Environmental Hazards and Human Health

Environment: combination of physical, chemical, and biological factors.

Hazard: anything that can cause injury, death, disease, damage to personal/public property, or deterioration or destruction of environmental components.

Risk: probability of suffering a loss as a result of exposure to a hazard.

Risk Perception• Origin (natural vs manmade)• Volition (voluntary vs imposed)• Effect Manifestation (immediate vs delayed)• Controllability (controlled vs chaotic)• Benefit (defined vs unclear)• Familiarity (experienced vs new)• Exposure (frequent vs occasional vs rare)• Necessity (true need vs luxury)

Causes of Human Mortality

Environmental Hazards• Cultural Hazards

– Consequence of choice– Risky behavior

• Biological Hazards– Animal attacks– Infectious disease

• Physical Hazards– Natural disaster– Prevention by avoidance

• Chemical Hazards– Manmade chemicals– Carcinogens (cause mutations, cancer)

To what cultural hazards do college students commonly subject themselves?

Cultural Hazards

Smoking-related Diseases

Regulation Of Smoking• Warning labels• Smoke-free zones in public places • FDA regulations • Lawsuits against the tobacco industry

Click the Death Clock to Calculate you estimated time of departure time

Infectious Diseases• Pathogenic bacteria, fungi, viruses, protozoans,

worms • More prevalent in but not exclusive to

developing countries• Crowding increases disease spread• Contamination of food and water

– Lack of resources for sanitation– Lack of education

• Climates for transmission of vector-borne diseases like malaria

Malarial Parasite Life Cycle

Worldwide Distribution of Malaria

Physical Hazards

• Natural disasters, e.g., tornadoes, floods, hurricanes, and wildfires

• Avoidance of risk important in prevention, e.g., building homes in flood plains, and living on the coast.

• Not all disasters can be avoided

Chemical Hazards• Result of industrialization• Exposure through ingestion, inhalation,

absorption through skin.– direct use vs accidental– Air, food,& water

• Many chemicals are toxic at low levels • 74 chemicals are known to be

carcinogenic

The Role of Poverty

• No money for health insurance.• Higher probability of exposure to

environmental hazards.

Environmental Health

• Factors contributing to the environmental health of a nation include:– Education– Nutrition– Commitment from government– More equitable distribution of wealth

Risk Analysis

• The process of evaluating the risks associated with a particular hazard before taking some action for its management.

• 4 steps to EPA risk analysis.– Hazard assessment (What chemicals cause

cancer)?– Dose-response assessment (how much)?– Exposure assessment (how long)?– Risk characterization (how many will die)?

Risk Assessment/Management

• Usually involves:– Cost-benefit analysis– Risk-benefit analysis– Public preferences

• Some suggest we use distributive justice in making decisions about risk – Ethical process of making certain that everyone

receives proper consideration– Should reduce environmental racism/injustice

Risk Assessment/Management

• Not a perfect system• Precautionary principle

– Lack of certainty should not be used as a reason for preventing environmental degradation/hazards