Enquiry Question 2: What are the complex causes of health risks?

Aims - To identify: - The complex causes of human health risk. - The relationship between socio-economic status and health-The links between some diseases and geographical features- Models that may help in the understanding of health risk causes and patterns

Starter:

1. In pairs / small groups list as many different common global diseases / health risks as you can. E.g. Cholera, Malaria, Measles, Aids, Skin Cancer etc.

1. What are the complex causes of health risk?

2. Using your own list and the additional list handed to you by your teacherState if you think the health risk is most likely to be in a)a High Income countryB) a Low Income Country.You should be prepared to give reasons for your choices. E.g. level of development, socio-economic link, pollution link, lifestyle link etc

Leading Causes of Death According to WHO 2004By broad income group A) Low Income Countries

Is this expected? Why might it be so high?

Traditional health risks associated with lower income countries.

Leading Causes of Death According to WHO 2004By broad income group B) High Income Countries

A lower number of deaths than in Low Income Countries Why? What are the %age differences?

Which of these diseases are directly linked to income / lifestyle choices?

Adult mortality rates by major cause group and region, 2004

0 2 4 6 8 10 12

Africa

Europe

South East Asia

Eastern Mediterranean

Americas

Western Pacific

High income

Death rate per 1000 adults aged 15–59 years

Cardiovascular diseases

Cancers

Other noncommunicable diseases

Injuries

HIVAIDS

Other infectious and parasitic diseases

Maternal and nutritional conditions

Age distribution of burden of disease by income group, 2004

The Complex Causes of Human Health Risk

The main environmental factors. Factor Comment

WATER Dirty Water = main causes of disease in developing world. Improving sanitation and water supply shown to cut infant mortality rate by average of 55%. Standing pools of water are esp. significant in disease transmission as they harbour vectors and parasites.

GEOLOGY UK has approx 2 000 deaths each year attributed to lung cancer caused by radon gas produced from the decay of uranium. It is naturally present in many rocks.

ECOLOGY If an ecosystem is placed under stress their ability to support a healthy population can be compromised

INSECT AND ANIMAL VECTORS

Both natural and human-induced changes in the habitats of disease carrying insects will alter the disease incidence pattern.

Factor Comment

OZONE DEPLETION

There is a direct link between ozone depletion and damage to DNA caused by UV-B radiation. The result is a major increase in the incidence of skin cancers (Melanomas) in many countries including the UK.

WEATHER Weather patterns have direct and indirect effects on mortality and morbidity rates. Within the EU, winter related illness is especially linked to mortality in the UK due to inadequate heating and clothing.

CLIMATE CHANGE The predictions are that climate change will have the following impacts on human health-Direct impacts e.g. increased mortality rates as extreme climate events (e.g. hurricanes) become more frequent- 2ndry, as tropical disease becomes more common in higher latitudes- tertiary as conflicts arise over increasingly scarce resources such as freshwater supplies.

Task: Identifying human factors responsible for increasing health risk.

• Human factors which increase health risk can be subdivided into:

a)Personal lifestyle choicesb)Factors outside individual decision making.

For each of the factors below you have to identify which are a) Personal lifestyle choices and those which are Factors

outside individual decision making.

SMOKING NOT DRINKING ALCOHOL FOLLOWING A VEGAN DIET POLLUTIONQUALITY OF HOUSING TAKING REGULAR EXERCISE WORK ENVIRONMENT ROAD SAFETY LEVELS DOWN-SIZING

AnswersPersonal lifestyle

choicesFactors outside

individual decision making.

SmokingFollowing a vegan DietNot drinking Alcohol

Taking regular exerciseDownsizing

PollutionQuality of HousingWork EnvironmentRoad Safety Levels

As societies have developed and along with this consumerism , the following health risks have increased: - Obesity- Depression- Diabetes.

According to the Population Health Research Institute in Canada Western diets cause over 1/3rd of all heart attacks

world-wide

They also identified 3 global dietary patterns:1)‘oriental’ characterised by a high intake of soy and tofu.2)‘prudent’ with a high intake of fruit and vegetables3)‘western’ where large amounts of fried foods, salty snacks, eggs and meat are eaten.

Diet Population Health Research Institute, Canada found that there were three global dietary patterns:

•“Oriental” – high consumption of fish, tofu and soy (high salt – strokes)

•“Western” – fried foods, salty snacks, eggs and red meat

•“Prudent” – high intake of fruit and vegetables

Those with Western diets accounted for 1/3 of all heart attacks worldwide. The salt content in Oriental can lead to strokes.

Prudent eaters were 30% less likely to suffer heart attacks than people who consume less fruit and vegetables (EQ4: 5 a day).

Type 2 diabetes is on the rise due to diet in many western countries.Persistent Organic Pollutants in your bloodstream are also likely to lead to diabetes (see info on POP).

Other Human Factors• Global village (as in swine flu example)• Poverty – malnutrition leading to kwashiorkor

and rickets (remember poverty exists in MEDCs as well – See LA example)

• Affluence – obesity, diabetes, coronary heart disease, cancer

• Education levels and status of women• Accidents

Chapter 2 of the UK green paper “Our Healthier Nation” 1998 highlights how the government sees the various causes of

poor health.

Circular graph showing main determinants of health (health map)

Health Risks and Pollution. Sources of Pollution linked to Health Risks

1. Air pollution kills an estimated 2.7 million to 3.0 million people every year.

Air Pollution hanging over the city of Bogota Colombia

2. Water pollution: globally 2.3 billion people suffer from diseases linked to water.

3. Pollution from Heavy MetalsMetals most dangerous to health include lead, mercury, cadmium, arsenic, copper, zinc, and chromium. Mercury can cause mutations and genetic damage, while copper, lead, and mercury can cause brain and bone damage

4. Persistent Organic Pollutants (POP’s)Human exposure to persistent organic pollutants (POPs) occurs in several ways—in foods, mostly as pesticide residues; occupationally, among farm workers who spray pesticides on crops; & through accidents, e.g. leaks in indoor storage areas. POPs are organic compounds that have long lives in the environment and undergo physical, chemical, and biological changes over time.

Investigating the different causes of health risk:

Case Study : John Snow and the Broad Street Pump – The Case of Cholera, London 1800’s.

Key Words

Epidemiology is the study of the distribution, occurrence and spread of disease.

Cholera: A water-borne disease caused by a bacterium which leads to severe and often fatal diarrhoea.

Epidemic(s) An infection rate which has reached a certain predetermined level in relation to the total population.miasmas Poisonous gases and vapours thought to infect the air.

The first comprehensive epidemiological study was undertaken by Dr John Snow, who analysed fatalities in the London cholera outbreak of 1854.