Toxicology 3 Flashcards Preview

4 Pharm Self > Toxicology 3 > Flashcards

Flashcards in Toxicology 3 Deck (79):
1

T-f-- most areas of USA have arsenic levels below .01mg/L. What is considered high?

T
>1mg is high

2

What does to much arsenic come from?

coal combustion and non-ferrous smelting

3

What form of Arsenic is the major toxic form?>

AsIII
[sodium arsenate is example NaAsO2]

4

What is the main use of arsenic?

pesticides

[other includes medicine, computer chips, glassware and paints]

5

What is the main ingredient in ant poison?

arsenic trioxide- tasteless…use for homicides

6

What keeps the high levels of arsenic in fish at check?

bound to betaine and is harmless and urinated out

7

T-F- arsenic is the 3rd most common cause of heavy metal induced death in the USA?

False- 2nd

8

What is the major routes of arsenic uptake?

GI and lung

9

What is arsenic half life=

3 days

10

What are the normal arsenic blood levels?

.03-.05 micrograms per dL

Total body burden is 1-10 mg mostly in skin hair and nails

11

Where is short term accumulation of arsenic?

liver, kidney, heart, and lung

12

Where is the long term storage of arsenic?

hair, nails and skin (affinity to keratin, SULFHYDRYL GROUPS!)

There is deposition in bones and teeth

13

What is the major route of arsenic excretion?

(sweat, hair, nails, teeth) > feces >urine

14

What is the mech of arsenic toxicity?

accumulates in mitoch. and inhibit mitoch enzymes w/ -SH groups

15

What are target organs of arsenic toxicity?

GI, Kidney, skin,
CV, nervous

16

What is dimercaprol and penicillamine used for?

chelation therapy in arsenic toxicity

17

T-F-- arsenic toxicity leads to vasoconstriction?

False- dilation

18

What are mouth symptoms of arsenic?

burning lips, garlic breath, constriction of throat.

19

Review what chronic arsenic exposure does?

muscle weakness
perspiration, skin pigmentation, dermatitis
numbness, burning feet soles,
vasodilation, heart arrhythmias
ischemic gangrene
Cancer
reproductive tox

20

T-F 13 million live with > 10 micrograms As/L

True

21

Is cadmium bioaccumated?

yes, we take up more than we can excrete

22

Where is cadmium released from?

coal burning, Zn missing smelting
[used in electroplating, galvanizing, NV-Cd batteries
4. color pigment

23

What is the normal daily uptake of cadmium?

10-40 microgram / day

24

where is most of the body burden for cadmium?

kidneys>liver

25

what haooens in acute oral cadmium exposure?

nausea, vomiting, death

26

What happens in acute respiratory exposure to cadmium?

pneumonitis, pulmonary eema, death

27

What is the treatment for cadmium toxicity?

none- support lung function

28

What happens in chronic chronic lung cadmium exposure? cardiovascular? bone?

1. COPD, BRONCHITIS, EMPHYSEMA
2. HYPERTENSION
3. PAIN, OSTEOMALACIA (Itai-itai disease japan- Ca metabolism disrupted due to damage)

29

What type of cancer doe cadmium exposure cause?

prostate (and lung, testes, kidney, stomach)

30

What happens to the kidneys with chronic cadmium exposure?

renal tubular disease, proteinuria, Fanconi's syndrome.

31

What is the T1/2 of cadmium in humans?

10-30 years---> accumulate it with age

32

Do we have a biological need for lead?

no

33

Where does most lead toxicities come from today? 2

1. paint, lead dust in households
2. recreation: shooting (and jewelry, stained glass, pottery, paint)

34

how many US children are at risk for lead poisoning?

100000, blood lleve > 10 micrograms/dL

35

Is lead problems worse in children?

yes their absorption is 41% and retention is 32% whereas adults are just a little over 5%

36

Where is lead sequestered in body?

RBCs

37

Doe lead replace Ca in hydroxyapatite in the bone more in children or adults? soft tissue?

1. adults is 90% and children is 70%
2. 5%adults, 30%childrne

38

How is lead secreted?

urine, milk , fetus

39

can lead pass BBB?

yes

40

is lead readily stored, absorbed and mobilized?

yes

41

Does led have a cumulation burden?

Yes

42

IS there a large margin between population levels and toxicity for lead?

No- narrow margin

43

What is t1/2 of lead in soft tissue? bone?

1. 28-36 days
2. 15-30 years (also a component of hair and nails as it combines with sulfhydryl groups

44

Acute lead poisoning in children causes what?

growth retardation, behavioral and lowered IQ problems

45

Whaat are the 4 keys parts of lead pathophysiology?

1. binds sulfhydryl groups
2. disrupts mitoch function
3. disrupts Ca dependent intracellular messengers
4. Inclusion bodies with a lot of lead

46

why do children have higher blood levels of lead than adults?

less goes to bone for storage

47

where does mercury naturally occur?

earth crust

48

when is mercury released?

coal burning, chlorine processing, waste incineration, and metals

49

What are the estimates for increased in atmospheric Hg due to humans?

2-3x or 1.5% per year

50

Does mercury display biomagnification of aquatic ecosystems?

yes

51

What form of mercury can bioaccumulate in fish?

methylmercury

52

what are CNS side effects of mercury?

constriction of vision, hearing loss, sensory disorder, ataxia, central disequilibrium

53

Does mercury damage the kidney? heart? what does it do in prenatal exposure?

1. yes
2. yes
3. retardation, blindness, cerebral palsy like syndrome

54

What is the body burden of mercury that leads to damage?

15-35 g
we intake 3-7 mg /day

55

What is the T1/2 of methyl mercury? what does this lead to?

70 days and it leads to bioaccumulation.

56

How many women have more mercury in blood stream than EPA considers safe?

8%

57

Review the following recommendations on seafood for women and children

1. do not eat shark, swordfish, king mackerel, or tilefish
2. eat up to 12 ounces a week of seafood low in mercury- shrimp, canned light tuna, salmon, pollock, catfish, WHITE TUNA HAS MORE MERCURY THAN CANNED
3. check local advisories about the safety of fish caught

58

Where do we get mercury in dentistry?

vapors from scrap amalgam are extremely dangerous [can not be discarded as regular trash] Its safety in dental fillings use is very controversial

59

What are 4 key characteristics of POPs?

persistent, highly toxic, evaporate and travel long distances hot to cold climates, accumulate in fatty tissue

60

What is trying to eliminate POPs from our environment?

Stockholm convention

61

What is dieldrin?

halogenated/cyclodiene- used against termites, textile pests, insects in agriculture

62

What is chlordane?

halogenated/cyclodiene- used against termites, broad spectrum

63

What is toxaphene?

halogenated/cyclodiene- applied to cotton, grains etc. and used against ticks and mites

64

What are the CNS effects of cyclodiene?

antagonize GABA r, uncontrolled state of excitation, dizziness, headache, convulsions, jerking

65

What are the GI effects of cylodienes?

nause, vomit, induction of liver enzymes C P450s etc

66

Can cyclodienes be absorbed through intact skin? carcinogenic?

yes
yes

67

What are polychlorinated biphenyls?

halogenated industrial compound- used for electrical equipment, prevents overheating, used in papers, sealants, plastics

68

Review the uses of PCBs?

capacitors, transformers, plasticizer, surface coatings, sealants CAULK, adhesive cutting oils, pesticide extenders, carbonless paper

69

Where are we exposed to PCBs?

1.food (bioaccumulation/biomagnification)
2. Air (outdoors, old buildings)

70

When was production of PCBs banned in US?

1970

71

When are new PCBs continuously produced?

bi products in paint (when green paint isn't green

72

What is a major PCB effect on the skin?

chloracne

73

What are the major PCB effects on the endocrine system?

disruption--> anti-estrogen/androgen, disrupts thyroid hormone homeostasis, OBESITY, METABOLIC SYNDROME, T2 diabetes

74

What is a chemical that causes a hormonal imbalance by out competing the body's natural hormones?

endocrine disruptor

[causes reproductive and preg. problems, lactation prob, neurodevelopment problems, intellectualproblems in children, etc.]

75

What are PBDEs?

polybrominated diphenylethers-- bromine flame retardants

penta, octa, deca

76

Where are PBDEs used?

electronic equipment, polyurethane foams, hard plastics

77

What country has the highest PBDE in human breast milk?

US then Canada
from flame retardant use in carpets

78

What are PDBEs toxic effects in humans?

unknown
possibly carcinogenic
[long term exposure has a greater effect than short term toxicity as the build up in your body]

79

How much of the body burden of a nursing mother is thought to be given to their child?

1/2!!!!