Presentation on theme: "Pesticides, Sarin Gas & Antidotes Was I Exposed? Was the Cure Worse?"— Presentation transcript:
1Pesticides, Sarin Gas & Antidotes Was I Exposed? Was the Cure Worse? Omowunmi (‘Wunmi) Osinubi, MD, M.Sc., MBA, FRCA.Associate Professor (Adjunct)Department of Occupational and Environmental HealthUniversity of Medicine and Dentistry of New Jersey -School of Public HealthOccupational & Environmental Health PhysicianWar Related Illness and Injury Study Center
2“On a nightly basis, we would spray our uniforms with pesticides… “On a nightly basis, we would spray our uniforms with pesticides…. We had to hang them outside so that the excess spray would dissipate in the air…. We were not supposed to put them on immediately after spraying them.…The sand fleas were a problem. We used to put flea collars around the legs of our cots, or we would put flea powder on the floor around our cots to try to keep the sand fleas away from us while we were sleeping…We slept with nets over us to keep the flies off….The flies were ungodly”--SSgt TS, Gulf War veteran (GRAC Report, 2008)
3Pesticides?Chemical substances used to control and destroy pests that interfere with man’s agricultural, environmental or amenity requirements.First use of synthetic pesticides –1940Consumption increasing worldwide2.26 million tons of active ingredients used in 2001As of 1999 – 74% of all US used at least one pesticide in the home.Utility based on selective toxicityEnvironmental toxins intentionally introduced to the environment
4Pesticides – Benefits Crop protection Food preservation Material PreservationDisease control
5Persistent Organic Pollutants (POPs) RisksAdverse impact on environment & ecosystemsTravel long distancesLow water & high fat solubilityPersist & bio-concentrateConcentrate in marine animalsAccumulate in the food chainMay produce toxic human effectsEconomic Poison
6Pesticides – Classification by Use Chemicals designed to kill, reduce, or repel pestsRats, mice, molesInsectsWeedsMouldsInsecticidesHerbicidesFungicidesRodenticidesInsect repellantsWood preservativesFumigants
7Pesticides – Classification By Use & Chemical Structure Different chemicals used for different purposesINSECTICIDES• Pyrethroids• Organophosphorus• Carbamates• Organochlorine• Manganese compoundsFUNGICIDES• Thiocarbamates• Dithiocarbamates• Cupric salts• Tiabendazoles• Triazoles• Dicarboximides• Dinitrophenoles• Organotin compounds• MiscellaneousRODENTICIDES• Warfarines• IndanodionesFUMIGANTS• Aluminium & zincphosphide• Methyl bromide• Ethylene dibromideHERBICIDES• Bipyridyls• Chlorophenoxy• Glyphosate• Acetanilides• TriazinesINSECT REPELLENTS• Diethyltoluamide (DEET)
8Routes of Exposure Ingestion Inhalation Dermal absorption BreastfeedingAccidental ingestionResidues in foodMouthingInhalationIndoor and outdoor sprayingOccupational exposureDermal absorptionAccidental contactResidues on surfacesContaminated clothingMedical use: scabies, head liceTransplacental
9Use of Pesticides in Gulf War Desert is home to large numbers of flying & biting insects and other pestsControl of disease-carrying pests is an important part of force protection & readiness in deployed settingsMilitary personnel issued pesticide creams, liquids, sprays to use on skin, uniforms & beddings; and pest strips, baits & sprays used in living quartersPersonal repellants – 33% cream or 75% liquid DEET on the skin, 0.5% Permathrine sprayed on uniformsTroops self-acquired pesticides –flea collars, citronella products, OFF e.t.c.Organochlorine – Lindane used for delousing in processing more than 87,000 enemy prisoners & US Army personnel for personal use.
10Local pest control services by host nations US military preventive medicine specialists & field sanitation teams did environmental spraying & fogging using various concentrations in areas were troops lived, ate & worked.OPs- Chlorpyrifos, diazinon & malathionCarbamates – propoxur & bendiocarbLocal pest control services by host nations?information on pesticides usedU.S. troops had available for use, at least 64 pesticides/related products37 active ingredients; 15 of which are “pesticides of concern”Pest control program was highly successful →low rates of arthropod borne illnesses.
11Routes of Exposure Ingestion Inhalation Dermal absorption BreastfeedingAccidental ingestionResidues in foodMouthingInhalationIndoor and outdoor sprayingOccupational exposureDermal absorptionAccidental contactResidues on surfacesContaminated clothingMedical use: scabies, head liceTransplacental
12Mechanisms of Pesticide Toxicity Local irritationMost pesticidesAllergic sensitizationFungicidesEnzyme inhibition (cholinesterases)Organophosphates (OPs) & carbamatesNeurotransmission altered (Calcium & GABA)OrganochlorinesOxidative damageParaquatUncoupling of oxidative phosphorylationGlyphosate
14Anti-Cholinesterases Organophosphates & Carbamates Commonly used as animal flea & tick powders, foggers, shampoos & dips, flea collars, household, garden & farm insecticidesMarketed under a variety of namesOPs - Chlopyrifos, parathion, diazinon, malathionCarbamates - carbofuran, aldicarb, and carbarylFat soluble – easily absorbed through the skinReadily transported throughout the body
15Mechanism of Action Organophosphates & Carbamates Inhibit the enzyme, acetylcholinesterase (AChE) which normally functions to degrade acetylcholine in nerve synapsesBuildup of acetylcholine (ACh)Overstimulation of ACh receptors.Effects of multiple exposures are additive (flea collar, insect repellant, home & lawn treatment)Effects can be long-lastingHighly toxic to animals, pets, livestock & humans
16Nerve Agents Muscarinic effects Nicotinic effects Excess Ach in CNS Postganglionic parasympatheticNicotinic effectsPreganglionic sympathetic & parasympatheticNeuromuscular junctionExcess Ach in CNSSpinal CordGangliaNEJNMJAutonomic Nervous SystemSomatic Nervous SystemAChEpl-SympatheticParasympatheticNE
17Effects of Cholinesterase Inhibition (Nerve Agents) MuscarinicNicotinicDiarrheaSalivationTachycardiaHypertensionMydriasisNeuromuscular junction**FasciculationWeaknessParalysisUrinationLacrimationMiosis**BradycardiaDefecationBronchorrheaGI symptomsBronchospasmEmesis** Most important effects after exposure to nerve agent(s)CNSAnxiety, confusion, ataxia, dysarthria,Seizures**Respiratory depression**Coma
18Nerve Agent Effects Based on Route of Exposure Route & OnsetMildModerateSevereVapor/AerosolImmediateRhinorrhea,secretions,slight dyspneaMiosis, eye pain,dim vision,pronounceddyspneaComa,convulsions,fasciculations,paralysisTopicalImmediate or DelayedLocalizedsweating &fasciculationsVomiting,diarrhea,secretionsMiosis, coma,generalized
19Management of Nerve Agent Acute Toxindromes PESTICIDEACUTESYMPTOMSDIAGNOSISTREATMENTOrganophosphatesClorpyriphosDiazinonAzinphosParathion"Irreversible"cholinesteraseinhibitionCholinergic crisis:- nausea, vomiting- hypersecretion- miosis- fasciculations- comaLow cholinesteraselevels in redblood cells- Decontamination- IV Atropine- Supportive care- Oximes (pralidoxime)CarbamatesCarbarylAldicarbReversiblelevels in RBCDecontaminationIV Atropine- NO Oximes
20Chemical Warfare Nerve Agents Anti-cholinesterases similar to OPsReadily absorbed by inhalation, ingestion & dermal contactRapidly fatal systemic effects may occurMost toxic chemical warfare agentsG-Type Nerve AgentsClear colorless liquids, volatile at ambient tempTabun (GA); Sarin (GB); Soman (GD)V-Type Nerve AgentsAmber liquid, low volatility unless high tempVX
21SarinDiscovered in 1938 in Germany by 2 scientists attempting to create stronger OPsMost toxic of the G-agents made by GermanyNamed in honor of its discoversSchrader Ambros Rudiger &Vand der LINdeWWW II - large amounts incorporated into artillery shellsNazi Germany ultimately decided not to use sarin against allied targets
222-(Fluoro-methylphosphoryl)oxypropane M190 Honest John chemical warhead section containing demonstration M134 GB (Sarin) bomblets.Sarin[(CH3)2CHO]CH3P(O)F2-(Fluoro-methylphosphoryl)oxypropane
23Shelf-life several weeks to months Shortened by impuritiesExtended by addition of certain oils, stabilizers or petroleum productsBinary chemical weaponsTwo precursors are stored separately in the same shellMixed to form agent immediately before or when shell is in flightDual benefit –solves problems of stability & safety of sarin munitions
24Sarin Health Effects Highly volatile & toxic cholinesterase inhibitor Vapors penetrate the skin & non-lethal dose causes permanent neurological damage500 X toxicity of cyanide, death within 1 minHealth effects similar to OPs & carbamatesAcetylcholine builds up at nerve endingsRunny nose, chest tightness, pupillary constriction, difficulty breathing, nausea, drooling, vomiting, defecation, urination, twitching, jerking, comatose, convulsive spasms & deathTreatmentIV atropine – muscarinic symptoms of poisoning onlyPralidoxime - regenerates cholinesterases if given ≤ 5 hours
25Sarin as Chemical Warfare Agent Early 1950’s – NATO adopted sarin as a standard chemical weaponU.S.S.R and US produced sarin for military purposes1953 – 20 yr old Royal Air Force Engineer died in human testing of sarin - told he was participating in a test to “cure the common cold”Classified as weapon of mass destruction in UN Resolution 687Production & stockpiling of sarin outlawed by the Chemical Weapons Convention of 1993
26Sarin & Terrorism Matsumoto: 1994 Tokyo: 1995 Japanese religious sect released impure sarin in a residential neighborhoodHospital visits - 500; Fatalities -7Tokyo: 1995Aum Shinrikyo sect released impure sarin in the subway system in rush hourHospital visits - > 5000; Fatalities -12
28Sarin in the Persian Gulf : Iraq used sarin against Iran during the Iraq-Iran war1988: Ethnic Kurd City of Halabja in Northern Iraq, was bombarded over 2 days with chemical cluster bombs including sarin5,000 died; 11,000 injured;Thousands more died of complications, diseases and birth defects years after the attackGulf War, Iraq still had large stockpiles of sarin, discovered by coalition forces
30Sarin in IraqOn May 14, 2004, Iraq insurgency fighters detonated a 155 mm shell with several liters of binary precursors of sarin.Shell designed to mix chemicals asit spins during flightDetonated shell released small amount of sarin gasTwo US soldiers were treated after displaying early symptoms of exposure to sarin.
31“My unit arrived in the Gulf the day before the air war started “My unit arrived in the Gulf the day before the air war started. We spent about 1 month in Saudi Arabia. Our chemical alarms went off several times during that month…we had to go to MOPP – level four...…While in Saudi Arabia, we started taking PB pills…about 3 days after, my eyes were jittery, my vision was jumping, I was seeing double, & I was nauseated. By the 4th day, I was vomiting a little blood, so I went to sick call, they told me to cut the dose in half…nothing to worry about…others in the unit had similar vision problems--SSgt TS, Gulf War veteran (GRAC Report, 2008)
32Exposure to PGW Chemical Weapons Iraqis had chemical weapons, US troops had successfully destroyed most of the chemical manufacturing & storage targets in an air offensiveIraq did not use nerve agents in PGWMarch Army detonated large caches of stored munitions in Khamisiyah area.Troops were potentially exposed to low-levels of nerve agents.No reports of high-level exposures with large number of soldiers with symptoms of nerve agent poisoning.
33Protecting the Troops from Chemical Warfare Nerve Agents Chemical agent detection & monitoring alarm systemsPersonal protective equipmentNerve agent prophylaxisPost-exposure treatment
34Multi-level Chemical Detection & Monitoring systems M8A1 – initial alarm, troops instructed to wear protective gear, detects nerve agents only at levels high enough to cause symptomsFalse alarm in the presence of screening smokes, signaling smokes, engine exhaust, rocket/missile propellant smokes, and electromagnetic pulse (EMP).Repeated false alarms →ignoring and/or disabling the systemsM256A1 detector kit: 20 – 25 mins to complete test, not useful as early warning monitor, less false positives, used to verify chemical agentsArmored FOX NBC Reconnaissance vehiclesM43A1 chemical agent detector, MM-1 mobile mass spectrometer
35Chemical detection equipment Chemical detection equipment. A soldier using an Improved Chemical Agent Monitor (ICAM).Automatic Chemical AgentDetector Alarm (ACADA)The M256A1 kit can manually detect &classify nerve, blister, and blood agentsin vapor or liquid form.
36Personal Protection Gear Mission Oriented Protective Posture (MOPP)Protective garments worn in a possible chemical eventProtective mask (a.k.a. gas mask), filters chemical, biological & irradiated particlesMask carrier – protects mask from damage, contains spare parts & nerve agent antidotesOver garments- worn over uniform, maximum airflow for cooling, prevents agents from reaching skin, smx with charcoal lining, strips of M9 detection paperGloves & boots – highly durable rubber