Environmental Hazards and Human Health Notes

Mercury as an Environmental Hazard

• Natural Sources: Released into the atmosphere from volcanoes, soil, and rocks.
• Human Exposure: Via consumption of fish and inhalation of mercury particles in the air.
• Health Implications: Significant health hazard; raises concerns about community exposure levels.

Health Hazards Overview

• Lifestyle Choices: Choices lead to health risks from biological, chemical, physical, and cultural hazards.
• Understanding Risk:
  • Risk: Probability of harm due to hazards (injury, disease, death).
  • Risk Assessment: Statistics to estimate potential harm.
  • Risk Management: Decisions on how to reduce risks and associated costs.

Types of Hazards

1. Biological Hazards: Pathogens causing disease.
2. Chemical Hazards: Present in air, water, soil, and food products.
3. Natural Hazards: Include natural disasters such as fires and earthquakes.
4. Cultural Hazards: Related to societal behaviors (e.g., poor living conditions).
5. Lifestyle Choices: Smoking, poor diet, etc.

Biological Hazards

• Infectious Diseases: Spread by bacteria, viruses, or parasites.
  • Nontransmissible: Diseases not passed between people, e.g., heart disease.
  • Transmissible: Spread via organisms.
  • Epidemic/Pandemic: Outbreaks affecting specific (epidemic) or global (pandemic) populations.

Examples of Viral Diseases

• Antibiotic Resistance: Ineffectiveness against viruses (e.g., HIV, hepatitis B).
• Avian Flu: Transmitted from birds to humans.

Ecological Medicine

• Integrity of ecosystems influences the spread of infectious diseases.
• Human Activities:
  • Deforestation for urbanization.
  • Hunting wildlife (e.g., bushmeat).
  • Illegal wildlife trade and industrialized meat production contribute to the spread of diseases.

Reducing Infectious Diseases

• Increase research on vaccines.
• Address poverty and malnutrition.
• Improve drinking water quality and reduce unnecessary antibiotic use.
• Strategies: Immunizing children, providing oral rehydration therapy.

Chemical Hazards

• Toxic Chemicals: Cause harm or death. Classifications include:
  • Carcinogens: Lead to cancer.
  • Mutagens: Create genetic mutations.
  • Teratogens: Cause birth defects.

Long-term Effects of Chemicals

• Certain chemicals disrupt the immune, nervous, and endocrine systems.
  • Neurotoxins: Impact cognitive functions, potentially leading to disabilities.
  • Endocrine Disruption: Mimic hormones, leading to growth and reproductive issues.

Common Sources of Chemicals

• Households may contain various toxic substances (e.g., baby bottles with BPA, flame retardants in furniture).

Evaluating Chemical Hazards

• Toxicity Measures:
  • Understanding potential for harm based on variables like age and genetic predisposition.
  • Solubility: Water-soluble toxins penetrate cell membranes more easily.
  • Persistence: Some chemicals resist breakdown, remaining in the body longer (e.g., PCBs).

Limitations of Toxicity Testing

• Case Studies: Employed to track effects post-exposure but may lack clarity on dosage.
• Epidemiological Studies: Compare health impacts but challenging due to complex exposures to multiple chemicals.

Global Health Risks

• Poverty: Major health risk affecting access to adequate health care, nutrition, and living conditions.
• Greatest risks derive from poverty, gender, and lifestyle choices (e.g., smoking).

Risk Perception and Management

• An informed approach involves evaluating risk, making educated choices about lifestyle, and seeking safer alternatives.
• Discussing risk allows for more thoughtful decisions about health and safety, especially against rising chemical exposures.

Pollution Prevention Strategies

• Substitutes: Finding safer alternatives for harmful chemicals.
• Precautionary Principle: Act to prevent potential harm rather than waiting for conclusive evidence.

Conclusion: Assessing Health Risks

• Implementing knowledge on risks allows communities to manage health more effectively and mitigate harmful chemical exposures. Awareness and lifestyle changes play critical roles in improving public health outcomes.