1. TOXICOLOGY

2. Is the study of the adverse effect of chemicals on living organisms. All chemicals and drugs have some degree of toxicity.

3. ROUTE OF CONTACT WITH THESE CHEMICALS Inhalation Oral Topical Self-injection

4. TARGET ORGANS Lungs via inhalation for gases, vapors Liver for ingested chemical by mouth Brain Kidney Heart

5. TOXIC ACTIONS Nonselective action Selective action: e.g., warfarin inhibiting specific clotting factors Immediate actions: e.g., OP poisoning Delayed action: e.g., exposure to asbestos

6. OCCUPATIONAL AND SPECIFIC ENVIRONMENTAL TOXINS A. Halogenated hydrocarbons: exposure is through ingestion or inhalation.

7. Carbon tetrachloride: contracted by consumption of contaminated drinking water, inhalation (low levels) Toxic effects: irritation of the eye and respiratory system at low levels. Nausea, vomiting, stupor, convulsion, coma and death from CNS depression at high levels Kidney and liver damage.

8. Chloroform: by ingestion or inhalation Toxic effect: hepatotoxicity, nephrotoxicity, arrythmias, nausea, vomiting, dizziness, headaches and stupor.

9. AROMATIC HYDROCARBONS Benzene: half of exposure is via tobacco smoke, combustion of fossil fuels including automobile gasoline, consumption of contaminated water. Toxic effect: are hematopoietic toxicities particularly leukemia (AML), agranulocytosis. Toluene: by automobile emissions, use of toluene-like degreasers, certain paints and furniture polish. Toxic effect: CNS depression, drowsiness, ataxia, tremors, impaired speech, hearing, vision, liver, kidney damage and death.

10. ALCOHOLS Methanol & Ethylene glycol: are oxidized to toxic products. Formic acid- methanol Glyoxylic, glycolic and oxalic acid- ethylene glycol Toxic effects: coma, seizures, hyperpnea, visual loss (esp with methanol), hypotension and nephrotoxicity (ethylene glycol). Antidote: fomepizole, IV ethanol

11. PESTICIDES Organophosphates and carbamate insecticides: toxicity is via inhibition of AchE resulting in accumulation of excess acetylcholine. Antidote: atropine + pralidoxime

12. RODENTICIDES Exposure is by accidental ingestion or suicidal ingestion e.g., warfarin.

13. HEAVY METALS Lead: exposure is by old paint chips, drinking water, industrial pollution, food and contaminated dust Distributed to soft tissues, teeth, hair and bone where it is detected by X-ray examination. Half life in blood- 1-2 months, in bone- 20 to 30 years. Toxic effects: CNS: headache, confusion, clumsiness, convulsion coma & rarely death if treated with chelation therapy. GIT: constipation, intestinal spasm BLOOD: hypochromic, microcytic anemia. Still birth, decrease fertility. Antidotes: dimercaprol, succimer

14. IRON: used as prenatal supplements and also for the treatment of anemias s/s of iron poisoning: severe GI distress leading to necrotizing gastroenteritis with hematemesis and bloody diarrhea, dyspnea, shock, coma Antidotes: deferoxamine IV, phlebotomy

15. Mercury: forms; 1. Elementary mercury: exposure is usually occupational by inhalation of the vapor. S/S: depression, tremors, memory loss, inflammation of the kidneys, decreased verbal skills & pulmonary toxicity. 2. inorganic mercury: e.g., mercuric chloride, exposure is usually occupational. Toxic effect: renal damage. 3. organic mercury: exposure is by ingestion of fish contaminated with methylmercury, dyes, fireworks, photography S/S: visual loss, loosening of teeth, paresthesias, ataxia, hearing loss, tremors, mental deterioration & movement disorders. Can be misdiagnosed as Parkinson's disease in the elderly. It is the most toxic of the 3 forms. Antidotes: activated charcoal, succimer and dimercaprol

16. Arsenic: seen as wood preservatives, pesticides, ant poisons s/s: gastroenteritis, hypotension, garlic scented breath, torsades, rice water stool, stocking glove neuropathy, skin pigmentation(raindrop pattern) Antidotes: activated charcoal, dimercaprol, penicillamine or succimer

17. GASES Carbon monoxide: colorless, odorless and tasteless gas. Sources: combustion of carbon materials, automobiles, poorly vented furnaces, fireplaces, wood-burning stoves, charcoal grills and kerosene space heaters. Toxic effects: is related to hypoxia within the brain and heart. Dyspnea, lethargy, confusion, headache, drowsiness, seizures, coma & death. antidote: removal of patient from source, 100% oxygen by face mask or endotracheal tube.

18. Cyanide: toxicity is as a result of inactivation of the enzyme cytochrome oxidase. Toxic effect: death due to respiratory arrest. Antidote: nitrite, thiosulfate Asbestos: exposure is by inhalation of the fibers. Abestosis, mesothelioma and lung cancer are associated with its exposure. Symptom: pain in the vicinity of the lesion, dyspnea and cough. Silica: occupational, seen in mine workers, construction sites and stone cutting. Is currently incurable.

19. ANTIDOTES Atropine: for intoxication by OP N-acetylcysteine: for acetaminophen toxicity. Sodium nitrite and sodium thiosulfate: for cyanide toxicity. Fomepizole: for methanol or ethylene glycol toxicity. Pralidoxime: for organophosphate poisoning by reactivation of acethylcholinesterase. CHELATORS: Dimercaprol: to chelate mercury,lead and arsenic Succimer: for mild lead, mercury intoxication. EDTA: back up for lead intoxication. Penicillamine: copper, iron, lead, mercury