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