3 Cd

Question 1

what is Cd?

Answer 1

cadmium
-atomic number 48
-non-essential metal
-silvery-white metal with lower melting point than many transition metals
-exists primarily as Cd2+

Question 2

what are the sources of cadmium?

Answer 2

-nickel-cadmium batterie
-electroplating
-galvanizing alloys (noncorrosive properties)
-red, orange and yellow pigment to colour glass
-cigarettes
-released as a by-product of zinc and lead smelting

Question 3

what is the dietary exposure of cadmium?

Answer 3

-major route of exposure

cadmium accumulates into plant tissues
-cadmium in soil=fallout from industrial emissions, contaminated fertilizers or soil
-cadmium in water=contaminated water taken up by the plant

-cadmium can also accumulate in foods such as shellfish, animal livers and kidneys

Question 4

what is inhalation exposure?

Answer 4

-industrial emissions

cigarette smoking
-non-occupational source
-doubles the lifetime body burden of cadmium

occupational exposures->airborne cadmium release
-refining zinc and lead ores
-iron production
-cement manufacture
-fossil fuel combustion
-paint pigment manufacturing
-cadmium-nickel battery manufacturing
-electroplating

Question 5

what is the absorption of cadmium?

Answer 5

inhalation absorption
-10-60% of the dose

gastrointestinal absorption
-5-10% of the dose

factors affecting absorption
-dietary protein
-Ca, Fe, Cu, Zn, Se
-vitamins C and D
-age
-sex

Question 6

what is the distribution of Cd?

Answer 6

-transported in the blood by binding to albumin and other high molecule-weight proteins
-Cd is transported into the cells through cadmium channels and through molecular mimicry

-liver
-kidneys
-pancreas
-spleen
-testies
-little to no accumulation in fetus

Question 7

what is the excretion of Cd?

Answer 7

-urine (significant route)
-feces (major route)
-milk
-hair
-sweat
-bile

-half life up to 30 years

Question 8

what are the biochemical effects of Cd?

Answer 8

-cell membranes
-nucleic acid synthesis
-ribosome and protein synthesis inhibition
-microsomal enzyme activity
-mitochondria
-carbohydrate metabolism
-other enzymes with thiol/sulfhydryl (-SH) groups

Question 9

what are the biological effects of cadmium?

Answer 9

-kidney*
-bone
-lung
-liver
-cardiovascular
-ovary and testis
-CNS
-anemia

Question 10

what are the effects on the kidneys?

Answer 10

cellular necrosis in the glomeruli and the tubular cells
-impairs renal function

erythropoietin
-impairs RBC synthesis

-kidney damage may be induced by cadmium-metallothionine complex

Question 11

what are the biomarkers of nephrotoxicity reflected by?

Answer 11

-beta2-microglobulin
-proteinuria
-hypercalcemia

Question 12

what are the effects on bones?

Answer 12

-changes in calcium metabolism
-increased calcium excretion
-decrease of calcium absorption

results in:
a) osteomalacia
b) osteoporosis
c) bone deformities

Question 13

what are the effects on the lungs?

Answer 13

acute
-pulmonary edema-> proliferation-> fibrosis-> scar tissue-> trouble breathing

chronic
-emphysema
-cardiac hypertrophy
-bronchitis

Question 14

what are the effects on the liver?

Answer 14

-accumulates
-steatosis
-steatohepatitis
-hepatocellular carcinoma
-reversible damage

Question 15

what are the effects on reproduction?

Answer 15

ovary and testis
-necrosis
-vascular damage
-prostate cancer
-leydig cell tumors

terotogenesis
-embryotoxic
-little placental transfer

Question 16

what are the other effects of Cd?

Answer 16

-CNS=subtle
-anemia=ferrochetalase
-immunosuppression=macrophages, T-lymphocytes
-mutagenesis=DNA repair impaired
-cardiovascular=hypertension

Question 17

what are the symptoms of acute toxicity?

Answer 17

-high dose toxicity in humans is rare

ingestion of highly contaminated food or water:
-irritation of gastrointestinal epithelium
-nausea
-vomiting
-abdominal pain

inhalation of cadmium fumes:
-pneumonitis
-pulmonary edema

Question 18

who is at risk for cadmium poisoning?

Answer 18

-young
-women
-smokers

Question 19

what is metallothionein?

Answer 19

-transport
-exertion
-protect from toxic levels

Question 20

what is the treatment of cadmium?

Answer 20

-chelation therapy can be used for acute toxicity-> causes many side effects
-can reverse Cd toxicity with Zn supplementation
-no effective treatment of long-term exposures

Question 21

what is the case study of cadmium?

Answer 21

-itai-itai disease (ouch-ouch disease)
-1962
-juntsu river area of japan
-cadmium contamination of rice

women most affected
-kidney dysfunction
-low calcium
-osteomalacia