Multi-Systems: Environmental Exposures Flashcards
Definition of Poison
- A quantitative concept strictly dependent on Dosage
- “all substances are poisons; the right dosage differentiates a poison from a remedy”
Definition of Xenobiotics
- Exogenous chemicals in the environment in air, water, food, and soil that may be absorbed into the body through inhalation, ingestion, and skin contact
(6) Air Pollutants Monitored by EPA
- Sulfur dioxide
- Carbon monoxide
- Ozone
- Nitrogen dioxide
- Lead
- Particulate matter
Effects of Ozone
- Decreased Lung function
- Increased Airway reactivity
- Lung Inflammation
- Decreased Exercise capacity
- Increased Hospitalizations
Effects of Nitrogen Dioxide
- Increased Airway reactivity
- Decreased Lung function
- Increased Respiratory Infections
Effects of Sulfur Dioxide
- Increased Respiratory symptoms
- Increased Mortality
- Increased Hospitilizations
- Decreased Lung functions
Effects of Acid Aerosols
- Altered Mucociliary clearance
- Increased Respiratory infections
- Decreased Lung function
- Increased Hospitalizations
Effects of Particulates
- Increased Respiratory Infections
- Decreased Lung function
- Excess Mortality
- Increased Attacks
Effects of Carbon Monoxide (CO)
- 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
Top Indoor Air Polluters
- Tobacco Smooke (1st)
- CO
- Nitrogen dioxide
- Asbestos
Lead Poisoning
- 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
Lead Absorption in Children and Adults?
- < 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.
How does Lead interfere with Cartilage and Bone?
- 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
How does Lead effect RBCs?
- 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
Mercury
- 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)
Arsenic
- Arsenic salts interfere w/ metabolism
- -> GI, Nervous system, Skin, Heart
- Tx for Acute Promyelocytic Leukemia
- Interference w/ Mitochondrial oxidative Phosphorylation
- -> replace the Phosphates in Adenosine Triphosphate
- Neurologic effects - 2 to 8 weeks - sensorimotor neuropathy, paresthesias, numbness, pain
- Skin changes - Hyperpigmentation and Hyperkeratosis
- Development of Cancers (Lung, Bladder, Skin)
- Arsenic induced skin tumors - multiple, palms and soles
- Non-malignant respiratory disease (exposed water)
Cadmium
- Toxic to the Kidneys and Lungs
- Increased production of Reactive Oxygen species
- Mining, Electroplating, Production of Nickel-cadmium batteries
- Food is the most important source of Cadmium exposure
- ZIP8 transporter uptake (normally zinc)
- Obstructive Lung Disease - alveolar epithelial cell necrosis
- Renal Tubular damage –> End-Stage Renal Disease
- Skeletal abnormalities
- Carbon monoxide
- Lead
- Solvents
- Cobalt
- Cadmium
Cardiovascular System - Heart Disease
- Isopropyl alcohol
- Wood dust
Respiratory - Nasal Cancer
- Radon
- Asbestos
- Silica
- Bis(chloromethyl)ether
- Nickel
- Arsenic
- Chromium
- Mustard gas
- Uranium
Respiratory - Lung Cancer
- Grain dust
- Coal dust
- Cadmium
Respiratory - Chornic Obstructive Lund Disease
- Beryllium
- Isocyanates
Respiratory - Hypersensitivity
- Ammonia
- Sulfur Oxides
- Formaldehyde
Respiratory - Irritation
- Silica
- Asbestos
- Cobalt
Respiratory - Fibrosis
- Solvents
- Acrylamide
- Methyl Chloride
- Mercury
- Lead
- Arsenic
- DDT
Nervous - Peripheral Neuropathies
- Chlordane
- Toluene
- Acrylamide
- Mercury
Nervous - Ataxic Gait
- Alcohols
- Ketones
- Aldehydes
- Solvents
Nervous - Central Nervous System Depression
- Ultraviolet Radiation
Nervous - Cataracts
- Mercury
- Lead
- Glycol ethers
- Solvents
Urinary - Renal Toxicity
- Nahthylamines
- 4-aminobiphenyl
- Benzidine
- Rubber products
Urinary - Bladder Cancer
- Lead
- Phthalate plasticizers
- Cadmium
Reproduction - Male Infertility
- Lead
- Mercury
Reproduction - Female Infertility / Stillbirths
- Mercury
- Polychlorinated biphenyls
Reproduction - Teratogenesis
- Benzene
Hematopoietic System - Leukemia
- Polychlorinated biphenyls
- Dioxins
- Herbicides
Skin - Folliculitis and Acneiform Dermatosis
- Ultraviolet Radiation to Skin
Skin - Cancer
- Vinyl Chloride
Gastrointestinal tract - Liver Angiosarcoma