1. Environmental Health
What is the relationship between the health of the planet and our own health?

2. Types of Environmental Health Hazards
Environmental health hazards can be biological, social, chemical, physical. Can you think of any environmental health hazards that exist here in Latrobe, PA?
Biological: Viruses, bacteria, and other organisms that cause disease
Social: Lifestyle choices that endanger health
Chemical: Harmful artificial and natural chemicals in the environment
Physical: Natural disasters and ongoing natural phenomena, such as UV radiation, that can cause health problems

3. how these hazards affect people.
Identifying hazards in the environment is just one part of environmental health. Scientists also want to understand
how these hazards affect people.
Epidemiology
Toxicology
The study of disease in human populations—how and where they occur and how they can be controlled
Often involves studying large groups over long periods
Can determine statistical associations between health hazards and effects, but can’t prove the hazards actually caused the effects
The study of how poisonous substances affect an organism’s health
Toxicity is a measure of how harmful a substance is.
Toxicologists look at toxicity by determining dose-response relationships.

4. Individual Responses
People respond differently to environmental hazards making it difficult to predict with certainty how hazards may affect specific people.
Sensitivity to hazards varies with age, sex, weight, and immune system health.
People with health issues like asthma, compromised immune systems are more sensitive.
Many diseases have genetic as well as environmental factors.
Much research has proven that breast cancer can be caused by either emvironmental or genetic factors…and if caught early can be curable.
Did You Know? Thalidomide, a drug that currently shows promise for treatment of Alzheimer's, AIDS, and some cancers, caused thousands of severe birth defects when it was used as an anti-nauseal in the 1950s and 60s.

5. Risk Assessment Scientists try to determine how likely it is that a given hazard will cause harm. With chemical hazards, scientists determine toxicity, human exposure, frequency of exposure, concentration of exposure, etc.
Risk: The probability that a hazard will cause harm
Risk assessment: The process of measuring risk
Takes into account:
The type of hazard
How frequently humans will be exposed to it
How sensitive people are to it

6. Biological and Social Health Hazards in the Environment
Three quarters of infectious disease deaths are caused by five types of diseases: respiratory infections, AIDS, diarrheal diseases, tuberculosis, and malaria.
Tuberculosis-causing bacteria
Biological and Social Health Hazards in the Environment

7. Infectious Diseases Caused by pathogens
Spread by human and animal contact and through contaminated food and water
Cause of almost half of all deaths in developing nations
Covering your mouth when you cough, washing your hands often, and staying home from school if you’re sick help prevent the spread of infectious disease.
Did You Know? In 2002, AIDS killed about 2 million people worldwide— almost equal to the entire population of Arkansas.

8. Emerging Diseases
Diseases appearing in the human population for the first time or suddenly beginning to spread rapidly
Humans have little or no resistance, and no vaccines have been developed.
Facilitated by increasing human mobility, growing antibiotic resistance, and environmental changes

9. Responding to Emerging Diseases
World Health Organization (WHO): Monitors health events worldwide and coordinates international responses to emerging diseases
Centers for Disease Control and Prevention (CDC): Responds to emerging diseases in the United States; the CDC developed pandemic plans to deal with the spread of the H1N1 flu virus.
Click HERE: History of Pandemics
H1N1 Virus

10. Social Hazards Some social hazards are easier to avoid than others.
Examples of social hazards include smoking, being exposed to secondhand smoke, living near an old toxic waste site, working with harmful chemicals, and eating fatty foods.

11. Chemical Health Hazards
Chemicals are all around us, and all of them can be harmful to our health in large enough amounts. In other words, “The dose makes the poison.”
Chemical Health Hazards
in the Environment

12. Chemical Hazards Any chemical can be harmful in large enough amounts.
A pollutant is something released into the environment that has some harmful impact on people and other organisms.
Chemical hazards are not necessarily pollutants, and pollutants are not necessarily chemical hazards.

13. Types of Chemical Hazards
Carcinogens: Cancer-causing chemicals
Chemical mutagens: Chemicals that cause genetic mutations
Teratogens: Chemicals that harm embryos and fetuses
Neurotoxins: Chemicals that affect the nervous system
Endocrine disruptors: Chemicals that interfere with the endocrine system
Allergens: Chemicals that over-activate the immune system
Dust mite protein is a common allergen.

14. Indoor Chemical Hazards

15. Radon Mitigation Systems

16. Sources of Outdoor Chemical Hazards
In the air: Natural sources, such as volcanic eruptions, or human sources, such as pesticides
In the ground: Pesticide use, improper disposal of electronics, etc.
In the water: Chemical runoff from land or direct drainage of toxic substances into water

17. Physical Health Hazards
Although we cannot prevent most natural disasters, there are steps that scientists, engineers, governments, and citizens can take to resist damage and deal with the aftermath.
A landslide caused by the Great Sichuan Earthquake in Sichuan Province, China
Physical Health Hazards
in the Environment

18. Physical Hazards
Physical hazards in the environment can pose health risks to humans.
Earth Quakes, Volcanos, Storms, and Avalanches are just some examples of natural disasters that can create environmental hazards.
We see biological hazards, chemical hazards, and social hazards result from natural disasters when they strike.
Although we cannot prevent these disasters, we can decrease our vulnerability to them.

19. Bioaccumulation and Biomagnification
Bioaccumulation: The buildup of toxic substances in the bodies of organisms
Biomagnification: The increased concentration of toxic substances with each step in a food chain
Persistent organic pollutants are biomagnified and stay in the environment for long periods of time and over long distances.
CLICK HERE: Mercury in fish

20. One third of death and disease in the least developed nations is a direct result of environmental causes.

21. Review Questions: Please answer ALL
What are the 4 types of environmental hazards?
What is the difference between epidemiology and toxicology?
Does everyone respond to environmental hazards in the same way? Why or why not?
How does the health of the environment influence biological hazards such as infectious disease?
How are social hazards linked to environmental impacts?
Make a chart listing each of the chemical hazard categories. Locate a specific example for each. ie: carcinogen example = xxxx
Find an example of something that is a bioaccumulator in humans and in the environment.
Explain the relationship between the health of the environment and the health of humans on the planet. Are they linked?