Environmental Hazards and Toxicology Quiz

Environmental Hazards

• Hazards are grouped as physical, chemical, biological, and cultural.
• Physical hazards include natural disasters like earthquakes, floods, and hurricanes.
• Chemical hazards involve toxic substances like pesticides, heavy metals, and endocrine disruptors.
• Biological hazards encompass pathogens, bacteria, viruses, and allergens.
• Cultural hazards are lifestyle factors such as smoking and poor diet.

Toxicology and Dose-Response

• Toxicology is the study of harmful substances' effects on organisms.
• Dose-response relationships show the effect of a substance at different dosages.
• LD₅₀ (Lethal Dose 50) is the dose killing 50% of exposed subjects.
• ED₅₀ (Effective Dose 50) is the dose causing a response in 50% of subjects.
• Threshold levels are the lowest dosages eliciting a specific effect.
• Acute exposures are short-term, high-dose effects; chronic exposures are long-term, low-dose effects.

Types of Toxic Substances

• Carcinogens cause cancer, such as asbestos and benzene.
• Mutagens cause DNA mutations, exemplified by radiation and certain chemicals like nitrites.
• Teratogens negatively impact embryonic development, including thalidomide and alcohol.
• Neurotoxins harm the nervous system, including lead and mercury.
• Endocrine disruptors interfere with hormone function, including BPA and DDT.

Bioaccumulation and Biomagnification

• Bioaccumulation is the buildup of substances in an organism over time.
• Biomagnification is the increased concentration of toxins up a food chain, like DDT in birds of prey and mercury in fish.

Risk Assessment and Risk Management

• Risk assessment involves identifying hazards, evaluating dose-response, assessing exposure, and characterizing risk.
• Risk management involves controlling or reducing risk exposure.

Epidemiology and Disease

• Epidemiology studies the spread and risk factors of diseases.
• Emerging infectious diseases are new or rapidly increasing illnesses, like COVID-19 and Zika virus.
• Zoonotic diseases are transmitted from animals to humans, including Ebola and rabies.

Pollution and Human Health

• Air pollution includes particulate matter, ozone, carbon monoxide, sulfur dioxide, and nitrogen oxides.
• Indoor air pollutants include radon and tobacco smoke.
• Water pollution includes heavy metals (lead, arsenic), pathogens (cholera, E. coli), and nutrient pollution (eutrophication).
• Soil and food contamination involves pesticides, herbicides, and heavy metals in crops.

Regulatory Agencies and Laws

• The EPA, FDA, and OSHA regulate environmental hazards, food safety, and workplace safety, respectively.
• Key laws include the Clean Air Act, Clean Water Act, Toxic Substances Control Act, and Safe Drinking Water Act.

Case Studies and Real-World Examples

• Minamata Disease resulted from mercury poisoning in Japan.
• The Bhopal Disaster involved a chemical leak in India.
• The Flint Water Crisis showed lead contamination in Michigan water.
• Rachel Carson's work on DDT and Silent Spring highlighted pesticide effects.