Environmental Toxins

Question 1

• irreversible
• parathion, malathion
• sarin, soman (nerve agents)

Answer 1

organophosphates, irreversible cholinesterase inhibitors

Question 2

• carbaryl, aldicarb, carbofuran, aminocarb

- 2PAM contraindicated

Answer 2

carbamates, cholinesterase inhibitors

Question 3

• salivation, lacrimation, urination, defecation
• diarrhea, pinpoint pupils, resp difficulty, pulm edema, cyanosis
• usually die from drowning in secretions

Answer 3

cholinesterase inhibitor insecticide poisoning

Question 4

• give small dose of atropine to block cholinergic effect
• 2PAM prior to aging
• support vitals

Answer 4

tx for cholinesterase inhibiting enzymes

Question 5

• free radicals –> lipid peroxidation in lungs

- tx is supportive

Answer 5

paraquat (herbicide)

Question 6

• carabon tetrachloride, chloroform, methylene chloride
• Cyp2E1 to CCl3 –> free radical in liver, lipid peroxidation –> calcium release –> hepatotoxic
• tx supportive

Answer 6

halogenated hydrocarbons

Question 7

• kerosone, diesel fueal, white spirit, polishes
• pulmonary irritation with inhalation, CNS depression, can see severe pneumonitis after aspiration of liquid
• tx: emesis, lavage w/o tracheal intubation contraindicated

Answer 7

aliphatic hydrocarbons

Question 8

• CNS stimulation early at low doses, then depression
• liver and kidney damage at high doses
• arrythmias enhanced, aplastic anemia and leukemia with long term exposure

Answer 8

aromatic hydrocarbons (benzene, toluene, xylene)

Question 9

• local irritation and corrosion of GI tract
• muscle weakness, convulsions and collapse due to calcium chelation
• renal tubular damage due to calcium oxalate precipitation
• tx: antidote is calcium gluconate IV, oral calcium, force fluids to prevent deposition in tubules

Answer 9

corrosives (oxalic acids, oxalates, bleaches, metal cleaners, rust removers)

Question 10

• GI irritation and necrosis, massive hemorrhage and hypovolemic shock
• dilute acid with water, milk of magnesia

Answer 10

corrosives (mineral acids, Hcl, sulfuric)

Question 11

• irritation, inflammation, tissue damage
• more penetrating than strong acids, death due to hypovolemic shock
• dilute with water

Answer 11

corrosive (strong alkali, hydroxides)

-soaps, cleansers, drain cleaner

Question 12

• oxidize hemoglobin (fe2+) to methemoglobin Fe3+ incapable of carrying oxygen
• chocolate colored blood, hypotension, hypoxia, cyanosis, convulsions
• only treat when 35% of Hb oxidized, use methylene blue to reduce back to hemoglobin

Answer 12

nitrites, aminophenols

Question 13

• odorless and colorless gas
• much greater affinity than oxygen for hemoglobin, can’t transport oxygen
• left shift: impairs ability of oxyhemoglobin to give up its oxygen to peripheral tissues
• cherry red blood, HA, dizzy, stupor d/t brain anoxia
• admin oxygen, hyperbaric if severe

Answer 13

carbon monoxide poisioning

Question 14

• colorless gas, smells like almonds
• inhibits cytochrome oxidase in mitochondria
• dizzy, headache, hypotension, unconsciousness, convulsions, respiratory failure
• rapid tx with hydroxycobalamin, give sodium thiosulfate
• old treatment: induce methemoglobinemia by admin of sodium nitrite in combo with sodium thiosulfate

Answer 14

cyanide poisoning

Question 15

• primary: dyspnea and discomfort
• weakness, respiratory impairment
• total disability, expirations prolonged and difficult, predisposition to TB, die of right heart failure
• carcinogen
• tx supportive

Answer 15

free crystalline silica (sand at construction site)

Question 16

• linear fibrosis in lungs, pleural adhesions and calcifications
• tumor after moderate exposure
• dyspnea, resp impairment, bronchogenic carcinoma and pleural mesothelioma

Answer 16

asbestos

Question 17

• bind to sulfhydryl groups on enzymes, interfere with cell metabolism
• AsH3 most toxic
• As5+ blocks ATP
• As3+ binds sulfhydryl groups in lipoic acid interfers with energy production
• acute: hemolysis and hemoglobinuria
• chronic: dermatitis, mees lines on nails, cirrhosis, polyneuritis, cancer
• dimercapor is chelator for acute
• succimer for chronic

Answer 17

arsenic and arsine

Question 18

• accumulates in body, stored in bones and nervous system
• acute inorganic toxicity –> GI irritation, kidney damage
• acute organic poisoning –> CNS
• chronic inorganic –> plumbism, lead lines on gum, basophilic erythrocyte stippling, accumulation of d-ALA –> microcytic anemia
• CNS effects more prominent in children, decreased IQ, hyperirritability, behavior distrubance
• neuromuscular effects, wrist/ankle drop due to degneration of peripheral nerves
• tx: at 5mcg/dL, metal chelators (cana2edta IV, dimercaprol, penicillamine, succimer)

Answer 18

lead poisoning

Question 19

• all inorganic is toxic, acute: GI symptoms
• metallic: volatile, acute chemical pneumonitis, noncardiogenic pulm edema
• inorganic: acute tubular necrosis, shock, diarrhea
• delayed: severe kidney damage, GI hemorrhage

Answer 19

mercury poisoning

Question 20

• early: salivation, stomatitis
• late: erethism, uncontrollable blushing, emotional instability, tremor
• hallucinations, tremor

Answer 20

chronic mercury exposure

Question 21

organic: parasthesia, muscle twitching, ataxia

Answer 21

mercury

Question 22

in tobacco –> kdiney, lung, CV, immune

-carcinogen, no chelator

Answer 22

cadmium

Question 23

Parkinsons like syndrome, no chelator

Answer 23

manganese

Question 24

treatment for lead and zinc poisoning?

Answer 24

Ca Na2EDTA

Question 25

used to chelate arsenic, lead, gold, inorganic mercury. can see CNS disturbance

Answer 25

dimercaprol

Question 26

chelates copper (good for Wilson’s), RA, given orally, don’t give in renal insufficiency

Answer 26

penicillamine

Question 27

given orally for lead poisoning in kids with >45 mcg/dL

Answer 27

succimer

Question 28

used for iron, can induce shock with rapid infusion, long term therapy leads to ocular damage

Answer 28

deferoxamine