6 history of metals

Question 1

what are the biological properties of metals?

Answer 1

-essential metals: trace amounts for life (Cu, Fe, Zn)
-non-essential metals: no known biological functions (Cd, Pb, Hg)

Question 2

why is metal pollution a problem?

Answer 2

-metals can neither be created nor destroyed (problematic environmental contaminants)
-metals are naturally occurring

Question 3

how are metals naturally occurring a bad thing?

Answer 3

anthropogenic activities increase metal exposure to organisms either because:
-metals are moved from biologically inaccessible to accessible compartments in the biosphere
-form of the metal is changed to more bioavailable or toxic form (ex: free ions)

Question 4

what is the graph of anthropogenic sources of environmental metal pollution?

Answer 4

Question 5

what are the routes of metal exposure to humans?

Answer 5

-ingestion: mouth
-inhalation: nose and lungs
-absorption: skin
-absorption: pregnancy (mother to fetus)

Question 6

what is lead (Pb)?

Answer 6

-a soft, heavy, bluish-gray metal found in the earth’s crust
-one of the seven ancient metals known to humans (Ag, Au, Cu, Fe, Hg, Pb, Sn)
-ductile and pliable, making it easy to use
-no biological functions but mimics calcium and iron

Question 7

how we might be exposed to Pb?

Answer 7

-paint (before 1978)
-in soil around homes
-gasoline (phase out in 1973)
-household dust
-drinking water
-workplaces
-old painted toys and furniture
-food and liquids stored in lead crystal or lead-glazed pottery or porcelain
-industries that release lead into the air
-hobbies that use lead
-folk remedies that contain lead

Question 8

what is a major source of human exposure to lead?

Answer 8

lead paints are still being used in many countries

Question 9

what are the harmful effects of Pb in humans?

Answer 9

-neurological effects/ brain damage
-anemia: Pb disrupts hemoglobin production
-reproductive failure: reduction in fertility
-kidney damage: can lead to “saturnine Gout”

Question 10

when did humans start using Pb?

Answer 10

-used by mankind since 4th millenium BC
-usage increase markedly during roman era
-romans recognized the toxicity of Pb and its fumes (might have led to the decline of roman empire)

Question 11

what is galena?

Answer 11

most important ore of lead
-a source of silver
-used since ancient times

Question 12

what happened during the bronze age?

Answer 12

3000 to 1200 BC
-the dawn of civilization: the alphabet, writing, weapons, cities, government, public works and civil and religious administrations

Question 13

what happened during the iron age?

Answer 13

1200 to 600 BC
-the emergence of iron tools and weapons, different agricultural practices

Question 14

what happened during the roman period?

Answer 14

70 to 324 AD
-romans constructed roads, amphitheater and public water supply

Question 15

what does greenland have evidence of?

Answer 15

hemispheric lead pollution two millennia ago by greek and roman civilizations

Question 16

what are some roman lead artifacts?

Answer 16

-water pipes
-ring-seals, jewelry, ingots, etc
-containers used in winery (also Pb acetate (sugar of lead) used as wine-sweetener

Question 17

what are the graphs of historical evidence of Pb poisoning in imperial rome?

Answer 17

Pb concentration in human skeleton from rome

Question 18

what is the medieval history of mass poisoning in humans?

Answer 18

-Pb poisoning became a plague in Europe and later in america during 15th-18th centuries
-in 16th century, paracelsus described it in medical literature as “the miner’s disease”
-in 18th century, Ramazzini wrote that the potters who worked with lead became “paralytic, lethargic with face having the color of lead”

Question 19

what is mercury (Hg)?

Answer 19

-thought to be one of the first metals used by humans
-mercury: roman name of greek god, Hermes
-have properties that people found novel and useful (ex: only metal liquid at room temp, easily vaporizes, form “amalgams”)
-commonly used by ancient egyptian and chinese civilization
-mercury found in an egyptian tomb dating from 1500 BC, and in the writing of a chinese alchemist around 4500 BC

Question 20

what is chronic toxicity of mercury?

Answer 20

-central nervous system disorders (ex: memory loss, cognitive disorders)
-permanent brain damage
-loss of vision
-kidney damage
-damage of reproductive health in adults, and development and growth of fetuses and infants

Question 21

what are the chemical speciation of mercury?

Answer 21

Question 22

what are the mass Hg poisoning in humans?

Answer 22

-during the 1500s in Spain, slaves sentenced to work in the mercury mines received the equivalent of a death sentence. very few survived more than three years in the poisonous atmosphere of the mines
-in the 18th century, mercury used to preserve “felt hat”. Made famous by “alice in wonderland”. Workers in the felt factories, go “mad” as a result of breathing the toxic mercury fumes
-in the 1500s, elemental mercury was used as an ointment in the treatment (albeit ineffectively) of syphilis (a european disease brought to america by the columbus’s army)

Question 23

what is occupational Hg exposure?

Answer 23

many other notable scientists have also suffered from mercury poisoning
-for example: as a part of his research studies, Newton boiled several pounds of mercury a day just before his period of insanity between 1692 and 1693
-it is likely that the mercury vapor was the cause of his malady
-however, in each case, the symptoms (and insanity) abated once the source of mercury was removed

Question 24

what is the summary?

Answer 24

-lead and mercury are two of the few metals that has been used by humans since ancient time
-mass poisoning of lead and mercury has occurred many times throughout human history
-did mass Pb poisoning lead to the decline of roman empire? a debatable issue, but strong evidence of lead poisoning in imperial rome exist