Term
| Closed cohort study - when to use? |
|
Definition
| a well-defined group of persons is followed over time as events of interest occur; can be conducted prospectively (longitudinal-- follow-up after exposure and continue often until death)or retrospectively (access roster of exposed and non exposed) |
|
|
Term
| Open cohort study - when to use? |
|
Definition
| population is monitored to collect the number of incident events and the amoutn of person-time at risk; youcan add people to the cohort. It is typically used in occupational settings where the number of jobs is constant but the individuals in those jobs change over time |
|
|
Term
| Cross sectional study - when to use? |
|
Definition
| information on exposure and outcome are collected at the same time, generally using the same questionnaire; often uses self-reporting |
|
|
Term
| Case control study - when to use? |
|
Definition
| participants are defined on basis of presence (case) or absence (control) of an outcome of interest; cases and controls are generally matched according to criteria such as age, gender, ethnicity etc and exposure is determined retrospectively |
|
|
Term
|
Definition
| selection of study subjects depends on both the exposure and the outcome of interest |
|
|
Term
| Information/observation bias |
|
Definition
| the measurement of either the exposure or the outcome of interest depends on the true value of the other parameter |
|
|
Term
|
Definition
the measurement of association between exposure and the outcome used in case-control studies; it is the ratio of odds in favor of the exposure of the cases (A/C) to the odds in favor of exposure among the non-cases (controls: B/D)
A/C: B/D |
|
|
Term
|
Definition
measure of association used in cohort studies; the ratio of the incidence rate of a disease/health outcome in an exposed group to the incidence rate of the disease or condition in a non-exposed group
A/A+B : C/C+D |
|
|
Term
| What do relative risk #s mean |
|
Definition
RR>1 the risk of disease is greater in the exposed group than in the non-exposed group
RR<1 possible protective effect |
|
|
Term
| Epidemiologic Triangle/Causality |
|
Definition
| Host (a person or organism that harbors an infectious agent under natural conditions) : Agent (a factor whose presence or absence is essential for disease occurrence): Environment (domain, external to human host, in which disease-causing agents may exist, survive, or originate) |
|
|
Term
|
Definition
certain criteria needs to be taken into account in the assessment of a causal association between an agent factor (A) and a disease (B)
* strength * consistency * specificity * temporality * biological gradient * plausability * coherence |
|
|
Term
| Hill's Criteria of Causality |
|
Definition
Strength- strong associations are more likely causal; weak associations may be confounding thus requiring a stronger determinant of disease (ex- air pollution and daily mortality)
Consistency: replication in different populations or study designs, consistency across strata (persons, places, times, circumstances) ex is smoking and lung cancer
Specificity: one to one relationship between cause and effect; difficult to gage when one-to-several relationships exist
Temporality: cause must precede effect and latency period must be appropriate for outcome of interset
Biological Gradient: dose-response relationship should be exhibited; nature of relationship; chance for measurement error
Plausibility: existence of a biologic mechanism |
|
|
Term
|
Definition
| examines how environmental exposures to chemical pollutants may present risks to biological organisms, particularly animals, birds and fish |
|
|
Term
|
Definition
Poison is any agent capable of producing a deleterious response in a biological system
Toxicity is the degree to which something is poisonous, related to a material's physical and chemical properties |
|
|
Term
|
Definition
| the amount of a susbstance administsered at one time - various types (exposure, absorbed, administered, total, external, internal, biologically effective) |
|
|
Term
| Dose-response relationship |
|
Definition
| correlative relationship between the characteristics of exposure to a chemical and the spectrum of effects caused by the chemical; a dose-response curve is a graph used to describe the effect of exposure to a chemical or toxic substance upon an organism sch as an experimental animal (you can also have an individual dose response curve and the ultimate measure of toxicity is cancer/non cancer and then death) |
|
|
Term
|
Definition
1 + 1 = 2
the combination of two chemicals produces an effect that is equal to their individual effects added together |
|
|
Term
|
Definition
1 + 1 > 2
combined effect of exposures to two or more chemicals is greater than the sum of their individual effects |
|
|
Term
|
Definition
0 + 1 --> 0 + 1.5
one chemical that is not toxic causes another chemical to become more toxic |
|
|
Term
|
Definition
1 + 1 < 2
two chemicals administered together interfere with each other's actions or one interferes with the action of the other (reduces the efficacy) |
|
|
Term
| name the chemical toxicity factors |
|
Definition
*route of entry into the body
*received dose of the chemical
*duration of exposure
*interactions that transpire among multiple chemicals
*individual sensitivity |
|
|
Term
|
Definition
acute: usually la single exposure for less than 24 hours
subacute: exposure for one month or less
subchronic: exposure for one to three months
chronic: exposure for more than three months |
|
|
Term
|
Definition
local effects: damage at the site where the chemical first comes into contact with the body (ex: poison ivy)
systemic effects: generalized distribution of the chemical throughout the body by the bloodstream to internal organs (ex: chicken pox)
target organ effects: some chemicals may confine their effects to specific organs
cancer vs noncancer |
|
|
Term
|
Definition
liquid, solid, contained gas, or sludge wastes that contain properties that are dangerous or potentially harmful to human health or the environment -- includes discarded commercial products (ex- cleaning fluids or pesticides) and by-products of manufacturing processes
* developed world generates most of the toxic wastes |
|
|
Term
| sources of hazardous waste |
|
Definition
* home use - pesticides, cleaning products, automotive products, painting supplies, & other flammable/nonflammable products
*medical waste - chemicals, infectious agents, & radioactive materials - production or testing of biologicals
* industrial hazardous waste - heavy metals from plating operations, toxic chemicals, solvents, & residues from the manufacture of pesticides (Love Canal)
* radioactive wastes - spent nuclear fuel and tailings from uranium processing
* mining wastes & extraction wastes - toxic chemicals left over from mining operations include acids and heavy metals |
|
|
Term
| characteristics of hazardous waste |
|
Definition
*ignitable (liquids, non-liquids, compressed gas, & oxidizers)
* corrosive (aqueous - pH less than or equal to 2 or pH greater than 12.5)
* reactive - includes chemicals that are unstable at STP, highly reqctive with water
* toxic - harmful or fatal when ingested or absorbed (ex- contain mercury or lead); when land disposed, contaminated liquid may leach from the waste and pollute ground water |
|
|
Term
| National Priorities List (NPL) |
|
Definition
EPA's list of the most serious uncontrolled or abandoned hazardous waste sites in the US identified for possible long-term remedial action under Superfund
- scored based on the HAzard Ranking System & updated at least once a year (score of 28.5/100) |
|
|
Term
| Superfund Cleanup Process |
|
Definition
1. preliminary assessment - is a threat posed to human health & environment? collect readily available information; determine whether further investigation is necessary
* site inspection - provide data necessary for HRS scoring; samples usually collected to determine what hazardous substances are present
* NPL Site listing process - - ???
- 4 pathways (groundwater migration, surface water migration, soil exposure, air migration)
* remedial investigation/feasibility study - collect data to characterize site conditions, determine, the nature of the waste, assess risk to human health & environment, & conduct treatability testing to evaluate the potential performance & cost of the treatment technologies that are being considered
- Feasibility study mechanism to develop, screen, & evaluate alternative remedial actions |
|
|
Term
|
Definition
1. source of contaminant
2. pathways of environmental transport |
|
|
Term
| historical context of water |
|
Definition
*Early-mid 1800's: annual death rate from waterborne typhoid fever averaged 30/100,000; users of municipal public water supplies had a chance of 1/4 to 1/5 to die from cholera, typhoid, or other enteric diseases (infections enter body through mouth/intestinal system)
* late 1800s: pollution concners in Boston adn NYC led to Boards of Health; rise of sanitary/PH engineers
1880s: establishment of engineering experiment stations |
|
|
Term
| current drinking water challenges |
|
Definition
* increasing population - 50% of world's pop resides in metro areas
* climate change - regional effects - drought, flooding, changes in precipitation patterns
* water sources- issues concnerning protection, new sources, depletion
~ by 2015, 36 US states estimated to face serious water shortages
~ by 2025, 2.5 billion in 48 countries will experience water stress or water scarcity
* emerging contaminants |
|
|
Term
|
Definition
| 1,000-1,700 m^3 renewable freshwater per person/year |
|
|
Term
|
Definition
| <1,000 m^3 renewable freshwater per person/year |
|
|
Term
|
Definition
the public water system in US - delivers water for human consumption through a pipe or pipes
- 57,000 community water systems
- 128,000 non-community water systems |
|
|
Term
| water infrastructure needs |
|
Definition
- aging infrastructure
- $335 billion estimated for pipe, treatment, storage, source, and other infrastructure needs for the 20 years (as of 2009)
- 35 states submitted "shovel-ready" infrastructure projects - most were 2-30x greater than the grant money to be received
- security needs! |
|
|
Term
|
Definition
|
|
Term
| how much of the world's water is freshwater vs saltwater |
|
Definition
| 97% saltwater (saline/oceans); 3% freshwater |
|
|
Term
| of the earth's fresh water how much is usable? |
|
Definition
|
|
Term
|
Definition
| rivers, lakes & reservoirs, oceans (but this requires desalination) |
|
|
Term
|
Definition
aquifers (sealed with no real time surface influences)
springs (groundwater under surface influence) |
|
|
Term
|
Definition
| the upper surface of saturated zone is free to rise and decline; when it rains the water level will rise -- a pollution concern that will possibly permeate through the soil |
|
|
Term
| confined aquifers (aka ?) |
|
Definition
aka artesian
- permeable layer confined by upper and lower layers that have low permeability (like rock, clay)
water is usually under pressure |
|
|
Term
| sources of water contamination |
|
Definition
*vandalism/terrorism
*agricultural - animals, fertilizers, pesticides, manure, runoff
*commercial - transportation related facilities, dry cleaners, golf courses, medical/research facilities
* industrial - chemical/electronic manufacturing, foundries, mining, petroleum production/storage
*residential - fuel oil, lawn maintenance, septic, sewer lines, swimming pools, household hazardous products
* other - hazardous waste landfills, incinerators landfills, sewer lines, road deicing, transfer stations |
|
|
Term
|
Definition
1. taste and odor
2. contaminants
3. microbiological organisms |
|
|
Term
| water quality reporting parameters |
|
Definition
- regulated contaminants
- radioactive contaminants
- unregulated chemical contaminants
- contaminants subject to an action level
- disinfection byproducts
- microbial contaminants |
|
|
Term
| drinking water treatment processes |
|
Definition
1. intake- tunnels, pump stations, shafts
2. clarification and filtration
3. disinfection - chlorine, UV treatment, chlorine dioxide, ozone
4. distribution |
|
|
Term
|
Definition
| physical removal process of particles in water -- chemical conditioning, aggregation, physical separation |
|
|
Term
|
Definition
| removal of particulate matter, turbidity, and pathogens from drinking water; selection based on budget, operational flexibility, space rquirements, target contaminants |
|
|
Term
|
Definition
- sand filters
- activated carbon (powdered/granular)
- membrane filtration (not effective for dissolved liquids, disinfection byproducts, taste/odor, total organic carbon) |
|
|
Term
| 4 major drinking water disinfection techniques |
|
Definition
1. free chlorine - most widely used for water & wastewater
+ powerful against bacteria, viruses, giardia; low cost and low maintenance
- forms carcinogenic disinfection byproducts; not effective against Cryptosporidium; safety concerns w/transportation and handling
2. chlorine dioxide - introduced for taste and odor control
+ improved taste & odor control; reduced color problems
- aggressive regulatory monitoring requirements related to health issues; higher cost; need to store multiple chemicals; need for more complicated analysis methods and skilled operators
3. UV light
+ physical process (no chemicals), taste and odor not affected, no toxic byproduct; residence time in the seconds (smaller reactors - lower costs); effective against many chlorine-resistant pathogens
- no measurable chemical residual to monitor performance; no standards for UV dose; no mechanism to protect finished waster as it moves through distribution system
4. Ozone- over 300 plants in US use
+ removes taste and odor compounds; aids in coagulation and microflocculation; increases TOC removal and improves filter performance; provides strong disinfection; decreases DBP formation by allowing chrloine feed later in process at LOWER DOSE
- can't be used as final disinfectant as highly unstable in water; high energy and chem costs; high equipment capital and maintenance costs |
|
|
Term
|
Definition
intuitive risk judgments used by citizens to evaluate hazards
- perceived risk is quantifiable |
|
|
Term
|
Definition
|
|
Term
|
Definition
also dread & unknown
- familiarity, catastrophic potential, control, equity, and knowledge are important factors
-increases with lack of control |
|
|
Term
| voluntary versus involuntary |
|
Definition
voluntary: more unknown, less dread
involuntary: more unkonwn, more dread
- acceptability of risk from an activity is proportional to benefits from the activity
- people accept risk from voluntary activities 100 times more than involuntary |
|
|
Term
| current world and US populations |
|
Definition
7.14 billion US (hit 7 billion last year)
317.4 billion world |
|
|
Term
| population distribution by age |
|
Definition
- before 2000 young outnumbered old
- population moer than doubled for people > 52 ; today 3 billion in 1960 and 7 billion 2011
- demographic transition |
|
|
Term
|
Definition
|
|
Term
| cost of product substitution |
|
Definition
|
|
Term
|
Definition
|
|
Term
| why is environmental epi important |
|
Definition
|
|
Term
|
Definition
|
|
