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Flashcards in Toxicology Deck (17)
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1
Q

carbon monoxide

A

Air Pollutant
Asphyxiant (along with cyanide)

Part of EPA six criteria for Air Quality
- CO, SO2, NO2, Ozone, PM, Lead

Source:
- Vehicles»»fire

Acute Respiratory Health Effects

2
Q

Sulfur Dioxide (SO2)

A

Source: Fossil Fuel, mostly coal

Environmental Problems: Acid rain, pH change in soil, metal leaching

Health effects:

  • Water soluble so damages upper airways
  • STRONG association with ASTHMA
Concentration and Effect:
3 ppm: easily detected odor
10 ppm: URI
20 ppm: Irritating toeyes
50-100ppm: max. tolerable 

Symptoms:
- Acute:
- Irritation, cough, burning, lacrimation, difficulty
swallowing
- Vomiting, diarrhea, abdominal pain, fever, headache,
vertigo, agitation, tremor, convulsion, pulmonary edema
- Toxicity most severe in patients with lung problems:
asthma, emphysema, bronchitis

  • Long term:
    • Aggravation of chronic cardiopulmonary disease
      (asthma, chronic obstruction, coronary artery disease)
    • Children: reduced lung function, increased upper
      respiratory infections

Pathophysiology:

  • SO2 + moisture in airways= SULFUROUS ACID
  • Irritation
3
Q

Nitrogen Oxides

A

Source:

  • Power Plants
  • Cars

Major source of Ozone
Not very water soluble
- penetrates deep into lungs

Potent respiratory tract toxin
- Clinical Features
- Bronchitis, pneumonia, hemorrhagic pulmonary
edema, alveolar damage

  • Pathophysiology
    • May cause lipid peroxidation, decreased ciliary
      movement, bronchoconstriction, enzyme inhibition

Toxicity:
- Decomposes in alveoli to nitrous acid (NHO2),
nitric acid (HNO3), and NO (vasodilator) on contact
with moisture

4
Q

Ozone

A

O3

Bluish gas, no or slightly pungent odor

5
Q

Ethanol

A

EtOH
Produced by yeast

Many Therapeutic Uses

1 unit = 10ml EtOH = 8g EtOh

Absorption:

  • Rapid
  • Food decreases rate in SI

Transport:
- To liver

Distribution:

  • Vd correlates with total body water (40 L)
  • Conc. depends on water conc.
  • Found in lipids also (brain)

BAC

  • Grams of EtOH/100ml blood
  • 1 drink results in .03%
  • Elimination is 1/2 drink per hour

Metabolism:

  • Mostly by ADH in LIVER, stomach
  • Aspirin inhibits ADH availability in stomach, and women have less ADH in stomach

ADH follows zero order (saturation kinetics)
- Average rate is 6-8 g EtOH/hr (3/4-1 drink)

Pharmacology

  • CNS: Depressant
  • Facilitates GABA
  • Inhibits NMDA glutamate receptors
  • Respiratory: Little effecct until high lvls (depress brainstem drive)

CV: Vasodilation (hypothermia), Increase HDL and decrease LDL (french paradox)

Renal:
- Increase urine flow: diuresis by two mechanisms, volume effect and inhibition of ADH

Sexual Function:

  • Frontal lobe dis-inhibitor
  • Depressant
  • Gonadal toxin

GI:

  • Low dose stim appetite
  • High dose depress appetite (due to high calories)

Liver:

  • Stimulate cytochrome p450
  • Produce ROS
  • Toxicity
    • Fatty liver, toxic hepatitis, cirrhosis

Acute Alcohol Poisoning
- Relaxed– Euphoric– Excited– confused–stupor–COMA–DEATH

Acute may cause HYPOGLYCEMIA due to inhibiting GLUCONEOGENESIS

Chronic Alcohol Abuse:
- Loss of appetite
- Vitamin and nutrient deficiencies
Ketotic (Wernicke- Korsakoff syndrome)
- Stomach ailments, ulcers and diarrhea
- Cardiomyopathy
- Coagulation defects
- Sexual impotence
6
Q

Isopropanol

A

Alcohol of Therapeutic use

Characteristics

  • Burning, bitter taste
  • 2nd most ingested alcohol

Source:

  • Rubbing alcohol (70%)
  • Windshield wiper fluid (50-85%)
  • Antifreeze (40-55%)
  • Window Cleaner (0-25%)

Kinetics

  • Rapid, complete uptake from GI tract
  • Metabolism to acetone
  • Slow elimination in kidneys (20-50%)
  • Lungs acetone breath

Toxicity
Twice as potent CNS depressant as EtOH

7
Q

Methanol

A

CH3OH

Characteristics

8
Q

Ethylene Glycol

A

Characteristics

9
Q

Arsenic

A

Metal
AsIII most toxic

Bioaccumulate: NO

  • Half Life: 3 days
  • Major route of exposure: lung, GI

Major target organ

  • Short Term:
    • Liver
    • Kidney
    • Heart
    • Lung
  • Long term:
    • Hair, nails, skin (KERATIN), binds to sulfhydryl groups in hair and nails

Major source

  • Pesticide, Medicine (chemo), Glassware paint
  • FOOD/Water
  • Occupational inhalation

2nd most common Heavy-Metal induced Death in USA (CHILDREN)

Pathophysiol

  • Inh. mito enzymes (lower ATP, higher ROS
  • Inh. SH enzymes

Symptoms:

  • 70-180 mg: LETHAL
  • Nausea, GI discomfort, Gastric bleeding, vomiting
  • Hepatosplenomegaly
  • Cardiac arrhythmia, vasodilation
  • Constriction of throat, difficulty swallowing
  • Shock, hypoxic convulsion, coma, death

Treatment:

  • Fluid replacement, BP support (dopamine)
  • Chelation

Current EPA Acceptable LVL:
- 10 mcg/L= 1/5000 cancer

10
Q

Cadmium

A

Metal

Bioaccumulate: YES!!!
- Half life 10-30 years

Major target organ

  • Lung: COPD, bronchitis, emphysema
  • CV: Systolic HTN
  • BONE: Itai-Itai (osteomalancia, Ca metabolism disrupted by vit D metabolism decrease in kidneys
  • Cancer

KIDNEY!!!!!, renal tubular disease, proteinuria, Fanconi’s syndrome in 50% of patients with 300 mcg/g kidney

Major source

  • FOOD: plants uptake from soil, shellfish, meats (liver, kidney)
  • SMOKING 1mgCD/year
  • Normal daily intake: 10-40 mcg/day
Pathophysiol
- GI absorption: 5-8 %
- RESPIRATORY: 15-30%
- Transport:
  - Blood
  - Liver
  - Kidneys
BODY BURDEN MOSTLY IN KIDNEYS
11
Q

Lead

A

Metal

Bioaccumulate: YES

  • Oral uptake: 5-15 adult (41% child)
  • RETENTION: (5% adults)(32% children)
  • Inhalation is very efficient at absorption/retention

Major target organ

  • CNS
  • Bone
  • GI
  • LOWERS IQ
  • Blood

Major source

  • FOOD
  • ENVIRONMENT: paint/lead dust
  • Recreational shooting (blood Pb level >30%)
  • 3 million tons of lead applied to older occupied housing
  • Crawling children are exposed to lead from dust and peeling paint
  • 1 million children at risk of lead poisoning (blood level >10 mcg/dl)

Pathophysiol

  • > 90 percent of lead sequestered in blood
  • Storage
    • 95% adults skeleton
    • 70% children skeleton
  • Soft Tissue
    • 5% adult skeleton
    • 30% children

Excretion in breast milk puts baby at risk

Crosses placenta so places the Fetus at risk also

Binds sulfhydryl groups

Disrupts mito function and interferes with oxphos

Neurotoxicity: Disrupts Ca dependent intracellular messengers and brain protein kinase C

Stimulates formation of inclusion bodies containing lead-protein

Higher intake in children, higher blood levels, higher risk for CNS toxicity

12
Q

Mercury

A

Metal

Bioaccumulate: YES
- T1/2: 70 days

Major target organ

  • CNS
  • Kidney
  • CV health damage
  • Prenatal: retardation, blindness, cerebral palsy-like syndromes (fetal Minamata disease)

Major source

  • Natural but exposed due to coal burning, (2-3x increase of atmospheric Hg)
  • Biomagnification: Incremental increase in conc. of a contaminant at each level of the food chain
  • Do not eat, shark, swordfish, king mackerel, or tilefish

Pathophysiol

  • Organic (alklmercury) most toxic over inorganic
  • Body burden: 15-35 g (50g)
  • Daily intake 3-7 mg/kg

Dentistry: Amalgam contains mercury and is controversial for use

13
Q

Dimercaprol

A

Chelator

14
Q

Penicillamine

A

Chelator

15
Q

Cyclodienes

A

POPs:
Dieldrin
Chlordane
Toxaphene

POPs are

16
Q

Polychlorinated Biphenyls

A

POPS

PCBs

Use

17
Q

Polybrominated diphenyl ethers

A

POPs

PBDEs

In rodents