Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

bio 381 > Lec 19 > Flashcards

Lec 19 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Heavy metals of concern

A

Mercury (Hg)

Lead (Pb)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Problems with heavy metals

A

Associated with particulate matter, easily transported in the atmosphere

Toxic, even in low concentrations

Can bioaccumulate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mercury

A

Extremely volatile liquid

Often mined in the form of cinnabar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Common forms of Mercury

A

Elemental mercury (Hg 0) (can be mixed with other metals)

Inorganic mercury (Mostly Hg 2+)

Organomercury (Mostly MeHg+) (Highly toxic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Organomercury

A

Compounds and ions of mercury, especially organomercury compounds are more toxic than elemental mercury

It is readily absorbed through skin and is bioavailable to organisms (as opposed to elemental and inorganic mercury)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The mercury cycle

A

Elemental mercury oxidates to become inorganic and methylates and bioaccumulates to become Organomercury which spreads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Methylation of Mercury

A

Ionized mercury in seawater and sediments cannot enter bacterial cells

With little or no oxygen available, some bacteria use SO4 for respiration, expelling sulfide as a waste product

Sulfide combined ionized mercury in seawater to form mercuric sulfide, which can diffuse into bacterial cells

Inside bacterial cells, a methyl group replaces the sulfide to produce monomethyl mercury, which diffuses into seawater and is taken up by phytoplankton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Methylation of mercury equation

A

SO4–>S

S+ Hg–> HgS

HgS + ? –> CH3Hg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Toxicity of mercury

A

Mercury is neurotoxin and teratogen

Increases oxidation and oxidative damage in the body, especially the brain

Exposure to mercury in pregnancy can cause severe birth defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Most instances of mercury poisoning due to contact with

A

Organomercury, and partially methylmercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is methylmercury so toxic

A

Relatively absorbed by the digestive tract of humans

From there it can be easily transported across the blood-brain barrier, and across the placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Amino acid L-cysteine and mercury

A

Mercury binds to L-cysteine and the body mistakes this complex for another amino acid and allows it to be transported across the blood-brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Minamata Bay

A

An area where a large amount of Methylmercury poisoning occurred

Caused by Chisso Corporation methylmercury wastewater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How did the mercury accumulate so much in people of Minamata Bay

A

The people had a large fish diet and bioaccumulated mercury from them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Asubpeeschoseewagong First Nation (Grassy Narrows)

A

Paper plant dumped tons of Hg into the river decades ago, causing debilitating health problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What can we do

A

Stop using coal/fossil fuels as energy

Stop using products with mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Mercury pollution prevention

A

Phase out waste incineration

Remove mercury from coal before it is burned

Switch from coal to natural gas and renewable energy resources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mercury pollution control

A

Sharply reduce mercury emissions from coal-burning plants and incinerators

Label all products containing mercury

Collect and recycle batteries and other products containing mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What to do in the meantime

A

Watch fish consumption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Lead

A

Mined from lead sulfide

Found near zinc ore deposits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Toxicity of lead

A

Neurotoxin

Can also cause blood disorders

Inhaled or ingested

Induces oxidative stress that can damage DNA and enzyme function

22
Q

Lead accumulates in what tissues

A

Blood

Soft tissues

Bone

Teeth

23
Q

Where is most sensitive to lead

A

The brain

24
Q

Lead causes

A

Intellectual disabilities and reduced brain size

25
Q

Where is most lead coming from

Canada 1970

A

Automobiles

26
Q

Where is most lead coming from

Canada 2009

A

Base metals smelting and refining

27
Q

Atmospheric lead emissions have

A

Greatly decreased

28
Q

Reasons lead decreased

A

Catalytic converters introduced (1970)

Introduction of unleaded fuel (1972)

Gasoline Regulations (1990)

29
Q

Lead bioaccumulates but does not

A

Biomagnify

30
Q

Wildlife that experience lead poisoning

A

Scavengers

Fish

31
Q

How to reduce lead exposure and lead pollution

A

Do not use products that have lead

Remove lead pipes and paint

Advocate for environmental remediation at sites with lead contamination

32
Q

Flint, Michigan

A

Northwest of Detroit, along the Flint River

Declining population, high poverty and minority population

33
Q

April 2014

Flint, Michigan

A

City switched drinking water source from the Detroit Water and Sewerage Department, to the Flint River to save money

34
Q

August-September 2014

Flint, Michigan

A

Boil advisory issued for coliform, city adds extra chlorine to water

35
Q

October 2014

Flint, Michigan

A

Michigan Department of Environmental Quality issues a statement saying declines in water quality due to cold weather and old pipes

General Motors stops using city water at Flint plant, saying it’s corroding automotive parts

36
Q

February 2015

Flint, Michigan

A

Government officials say there is nothing to worry about

Meantime the lead concentration is 104 micrograms/L (limit is 15 micrograms/L)

37
Q

March 2015

Flint, Michigan

A

Lead levels up to 395 micrograms/L

38
Q

July 2015

Flint, Michigan

A

Residents finally told to get tested

39
Q

September 2015

Flint, Michigan

A

Scientists alert that corrosiveness of water from Flint River may leach out of city pipes and additives are used to control corrosion from chlorine

Doctors tell people to stop using water

40
Q

October 2015

Flint, Michigan

A

City tells citizens to stop using city water

Flint Reconnects to Detroit’s water

41
Q

December 2015

Flint, Michigan

A

City uses additional corrosion controls and declares state of emergency

42
Q

January 2016

Flint, Michigan

A

State of emergency declare for county

Federal state of emergency declared

43
Q

February 2017

Flint, Michigan

A

Case of Legionnaire’s disease linked to poor water quality in Flint

44
Q

Today

Flint, Michigan

A

Lead levels below federal guidelines, water lines slowly being replaced

45
Q

Before

Treated Detroit water

A

Phosphate corrosion inhibitor helps maintain a mineral passivation layer on the inside of Flint’s pipes, protecting them from corrosion

Chlorine disinfectant levels remain stable

46
Q

After

Treated Flint River Water

A

Lack of corrosion inhibitor

High Chloride levels

As the pipes corrode, chlorine disinfectant breaks down

Oxidants such as O2 corrode pipes and leach soluble metal

47
Q

Orthophosphate decreases

A

Corrosion

48
Q

Chlorine increases

A

Corrosion

49
Q

More lead means

A

More iron (rusty water)

BAD

50
Q

Who’s to blame for Flint Michigan

A

A lot of officials have resigned and/or faced criminal charges

EPA criticized for not taking more immediate action

51
Q

Lead poisoning prevention

A

Replace lead pipes and plumbing

Phase out leaded gasoline

Phase out waste incineration

Ban use of lead solder

Ban use of lead in computers and TVs

Band lead glazing for ceramic-ware

Wash fresh fruit and veggies

52
Q

Lead poisoning control

A

Remove leaded paint and dust from older houses and apartments

Sharply reduce lead emissions from incinerators

Remove lead from TV sets and computer monitors before incineration or land disposal

Blood test for lead by age 1

Test for lead in ceramic-ware

bio 381 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions