Multi-Systems: Environmental Exposures Flashcards
1
Q
Definition of Poison
A
- A quantitative concept strictly dependent on Dosage
- “all substances are poisons; the right dosage differentiates a poison from a remedy”
2
Q
Definition of Xenobiotics
A
- Exogenous chemicals in the environment in air, water, food, and soil that may be absorbed into the body through inhalation, ingestion, and skin contact
3
Q
(6) Air Pollutants Monitored by EPA
A
- Sulfur dioxide
- Carbon monoxide
- Ozone
- Nitrogen dioxide
- Lead
- Particulate matter
4
Q
Effects of Ozone
A
- Decreased Lung function
- Increased Airway reactivity
- Lung Inflammation
- Decreased Exercise capacity
- Increased Hospitalizations
5
Q
Effects of Nitrogen Dioxide
A
- Increased Airway reactivity
- Decreased Lung function
- Increased Respiratory Infections
6
Q
Effects of Sulfur Dioxide
A
- Increased Respiratory symptoms
- Increased Mortality
- Increased Hospitilizations
- Decreased Lung functions
7
Q
Effects of Acid Aerosols
A
- Altered Mucociliary clearance
- Increased Respiratory infections
- Decreased Lung function
- Increased Hospitalizations
8
Q
Effects of Particulates
A
- Increased Respiratory Infections
- Decreased Lung function
- Excess Mortality
- Increased Attacks
9
Q
Effects of Carbon Monoxide (CO)
A
- CO kills by inducing CNS depression (insidiously and unaware)
- Hemoglobin has a 200-fold Greater affinity for CO than Oxygen
- Carboxyhemoglobin cannot carry O2
- Systemic hypoxia (20 - 30%)
- Unconciousness / Death (60 - 70%)
- Acute Poisoning is marked by a Characteristic Generalized Cherry-red color of the Skin and Mucous membranes
- Brain: slightly edematous, with Punctate Hemorrhages and hypoxia-induced neuronal changes
10
Q
Top Indoor Air Polluters
A
- Tobacco Smooke (1st)
- CO
- Nitrogen dioxide
- Asbestos
11
Q
Lead Poisoning
A
- Binds to Sulfhydryl Groups in Proteins
- Interferes w/ Calcium Metabolism
- -> Hematologic, Skeletal, Neurologic, GI, Renal Toxicity
- House paints and Gasoline
- Mining, Foundries, Batteries, and Spray Painting
- Intellectual capacity, Behavioral problems (Hyperactivity and Poor orginizational skills)
- Decreased IQ, Hearing, Growth, Impaired peripheral nerve function, Fetal effects by Transplacental transfer
12
Q
Lead Absorption in Children and Adults?
A
- < 15% Adults - peripheral neuropathis
- > 50% Children - Higher intestinal absorption –> Higher susceptibility to Brain damage due to increased permeable BBB –> inhibition of neurotransmitters due to disruption of Calcium Homeostasis.
13
Q
How does Lead interfere with Cartilage and Bone?
A
- Lead interferes w/ the normal remodeling of cartilage and Primary bone Trabeculae in the Epiphysis in Children
- This Increased Bone density detected as Radiodense “Lead Lines” (Gums –> Hyperpigmentation)
- Inhibits Fracture healing by increasing Chondrogenesis and Delaying Cartilage mineralization
14
Q
How does Lead effect RBCs?
A
- Lead inhibits the activity of (2) enzymes involved in Heme synthesis
- Aminolevulinic acid dehydratase
- Ferrochelatase –> catalyzes the incorporation of Fe into Protoporphyrin
- -> inhibition causes rise in Protoporphyrin lvls
- -> Microcytic Hypochromic anemia stemming from Hemoglobin synthesis
15
Q
Mercury
A
- Binds to Sulfhydryl groups in certain Proteins w/ High affinity –> Damage to CNS and Kidneys
- Tremor
- Gingivitis
- Bizarre Behaviour (Mad Hatter)
- Contaminated Fish (methyl mercury)
- Dental amalgams (metallic mercury)
- Lipid solubility accumulation in Brain
- Intracellular glutathione –> Sulfhydryl donor (protective)
