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Flashcards

Chapter 17: Human Health and Environmental Risks

sabrinapar22 Inglês 62 flashcards

Chapter 17: Human Health and Environmental Risks

Flashcards do conjunto (62)

  1. 1What are the three major categories of risks that can harm human health?-physical (environmental factors such as natural disasters, exposure to UV radiation, radioactive substances)
    -biological (associated with diseases)
    -chemical (exposure to chemicals)
  2. 2What is a disease?any impaired function of the body with a characteristic set of symptoms
  3. 3Which category of human health risks causes the most human deaths?biological
    -3/4 of human deaths worldwide
  4. 4infectious diseasescaused by infectious agents (pathogens)
    -eg. pneumonia, STDs
  5. 5Which six types of illnesses account for 94% of all deaths caused by infectious diseases?-respiratory infections 30%
    -HIV/AIDS 21%
    -diarrheal diseases 14%
    -tuberculosis 12%
    -malaria 9%
    -childhood diseases 8%
    -other 6%
  6. 6chronic diseasesslowly impair the functioning of a person's body
    -eg. heart disease, cancers
  7. 7acute diseasesrapidly impair the functioning of a person's body
    -eg. Ebola
  8. 8leading health risks for chronic disease of low income countries, from greatest risk to least-low weight during childhood
    -high blood pressure
    -unsafe sex
    -unsafe water, sanitation, hygiene
    -high blood glucose
    -indoor smoke from solid fuels
    -tobacco use
    -physical inactivity
    -suboptimal breast feeding
    -high cholesterol
  9. 9leading health risks for chronic disease of high income countries, from greatest risk to least-tobacco use
    -high blood pressure
    -overweight and obesity
    -physical inactivity
    -high blood glucose
    -high cholesterol
    -low fruit and vegetable intake
    -urban outdoor air pollution
    -alcohol use
    -occupational risks
  10. 10epidemica rapid increase in disease caused by a pathogen
  11. 11pandemican epidemic that occurs over a large geographic region such as an entire continent
  12. 12plague-bubonic plague, Black Death
    -caused by infection from bacterium Yersinia pestis carried by fleas
    -transmitted to people by flea bites or contact with rodents
    -swollen glands, black spots on skin, extreme pain
    -killed 1/4 of European population in 1300s
    -last major pandemic occurred in 1900s Asia
    -antibiotics kill bacterium if infected
  13. 13malaria-caused by infection from protists in genus Plasmodium
    --parasite spends one stage of life in mosquito and another stage inside a human
    -flulike symptoms
    -350 to 500 million/year infected
    -1 million people die (mostly under age of five)
    -subsaharan Africa, Asia, Middle East, Central and South America
    -eradicated in US through use of DDT
  14. 14tuberculosis-caused by becterium Mycobacterium tuberculosis
    -highly contagious, spread when parseon coughs and expels bacteria in air
    -bacteria persists for several hours
    -infects lungs
    -weakness, night sweats, coughing blood
    -1/3 of world population is infected
    -9 million/year infected, 2 million die
    -treated by taking antibiotics for 1 year
  15. 15What happens when a patient does not take the prescribed dose of medicine for the full duration time?-pathogen quickly rebuilds population
    -the last few bacteria are the most resistant to drugs
    -20% of infected people in Russia and Africa carry drug resistant strain
  16. 16emergent infectious diseasesinfectious diseases that were previously not described or have not been common for at least the prior 20 years
    -world average of 1 emergent disease / year
    -pathogens jump unexpectedly from animal hosts to human hosts
  17. 17AIDS-Acquired Immune Deficiency Syndrome
    -caused by HIV
  18. 18HIV-Human Immunodeficiency Virus
    -spread through sexual contact, shared drug needles
    -hunters in Cameroon ate infected chimpanzees
    -33 million infected with HIV
    -25 million died from AIDS related illnesses
    -antiviral drugs extend life
  19. 19Ebola Hemorrhagic Fever-caused by Ebola virus
    -50 to 89% death rate of infected individuals
    -fever, vomiting, internal and external bleeding
    -no drugs
    -no known source; primates suspected
  20. 20Mad Cow disease-bovine spongiform encephalopathy BSE
    -pathogen slowly damages cow's nervous system
    -prions in brain mutate into deadly proteins that act as pathogens
    -loss of coordination, death
    -transmitted to other cows by eating infected nervous system
    -transmitted to humans by infected meat, can't be destroyed by cooking
    -humans develop Creutzfeldt Jakob disease
  21. 21bird flu-Spanish flu, avian influenza
    -cause by H1N1 virus
    -fatal to domesticated birds
    -H5N1 jumps from birds to people
    -humans have few defenses against H5N1 because we have no evolutionary history with it
    -destroy birds to stop disease
    -mutations could allow disease to be spread among people, will kill 150 million
  22. 22West Nile Virus-transmitted among birds by mosquitoes
    -1973 West Nile first human case
    -inflammation of brain leads to illness and death
    -arrived in NY 1999, highest number of infections in 2002 and 2003
  23. 23How are diseases combated in low income countries?-improvement in nutrition, availability of drinking water, proper sanitation
  24. 24How is disease combated in high income countries?-promote healthier lifestyle choices (physical activity, balanced diet, limit of excess food and tobacco use)
  25. 25How is disease combated in both high and low income countries?-continued education about the spread of diseases
    -rapid response plans when new diseases appear
  26. 26neurotoxins-chemicals that disrupt the nervous system of animals
    -eg. insecticides interfere with insect's nervous system
    -lead and mercury cause damage to human's kidneys, brain, and nervous system
    -lead exposure has declined, mercury remains a problem
  27. 27carcinogens-chemicals that cause cancer
    -cell damage, uncontrolled cell growth caused by interference with cell's metabolic processes or by damaging the genetic material of the cell (mutagens)
    -eg. asbestos, radon, formaldehyde, tobacco chemicals
  28. 28mutagenscarcinogens that cause damage to the genetic material of a cell
  29. 29teratogens-chemicals that interfere with the normal development of embryos or fetuses
    -eg. alcohol reduces growth of fetus and damages brain/nervous system
  30. 30allergens-chemicals that cause allergic reactions
    -capable of causing an abnormally high response from immune system, causing breathing difficulties and death
    -eg. chemicals in peanuts milk, drugs
  31. 31endocrine disruptors-chemicals that interfere with the normal functioning of hormones in an animal's body
    -endocrine disruptors cause low sperm counts in men and increased risk of breast cancer in women
  32. 32dose-response studies-expose animals or plants to different amounts of a chemical and then observe a variety of possible responses (mortality, changes in behavior/reproduction), but mainly mortality
    -sub lethal effects
    -chemical amounts measured as concentration in air, water, food or as dose absorbed/consumed b the organism
    -1-4 days (acute studies)
  33. 33What does a graph for a dose-response study generally look like?-s shaped curve
    -threshold: dose at which an effect can be detected
  34. 34LD50-lethal dose that kills 50% of individuals
    -assesses relative toxicity of a chemical
    -compare to other tests
    -mice/rats represent mammals
    -pigeons/quail represent birds
    -trout represent fish
    -water fleas represent invertebrates
  35. 35sublethal effectsharmful effects that a chemical might have
  36. 36ED50effective dose that causes 50% of the population to display harmful but nonlethal effects
  37. 37Toxic Substances Control Act of 1976-gives EPA authority to regulate many chemicals, though excluding food, cosmetics, and pesticides
  38. 38Federal Insecticide, Fungicide, and Rodenticide Act of 1996manufacturer must demonstrate that a pesticide will not generally cause unreasonable adverse effects on the environment
  39. 39How is the safe concentration of chemicals calculated for animals?-LD50 value divided by 10
  40. 40How is the safe concentration of chemicals calculated for humans?LD50/ED50 values from rats and mice divided by 1000
  41. 41chronic studies-last from the time an organism is very young to when it is old enough to reproduce
    -examine long term effects of chemicals on survival and reproduction
  42. 42epidemiologyfield of science that strives to understand the causes of illness and disease in human and wildlife populations
    -retrospective and prospective studies
  43. 43retrospective studiesmonitor people who have been exposed to a chemical at some time in the past
    -group of exposed and group of unexposed
    -Bhopal, India Union Carbide factory explosion: 36000 kg of gas killed 17000 people and 100,000 ill people
  44. 44prospective studiesmonitor people who might become exposed to harmful chemicals in the future
    -eg. ask participants to track amount of alcohol they drink for 40 years and determine if habits are associated with health problems
    -synergistic interactions are a concern
  45. 45synergistic interactionstwo risks together cause more harm than one would expect based on their individual risks
  46. 46What factors determine the concentrations of chemicals that organisms experience?-routes of exposure
    -solubility of chemicals, bioaccumulation, and biomagnification
    -persistence
  47. 47routes of exposurethe ways in which an individual might come into contact with a chemical
    -eg. air, food, soil, water
  48. 48solubilityhow well a chemical can dissolve in a liquid
    -water soluble: groundwater, surface water
    -oil/fat soluble: soil, fat tissues
  49. 49bioaccumulation-increased concentration of a chemical within an organism over time
  50. 50process of bioaccumulation-individual incorporates small amounts of a chemical from the environment into its body
    -chemical accumulates in fatty tissues and concentration increases over time
  51. 51What factors does the rate of accumulation of a chemical in an organism depend on?-concentration of the chemical in the environment
    -rate the animal takes up each source of the chemical
    -rate at which the chemical breaks down in the animal
    -rate at which it is excreted by the animal
  52. 52biomagnificationincrease in chemical concentration in animal tissues as the chemical moves up the food chain
    -each trophic level is exposed to higher concentrations of the chemicals from the food it consumes    biomagnification
  53. 53persistencehow long the chemical remains in the environment
  54. 54What factors determine a chemical's persistence?-temperature
    -pH
    -whether the chemical is in water or soil
    -whether the chemical can be degraded by sunlight
    -whether the chemical can be broken down by microbes
  55. 55How do scientists measure the persistence of a chemicalobserve the time needed for the chemical to degrade to half its original concentration (half life)
  56. 56environmental hazardanything in our environment that can potentially cause harm
    -eg. pollutants, draining swamps, volcanoes
  57. 57risk assessment-identify a potential hazard and determine the magnitude of the potential harm
  58. 58qualitative risk assessmentjudgements based on perceptions but that are not based on actual data
    -eg. slowing down when driving down a wet driveway
  59. 59perceived risk vs. actual riskto manage our risks effectively, we need to ask how closely our perceptions of risk match the reality of actual risk
  60. 60quantitative risk assessment-risk = probability of being exposed to a hazard x probability of being harmed if exposed
    -the risk of a rare event that has a high likelihood of causing harm can be equal to the risk of a common event that has a low likelihood of causing harm
  61. 61risk acceptance-level of risk that can be tolerated
    -causes conflict between those willing to live with the risk and those who are not willing
  62. 62risk management-balance possible harm against other considerations
    -integrates data on risk assessment/analysis with a number of additional factors (economic, social, ethical, political)
    -regulatory
    -eg. arsenic levels in drinking water

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FlashCards sobre Chapter 17: Human Health and Environmental Risks, criado por sabrinapar22 em 03-03-2015.
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sabrinapar22
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