Environmental Factors Chapter 7

Chapter 7: Environmental Factors

• Environmental factors significantly contribute to death, including microbial agents.
• Environmental health is a public health approach to preventing diseases and injuries from environmental hazards.
• This focus is on human impacts, not just the environment itself.

Environmental Hazards

• Chemicals: Unexpected chemical releases (e.g., spills, DDT) are particularly dangerous.
• Radiation: Exposure to radiation, including radon, is hazardous.
• Metals: Metals like lead pose environmental risks.
• Particles and fibers: Air pollutants, including fibers and particles, are harmful.
• Biological agents: Toxins and biological agents from organisms are dangerous.

Environmental Pathways

• Environmental pathways carry these hazards.
• Air: A primary pathway for environmental hazards.
• Water (surface and groundwater): Water sources can carry pollutants.
• Soil: Soil pollutants can be harmful.
• Food: Food can be contaminated with toxins or pollutants.
• Solid waste: Solid waste may contain harmful substances.
• Non-food products: Other products can also hold hazards.

Routes of Exposure

• Inhalation: Breathing in harmful substances.
• Ingestion: Eating or drinking contaminated substances.
• Absorption: Harmful substances entering the body through skin contact.

Common Health Effects

• Cancer: A frequent health effect from environmental exposure.
• Neurological damage: Environmental exposures can harm the nervous system.
• Poisoning: Exposure to pollutants or toxins results in poisoning.
• Lung and kidney disease: Environmental hazards can damage respiratory and renal systems.
• Skin problems: Environmental exposure causes skin issues.
• Endocrine system disorders: Environmental hazards can disrupt hormone balance.
• Birth defects: Exposure to harmful substances during development can cause birth defects.
• Food- and water-borne diseases: Food and water contaminated by environmental hazards can cause illnesses.

Air Pollution

• Causes: Combustion (power plants, vehicles), industrial processes, and livestock contribute to air pollution and release toxic gases.
• Clean Air Act (1970): Federal legislation to manage and set air quality standards.
• Air pollutants: Criteria pollutants (particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, ground-level ozone, and lead) and hazardous air pollutants are key concerns.
• Indoor air pollution: Indoor environmental hazards include tobacco smoke, radon, formaldehyde, and airborne microbes.

Water Pollution

• Causes: Point-source pollution (e.g., sewage, industrial discharge).

Solid Waste

• Solid waste disposal: Methods for managing solid waste, including landfills.
• 1972 Marine Protection, Research, and Sanctuaries Act: Regulates ocean dumping.
• 1976 Resource Conservation and Recovery Act: Regulates hazardous waste.
• 1980 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): The Superfund program addresses hazardous waste sites.

Food Safety

• Foodborne illness: Exposure to bacteria, parasites, or toxins in food.
• Pesticides, Mercury in Fish, and other contaminants: Harmful substances in food.
• Additives (vitamins/minerals, preservatives, antibiotics, growth hormones): Some additives are potentially harmful.

Genetically Modified Organisms

• Food and Drug Act (1906) regulates genetically modified organisms.

Risk Assessment

• A multi-step process to evaluate the likelihood of harmful health effects from environmental exposure.

Hazard Identification

• Epidemiological studies and animal studies ascertain whether exposure to particular agents causes adverse health effects.

Dose-Response Estimation

• Assessing the link between exposure levels and health effects (how much exposure is needed to cause adverse health effects).

Exposure Assessment

• Determining the number of people exposed to an agent and the amount of exposure.

Risk Characterization

• synthesizing the steps to conclude if there is a risk, and what the nature of the risk is.