Environmental Health Exam 1

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Environmental Health Exam 1
2013-03-11 13:12:26
environmental health

environmental health exam 1 cards
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  1. ecology
    the study of the interactions between organisms and their environments including living(biotic) and nonliving(abiotic) components.
  2. subdisciplines of ecology
    • ecosystem ecology
    • community ecology
    • population ecology
  3. ecosystem ecology
    • whole systems view
    • ecosystem as unit of study
    • emphasis on energy and material cycles
  4. community ecology
    • interactions of species
    • emphasis on species' composition and diversity
  5. population ecology
    • population-level processes
    • emphasis on population dynamics and regulation and on interspecies interactions
  6. ecosystem scales
    • world: biosphere
    • nation(region): biome (biological province)
    • state: landscape
    • county or district: ecosystem
    • municipality: biotic community
    • household: population (species)
    • individual: organism
  7. ecosystem ecology
    • stresses energy flows and material cycles
    • including the ways in which energy and materials are modified by human activities
  8. ecosystem
    formed by the interactions of living organisms with their physical environment.
  9. biome
    • major ecological zones
    • defined by the kind of vegetation
    • vegetation is determined by: precipitation, temperature and availability of soil nurients
  10. trophic structures
    • "food chain"
    • the organization of ecosystem by feeding levels
    • often conceptualized as a pyramid
  11. trophic level
    the position that an organism occupies on the pyramid
  12. first trophic level
    • autotrophs or primary producers
    • convert sunlight into energy
  13. primary consumers
    • feed upon primary producers
    • fed upon by secondary consumers or heterotrophs
  14. habitat diversity
    • as the habitat area increases,  intp a lergerso do the amount of resources and the variety of resources
    • greater extent and diversity of habitat translates into a larger number of species supported
  15. competitive exclusion principle
    no two species can occupy the same niche
  16. niche
    the particular needs of a species and its role in its community
  17. population ecology
    attempts to explain the dynamics of species populations and interactions among species as well as relationships between species and their physical environments
  18. population
    • a group of interbreeding individuals in a particular locality.
    • elemental factors affecting population size are: births, deaths, immigration, and emmigration
  19. density-independent regulation of population (factors)
    • temperature
    • humidity
    • rainfall
    • operate independently of population density and affect population size
  20. density-dependent regulation of population (factors)
    • competeition
    • predation
    • parasitism
    • affect population size to a greater degree when there is a greater population density
  21. carrying capacity
    the population size that can be supported in a  given area within the limits of available food, habitat, water, and other needed resources
  22. biodiversity
    • refers to:
    • the organismic variety at the various levels of organizational hierarchy 
    • to genetic diversity among individual organisms.
    • more species or species population with bigger differences makes a greater biodiversity
    • ecosystems w/greater biodiversity has better air, water, and soil quality and regulate pathogens better
  23. climate change on disease
    • can increase disease
    • malaria
  24. human threats to biodiversity
    • wetland draining
    • farming and agriculture
    • human population growth
    • deforestation, flooding droughts
    • dead zones from nutrient runoff into oceans
    • water projects, dams
    • global warming
    • war and conflict
    • new species
  25. diversity and human health
    • more plants and animals for food
    • natural medicines
    • greater filtration for pollution
    • clothes and pest protection from plant
    • detox pollutants
    • animals provide food and eat pests
  26. health effects of biodiversity loss
    • antiobiotic resistant illnesses
    • allergies
    • nutritional deficiency
    • increase water contamination
    • crop loss/hunger
    • more severe weather
    • incalculable loss of natural medicines
  27. toxicology
    the study of the adverse affects of chemicals on living organisms
  28. toxic agent
    • a material or factor that can be harmful to biological systems
    • ex: asbestos, noise
  29. toxicity
    the degree to which something is poisonous, or the amount of a substance that can produce a deleterious effect
  30. toxic substance
    a "material" that has toxic properties
  31. toxicant
    toxic substances that are man-made or that result from human (anthropogenic) activities
  32. toxin
    a toxic substance made by living organisms (plans, animals,microorganisms)
  33. xenobiotic
    • chemical substances that are foreign to the biological system in question
    • they include naturally occurring compounds, drugs, environmental agents, carcinogens, insecticides and other compounds
  34. poison
    any agent capable of producing a deleterious response in a biological system
  35. dose
    the amount of a substance delivered at one time
  36. LD50
    • dose value that represents the dosage that causes death in 50% of exposed animals.
    • mg/kg body weight
  37. threshold
    the lowest dose at which a particular response may occur
  38. factors that affect responses to toxic chemicals
    • age
    • gender
    • genetic background
    • nutrition
    • race
    • health status
    • medications
    • alcohol
    • pregnancy
  39. routes of exposure
    • gastrointestinal tract (ingestion)
    • respiratory (inhalation)
    • Skin (dermal/absorption)
  40. acute
    usually a single exposure for less than 24 hours
  41. subacute
    exposure for one month or less
  42. subchronic
    exposure for more than three months
  43. chronic
    exposure for more than three months
  44. additivity
    the combination of two chemicals produces an effect that is equal to their individual effects added together
  45. synergism
    the combined effect of exposure to two or more chemicals is greater to their individual effects
  46. potentiation
    exposure to one chemical (that is not toxic) causes another chemical to become more toxic
  47. antagonism
    two chemicals administered together interfere with each other's actions, or one interferes with the action of the other
  48. toxicokinetics
    the processes in the toxicological sequence of absorption, distribution, metabolism and excretion
  49. primary sites of absorption of xenobiotics
    • gastrointestinal tract
    • lungs
    • skin
  50. distribution
    • once in the bloodstream, a toxicant can be distributed through the body.
    • generally follow the rules of diffusion--> low to high
  51. metabolism/biotransformation
    • a process mediated by enzymes
    • majority occurs in the liver
    • makes products more polar and more water soluble--->excreted in urine
  52. excretion
    major route of excretion is through the kidneys (renal)
  53. bioconcentration
    rate of uptake of contaminant from water greater than rate of 'depuration' or movement from organism to water
  54. bioaccumulation
    uptake from both food and water within trophic levels or between adjacent trophic levels
  55. biomagnification
    increase in concentration of contaminant in successive levels of a food chain
  56. in vivo testing (animal)
    animals are exposed to a carcinogen at several dose levels. There is also a placebo group. the animals are observed for a defined period of time and then sacrificed to check for evidence of neoplasm
  57. in vitro
    • involves exposures of cell systems such as bacteria or cultured human cells to a potential toxin
    • cellular responses such as mutation are observed and help to predict human responses
    • less expensive and faster, but not as reliable as animal testing or epidemiological studies
  58. contributions of epidemiology to environmental health
    • concern with populations
    • use of observational data
    • methodology for study designs
    • descriptive and analytic studies
  59. prevalence
    the proportion of a population with a problem at a designated time
  60. incidence
    the rate of a new problem during a period of time
  61. descriptive study
    • depiction of the occurrence of disease in populations according to classification by person, place and time variables
    • can also serve the purpose of gathering information to provide a basis for more in depth
  62. analytic
    examines causal (etilogic) hypotheses regarding the association between human exposures and health conditions
  63. cohort study
    • analytic
    • a study that classifies subjects according to their exposure to a factor of interest and hen observes them over time to document the occurrence or incidence of new cases of diseases or other health events
  64. case control study
    • analytic
    • use an opposite approach to that of cohort studies
    • begins with diseased and non diseased and groups and looks backward in time
  65. cross sectional study
    • analytical
    • also known as prevalence studies
    • these studies tend to measure exposure and disease at the same time.
  66. intervention study
    • analytical
    • these studies are designed to test outcomes associated with intentional changes in the status of research of research studies
  67. randomized controlled trial
    • analytical
    • involves manipulation of an exposure variable and random assignment of subjects to either treatment or control groups
    • typically used to test the efficacy of new meds, med regimens and vaccines
  68. quasi experimental
    • analytical
    • similar to randomized controlled trial
    • subjects are not randomly allocated to groups
    • sometimes due to constraints
  69. host
    a person or other living animal, including birds and arthropods, that affords subsistence or lodgement to an infectious agent under natural conditions
  70. agent
    refers to a factor such as a microorganism, chemical substance or form of radiation, whose presence, excessive presence or relative absence for the occurrence of a disease
  71. environment
    • is defined as the domain in which disease causing agents my exist, survive or originate
    • it consists of all that which is external to the individual host.
  72. Hill's criteria of causality (7)
    • strength of association
    • consistency of findings
    • temporality
    • biological gradient
    • biologic or theoretical plausibility
    • coherence with established knowledge
  73. bias
    occurs when the relationship between exposure and disease in the study population is not representative of the true relation between exposure and disease in the general population because the investigator has selected the study population in a non representative way
  74. healthy worker effect
    • selection bias
    • occurs when workers are compared to the general popualtion
    • workers are healthier than the the general population
  75. confounding
    refers to the distortion of the exposure-disease relationship by a third variable that is associated both with exposure and with disease
  76. latency period
    the time interval between initial exposure and appearance of a disease or its manifestation in the host
  77. risk assessment
    provides qualitative or quantitative on of the estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences
  78. 4 steps of risk assessment
    • 1: hazard identification
    • 2: dose-response assessment
    • 3: exposure assessment
    • 4: risk characterization
  79. hazard identification
    does the agent cause adverse effects?
  80. dose-response assessment
    what is the relationship between the does and the response?
  81. exposure assessment
    what are the types and levels of exposure?
  82. risk characterization
    • what is the estimated probability of incidence or adverse effects?
    • how robust is the evidence?
    • how certain is the evaluation?
  83. hazard
    inherent capability of an agent or situation to have an adverse affect
  84. hazard identification
    examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgement about the strength of that evidence.
  85. a dose-response assessment
    measures the association between the amount of exposure and the occurrence of unwanted health effects.
  86. a exposure assessment
    • who or what is exposed
    • how does the exposure occur
    • how much exposure occurs
    • how often and how long does exposure occur, frequency and duration
  87. a risk characterization
    estimates the incidence of adverse health effects in a given population as a result of exposure to a hazard
  88. risk management
    • follows risk characterization and seeks to control exposures to toxic chemicals in teh environment
    • formation and enactment of regulations
  89. limits of risk assessment
    • the ability to extrapolate toxicity findings
    • the creation of arbitrary, numerous "uncertainty factors" for toxic exposures
  90. municipal solid waste
    • trash or garbage
    • food waste
    • papers
    • batteries
    • organic materials
    • packaging
    • furniture
    • clothing
    • bottles
  91. recycling
    the process of minimizing waste generation by recovering and reprocessing usable products that might otherwise become waste
  92. source reduction
    reducing the amount of waste created, reusing whenever possible and then recycling what is left
  93. composting
    • the controlled decomposition of organic materials such as leaves, grass, and food scraps by microorganisms
    • produces a useful material that resembles soil and tha can be used in gardening
  94. medical waste
    any solid waste that is generated in the diagnosis, treatment, or immunization of humans or animals, in research pertaining therto, or the production or testing of biologicals
  95. stages of sewage treatment
    • primary: the stage aims to remove large materials, which can be composted or shipped to landfills
    • secondary: promotes microbial digestion of organic material that remains in the sewage. microorganisms that are present naturally in sewage may be added to enhance microbial action aid in the digestion of liquid during aeration
  96. tertiary treatment
    high-level processing is directed at removal of remaining solids and microorganisms from the liquid portion of sewage. various methods exist