Published on January 17, 2008
US Army School of Aviation MedicineAviation Toxicology: US Army School of Aviation Medicine Aviation Toxicology U.S. Army Moral Compass: U.S. Army Moral Compass Courage Integrity Duty Respect Honor Loyalty Selfless-Service Why learn about Toxic Hazards?: Why learn about Toxic Hazards? As Leaders, you have a responsibility to: Mission Men Me Toxic Substances are all around you, Be Aware! History: History More than 1 million personnel work in the Aerospace Environment Pilots, mechanics, ground crew, and aircrew Each of these job identifications are exposed to unique toxicological profiles. 1993 - 685,000 pilots in the US 1993 - 401,080 aircraft mechanics in US History - The first noted Toxicological Hazard: History - The first noted Toxicological Hazard First fuels used Castor oil mix for lubrication This caused a continual mist of castor oil to be spayed across the pilot To counteract the spray, aviators wore long scarves to wipe mist from their goggles Guess what the ingested/inhaled castor oil did to the Body?? Definitions: Definitions Toxic - Anything that has the potential to produce harmful effects on an organism. Toxicology - The scientific study of poisons, physical or chemical agents and the injury caused to living cells Exposure - The actual contact of the harmful substance with the biological organism. Definitions (con’d): Definitions (con’d) Acute Exposure- A single exposure over a short period of time. Chronic Exposure- Long term or repeated exposures. Slide8: Questions? Factors Affecting Toxicity: Factors Affecting Toxicity Dose Route of Entry (Method of Exposure) Extent of Retention Rate of Excretion Physiochemical Factors Environmental Factors Physiological Factors Dose: Dose Amount of Toxic agent to which the body is exposed. Routes of Entry: Routes of Entry Inhalation Absorption Ingestion Inhalation: Inhalation The most important method Area of alveoli is approximately equal to double tennis court. When inhaled, most toxins absorb directly into blood stream. Absorption: Absorption Involves skin contact Can contact skin through or from clothing. Ingestion: Ingestion Involves taking the toxin through the mouth. Either intentionally or unintentionally. Eating, drinking or smoking after AC preflight ? Chewing Tobacco during AC preflight ? Toxin Accumulation / Elimination : Toxin Accumulation / Elimination Retention - How long the toxin is kept in the body. Excretion - How quickly the body rids itself of the toxin. Physiochemical Factors: Physiochemical Factors The biochemical processing of toxins within the body. The Target Organ(s) of various toxins. Environment Factors: Environment Factors Toxicity may be affected by Atmospheric Pressure Temperature Humidity Physiological Factors: Physiological Factors Metabolism Age, concurrent illness, medications Amount of Body Fat Urine drug screen Genetics Race, Sex Questions?: Questions? Sources of Toxic Hazards in Flight: Sources of Toxic Hazards in Flight Aviation Fuels: Aviation Fuels A combination of multiple >200 petroleum products Toluene, xylene, benzene, naphthalene's Army Jet engines uses JP-8 (Kerosene - principal agent) Principal hazard is vapor inhalation Symptoms of Exposure Aviation Fuels (Symptoms of Acute Exposure): Aviation Fuels (Symptoms of Acute Exposure) Neurological Light-headedness, confusion, fatigue, coma, slurred speech, respiratory failure, impaired psychomotor Cardio / Respiratory Irregular heart beats, coughing, choking, wheezing Gastrointestinal Nausea, vomiting, easily absorbed through mouth Skin Chemical burns, irritation due to the drying effect Products of Combustion (Results from Thermal Decomposition): Products of Combustion (Results from Thermal Decomposition) Carbon Monoxide Nitrogen Oxides Sulfur Dioxides Carbon Monoxide: Carbon Monoxide Most common cause of fatal poisonings in USA Product of incomplete combustion CO is a colorless, odorless gas Binds to hemoglobin 215x greater than Oxygen Engine Exhaust Gases Reciprocating 8.5% CO at takeoff, 3.0% CO at cruise Turbine CO exhaust from warm engine - Minimal Carbon Monoxide (Symptoms): Carbon Monoxide (Symptoms) Headache, weakness, dizziness, nausea, confusion, loss of consciousness. Class cherry red coloration of lips not seen until CO concentration is > 40% Isocyanates & Hydrogen Cyanides : Isocyanates & Hydrogen Cyanides A product of thermal decomposition from: Nylon, foam seats, plastics, wool, silk, synthetic rubber, paper, polymers Fluorocarbon plastics used as insulation on electrical wiring in aircraft. Produces Phosgene when burned Used in WW II as a chemical agent Symptoms Eye irritation, coughing, choking, wheezing, nausea Solvents - Degreasers: Solvents - Degreasers Organic bases used to dissolve other substances Tolulene 1,1,1 Trichloroethylene (TCE) 1,1,1 Trichloroethane (TCA) Methyl-ethyl-ketone [MEK] Cleaning solvent specified by -10 Explosive, depletes the ozone Cancer Solvents - Degreasers (Symptoms): Solvents - Degreasers (Symptoms) Neurological Headaches,dizziness, confusion, “drunkenness”, impaired psychomotor skills, affective changes Respiratory Irritant to eyes, nose, throat Skin Hand eczema due to the drying effect Lubricants: Lubricants Relatively non-toxic Although cancer increase is suggested. Frequently contaminated with bacteria, yeast, molds Respiratory Exposure to oil mist can cause a chemical pneumonitis Oil vapor may cause irritation to eyes and lungs. Larger doses can cause headache, nausea and vomiting. Oil induced dermatitis (allergic or irritant) common Hydraulic Fluids: Hydraulic Fluids Groups Petroleum-based, Castor-oil based, Silicon-based Phosphate ester-based “Skydrol” most common hydraulic fluids Dibutyl phenyl phosphate + tributyl phosphate Tricresyl phosphate organophosphate-induced delayed neurotoxicity “Nerve Agent-Like Activity” Known to cause dermatitis Fire Extinguishing Agents: Fire Extinguishing Agents Halogenated Hydrocarbons Carbon Dioxide AFFF Foam Halon: Halon 1301 Halon determined by their composition #C | #F | #CL| #Br 1 3 0 1 Displaces Oxygen Cardiac Sensitizer, CNS depressant Used in Ground and “Onboard” Extinguishers Illegal in Civilian Sector Ozone depletion. Carbon Tetrachloride: Carbon Tetrachloride Probably you will never see Sometimes used a cleaning fluid Known to release Phosgene when heated Exposure causes damage to: CNS Liver Kidney Carbon Dioxide (CO2): Carbon Dioxide (CO2) Danger most often in confined area >10% CO2 can cause collapse, LOC, death AFFF “Aqueous Film Forming Foam”: AFFF “Aqueous Film Forming Foam” Found mainly around flight line Nontoxic Protein based (“Soap Suds”) Advanced Composite Materials: Advanced Composite Materials Liberates particulate matter as well as toxic fumes Abrading composites releases particulate matter, including boron, graphite and fiberglass. Epoxy Resins burning produce cyanide. Heavy Metals: Heavy Metals Zinc (Used in paint and plating) Metal Fume Fever, chemical pneumonia Chromium (Used in plating) “Chrome ulcers” of skin and “Chrome holes” of the nose Beryllium Extremely toxic to lungs OH-58D (mast mounted IR scope) Heavy Metals: Heavy Metals Cadmium (Used in batteries and electroplating) Metal Fume Fever Damages kidneys, prostate cancer All AC wiping go into Cadmium waste barrels Mag-Thorium P-55 engine (Chinook, Huey, 58-C) Insecticides: Insecticides Organophosphates & Carbamates: Organophosphates & Carbamates Commonly used insecticides Cause inhibition of the enzyme cholinesterase Better known to the military as Nerve Agent. Absorbed through the skin and/or ingestion Batteries: Batteries Traditionally a source of both lead and sulfuric acid Produces hydrogen gas (explosive) during charge/discharge. Dry cell batteries will explode in fire but not toxic hazard Slide42: Questions? Cockpit Protective Measures : Cockpit Protective Measures Smoke and fumes may come from unknown source. May or may not be toxic All smoke decreases situational awareness. Rapid ventilation of the cockpit followed by landing ASAP. Get Medical evaluation ASAP Personal Protective Measures: Personal Protective Measures Avoid Contamination of NOMEX by Aviation fuels Flame retardant feature is lost If not removed quickly, chemical burn to the skin is possible. Avoid possibility of fire Avoid contaminated rags/materials in cockpit. General Protective Measures on the Flight Line....: General Protective Measures on the Flight Line.... Adequate ventilation in hanger area. Know Evacuation Plan for your area Know which Hazardous Material in your AO Use your protective equipment Avoid “Dumb Attacks”! Slide46: Questions?