7️⃣ Climate & chemicals Flashcards
(21 cards)
Name environmental contributors to human disease.
Climate change, chronic under-nutrition, toxins/pollution.
Which leading risk factors did GBD 2021 identify?
High BP, smoking, high blood sugar, ambient particulate air pollution (present at all socioeconomic levels).
List major environmental risk categories.
Air pollution; chemical exposure; prescription/recreational drugs; radiation (including UV); poor nutrition.
How does climate change impact disease burden?
↑ cardiovascular/respiratory disease (heatwaves, pollution); ↑ waterborne infections (flood-related); ↑ vector-borne diseases (expanded vectors); ↑ malnutrition (crop disruption).
Define toxicology and the dose-response principle.
Science of poisons and their effects; “the dose makes the poison”—toxicity depends on amount and nature of exposure.
Why is toxicology important?
It informs how environmental chemicals impact health and guides policies and treatments to mitigate exposures.
What are xenobiotics and entry routes?
Exogenous chemicals (pollutants, drugs, industrial), entering via inhalation, ingestion, or skin contact.
Outline Phase I and Phase II metabolism.
Phase I: hydrolysis/oxidation/reduction by cytochrome P450 → primary metabolites; Phase II: conjugation → water-soluble secondary metabolites for excretion.
How do P450 polymorphisms affect toxicity?
Variations in CYP enzyme activity influence individual susceptibility to toxins (e.g., acetaminophen, alcohol).
What damage can toxic metabolites cause?
Reactive species damage macromolecules (DNA, proteins, lipids) → cell injury/death depending on dose, duration, and tissue.
List key air pollutants and their mechanisms.
SO₂ → sulfuric acid formation, airway irritation; CO → binds Hb >200× O₂ affinity → hypoxia; O₃ → ROS, lung inflammation; NO₂ → ozone precursor; PM<10 µm → alveolar inflammation via macrophages/neutrophils.
Describe asbestos exposure and disease.
Fibrous silicate in insulation/building materials; inhaled fibers cause inflammation and mesothelioma and other cancers; household secondary exposure (e.g., dust on clothing).
What are formaldehyde’s effects?
Present in paints, adhesives, furniture; causes respiratory irritation and is carcinogenic.
How does lead toxicity occur?
Environmental/occupational exposure → ROS generation → hematologic, skeletal, neurologic, GI, renal damage.
What are bioaerosols?
Airborne microbes (e.g., Legionella) and allergens (dust mites, mold) causing infections and hypersensitivity (asthma, rhinitis).
Name chemical, physical, and nutritional pollutant sources.
Chemical: alcohol, tobacco, drugs, heavy metals, agro/industrial chemicals, air pollutants; Physical: trauma, thermal, electrical, ionizing radiation; Nutritional: under- and overnutrition.
What regulatory body monitors air quality in Victoria?
The Victorian Environment Protection Authority (EPA).
Summarize the Wittenoom asbestos case.
Former blue asbestos mine; ~20,000 workers/residents; >2,000 deaths from mesothelioma/diseases; site abandoned and removed from maps.
What are the health consequences of smoking?
> 4,000 substances, >60 carcinogens; causes cancers, CVD, COPD (bronchitis, emphysema), pregnancy complications (miscarriage, IUGR).
Describe alcohol metabolism and toxicity mechanisms.
Metabolized in liver by ADH, CYP2E1 (MES), catalase → acetaldehyde + ROS → steatosis, cirrhosis, HCC, gastritis, pancreatitis, Wernicke’s, cardiomyopathy, FAS.
List therapeutic-drug toxicities.
Anticoagulants (warfarin, dabigatran → bleeding); analgesics (acetaminophen → toxic intermediate, liver necrosis in OD); OCPs (↑ thromboembolism, protect vs endometrial/ovarian cancer); aspirin (acute OD: alkalosis→acidosis; chronic: salicylism, GI bleeding).
