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Chapter 11 Pollutants — Transcript

by Jeffrey Ashley · 6,074 words · 968 segments · language en · Watch on YouTube

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0:00I'm Dr. Jeff Ashley and welcome to
0:02chapter 11. Let's get started. Chapter
0:0511 deals with marine pollution and very
0:08broadly defined pollution is defined as
0:11a harmful substance. Well, there's a
0:13whole bunch of harmful substances.
0:15There's a harmful substance like plastic
0:17waste that you see in this image. And
0:19there's also harmful pollution that we
0:21don't see, chemicals. We're going to be
0:23talking about the whole spectrum of
0:25marine pollution. It's also worth noting
0:28that aside from chemicals and plastic
0:32waste, as you see here, noise, heat, and
0:35light can also act as pollution. Think
0:38of the noise from a offshore windmill.
0:41Or think of the water that is heated and
0:44discharged from a power plant. Also,
0:47think of light, light on the coastline
0:49impacting sea turtle migration and egg
0:52laying. So marine pollution can be
0:54harmful to an ecosystem and those
0:56organisms including humans living in
0:59that system. Pollution can also provide
1:01a hindrance to marine activities such as
1:03shipping and also marine pollution
1:05decreases the quality of seawater. Here
1:08we have an image of various sources of
1:11marine pollution such as sunken
1:13containers, leaking fuel, beach
1:16pollution, heavy metal waste, plastic,
1:19and some other things called hazardous
1:21chemicals, which we'll get more detailed
1:23with in a moment. So, there's an adage
1:26in environmental chemistry that says the
1:28solution to pollution is dilution. So, a
1:32lot of the pollutants were once thought
1:35to be disposable in the open ocean
1:38because the ocean is so vast it would
1:39dilute any of these pollutants. However,
1:42the long-term effects of diluting
1:44pollutants in the open ocean is unknown
1:47and there's still a hotly debated issue
1:50about dumping waste in the ocean. In
1:52general, these are the main types of
1:53marine pollution, some of which we'll be
1:56discussing in this chapter. petroleum or
1:58oil, sewage sludge, legacy organic
2:02contaminants. These are contaminants
2:04that are largely organic in nature. Some
2:07of them may be metalbased, but largely
2:09organic that were banned from use many
2:12years ago, but are still present because
2:15they do not degrade. And there's a whole
2:17slew of current use chemicals and
2:19emerging contaminants of concern. As I
2:21mentioned, heavy metals can be of
2:23concern and act as a pollutant. And the
2:25most vicious one, at least in the open
2:27ocean, is probably mercury due to its
2:29bioaccumulative nature. And we can't
2:31forget what's called nonpoint source
2:34pollution. Pollution coming from various
2:36diffuse sources. So, let's dig down a
2:38little deeper in each one of these
2:40pollutant categories. Let's start off
2:42with petroleum, commonly called oil.
2:45It's naturally occurring liquid made of
2:47largely hydrocarbons, hydrogen, carbon.
2:50However, oil spills often happen. These
2:53can happen because of extraction
2:56purposes or from oil spills from tankers
2:59and sometimes just leaking oil from
3:01loading and unloading practices. In this
3:04figure we can see a comparison of some
3:06notable oil spills. Here we see from
3:081989 the exound Valdis which happened in
3:12Alaska. We have a Mexican incident
3:15called itak in 1979. We have more
3:18recently the Deep Water Horizon in the
3:20Gulf of Mexico. In the Persian Gulf, we
3:23have uh intentional release of petroleum
3:26into the Persian Gulf. And as a
3:28comparison on the right in blue, we have
3:31the annual oil input from other sources.
3:34These are sources not from spillage or
3:37accidents. These are just natural seeps
3:39and regular human activities such as
3:41transportation. In 1991 in Kuwait, there
3:45was an intentional dumping of oil into
3:46the Persian Gulf by Iraq. More than 98
3:50million lers of spilled oil was dumped
3:53into the Persian Gulf. This is 20 times
3:55the amount of the Exxon Vald accident
3:57happening in Alaska. X talk number one
3:59in Mexico was the largest spill from a
4:02well and it happened in 2010. It took
4:05about 10 months to cap that. This
4:07accident spilled 530 million L of oil.
4:11And some of you remember this, the Deep
4:13Water Horizon. Again, there was an
4:14explosion on this oil rig and it leaked
4:17oil into the Gulf of Mexico. Other
4:19notable oil spills include the Iranian
4:21oil tanker in 2018 when it collided with
4:25another boat. It leaked around 570,000 L
4:28of petroleum distillate into the South
4:30China Sea. The tanker burned and sank.
4:33So why should we worry about this
4:35petroleum release by accidents or
4:37natural seepage? Well, petroleum
4:40contains toxic compounds capable of
4:42causing injury or death to organisms
4:45including humans. Within petroleum,
4:47which is a largely hydrocarbon based
4:49mixture, there are molecules called
4:51polyyclic aromatic hydrocarbons or PAs
4:54for short. Some of these PAHs are
4:58designated as carcinogenic. So,
5:00petroleum can cause sickness to humans,
5:02animals, and even in plants at small
5:04doses. and it can have long-term impacts
5:06on organisms such as changing gene
5:09expression, developmental abnormalities,
5:12and decreased embryo survival for some
5:15organisms. Here's a image of potential
5:17oil impacts on sea turtle life history.
5:20Petroleum deposits near or onshore may
5:23influence egglang. Offshore floating oil
5:26may influence feeding. For wind and
5:28currents, floating oil may be dispersed
5:31and enter the water column where it
5:33could amalgamate into clumps and settle.
5:35You can see from this image as well that
5:37even the oil vapors may be detrimental
5:40to sea turtle behavior and survival. Oil
5:43being hydrophobic does not like to be
5:45easily dispersed in water. Therefore, it
5:48will cling to anything that is there.
5:52Inorganic materials, floating trash, and
5:55also organisms. Marine organism fur or
5:58feathers lose insulation properties when
6:00covered in oil and result in high
6:03fatality rates. Just to give you an idea
6:05of some of the research that was done
6:06after the Exxon Vald oil spill in
6:09Alaska, we have a graph here of four
6:12different species. Bald eagle, corrant,
6:16harbor seal and pacific herring. It's
6:18interesting that the bald eagle and
6:22corriral effects after the spill
6:25recovered and in some cases were removed
6:27from the endangered list such as the
6:29bald eagle or they rebounded to higher
6:31levels. Not the case with the harbor
6:33seal. After the spill, populations
6:36decreased. We also see that the Pacific
6:38herring suffered detrimental effects and
6:41never recovered. However, the collapse
6:43right here four years later was
6:45unrelated to an oil spill and likely due
6:47to over fishing. So, we went through
6:48many examples of accidental spillage of
6:52petroleum in the marine environment.
6:54However, there is another source and
6:56that's natural seeps of petroleum.
6:58Around 53% of petroleum in the oceans is
7:02based on human activity. However, that
7:04leaves 47% from these natural seeps at
7:07the bottom of the ocean. Large-scale oil
7:09spills can be cleaned up, but as we saw
7:11in some of those figures and stats, it
7:13takes a very long period of time. At
7:16sea, dispersants can be used to break up
7:18the oil and either enhance its settling
7:21through the water column or enhance its
7:24volatility. Speaking of volatility, one
7:27mechanism is through burning the oil
7:29slick on top of the sea. Another
7:31mechanism may be holding that slick of
7:34oil by way of surrounding it with booms.
7:38Also, because oil is now resting on the
7:40sea surface, it can be skimmed and
7:43collected. If you're onshore, absorbent
7:45material can be laid down which absorbs
7:48the oil and then now that is collected.
7:50Again, we can use booms to try to corral
7:54the oil slick and also employ burning
7:57techniques and we can use dispersants
7:59and manual labor such as this and clean
8:02up that slick both on the water column
8:05and on the coastline. So here we see
8:08many mechanisms that act to disperse or
8:12transport oil. And here we have a fresh
8:14oil slick on the surface. When oil mixes
8:17with water, I said it doesn't do very
8:19well. It's emissible, but it creates an
8:22emulsion much as you would see when you
8:24have oil and vinegar salad dressing and
8:26you mix it up and you get that emulsion.
8:29That's the same thing that's happening
8:30here on the sea surface. Eventually,
8:32that emulsion will turn into a frothy
8:34mousse at longer periods of time and
8:37that could be dispersed. Petroleum is a
8:40suite of hydrocarbons of various
8:42molecular weights. Lower molecular
8:45weight hydrocarbons tend to vaporize
8:48into the atmosphere rather quickly. Oil
8:51is also photo oxidized by the UV light
8:54and it could evaporate. Heavy molecular
8:56weight hydrocarbons within that oil have
8:59a tendency to settle out. So they
9:01conglomerate together and they may
9:02settle out. The repository of oil from
9:05this conglomeration is at the bottom of
9:07the sea. Here biodegradation by bacteria
9:10may happen. Also here we have a natural
9:12seep of oil which is releasing oil up
9:15into the water column. Another way that
9:17you can clean up oil spills is actually
9:19through bio remediation using bacteria
9:21or fungi to help clean up these oil
9:24spills. The rate that they do this is
9:27approximately 53 to 63% within the first
9:30month of treatment. So what you have to
9:32do is release bacteria or fungi directly
9:34into the marine environment creating
9:36these conditions to stimulate the growth
9:38naturally. So here we have oil spillage.
9:40The hydrocarbons from the oil act as
9:42food sources for bacteria which utilize
9:45that and produce carbon dioxide and
9:47water. Because of these historic
9:49accidents which have released massive
9:51amounts of petroleum into marine
9:53environments, the oil pollution act 1990
9:56was created. In that act was defined a
9:59fiscal responsibility for cleanup. So
10:01whatever company or individual was
10:04accidentally spilling this or
10:06intentionally they were responsible for
10:08the cleanup. Historic accidents also
10:10prompted singlehole tankers to be barred
10:12from the US ports and not allowed within
10:15320 km of France and Spain. This
10:17instigated ship makers or ship builders
10:19to build double hold tankers. This issue
10:22of burning hydrocarbons may in your mind
10:24be probably not a great idea because it
10:27creates air pollution. Indeed, it does,
10:29but it gets the oil off of the sea
10:32surface and transfers it into another
10:35compartment of the hydrosphere. In 1999,
10:38a Japanese-owned freighter ran a ground
10:40near the Oregon coast. It was
10:42intentionally burned to prevent a larger
10:44oil spill. Let's shift to another marine
10:46pollutant, and that's sewage sludge.
10:48Sewage comes from primarily human waste
10:51that is treated at a wastewater
10:53treatment plant to various degrees and
10:54then released into water bodies.
10:56Sometimes estuaries, coastal systems,
10:59rivers that end up in the ocean. Sewage
11:00sludge contains human waste that has
11:03been treated, oil, zinc, copper, other
11:06heavy metals, a whole slew of pesticides
11:08and other chemicals, including
11:10pharmaceuticals. Just think of all the
11:12things that people ingest. Those things
11:15are often metabolized or even unused by
11:18the body and they're excreted to some
11:20degree in our waste water. Primarily,
11:22there are two ways to treat waste and
11:25that's through primary treatment where
11:26solids are allowed to settle and then
11:28they are dewatered. Those solids are
11:31usually applied to agricultural land,
11:34believe it or not. Then there's
11:35secondary treatment where the sludge is
11:37exposed to bacteria killing chlorine.
11:39There's actually no dumping of sewage or
11:42it's called sludge in the ocean after
11:451981. And this was prompted by and large
11:48by the Clean Water Act in 1972 which
11:51laid the groundwork to instill stricter
11:53regulations for offshore or marine
11:56discharge of sewage sludge. However,
11:58there are many exceptions and waiverss.
12:00Here we see a recent photo of a cruise
12:02ship unloading its sludge, again
12:05human-based, into the marine
12:07environment. New York and even
12:09Philadelphia used to do offshore
12:11disposal of sewage sludge. First, they
12:13did it in shallow waters, but this
12:15proved detrimental. Sewage sludge
12:17contains not only pollutants or
12:19potential toxins, but also nutrients
12:21which fuel phytolanonic growth. Too much
12:23growth is bad for these coastal systems
12:25as we'll see in subsequent chapters.
12:27Deeper water sites were then chosen.
12:29Finally, in 1992, they ceased disposal
12:32altogether and this was at the 106 milei
12:35site. In 1993, all sewage is disposed on
12:38land. So, we've seen this list before,
12:41but I want to just give you more
12:42information. There's a lot of
12:43information here if you're interested in
12:45this, but here's the various types of
12:48chemical contaminants in the marine
12:49environment. This includes things like
12:51POPs or persistent organic pollutants.
12:54These are human-made chemicals that were
12:57created to be very resilient and
12:59persistent, and they've done a good job
13:01because they're still around. Examples
13:03of these include the band chemical
13:06called DDT and also the band chemical
13:09called polycllorinated bifphenols or
13:11PCBs. We have endocrine disrupting
13:13chemicals which interfere with the
13:14endocrine system of both humans and
13:16other organisms leading to reproductive
13:19problems and other health issues. We
13:20have a whole slew of heavy metals
13:22including lead, mercury, and cadmium.
13:25And these are known to be toxic at
13:26certain levels. And as I said, as
13:28humans, we're using a whole bunch of
13:29pharmaceuticals. They can actually end
13:32up in wastewater releases from
13:34wastewater treatment plants and disrupt
13:37the marine environment. And we'll touch
13:38upon this, but there are microplastics,
13:40these tiny pieces of plastic that can
13:42enter the ocean and be ingested by
13:44marine marine organisms and also humans.
13:47So, quickly, let's run through the
13:48sources of chemical contamination. We
13:50have runoff from agricultural land. We
13:52have industrial discharges. As we said,
13:55we have sewage treatment plants
13:56releasing this. They do treat it, but
13:58not fully.
14:00uh we have oil and chemical spills and
14:03we also have plastic waste. So what are
14:05the impacts of all this chemical
14:07contamination? Well, a major one is
14:09toxicity to marine organisms leading to
14:12illness and death and even population
14:14declines. But even sublethal effects can
14:16be seen like changes in reproductive
14:18behavior. We have disruptions in the
14:20food chain. Chemicals can accumulate in
14:22the food chain leading to toxicity at
14:24top predators like seabirds and marine
14:26organisms. reproductive problems. They
14:29can disrupt the endocrine system, like I
14:31said, and lead to reduced populations
14:33due to decreased reproductive viability.
14:36We have habitat destruction. Chemical
14:38contamination can harm habitats like
14:40coral reefs and seaggrass beds. And we
14:42have lastly, the money factor, economic
14:45impacts. Chemical contamination can
14:47affect fisheries, tourism, and other
14:50industries that depend upon a healthy
14:52marine environment. So, you might have
14:53heard of this chemical, DDT. It was
14:55found to decline bird populations. It
14:58thins eggshells. After the effects in
15:01the 60s and 70s were observed and
15:04studied by scientists, it was banned in
15:06the United States in 1972. One of the
15:09leading scientists at the time and
15:11author was Rachel Carson, who's from
15:14Pennsylvania, and she wrote Silent
15:16Spring, which signaled the rise of the
15:19use of pesticides, including DDT, and
15:22their potential negative effects on the
15:24ecosystem and on human health. If you
15:26click on this URL, it will take you to a
15:29fascinating biography. We're going to
15:31play a little bit of that just to give
15:32you an idea of what was going on at that
15:34time and the rampant use of pesticides.
15:37Then friends told her about a US
15:39Department of Agriculture program to
15:42eradicate the fire ant. And more than a
15:44decade after she'd proposed the piece
15:46about DDT to readers digest, pesticides
15:50came roaring back into her
15:52consciousness. The fire ant is believed
15:54to have entered this country from South
15:56America in 1925. The destructive insect
15:59has brought heavy losses to crops in
16:01Alabama, Mississippi, and Louisiana.
16:03Once they swarm across a field like
16:05this, nothing survives.
16:10The fire ant was the perfect invasive
16:13species for the Cold War era. They were
16:16red. They snuck into the country. They
16:19were subversive and they were mostly
16:23annoying. For some reason, the
16:25Department of Agriculture got it in
16:27their head that scientists there that
16:29this would be a perfect demonstration of
16:31the power pesticides to solve a nagging
16:36problem. The enthusiasm for DDT and
16:39other synthetic pesticides had given way
16:42to the conviction that science could do
16:44far more than control insects and other
16:47unwanted pests. The objective now was
16:50eradication.
16:52It meant extermination. extermination of
16:54a
16:56species. So in 1955 you see the advent
17:00of the World Health Organization's
17:01malaria eradication program which was in
17:04many ways designed to exterminate not
17:07the problem of malaria but the problem
17:09of
17:11mosquitoes. The fire ant eradication
17:14program was the same idea.
17:17Scientists are convinced that this is
17:20the right way to go. And if we fail,
17:23then we're going to fail humanity. It
17:26becomes this all or nothing
17:31equation. And so what we see in the
17:331950s is tremendous amounts of money
17:35going into studying pest killing. not so
17:38much money going into studying broader
17:40questions of wildlife biology, broader
17:43questions of environmental health,
17:45broader questions of environmental
17:46toxicity.
17:48The people involved, the scientists and
17:52whatnot who are inventing pesticides
17:54think they're doing God's work and that
17:57they're also helping the United States
17:59keep its edge in the cold war
18:02environment.
18:04the department of agriculture and the
18:06chemical industry at say one of the
18:08reasons that we have such a rich
18:10material life is that we have found ways
18:13to control these problems to maximize
18:15food and fiber production and it's one
18:18of the things that distinguishes the US
18:20and its allies from the communist
18:23block. Our standard of living is so much
18:26higher and we owe it to human ingenuity.
18:31In 1957, in the USDA's allout war
18:35against the fire ant, some 20 million
18:37acres in the south were doused with
18:39pesticides, killing not only ants but
18:42blackbirds and metallarks, armadillos
18:45and
18:47apos. The sprayed areas, as one Alabama
18:51agricultural official reported, rireed
18:53with the odor of decaying wildlife.
18:58The hunting fishing community was
19:00outraged. County agricultural agents
19:03dropped their support for the project
19:05and it really was a black eye for the
19:07Department of Agriculture, but it was a
19:09warning for
19:11Carson. What concerned Carson was not
19:14merely that synthetic pesticides had
19:16unintended consequences, but that
19:18substances about which so little was
19:21known were now practically
19:24ubiquitous. widely employed by
19:27government agencies to protect health
19:29and agriculture as well as American
19:31interests abroad. Synthetic pesticides
19:34also were sold directly to consumers who
19:37by 1957 could choose from an array of
19:40some 6,000 different
19:43products. You could get uh shelf paper
19:46for your kitchen cabinets that was
19:48impregnated with
19:50DDT. You could get paints and varnishes
19:52that had DDT in them.
19:55One of my favorite devices, and my
19:58father owned this, was um a cylinder
20:01about the size and shape of a beer can,
20:03and it had DDT in it. It attached to the
20:06muffler of your lawn mower. So, the hot
20:08exhaust gas would volatilize the DDT and
20:11spray a fog out across your yard. So, if
20:13you were having company over for a
20:15picnic later, you could you could poison
20:17the grass before they got there and
20:18nobody would get a mosquito bite. PCBs
20:21or polycllorinated bifphenols are legacy
20:24contaminants that are banned in most
20:27countries worldwide but were used
20:29prevalently from the 1920s to around the
20:321960s and 70s. It was used as a liquid
20:35coolant and insulation in power
20:36transformers but it also had other uses
20:38including wiring paints cocking and
20:41hydraulic oils. It can cause harmful
20:43genetic mutations and reproductive
20:45issues. PCBs stand for polycllorinated
20:49biphenals. So for this we're just going
20:51to call them
20:52PCBs. PCBs belong to a broad family of
20:56man-made organic chemicals. PCBs are
20:59known to be toxic to humans and other
21:02organisms. So a little history. PCBs
21:06were first introduced or manufactured in
21:08the 1920s. They were considered
21:10invaluable in electrical equipment and
21:12in buildings and in machinery.
21:15PCBs were used because of their fire
21:17resistance, chemical stability and
21:20electrical insulating properties. They
21:22were also used as plasticizers and
21:25paints, plastics and rubber products and
21:27in pigments and dyes and carbonless copy
21:30paper and many other industrial
21:33applications. Within only a few
21:35generations, PCBs had spread all over
21:38the world. They were found in both
21:40animals and humans as well as in food
21:42products.
21:44Consumers did not know that PCBs were
21:46harmful to people. That is until a
21:49serious poisoning incident happened in
21:51Japan in
21:531968. This incident shed new light on
21:56PCBs and prompted much further research.
21:59By 1979, as a result of that research,
22:02the manufacturing of PCBs was banned,
22:05not just in the United States, but also
22:08internationally. So, if PCBs were banned
22:11back in 1979, why is there a need to
22:14make laws about them now? Although PCBs
22:17are no longer intentionally added to
22:19products manufactured in the US, they
22:22can still be and are inadvertently
22:24created when high heat and chlorine are
22:26used during some manufacturing
22:28processes. These inadvertently generated
22:31PCBs are found in some consumer products
22:33today. Also, PCBs can be released into
22:36the environment from poorly maintained
22:39hazardous waste sites that contain PCBs,
22:42illegal or improper dumping of PCBs,
22:44wastes, leaks or releases from
22:46electrical transformers containing PCBs,
22:49and disposal of PCBs containing consumer
22:52products into municipal or other
22:55landfills not designed to handle
22:56hazardous waste. PCBs may also be
22:59released into the environment by the
23:01burning of some waste in municipal and
23:03industrial incinerators. They may remain
23:06for long periods of time cycling between
23:08the air and the water and the soil and
23:11the biota that is the animal and plant
23:13life and PCBs can be carried long
23:15distances and have been found in snow
23:18and seawater in areas far from where
23:20they were released into the environment.
23:23Consequently, PCBs are found all over
23:26the world. In general, the lighter the
23:29form of PCBs, the further it can be
23:31transported from the source of
23:33contamination. Perhaps you have seen
23:35these signs posted on the shores of our
23:37Washington
23:38waterways. Washington is not alone. Many
23:41states have established fish and
23:43wildlife consumption advisories because
23:45of PCBs.
23:47It is important to note that the levels
23:49of PCBs found in products tested are
23:52unlikely to pose an immediate threat to
23:54human health. The concern is that the
23:57small amounts of PCBs released to the
23:59environment from thousands or millions
24:01of these products can build up through
24:03the food chain, eventually posing risks
24:06for people exposed by eating fish or
24:09causing health effects for other top
24:11level consumers such as orcas.
24:14This is called
24:16biomagnification. And here is an
24:18illustration of how it
24:19happens. PCBs are released from multiple
24:22sources into the environment. PCBs also
24:25accumulate in the leaves and above
24:27ground parts of plants and food crops.
24:30Eventually, they end up in our
24:33waterways. These small amounts of PCBs
24:36are absorbed by phytolanton and then zoh
24:39plankton who of course eat the
24:41phytolankton. This is where it's easier
24:43for us to see the biomagnification
24:45process. The small fish who eats the zoh
24:48plankton doesn't just eat one. This
24:50small fish must eat millions of the
24:52zohop plankton to survive. And now the
24:54small fish contains multiplied amounts
24:56of PCBs in comparison to the PCBs in one
25:00zip plankton.
25:01In turn, the larger fish also must eat
25:04thousands of smaller fish to survive,
25:06thereby causing it to contain amounts of
25:08PCBs that are multiplied by the
25:10thousands in comparison to the amount of
25:12PCBs in the smaller fish. When top level
25:15consumers eat these fish, those PCBs are
25:19biomagnified and they are now at much
25:21higher levels. Replace the orca in this
25:24picture with a human and now you can see
25:26why these signs of fish consumption
25:28limits are posted. That was a great
25:30video introducing PCBs, but I just want
25:32to get back to a little bit of the
25:34chemistry and the structure. What do
25:35these things look like? There's an S on
25:37the PCB because they are actually a
25:40whole suite. 209 possible confirmations
25:45of one molecule. So PCBs are a biphenol
25:48ring. So here's like a benzene ring and
25:51a benzene ring over here, but they're
25:53fused. So two or by phenols that are
25:56fused together at each one of these
25:59locations and there's 1 2 3 4 5 6 7 8 9
26:0310 locations. You can have varying
26:06degrees of chlorination. So you can have
26:09in exist this example actually five
26:12chlorines on this and that would be one
26:14possible confirmation or structure for a
26:18PCB and it would have its own unique
26:20name. There are 28 other possible
26:24confirmations based on the location of
26:26where you chlorinate that. Now let's
26:28turn our attention to another pollutant
26:30and this is again a chemical contaminant
26:32named mercury. Mercury in its elemental
26:35form is not so toxic toxic but once it
26:37gets into the environment mercury is
26:40then transformed into methyl mercury.
26:42Methyl mercury is toxic to most living
26:45organisms. The story of its toxicity
26:47began to emerge in Minamata Bay in
26:50Japan. A chemical plant was releasing
26:52large amounts of mercury and that
26:54mercury was in the environment and just
26:57we saw in that video methyl mercury has
27:00the ability to bioaccumulate so it gets
27:03more and more enriched as you go up the
27:05food chain. The first reported
27:07ecological changes were in 1950 and by
27:111953 there was human poisoning. Exposure
27:14to methyl mercury causes a neurological
27:16disorder. In 1908, a chemical factory
27:20opened in the coastal village of
27:21Minamata, Japan. The factory ran by
27:24Chiso Corporation began to rapidly
27:26expand and create new products for the
27:28next half century. But little did the
27:30residents of Minamata know, the actions
27:33and negligence of this factory would
27:35lead to the largest mercury pollution
27:37disaster in history, changing the fate
27:39of the world forever. It wasn't until
27:42the 1950s that residents began to notice
27:44several afflictions. It began with
27:46numbness, muscle weakness, and loss of
27:48coordination, but quickly progressed to
27:50intense neurological disorders and
27:52regular birth defects. As cases began to
27:55pop up more and more frequently, an
27:57early epidemiological study announced
27:59that an epidemic of an unknown disease
28:02of the central nervous system was
28:04spreading around the village. No one
28:05knew the cause of what was happening,
28:07but clearly there was one. If you're
28:09interested, you can play the rest of
28:11that and I have the URL linked to this
28:13image. It's rather a misnomer by calling
28:16it minimata disease because it's really
28:18not a disease. It's a neurological
28:22impairment based on methyl mercury
28:24exposure, but still people call it
28:26minimata disease or ouch ouch disease.
28:29So, as we saw in that video, some of
28:31these organic contaminants and also
28:34methyl mercury can biocumulate and also
28:37biomagnify. So what's the difference?
28:40Bioaccumulation was is where organisms
28:43can concentrate the pollutant from
28:44seawater. However, magnification is
28:47organisms gain more and more of that
28:49pollutant by eating other contaminated
28:52organisms. It was really put into action
28:54in that video that you watched. So
28:56although bioaccumulation happens on each
28:59trophic level to each of these species
29:01or organisms, biomagnification is that
29:04enhancement as you go up the food chain.
29:07And here we see another image of
29:09biomagnification. It's concentrating
29:11these toxins. The higher up you go. So
29:15although at the base of the food chain
29:17you could have a toxin in the water, it
29:19will start to accumulate in phytolanton
29:21and zoplankton, small fish, larger fish.
29:24A top predator like an offspray eating a
29:28lot of the concentrated large fish
29:30species will then get a massive dose of
29:33these contaminants. Some of these
29:36contaminants reside in the bodies of
29:38organisms for long periods of time,
29:40especially in the fat tissue because
29:42they're lipopilic. Some of these
29:44contaminants can also be metabolized to
29:46some degree by organisms. So, in the
29:48case of mercury and also PCBs, what's a
29:51safe level? Well, safe levels of
29:53contaminants are determined by a number
29:56of things. They're determined by the
29:58rate of fish consumption by humans, the
30:00amount of the chemical within that fish,
30:03and also minimum ingestion rate of
30:05mercury to cause damages. It gets
30:07complicated, but here we have a graph of
30:09the methyl mercury concentrations in
30:11fish and also the fish consumption rate,
30:14how much fish people are eating. If you
30:16eat once in a while a contaminated fish,
30:18it's al primarily safe. But if you
30:21continue to ingest that at a frequent
30:23rate, you might get into an area where
30:26the FDA, the Food and Drug
30:27Administration has set a limit over
30:30that, you get into danger or extreme
30:32danger areas. So there's a whole slew of
30:34other chemical pollutants, too many to
30:36name here, but these include
30:38prescription, non-prescription, and
30:40illegal drugs from municipal waste
30:42treatments. Remember, anything that we
30:44ingest in human bodies is excreted and
30:47that ends up at a wastewater treatment
30:49plant. Those plants do not have the
30:51capability of removing those chemicals
30:54and they end up in receiving waters and
30:56eventually in the marine environment.
30:58Some of these chemicals break down but
31:00some do not and some travel long
31:02distances and eventually reside in the
31:03ocean. We also have hormones, human
31:06hormones, things like caffeine, nicotine
31:08metabolites again from humanbased use
31:11and excretion. And we also have
31:13fertilizers from agricultural practices
31:16or even making our lawns green. We also
31:19have
31:20radionuclides. This is from the
31:22Fukushima accident that happened in
31:24Japan caused by the tsunami. And we have
31:27Noah, the National Oceanic and
31:29Atmospheric Administration monitoring
31:32those radionuclides as they travel in
31:35the Pacific Ocean. We also have to
31:37mention non-point source pollution and
31:39also trash. So non-point source solution
31:42is often called poison runoff. It has a
31:45whole slew of sources, but they're duse.
31:49Think of runoff after a rain event
31:51washing over the surface of the roads,
31:54the land, enveloping the trash, also
31:59solubilizing pesticides and fertilizer,
32:01and also road oil that will end up in
32:04the marine environment eventually.
32:05Non-point sources are difficult to
32:07pinpoint. Imagine trash washed down the
32:10storm drain to the ocean or road oil,
32:13pesticides. As we mentioned, plastics
32:15are vast majority of the marine
32:17environment debris. They usually float
32:19and they're not readily biodegradable.
32:21Macrol plastics such as floating bottles
32:24will eventually disperse into smaller
32:26plastics and eventually become what we
32:28term microlastics. So, we've all seen
32:30the images of six-pack rings entangling
32:33fish, marine mammals, and birds. They
32:36can choke turtles. they're mistaken for
32:39food and birds can ingest a large amount
32:41of this and possibly die of starvation.
32:43So here you see some images of the
32:46entanglement of plastics in marine
32:49organisms such as a seal
32:52um birds and also this is a
32:55quintessential photograph from National
32:57Geographic from a while ago. Uh this is
33:00a uh bird, an albatross that was uh
33:04found dead on the Midway Islands and
33:06they cut open uh to do a necropsy to see
33:09what was in its stomach and they laid
33:12out the contents of the stomach and that
33:14can be seen in this circle. So you see
33:16if we zoomed in here a lighter um
33:19buttons, bottle caps and this bird died
33:22of starvation. Obviously, it is now
33:24illegal to dump plastic anywhere in the
33:26ocean. And floating plastic can attract
33:29oils and toxic compounds to it.
33:31Remember, a lot of these organic
33:33pollutants and methyl mercury to a
33:35degree are hydrophobic. So, they want to
33:38glum onto something. They can glum onto
33:41phytolanton, but it can also be an
33:44inorganic human-based material such as
33:47plastics. So, not only are plastics bad
33:50for marine organisms who eat them, but
33:52they also now have a coating of these
33:54potential toxic compounds on them. So,
33:56if you're wondering, can dumping occur
33:59in the open ocean? Well, here are the
34:01regulations. And we can see outside of
34:0325 miles that you can actually dump a
34:06lot of this stuff like paper, rags,
34:10glass, and again, all of these it's
34:13illegal to dump plastic. So there are
34:15many documentaries out there on the
34:17revolution of plastics and they debuted
34:19in
34:201869 and wildly they became increasingly
34:25um predominant in uh our human life. If
34:29you just wake up and just look around
34:31your room uh think of all the things
34:34that are made from plastic. So we're now
34:36realizing the dangers of plastic, not
34:38only macrolastic, but when macroplastics
34:40uh degrade somewhat or fall into smaller
34:44pieces, they can be ingested by
34:47organisms or they can have uh
34:50contaminants accumulating on them as
34:51well. But plastics have been beneficial
34:54to humans and a couple of the things
34:56that have saved lives are such things as
34:58incubators, airbags, and safety
35:00equipment such as helmets. Smaller
35:02plastics are pretty harmful. Again,
35:05through ingestion, it can decrease the
35:07ability of organisms to live and also a
35:09coating of these contaminants can cause
35:11a little tox effect on organisms as
35:14well. Nerdles are these small
35:16pre-production plastic pellets. These
35:18are the precursor to any of our products
35:20and these are shipped worldwide. So,
35:22they're really small, they're
35:23lightweight, they can be blown
35:25everywhere if it's an open container.
35:27They're found in ocean and all beaches
35:29due to spilages. For example, in Orange
35:31County, California, 98% of the beach
35:34debris were these nerdles. So, I
35:35mentioned microplastics. Microplastics
35:37are a group of plastics defined by
35:40anything less than 5 mm or smaller. Uh
35:44that can include micro beads, micro
35:46fragments, and uh micro filaments as
35:50well. In particular, micro beads um they
35:53were prevalent and they were banned at
35:55least in this country from any consumer
35:57product. Um, these used to be
36:00emulsifiers or exfoliating agents in
36:03such things as toothpaste or face
36:05scrubs. Nerdles have the ability once
36:07again to transport pollutants because
36:09the absorption onto that and then they
36:12could be eaten by organisms. This is one
36:14recent study not looking at the effects
36:16but just quantifying the amount of
36:18plastics that are in the human body. and
36:21they looked at human brains and they
36:23said the human brain can contain as much
36:25as a plastic spoon worth of
36:28microlastics. Again, these are
36:30microplastics that you can't see with
36:32the naked eye. They're 5 mm or less,
36:34usually less. They can be accumulating
36:37in a human through ingestion of
36:40contaminated material or even through
36:42inhalation. Here we have a great example
36:44of the Eastern Pacific garbage patch,
36:46which is essentially a gy. Here's the
36:49North Pacific uh gy, but that gy is um
36:54coalescing all of this floatable
36:56garbage. So, how do we reduce the amount
36:59of plastic in the ocean? Well, we can
37:00limit use of plastics and recycle
37:02plastics, but recycling of plastic is
37:05still in its infancy because the cost
37:07benefit analysis is not truly there. We
37:10can ban plastic like we did in
37:12Philadelphia and was done in 2014 in
37:15California. And we can also instill
37:17regulations. So in 1988 the
37:19international convention for the
37:20prevention of pollution from ships
37:22marpole was proposed treating the uh
37:26this was this treaty banned the disposal
37:28of plastics at sea. I also need to
37:30mention that we think of these plastic
37:31bottles and our plastic
37:35um toys being the culprits and they they
37:38are to an extent but there is a massive
37:41network of derelic fishing gear. that
37:44fishing gear is largely nylon. It
37:47entangles organisms and it actually
37:49degrades. So you find these
37:51microfilaments in a lot of organisms.
37:54I'll mention one last thing and this
37:55comes from my study of about 2 years ago
37:57and we looked at microlastics in a
38:01filter feeder organism a ribbed muscle.
38:04And the predominant type of microplastic
38:06was microexiles or
38:09microfibers and these come from all our
38:11synthetic clothes that we wear. So think
38:14of that nice warm polar techch jacket
38:16that you have that is made from
38:18petroleum products and every time you
38:20wash it a large majority of that surface
38:25uh is sloughed off and enters the
38:27wastewater treatment plant. Again they
38:29can't filter out these microplastics.
38:31They're too small and there's no
38:32capability of doing it and they enter
38:34the marine environment. One last thing I
38:36have to mention is this biological
38:38pollution and this is largely called
38:40non-native species. These are species
38:42that exist in environments, but they
38:44weren't there uh naturally. So, these
38:47are intentional or even accidental
38:49introductions of species into a marine
38:51environment. They outco compete and
38:53dominate the native populations of
38:55organisms. Invasive species can cause
38:57extensive damage annually. And not from
39:00the marine environment, but from the
39:01Great Lakes of North America is the
39:04zebra muscle. and it drove out lo local
39:06muscles, altered the ecology of the
39:08freshwater lakes and streams, and
39:10blocked water pipes in industrial
39:12facilities. All right. So, this was a
39:14rather depressing survey of marine
39:16pollution, but I hope you're more aware
39:18of the sources and the potential impacts
39:21of these marine pollutants.

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