Final Exam Questions Flashcards
Risk – define it and what the components of risk are. How do humans view things as risky or not? How should humans view risk?
The two components to risk are the:
1. The probability that an event will occur
2. The consequence of the event if it occurs
Humans view risk by how much control we have over it
What are Four factors in Risk assessment?
- Hazard Identification
- Dose Response Assessment
- Exposure assessment
- Risk characterization.
Describe the guiding equations of risk and how to manipulate them – what do the variables mean and how do the relationships mean
- I – Intake
- CR – Rate of Contact – the concentration or how often and how much
- EF - exposure frequency
- ED – Duration of Exposure – a week? A year?
- BW- Body Weight
- AT- Period of the Average Time (averaging time) – if it increases dose decreases
- C – Concentration
Incidence vs. Prevalence
- Incidence – the number of new cases in a time period
- Prevalence – the total amount of individual with a disease at any given point in time
o Express prevalence as a rate in comparison to the total population
Environmental Risk Factors- What are the top environmental risk factors for mortality
Air quality number 1 cause of mortality world wide.
Pollution of air and water
Greenhouse Gases
Major Outdoor Air Pollutants?
- NAAQS (National Ambient Air quality Standards) vs. non-NAAQS –
o Sulfer Dioxide – Coal power plants – scrubbers, 0.5 ppm
o Particulate Matter (pm 10) - Baghouse - ? – 150 ug/m
o Fine Particulate Matter (pm 2.50) - baghouse- ? – 35 ug/m
o Carbon Monoxide - ?
o Ozone -?
o Nitrogen Dioxide – Cadalydic converter
o Lead
Ozone how is it formed, what caused the ozone hole and how is it getting fixed
Ozone is formed in the athmoshpere by UVB radiation splitting oxygen. Chlorofluorocarbons (CFCs) were breaking down the ozone layer Chlorine, bromine, and fluorine acted as catalysts, we have stopped using them (montreal protocol).
Different smogs- how are they formed, what are they comprised of
- Photochemical SMOG – Made from VOCs and NOx + Sunlight – gasoline burning cars main source.
- Industrial Smog – Due primarily to industrial sources, emissions of smoke combine with fog – due to coal with emission sulfur and soot (SO2)
- Atmospheric Brown Clouds – cause by burning fossil fuels/farm wastes, made up of black carbon particle and soot, darkens the sky, lots of particulate matter.
temperature inversion- what is it and how does it result in poor air quality?
Hot air crests over something, trapping cold air closer to the ground, which also traps the pollutants near the ground
Air pollution control devices – Catalytic Converter, bag houses, scrubbers (coal facorties, sulfer dioxide). What are they and how do they work?
- Catalytic Converters – installed in vehicles and all the exhaust goes through it, reduces NOx, oxidizes VOC and CO to CO2. Section are 1 – Heat shield, 2 reduction catalyst for NOx, 3 air from air pump, 4 Oxidation catalyst for CO and hydrocarbons.
- Scrubbers – remove Sulfur Dioxide at Coal power plants – gas goes in and is mixed with others, comes out as water vapor, CO2 etc.
- Bag houses – Used especially in mills or factories with a lot of dust, bag house are towers with fabric bags in them. When the dusty air enters, it gets trapped in the bags and falls down while the clean air escapes.
acid deposition and acid rain- where does it come from, how is it formed, what are the results
- Acid precipitation is any precipitation with a pH less than 5.5. It comes from burning fossil fuels that release sulfur dioxide (coal) and nitrogen oxide (cars) into the air. As a result, marble and limestone sculptures are destroyed, nutrients and calcium are leached from the soil, and the acidification of lakes and destruction of fish population.
Natural air pollution controls
- The Hydroxyl Radical – from the little bit of UV not broken down the stratosphere, it the reacts with water and oxygen to produce ozone in the troposphere – ozone reacts with VOCs and other naturally occurring pollutants
- Sea salts and resulting rain – nuclei for formation of raindrops – rain the washes out particulates
- Sunlight – breaks down organic molecules (e.g. VOCs from trees)
Indoor air pollution – how is it different outdoor air pollution (name and explain at least 4)
- Sources – there are different sources for things. VOCs are a big thing indoors because of al the fragrances.
o Candles, ozone, gas stoves - Walls and surfaces – area/volume : indoor 300-1000 times more than outdoors, and increase interactions with pollutants
- Environmental conditions – Temperature, Humidity, ventilation
- Occupants – can manipulate everything and add through biological functions.
- Microbiology – viruses, bacteria and fungi, mold
Ways one can improve their indoor air quality (name 4)
- Ventilate
- Remove combustion – anything that uses fire
- Control moisture
- Minimis odorous products
- Change your air filter
- Wash clothes before wearing
- Avoid carpet
- Get a dog not a cat
Water pollution- 5 main pollutants and specific examples as well as tests in wastewater treatment plants
to determine if contamination of wastewater is occurring
- Pathogens – disease causing organisms (bacteria, viruses, parasites) – Fecal Coliform Test – is there E – coli in the water?
- Organic matter – Encourage bacterial growth and depleted oxygen in lakes and streams – BOD – measure the amount of organic material in the water.
- Nutrients – Nitrogen and Phosphorus that case rapid plant and animal growth to unsustainable levels
- Chemical/Toxins – Metals, synthetic organic chemicals, acids, air pollution fallout (mercury) – test for specific ones.
- Solids – Rags, plastic, sand, gravel, fecal matter, food wastes, suspend particles, silt – color of water
Steps of a wastewater treatment plant
- Primary treatment (physical) – Removes debris, grit an particulate organic matter
o Bare and debris Screem
o Grit chamber
o Primary clarifiers – tanks where particulate matter settles to the bottom and oil ly materials float - Secondary treatment (Biological) - Breaks down organic wastes and pathogens
o Trickling filter system – water sprinkled on rocks 6 -15 ft deep1
o Activated sludge – tank with air bubbling system
Oxygen added to enhance respiration and growth. - Removal of Nitrogen and Phosphorus
o Using a combination of anerobic and anoxic tanks, organic and inorganic nitrogen can be converted to nitrogen gas
o Phosphorus can be removed by either chemical or physical processes (something bonds) - Secondary clarification
o Flocculation and sedimentation – organic materal still in water gathers into clumps (flocs) and falls to floor as sludge
o Disinfection to get rid of pathogens – 3 methods
Clorine
Ozone
UV radiation
How is a septic tank different from a wastewater treatment plant?
A septic tank is much smaller and has less steps
Effects of topsoil runoff
enriched plant growth which leads to dead zones
BOD and DO, what are they and how do we remove them? How are they related and how do remove the BOD to prevent DO ( Dissolved oxygen
- Organic material DO- Measure by Biochemical Oxygen Demand – we need to supply more oxygen – via trickling water filter and activated sludge
nutrients and the problems they cause – phytoplankton, cultural eutrophication, fish kills
- As more nutrients are in the water, phytoplankton rapidly begins to grow, increasing the turbidity of the water. This then shads out the SAV that live in the water, resulting in in the loss of food, habitats, and dissolved oxygen for their photosynthesis.
Cultural Eutrophication- steps to form dead zone
- The entire process of eutrophication starts with nutrient enrichment, then the growth and death of phytoplankton, then the accumulation of detritus, the following growth of bacteria, and the depletion of dissolved oxygen, which suffocates animals.
Fecal Oral Pathways
See chart
Waste management hierarchy- know the four steps and examples for each
o Source Reduction and reuse – using up all scraps of fabric in an outfit
o Recycling/composting – glass bottles – some fabric
o Energy Recovery – burning
o Treatment and disposal
US Federal Environmental Regulations- CAA, Clean Water Act, RCRA
Clean Air Act-
* Clean Water Act
* Resource Conservation and Recovery Act
