
Primary sir pollutant is contaminant which enters directly into the atmosphere
What is a secondary air pollutant?
Secondary: contaminants enter the atmosphere through chemical transformation.
Who invented the word smog and in what year did it happen?
Harold Des- 1911
What are the two types of fogs?
London- Type smog
Los-Angeles Type smog
What is the main source for London- type smog?
Burning coal (industrial activity) leads to emissions of sulfur dioxide and dust.
What is the main source of Los- Angeles ( photochemical) smog?
Results of emissions from traffic.
What happens during Los-Angeles smog?
Nitrogen oxides from automobile exhausts and hydrocarbons from various anthropogenic and biogenic sources react in the presence of sunlight to produce a noxious mixture of aerosols and gases.
What are the components that is contained in smog?
Tropospheric ozone, formaldehyde, ketones and PAN (peroxyacetyl nitrates).
What are the main air pollutants found in London- type smog?
Carbon oxide
Sulphur dioxide
What are the main air pollutants found in Los- Angeles smog type?
Tropospheric ozone
Nitrogen Oxide
Nitrogen dioxide
Carbon oxide
What is “ ground level ozone or bad ozone” created by?
Ground level ozone (“Bad ozone”) is created by a chemical reaction between oxides of nitrogen (NO2) and volatile organic compounds (VOC) in the presence of sunlight.
What are methods used in the control of tropospheric ozone?
- Reduce NOx emissions from power plants and industrial combustion sources.
*Introducing low emission cars and trucks.
*Using “cleaner” gasoline
*Improving vehicle inspection programs
What are factors that affect the indoor environmental quality and creature comfort?
*Temperature and humidity.
*Bio-aerosols
*Volatile organic compounds (VOCs)
*Microbial volatile organic compounds (MVOCs).
*Fresh air supply
(Carbon dioxide – a surrogate for fresh air supply.)
What are factors that contribute towards indoor air quality problems?
1.Sources of pollutants or odours.
2.Design, maintenance and operation of building ventilation systems.
3.Moisture & humidity.
4.Occupant perceptions and susceptibilities.
What percentage is ideal for humidity?
50% ideal
What is known as Conservancy?
Sanitation systems in which fecal matter is retained in a closet apparatus rather than being water-carried.
The term Excreta can be defined as?
Waste matter eliminated from the body (faeces & urine): about 150 gms.; contains about 400 billion E. coli; 0.2 billion FC & about 0.45 billion streptococci /person/day
Fill in the blanks. “ Black water comes from _____, ______ and _______.”
Water closet, Latrines and Aqua privy flushing.
