population and the environment Flashcards
define population
amount of people in a defined area
define population parameter
different ways population is measured
examples of population parameters
distribution, density, numbers, change
define distribution
give an example
how a population is spread globally and regionally
Egypt is unevenly distributed as people live closer to the Nile
define population density
measurement of population per unit area
define numbers
how is is recorded and how often
the amount of people in a defined area
census take place every 5-10 years
define population change
increases and decreases over time
name the 3 environmental factors that affect population
climate, soil fertility, natural resources
why does climate affect population
- people tend to not live in areas of extreme climate (polar, desert)
- higher population density between tropics where climates are more manageable
- affects food productivity negatively and positively (yield, types of crops, droughts or floods)
- drive levels of diseases like malaria
- climate change (housing, food, water)
why does soil fertility affect population
- water and nutritional content in soil affects agriculture
- volcanic soils are prone to hazards so less people live there
how do natural resources affect population
- clean water supply needed for hydration, irrigation, sanitation
- areas with fossil fuels have better energy supply
- areas where natural resources can be exploited have more people so they can earn money
define health
state of complete physical, mental and social well being
define life expectancy
number of years a person is expected to live from north in a country
define prevalence rate
number of people in a given population who are suffering from a particular condition
define infectious diseases
disease caused by organisms and can spread
define mortality
death of people
define disability-adjusted life years
the number of years of healthy life lost by being in poor health
define morbidity
illness and reporting of diseases
define attack rate
number of cases of a disease diagnoses in an area divided by total population over the period of an epidemic
define infant mortality rate
number of deaths per children under 1 per 1000 live births
define non communicable disease
disease that is not caused by infectious agents
define case mortality rate
number of people dying from a disease divided by the number of those diagnosed as having the disease
define incidence rate
number of people in a population who develop a particular condition in a particular period of time
define epidemic
infectious disease in a community at a particular time
define pandemic
disease prevalent over a whole country or world
how has economic improvements improved health
- technology for food production increases food security and decreases famine and malnutrition
- transport- medical supplies
- improvements in sewage
- trading of resources
how has social improvements improved health
- improved sanitation
- better education on diseases
- vaccines and medication
- better training on medical staff
- aid programmes in developing countries
what is the epidemiological transition model
by Abdul Omra in 1971- over time as a country develops there will be a transition from infectious to non-communicable diseases
feature of phase 1 of ETM
- 20-40 LE
- poor sanitation
- unreliable food supply
- infectious and nutritional deficiencies
features of phase 2 of ETM
- 30-50 years LE
- improved sanitation
- better diets
- advances in medicine
- reduced number of infections
- increases in cardiovascular diseases
features of phase 3 of ETM
- 50-60 years ETM
- increased ageing
- poor diets
- less activity
- addictions
- high blood pressure, obesity, diabetes
- smoking related diseases
features of phase 4 of ETM
- 70+ years LE
- reduce risk behaviour
- health promotion
- disease prevention
- new treatments
- heart disease, strokes, cancers
- more ageing disease like dementia
features of phase 5a of ETM
- potential reversal of LE
- lack of exercise
- ignoring risk behaviours
- chronic heart disease, stroke, congestive heart diseases
features of phase 5b of ETM
- reversal of LE
- globalisation of disease due to travel
- increase in population density
- concerns about vaccines
- revolution of microbes and it’s resistance
- virus evolving and causing pandemics (SARS and COVID)
- reemergence of TB, measles, whooping cough
explain classical/western model of ETM
slow decline in death rate and lower fertility
explain accelerated model of ETM
falls in mortality are much more rapid
explain contemporary/delayed model of ETM
decreases in mortality but no decline in fertility
work of John Snow in 1854
mapped cholera but using a dot distribution map of London to discover the contaminated water pump in Soho
how does climate impact the prevalence of diseases
- vector borne diseases like malaria like high temperatures and humidity
- droughts and floods can lead to crop failure and famines
- seasonal affective disorder
- allergies like hayfever
- valley fever from the spreading of fungus
- extreme cold= pneumonia
- extreme hot= heat strokes
- high temperature promote food borne diseases like salmonella
how does topography affect disease prevalence
- low lying areas like flood plains are prone to water borne diseases from poor drainage and stagnant waters- India on Ganges floodplain
how does air quality affect disease prevalence
- 2017- 42 million deaths caused by ambient air
- LICs and NEEs like a India more at risk due to industries
- burning fossil fuels
- respiratory problems
- 80% of air pollution deaths link to heart diseases and strokes
- 2.5 billion rural households use solid fuels- women and children at risk
air quality in china
- rapid industrialisation, transportation. coal power plants
- 1.4 million premature deaths due to u healthy levels of PM2.5 in 2019
- 6 states in China are rates poor in air quality like Tianjin and Shanghai
- air pollution has fallen by 42.3% 2013-2021
how does water quality affect prevalence of disease
- 2 million deaths are from unsafe water and poor sanitation
- diarrhoea diseases like cholera
- stagnant waters in man made reservoirs promote mosquitoes
- oil spills contaminate water and lead to digestive problems
- 260 million cases of schistosomiasis due to parasitic worms
- toxicants can poison water
water quality india
- contaminated ground water
- stunted growth, bone deformity, liver diseases
- 70% of surface water is unfit for consumption
- 2.3 million premature deaths in 2019
features of malaria
- tropical vector borne disease
- transmitted by female Anopheles mosquito
- children under 5 are most vulnerable, make up 67% of all cases
- increased prevention has led to 60% reduction in mortality since 2000
- plasmodium f most common
distribution of malaria
- sub-saharan africa has the highest concentration of cases worldwide
- common in south asia like india due to monsoons
- climate change may lead to more unexpected places having cases
physical factors affecting incidence of malaria
- average temperature 16-32C
- hotter temperatures speed up malaria cycle
- more active at dawn and dusk
- breed in clean, warm, stagnant water and encouraged my rainfall
- areas with less seasonal variation (coasts) have higher chance of susceptible
- less transmission in altitudes above 1500m and rainfall below 1000m
socioeconomic factors affecting incidence of malaria
- urbanisation- lower transmission in urban areas due to pollution, or faster transmission from high population density
- lack of healthcare and education
- low immunity in groups like children and elderly
- disease of poverty (58% of global burden come from poorest 20%)
- occupation- farmers in rice paddy
- income affects treatment
- poor house infrastructure
malaria impacts on economic well being
- costs globally are around $15-18 billion
- economic costs for families for medication, travel, treatments
- economic costs for government for drugs, education, medical staff
- loss of work
management and mitigation strategies of malaria
- vector control
- insecticide- treated mosquito nets
- indoor residual spraying with pyrethroid insecticide
- mosquito could
- anti-malarial drugs
- RTS,S vaccine
- artemisinin- based combination therapy (ACT)
- roll back malaria programme
- WHO wants to eliminate malaria from 35 countries
features of coronary/ ischaemic heart disease
- disease of affluence
- leading causes of death worldwide- 9.5 million deaths annually
- 2.3 million people living with CHD in UK
- symptoms: angina (chest pain), heart attacks and heart failure
malaria in nigeria
- 97% of population at risk
- year round transmission in the South and 3 months or less in the North
- 27% of malaria burden globally
factors for malaria in nigeria
- 26.9C and 1165mm rain
- overcrowding- 22 million housing shortages in 2018
- 83 million Nigerians lack access to healthcare
- lack of piped water and more stagnant waters
impacts of malaria in nigeria
- 20% of all deaths under 5 in 2021
- WHO- annual reduction of 1.4% in Africas economic growth
management of malaria in nigeria
- national malaria elimination program (NMEP) made a plan to reduce malaria morbidity to less thag 10% by 2025
- world bank and african development bank helptowards malaria combat
- SuNMaP distribute nets and educate people
features of chd
- disease of affluence
- leading cause of death worldwide- 9.5 million deaths annually
- 2.3 million people living with chd in UK
- symptoms: angina, heart attacks and heart failure
physical factors leading to chd
- air quality- industrialisation has lead to increased expose to PM
- optimum temperature range where CHD mortality is lowest because extreme temperatures puts strain on cardiovascular system, varies regionally (19.3-22.3C in London)
- changing relief requires more physical effort
- food- Japanese diet of fish increases CHD
socio-economic factors leading to chd
- 1 in 7 men and 1 in 12 women
- social deprivation- premature deaths by CHD 3x higher in North
- tobacco use- lowers good cholesterol
- alcohol use- raised blood sugar, bad cholesterol
- high blood pressure
- poor nutrition
- overweight/ obesity
- diabetes
- infrequency exercise
- ethnicity- south asian higher risk of heart disease in UK
- family history
- rapid urbanisation- poor housing, pollution, convenience lifestyle
impacts of chd on health
- angina
- heart attack
- bypass surgery
- rehabilitation
- people taking medications
impacts of chd on economic well being
- healthcare cost- 2018 £9 billion to NHS
- loss of productivity - 2018 £19 billion lost to UK
- costs linked to smoking related diseases - global loss of $200 billion per year
- loss of income due to time of work
management and mitigation of chd
- health education- promote healthy choices
- policy and legislation - tobacco policies, taxes on foods, more cycle paths and green spaces
- medical treatment and secondary prevention- statins, stents, beta blockers, blood thinning, angiotensin, surgeries
role of international agencies in promoting health
work with governments to spread awareness and distribute resources (top down)
examples of international agencies and what they do
WHO- combating infectious diseases, supporting mother and babies, helped to eradicate smallpox 1980, supporting with sdvice with Covid, HIV etc
UNIAIDS- improving access and care for HIV/AIDS
UNICEF- reduce child mortality
World Bank- fight poverty
World food programme- eradicate hunger globally
role of NGOs in promoting health
funded by public donation to directly help communities (bottom up)
work of Tam Tam Africa
- distributed tens of thousands of bed nets across Africa
- UYO Nigeria 300 nets for women with high risk pregnancies and cash transfers to incentivise them visiting health clinics
- target pregnant women and children
work of Gates Foundation
- 5% of $4.3 bil invested annually fighting against malaria
- map malaria and show where, when and who it affects
- invests in partners to have large scale access to bed nets, tests, medicines
- $140 million commitment over 4 years to support new initaiaties directed by African Leaders to end malaria
work of MSF
- employs 35,000 people globally
- 90% recruiter locally
- 2018, 96.2% come from 6.5 million individual donors
- does not accept contributions from companies compromising their ability to provide independent care
- refuse funding from EU as they stopped migrants fleeing Middle East
work of global heart network
- technology platform to address provision of cardiac care globally
- faster communication, large database to share information, fundraising
feature of ozone depletion
- caused by halogenated chemicals like CFCs found in fridges, insulation and spray cans
- destroy ozone layer and allow UV to come in
- chemicals react with and destroy ozone molecule in extreme cold
polar regions
effect on health of ozone depletion
- lead to skin cancer where 90% of non-melanoma cases are through UV exposure
- lead to cataracts and 10% depletion of ozone layer and 2 million new cases every year
climate change impact on health and environment
- storm and weather events
- air and water pollution
- vector borne diseases spread more
- trauma and psychological effects
- 2030-2050 250,000 additional deaths per year from climate change
thermal stress and health
- 900 excess deaths in UK by heatwaves in 2019
- dehydration and heat strokes
- wild firee, smogs, water shortages
- less winter mortality and more heat related mortality
changing of vector borne diseases and effect on health
- warmer temperatures and changing precipitous
- aedes mosquito carrying dengue could expose additional 1 billion people but end of century
- malaria spread to other places like europe as they get hotter
- last longer and spread to more places
changing agricultural productivity and effect on health
- increased yield mid and high latitudes
- crops like maize can be grown in lower latitudes
- longer growing season in places like russia
- droughts and floods
- places may become too dry
- more pests and aphids
- less water along Nile
changing nutritional standards and effect on health
- different crops available
- increased food prices and may lower dietary quality
- increased livestock production like cattle and produce more methane
- more clearance of forests
- weather hazards can lead to famine
- promotion of healthier diets to reduce climate change
- deficiencies from lack of availability
what causes population change
natural change- difference crude birth rate and crude death rate
migration change- difference between immigrants and emigrants
define crude birth rate
number of live births per 1000 of a population per year
define crude death rate
number of deaths per 1000 of a population per year
define emigrant
person leaving their home area or country in order to settle elsewhere
define immigrant
person moving into an area of country in order to settle here
define life expectancy
average number of years a person is expected to live depending on the year and location they were born
define total fertility rate
number on average of children born per woman of the reproductive age in an area or country
define replacement fertility rate
number of children each woman needs to have to maintain current population levels
define growth rate
% change in a year of population
factors affecting natural population change
-growth rates and replacement fertility (2.3)
- infant mortality
- affluence
- healthcare
- education
- religion- catholicism and islam condemn contraception
- gender
- child marriage
- population policies
explain chinas one child policy
introduced policies to control the baby boom and stop strain on resources. however they took it away in 2015 and increased to two children to enjoy rage women to have children as there is a rapidly ageing population
what is the dtm
developed by warren Thompson in 1929 and is based on recorded changes since the industrial revolution of natural population change
describe stage 1 of DTM
- high stationary or fluctuating
- few remote groups
- BR high and DR high
- stable and fluctuating population
- children needed to work on land
- disease, famine, poor medical knowledge, no contraception
- religious reasons
describe stage 2 of DTM
- early expanding
- Niger, Angola
- BR high and DR falling rapidly
- very rapid natural increase
- no family planning and children needs to work
- improvement in food and clear water and medical vaccines
describe stage 3 of DTM
- late expanding
- Egypt, Pakistan
- BR starts to fall and DR falls more slowly
- natural increase slows
- fewer children needed
- contraception and improvements to food, healthcare and hygeine
describe stage 4 of DTM
- low stationary or fluctuating
- UK, USA
- BR low, DR levels out
- slow increase
- more family planning
- more women working
- good healthcare
describe stage 5 of DTM
- decline
- Japan, Germany
- Br falls and DR remains low
- small natural decrease
- elderly population as less people in reproductive ages
- higher population reaching life expectancy
strengths of DTM
- easy to compare
- theoretically works and is easy to understand
- can show development
limitations of DTM
- eurocentric view
- assumes all countries go in certain order, unlike China which skipped a stage
- original model didn’t have 5th stage so it is outdated
- doesn’t include migration
- government and political intervention
- doesn’t show differences within high and low income, or urban and rural
how does niger fit into stage 2 of DTM
- droughts and desertification affect good supply
- internal conflict
- muslim
dominated country so religious reasons lead to high birth rates - mainly primary sector so slow economic development and children needed to work
- death rates lower than expected due to NGOs
- young population with 49% under 15
- 6.4 fertility rate
how does canada fit into stage 4 of DTM
- range of climatic types
- mountainous and tundra- hard to live in
- rich in minerals
- large country with small population 37 million
- tertiary sector
why doesnt canada fit into DTM
migration increases younger population and increases the population which stops it from going into stage 5