environmental basis of disease Flashcards
epidemiology =
patterns of disease frequency in populations and distribution by person, place and time
what does the epidemiology assume?
disease doesn’t occur randomly
disease has identifiable causes
what is the aims of epidemiology?
describe population health status
explain aetiology
predict disease occurrence
control disease distribution
epidemic =
pandemic =
disease outbreak within a population
disease outbreak across populations
what 3 factors make up the epidemiological triangle?
HOST
(controllable/uncontrollable, intrinsic factors, genetics, immunisation, age, sex, behaviour, physiological state)
AGENT
(nutritive, chemical, physical, infectious)
ENVIRONMENT
(physical, socioeconomic)
what migrant study was used to look at people with similar genetics in different environments?
Japanese people in Japan and migrating to California
looked at different cancer sites as different disease rates in different countries (why?)
higher rates of stomach/liver cancer in Japan
higher rates of colon/prostate cancer in California
(due to differences in diet/culture)
what are the dates of John Snow and his work looking at cholera?
1813-1853
describe John snows contribution
hypothesised cholera was spread in water
he mapped the incidence of disease
cases were concentrated in certain areas around certain water pumps
dirty pumps were replaced → incidences decreased
vibrio cholera bacterium was discovered 25 years after his death
stats of smoking: \_\_\_ deaths per day in the UK \_\_\_\_\_ deaths per year \_\_\_\_ years lower life expectancy \_\_\_\_ million deaths per year worldwide
320
120,000
7.5
4
has smoking prevalence increased or decreased?
decreased
there is a lag of decades between smoking and lung cancer development
what are the factors behind smoking addiction?
highly addictive, habit, socioeconomic influences, often poor people smoke as a stress reliever, family history of smoking, peer pressure
what are the major health consequences of smoking?
cancers, respiratory diseases (COPD), vascular diseases (CHD and peripheral vascular diseases)
→ nicotine is a vasoconstrictor
pregnancy and birth complications
__% of smokers want to give up (less than __% succeed)
__% heart attack smokers relapse within _ days of intensive care
__% of patients with larynectomies try smoking again
__% of lung cancer/lung removal patients smoke again
70, 50
40
50
50
what happens to the alveoli in pulmonary emphysema?
alveoli are degraded and enlarged
due to:
→ destruction of cells in alveolar walls
→ loss of elastin surrounding alveoli
health alveoli have an ____ balance of ______ and ______
equal, proteases, antiproteases
emphysema has _____ proteases than antiproteases
more
what is the genetic cause of pulmonary emphysema
genetic cause = decreased a-antitrysin → reduces antiproteases
environmental cause → smoking → inhaling toxins increases proteases
oxidative toxins from smoking cause _______ in alveoli to release chemotactic factors. these include _____ (IL-8) and _________
macrophages
interleukins
metalloproteases
what do metalloproteases do?
what does IL-8 do?
damage alveoli walls
attract neutrophils that release elastase which break down alveolar walls
what are the effects of pulmonary emphysema?
reduced surface area for gas exchange
alveoli has inability to recoil and expel CO2 → lower CO2 gradients so less O2 enters bloodstream
gas becomes trapped in alveoli because it can’t be expelled
what factors determine whether exposure leads to disease?
chemical + biological composition of particles
shape and size of particles
dose, conc, duration of exposure
pre existing health
genetic status
concurrent exposure to other toxic agents
what are the 2 main responses to occupational lung disease?
allergic and pneumoconiosis
disease examples of allergic response
rhinitis, asthma, laryngitis, extrinsic allergic alveolitis
itis = inflammation
pneumoconiosis =
dust associated disease
co-existing disease may aggravate response