Toxicology: Metals

Yes.

Recap from 5: What must a toxin do in the cell to have bad effects?

Interact with something in the cell; disrupt mitochondria. Duh.

What are the major toxic metals?

Arsenic, Cadmium, Mercury, Nickel, and Lead.

What are the major essential metals?

Iron, Copper, Zinc, Selenium, Magnesium…

Which metals are used in medicine?

Aluminum, Lithium, Gold, Platinum…

What does heavy metals mean, historically?

Based off of atomic weights… Though this is a pretty useless distinction.

How do metals differ from other toxicants?

They are natural and break down very slowly.

As well as many being essential in the cell, such as Zinc.

What kind of dose response curve would a necessary metal like Zinc have?

A ‘‘U‘ shape.

What are some toxic effects of metals in the body?

Inhibit enzymes, trade electrons (bad,) or replace metals that we actually need by binding to their targets.

What types of proteins interact with metals?

2) Metallothioneins are very good at binding to 2+ metals, keeping them from interacting with other things destructively, making them a good biomarker.

4) Ferritin is often increased during a bacterial infection

What type of mercury are we most worried about?

Methylmercury — a potent neurotoxin.

Why was mercury used in mining?

It’s good at binding to other metals, drawing them out of their rock. You can then burn away the liquid mercury and be left with only your desired metal.

Electrofishing?

Like in Breath of the Wild!

(Is the safest way to collect fish without damaging them. I do assume that they die though.)

Why is vapour liquid dangerous?

Will readily cross the blood brain barrier where it will bind to molecules. (Though the salt is less toxic.)

Why do why convert the liquid/vapour mercury into salts?

It is less soluble, and does not cross the blood brain barrier.

Where does salt mercury accumulate in the body?

The kidneys.

Why is organic mercury so dangerous?

It is readily absorbed by the digestive system, and likes to head straight to the brain to fuck with your neurons.

What, specifically does methylmercury target?

The astrocytes, which surround and support neurons.

Where does organic mercury come from?

Volcanoes and coal vapours release Hg0, which is converted to Hg2+ in the atmosphere.

Where does Hg2+ go after being released in the air?

It rains down and end up in our water system, which is why fish is the main source.

They’re walleye, not pickerel.

If you learn one thing in this class, learn that.

What is another name for mercury exposure?

Minamata disease

What animals are contain the most mercury?

Top predators, particularly in fish.

Best invasive species in Mb?

Black crappie.

What else could contribute to MeHg conversion in aquatic systems?

Deadass why would algae blooms do anything at all.

What else could contribute to MeHg conversion in aquatic systems (in Mb)?

Hydrodams.

Question: Does flooding made mercury worse or better?

What useful element in the body is Lead like?

Calcium — making children extra susceptible because they try to Calcium-max but end up Lead-maxxing.

What is the main toxicity of Lead?

The fact that it is so similar to Ca2+.

High amounts of Calcium in cells triggers programmed cell death. Hm!

Calcium is also used in action potentials — This does not happen correctly if your body uses Lead instead.

How does Pb effect oxygen delivery?

genuinely don’t know bruh.

What was the historical way to get your triple-daily Lead dose?

Gasoline!

Was used as an ‘anti-knocking‘ measure (keeps the car quiet.)

What did we replace Pb with?

Manganese, which is basically just the exact same.

How else should you get your lead?

Old paint, … Old pipes,… THAT’S MY PIPE!!!! FAHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Lead has a _____ half-life in the blood, so if you constantly have lead in your blood than:

you are being chronically exposed.

What happens when we banned lead in gas?

The amount of lead in the air dropped off immediately.

tell me everything you know about the flint water crisis or so help me god

when the city switched to city water, which contained chlorine, the chlorine formed trihalomethanes, which made the water more corrosive, and lead leech out of the pipes a whole bunch. So then they added Orthophosphates to decrease the organic matter, but that just made the lead even more powerful.

lead has a _____ long half-life in the brain?

2 ½ years.

can’t be killed if you weren’t born, that’s what I always say.

girl fuck them kids

fun fact: orthophosphates are cheap.

if your house is older than _____ you have lead.

1950.

Do Brita filters get lead out?

No!

In 2000, Winnipeg started adding 2mg/L of orthophosphate to dry and stop the lead.

costs 200k/year.

back of the napkin math!

Stealing that.

KEN, I DON’T HAVE A HOME

jk I do but it’s far away

Slide 44: Lead was often put in b_____ which:

introduced lead to the ecosystem, if their target lived and fucked off and then got eaten.

Slide 44 extra: Lead f_______ ______ adds lead to the environment, so they are banned in national parks.

fishing tackle.

Lead bullets are responsible for increased lead in bald eagle bones,

to the point of toxicity/ decreased lifespan.

Lead accumulation is worse for bald eagles in the:

winter months.

What metal causes the biggest problem in gold mining?

Arsenic.

What forms of arsenic are the most toxic?

The ionic forms.

What’s the easiest way to get your arsenic?

Drinking water, or eating things that live in the drinking water source.

How did we get the arsenic into the drinking water?

Pesticides, poisoning the opps, treating wood. (Back in the day.)

Arsenic is similar to what compound that we crave:

Phosphate.

What does arsenic do?

Necrosis in the GI tract, interferes with ATP synthesis.

Mee’s Lines:

accumulate ~6weeks after exposure of arsenic.

What else does it cause?

Free radicals/reactive O2, = cancer.

Arsenic also fucks with epi______

genetics.

What’s the main way to get Cadmium?

Food, or drinking water if your pipes are galvanized.

What’s the worst food (or best if you want cadmium) for cadmium?

Mushrooms.

what’s the worst spice(s) for cadmium?

ginger and cinnamon.

What makes cadmium suck so much in your lungs?

Long half-life. 30 years!! Gahdamn.

Where does cadmium chill in your body?

Liver and kidneys.

what’s the coolest ways for metals to travel around your body?

attach to the red blood cells instead of iron ;)

What’s the main way to get your unhealthy copper?

Leeching of copper from containers or pipes into stuff we drink.

What makes copper suck so much as a toxin?

because we literally need it, our body is super good at absorbing it. Then you get liver necrosis or Wilson’s disease.

Wut’s Wilson’s disease?

igbtyot

what’s he bigger issue with copper?

acutely toxic for many aquatic animals, or at least really fucks their shit up. (blocks their sensors that are like the special nose, and binding to the olfactory cells. No more sense of smell!)

why does no sense of smell suck for fishes?

many fish use chemicals as cues to migration. No smell = no migration.

also, if one of your friends gets eaten, your dead friends fucked up chemicals are all over the place and the fish can smell that and know there’s danger/predators,…. unless they can’t smell of course.

Slide 16 of pt 2:

action potentials of a fishes smell cells before and after being exposed to copper.

Selenium sucks because the difference between ___________ and ____________________________

Selenium sucks because the difference between necessary dose and lethal dose in our body is very small.

How to count the fishes age:

Count the rings on the fishes eardrums (otoliths).

A: got it from mom

B: got it from the environment