Antarctic sea ice may be a source of mercury in southern ocean fish and birds

From the UNIVERSITY OF MELBOURNE

New research has found methylmercury — a potent neurotoxin — in sea ice in the Southern Ocean.

This is an Iceberg in Antarctic sea ice. CREDIT Caitlin Gionfriddo, University of Melbourne

This is an Iceberg in Antarctic sea ice. CREDIT Caitlin Gionfriddo, University of Melbourne

Published today in the journal Nature Microbiology, the results are the first to show that sea-ice bacteria can change mercury into methylmercury, a more toxic form that can contaminate the marine environment, including fish and birds.

If ingested, methylmercury can travel to the brain, causing developmental and physical problems in foetuses, infants and children.

The findings were made by an international team of researchers led by Ms Caitlin Gionfriddo and Dr John Moreau from the University of Melbourne, and also included scientists from the Centre for Systems Genomics at the University of Melbourne, the US Geological Survey and Lawrence Livermore National Lab.

Methylmercury builds up in the food web through a process called ‘biomagnification’, said Ms Gionfriddo, PhD candidate from the School of Earth Sciences, University of Melbourne.

“Larger fish eat smaller contaminated fish, and continuously accumulate methylmercury at harmful levels for human consumption,” Ms Gionfriddo said.

The team wanted to understand more about how the most toxic form of mercury enters the marine environment, and the food we eat.

Ms Gionfriddo spent two months aboard the icebreaker Aurora Australis to collect samples of Antarctic sea ice during an expedition mounted by the Australian Antarctic Division.

The ice was analysed for different forms of mercury, including methylmercury, at the US Geological Survey in Wisconsin (USA). The DNA and proteins from sea ice microorganisms were studied at the University of Melbourne (AUS) and Lawrence Livermore National Lab (USA).

Mercury is a heavy metal pollutant that can be released into the environment through volcanic eruptions and re-released from vegetation during bushfires. It is also created through human activity, such as gold smelting and burning fossil fuels.

University of Melbourne geomicrobiologist and team leader, Dr John Moreau, said that the results confirmed the presence of bacteria in the sea ice with the genetic ability to convert mercury into the more toxic form.

These findings highlight the importance of eliminating mercury pollution from the environment, and following current recommendations to limit consumption of certain types of fish[1], say the researchers.

“These results are the first to identify a particular genus of bacteria, Nitrospina, as capable of producing methylmercury in Antarctic ice,” Dr Moreau said.

“The presence of these potential mercury-methylating bacteria raises an interesting question,” he added. “Could they also play a role in forming the methylmercury observed in the oceans worldwide?”

The team are keen to understand this process in the next steps of their research.

“Mercury has a long lifecycle in the atmosphere, up to a year,” said co-author Dr Robyn Schofield. “This means that mercury released through fossil fuel burning from countries over 3000 km away goes up in the atmosphere and ends up in Antarctica.”

“The deposition of mercury into the sea occurs all year-long but increases during the Antarctic spring, when the sunlight returning causes reactions that boost the amount of mercury that falls onto sea ice and the ocean,” Ms Gionfriddo added.

“We need to understand more about marine mercury pollution,” said Dr Moreau, “Particularly in a warming climate and when depleted fish stocks means more seafood companies are looking south.”

###

This project was supported through funding from the Australian Government’s Antarctic Science Grant Program (AAS4032) and The University of Melbourne Joyce Lambert Antarctic Research Seed Funding Grant (no. 501325).

[1]. Source: Food Standards Australia and New Zealand http://www.foodstandards.gov.au/consumer/chemicals/mercury/Pages/default.aspx

Advertisements

86 thoughts on “Antarctic sea ice may be a source of mercury in southern ocean fish and birds

  1. And, of course, there are no natural sources of mercury in and around Antarctica (such as perhaps sea/sub-glacial volcanos or other seeps) to provide the bacteria with mercury to methylate. Of course, why would there be mercury methylating bacteria in Antarctica without mercury there. Obviously, all of these bacteria evolved this ability only after the evil human degradation of the environment. Yes, that’s the ticket.

      • I am seriously confused. They forgot to explain how global warming makes this problem worse.
        P.S. Don’t eat penguin more than twice a week.

      • Well if those fish are dumb enough to be eating the Antarctic ice, then they deserve what they get. They are also likely to get overdosed on both sea salt, and CO2 which is also in that ice.

        g

      • I checked with my local fish market.

        They currently do not serve any fish from Antarctica; and they haven’t been aloud to serve up seagulls for some years now.

        g

      • Crap—- and I really like the tuna with the mercury in it. Been eating it for almost 70 years. Must explain my 160 IQ.

      • whales migrate to the southern ocean. the Japanese kill and eat the whales. as well as a whole lots fish.
        are there any probs with the Japanese health wise? Biomagnification in the whales?

      • Partially correct. Methyl-mercury is organic, but that is what makes it so much more toxic.

        Based on what this article presents, it appears that mercury from volcanos and burning coal is elemental (and less toxic), but then this evil mercury-methylating bacteria (that is a fun word!) trans-mutates the mercury into the highly toxic organic methyl-mercury.

        It would seem that the real solution is to eliminate the evil mercury-methylating bacteria.

    • “Mercury levels in yellowfin tuna caught off the coast of Hawaii have not changed in 27 years, despite a considerable increase in atmospheric mercury during this time, according to a new study. The findings suggest that the high levels of mercury that have been found in tuna and other ocean fish may not be coming from pollution, but from natural sources.”
      https://www.sciencedaily.com/releases/2003/12/031205053316.htm

    • You hit it first time, Wayne. You can add the continuously erupting Mt Erebus, on the Northern coast of Antarctica. Given the molecular weight of Mercury, the particles containing it which drift around the atmosphere for up to a year must be incredibly tiny.
      The one thing modern scientists all have in common, is a misguided belief in their own importance, which is revealed to the adoring public when they invariably insist that their line of research “needs more understanding”. It is beyond obvious to all here that they really mean “give me lots more grant money so I can holiday in exotic locations”.

    • I wonder if its ever occurred to these geniuses that a glacier is itself, a great big natural mining operation on the bedrock it overrides.

  2. ““We need to understand more about marine mercury pollution,” said Dr Moreau, “Particularly in a warming climate and when depleted fish stocks means more seafood companies are looking south.”” – You knew they would link it to CAGW to try and justify more money for the next study, didn’t you?

    Nothing fishy going on, just the usual grant whoring.

    • Of course. Depleted fishing grounds have nothing to do with human’s overfishing/lax regulation/inept regulation–too strong or too weak and a general misunderstanding between fishermen, scientists, and policy makers. OH NO! It’s the evil FOSSIL FUELS and CAGW to blame.

      My understanding is that mercury never goes away, it switches back and forth between forms but it’s always there until it’s buried in sediment and it’s due date has passed.

      THE interesting part of the article–is the microbe they discovered. THAT is cool. But you can’t have some new cool discovery without the rehash of how we are destroying the world because we like heat and light…to say nothing of the diesel fuel needed to run that ship while they did their research….:)

      • I have seen very few elements ever go away. Some of the heavy ones, a light one or two, but most of them just hang around. Iron is an excellent example. Once you get to iron, you are in the lowest nuclear state, The only thing that happens after that is that if it is in a stellar core, it cannot produce radiative pressure and collapses to basically a neutron star state.

        But yes, you can kick lead, mercury, etc. around, but you cannot make them go away.

        As for the bunker oil, they are driving toward using ng for bunkering more and more. Not at all a bad idea.

  3. I don’t understand why this is major news. It has been known since the 1960’s that bacteria produce methylmercury. The range of bacteria know to do that has steadily widened since the 1960s. In 2013 ORNL identified the two bacterial genes responsible, hgcA and hgcB. Since then, ever more bacteria have been identified carrying those genes, imcluding now invertebrate symbionts. Utterly unsurprising that some newly discovered sea ice bacteria would have those genes also. Bacteria can swap genes directly (drug resistance) and methylation followed by excretion is a fitness mechanism; metallic mercury is toxic to bacteria just like methylmercury is toxic to birds and mammals. Previously known mercury methylating bacteria include gram positives and negatives, aerobics and anaerobics, fresh water and ocean water. NCBI has a large database of papers on this because of the neurotoxicity danger.
    The known solution is not more Australian research. It is using low/no mercury coal and/or scrubbing the mercury from fluegas using activated charcoal, as is done everywhere in the US but not China.

      • Good job until you blamed him for something he did not do.

        He merely mentioned something China does not do. He didn’t “blame” them for externalities.

    • Thank you for your contribution. Informative, while drawing our attention to what the West has already done to help solve a problem while our global elites have made it worse by moving all of our manufacturing to China for cheap labor.

    • ristvan,

      It is my impression that anaerobic bacteria are the most common agents of methylation. Since these new bacteria apparently survive inside ice, in an oxygen-poor environment, it isn’t too surprising that they have the ability to cleanse their local environment by creating a volatile mercury compound.

      The authors of this report are assuming that metallic mercury from burning coal, with an atmospheric longevity of “up to a year,” makes it from the NH to the SH in less time than that to become a major source of contamination. I think that needs a little more study. There is no shortage of mercury in the oceans because of the Black Smokers along spreading centers contributing in oxygen-poor environments.

      I’m not sure that there is such a thing as “no mercury coal.”

  4. “Mercury is a heavy metal pollutant that can be released into the environment through volcanic eruptions and re-released from vegetation during bushfires. It is also created through human activity, such as gold smelting and burning fossil fuels.”

    Its an alchemists dream, creating the elements. Who knew creating mercury was so simple.

      • Wrong. See the arl.noaa.gov report on atmospheric mercury. Easy Google search key posted in other subcomments. Biggest US source in 1999 was utility coal. Biggest 1999 China source was metallurgy (steel from coking coal). China had the highest density of atmospheric mercury pollution in the world when the report was done. Probably worse now.

      • Ristan

        A lot of mercury in the air comes from the ocean. I am not convinced that ice anywhere is a significant source. The article is more about finding a new bacterium that digests it than about its significance as a source.

        You may recall I wrote some time ago about visiting the atmospheric monitoring station at Cape Point outside Cape Town. The scientist in charge explained they had switched from daily reporting (1 figure) to hourly reporting (24 numbers per day). They discovered to their amazement that the air streaming in from Antarctica sometimes had no mercury in it at all for up to several hours at a time.

        The only explanation is that there are biological process(es) taking place in the atmosphere stripping it out – all of it. I think the mercury cycle is poorly and partially understood.

        The airborne mercury monitoring station in Northern Canada also shows wide hourly variations. In short it is poorly mixed in the atmosphere which should be impossible if there are no atmospheric/airborne processes stripping it out.

        As for the power station theory, there has yet to be demonstrated in N America a ‘mercury plume’ measured downwind from a power plant. We had an article on that here at WUWT.

        It would be good to hear from contributor to this venue Prof Philip Lloyd who is a recognised expert on the subject of environmental mercury.

    • Mercury was long known to alchemists and often used by them in their fabricated experiments to produce gold from lead.

      Mercury’s chemical symbol, Hg, comes from the Greek “hydrargyrum” meaning liquid silver”

      In spite of Dartmouth’s claim that cinnabar mines are the only known sources for mercury, mercury is often a component in sulphide derived deposits, including iron, gold, silver, copper, lead (galena) deposits. Sulphide deposits are mostly tectonic/magmatic/volcanic driven.

      The use of an amalgam of mercury and gold to gild objects was known to the ancient arabs eventually culminating in the French practice of Ormolu, gilding objects.

      “Ormolu (from French ‘or moulu’, signifying ground or pounded gold) is an 18th-century English term for applying finely ground, high-carat gold in a mercury amalgam to an object of bronze.The mercury is driven off in a kiln leaving behind a gold-coloured veneer known as ‘gilt bronze’.

      The manufacture of true ormolu employs a process known as mercury-gilding or fire-gilding, in which a solution of nitrate of mercury is applied to a piece of copper, brass, or bronze, followed by the application of an amalgam of gold and mercury. The item was then exposed to extreme heat until the mercury burned off and the gold remained, adhered to the metal object.”

      “In the mid-nineteenth century, many items including spectacle frames, candelabra and the dome of the cathedral church of St. Isaac’s in St. Petersburg, were gilt by this very dangerous method, often resulting in death and/or severe disability of the artisan. It is reported that some 60 craftsmen died from the resultant mercury poisoning from the gilding of the cathedral dome of St. Isaac’s.”

      Cinnabar mines are common enough, so too are iron, lead and copper mines.

      The only reason any surface exposure of minerals do not actively leach mercury would be because past rainfall already leached the easy solubles.

      Much as fossil bones attract and concentrate uranium compounds, carbon deposits filter out and concentrate mercury.
      The good new is that much of the mercury compounds in coal, oil, lignite,… are pyrite related and often easily washed out.

      Figure 2 shows a general comparison of average mercury content on an equal energy basis (in lb Hg/1012 Btu [pounds of mercury per 10 12 British thermal units]) between different coal basins (Tewalt and others, 2001). This map, generated from the U.S. Geological Survey COALQUAL database, shows that Illinois Basin coal is one of the lowest mercury-input-loading basins, with 7.8 lb Hg/1012 Btu as an average value. This map was based on 255 samples for the Illinois Basin, most of them collected in Illinois.”

      Figure 2:

      “This study shows that conventional cleaning is usually an efficient method of reducing mercury content before combustion. For the coal beds studied, an average reduction in mercury concentrations (on an equal energy unit basis) on 14 full-channel samples is 39 percent. However, the degree of reduction varies widely. Variations between individual seams are not greater than within a single seam. The persent of mercury reduction is most consistent in the Danville coal, and the least consistent in the Lower Block (fig. 5).”

      Figure 5:

      Any sulphide mineral deposit is a potential source of mercury. Nor does it require that man disturb the source to release the minerals.
      http://www.mapsofworld.com/world-mineral-map.htm

      Nor are the allegedly pure Antarctica environs free of sulphide sources and vents. Especially since Western Antarctica includes the southern nadir of the ‘Ring of Fire’.
      http://www.minersoc.org/pages/Archive-MM/Volume_59/59-396-429.pdf

      http://www.mindat.org/photo-153095.html
      Pyrite : FeS2
      Spatulate Ridge Camp, Mountaineer Range, Victoria Land, Eastern Antarctica, Antarctica
      A 5.5mm Pyrite crystal in dacite rock. The Pyrite is covered in brown Limonite. Specimen was found in february 1983 during the Ganovex III expedition.”

      • And there are often mercury ‘halos’ around gold deposits. They have been used as prospecting tools by mapping the mercury vapor in the air, which results from the mercury in the soil and rocks being vaporized by heating from the sun.

        There were plans to build a subdivision on the hill in New Almaden (San Jose, CA) where considerable mercury had been mined, starting during the gold rush. However, it was discovered that the mercury vapor in the air was high enough to be of concern. Instead, Santa Clara County turned it into a park. One time when hiking there, I saw some teenagers going down the hill with backpacks stuffed with marijuana that they had apparently grown there. I’m sure that particular batch of ‘weed’ had anomalously high levels of mercury that they and others would subsequently inhale.

  5. First of all eating fish is good for the brain. The first step in fixing a problem is to check to see if it already fixed.

    For mercury checking is easy. Take hair and blood samples of people, especially those who eat lots of fish. Is the level of mercury above the threshold of harm? Yes or no!

    In the US, the answer is no according to the CDC. They do good work on environmental pollutants and the studies can be found online.

    So no problems that requires new solutions.

    “It is also created through human activity, such as gold smelting and burning fossil fuels.”

    Mercury is not created man. Mercury is ubiquitous in the environment but some human activities release mercury back to the environment.

    In the US, regulations have addressed significant sources of mercury. Burning fossil fuel was never significant, and no studies ever showed that. Nevertheless, the war on coal resulted on regulating emissions on US coal fired power plants.

    Another example of making electricity more expensive without a corresponding benefit.

    This is one of those subjects that I studied extensively. It is contrary to what the media and watermelons tells you. Feel free to post links but read them carefully first.

    • Retired Kit

      “…some human activities release mercury back to the environment.”

      Agreed in principle. Also mercury is released in various chemical forms some of which are more of a hazard than others. Alarming reports tend to be written in a way that demonizes the element itself, like ‘carbon pollution’ is used to associate CO2 with black soot.

      China having ‘the highest’ atmospheric mercury content doesn’t tell us a) if it is in a hazardous form or b) if the concentration of the hazardous form is hazardous to health. Because so many alarmists are ignorant of the subjects on which they so happily speak doesn’t mean we should not check their sources.

  6. The solution seems obvious. Expand the ozone hole to kill off these methylmercury-forming bacteria. Honey, please turn down the air conditioning. Take that, John Kerry! (/sarc)

  7. “Mercury has a long lifecycle in the atmosphere, up to a year” For real? I would think a heavy atom like that would fall out quickly. I can see, possibly, mercury released from a volcanic eruption being driven high into the atmosphere taking some time to fall out, but mercury released by a coal furnace or an automobile isn’t going to rise very high. Sort of amazes me.

    • While mercury is dense (heavy), it is liquid at room temperature and volatile.

      That is important when looking at the pathways into the body. Inhalation is worse that swallowing.

      If something is a big problem, there should be lots of real smoking guns but mercury poisoning is rarely seen by US doctors.

      I read an interesting report on mercury poisoning. A teenage boy was brought to the ER because he was unable to walk. He claimed he was not taking drugs but that was the first thing they test for. The doctors were baffled. They had read about mercury poisoning but had never seen it. A simple blood test confirmed it and a chelation therapy was started.

      Then the doctors notice his younger sister could not sit still. Tested her, mercury big time. Same for the parents who are less symptomatic. When they tested, their house it had high levels of volatile mercury that the family was breathing. Indoor air pollution from conserving energy.

      The source was a mercury switch in the gas meter. The gas company was replacing gas meter. They went back and checked the houses and 9000 homes were contaminated.

      I found the report interesting from a safety standpoint. Heating with gas is hazardous. Statistically it is very safe but gas explosions do occur. Because of the odor, people evacuate before the explosion. From an economic standpoint, extra precautions to prevent spilling mercury would have saved lots of cleanup costs.

      • ” Retired Kit P August 1, 2016 at 12:19 pm

        “That is important when looking at the pathways into the body. Inhalation is worse that swallowing. ”

        Which is why there is danger in breaking a CFL light bulb and why they should not be cast into the garbage.

    • TO, google atmospheric residence time of mercury. Takes you straight to an 87 page arl.noaa.gov report from 2000, with data from 1999. Residence time depends on mercury species. For the metal itself, 6 months-2 years. For the oxide as part of a particle ( untrapped fine fly ash) one week. And in fact the largest US source is utility coal burning. And the largest global emitter is China metallurgy (steel based on coking coal). Has a global mercury atmospheric density map also.

      • The values for residence time offend my sensibilities. My first reaction is to apply an equation of the form:

        v = E·e^(-t/τ)

        where:

        v = instantaneous value
        E = initial value
        e = 2.718… base of natural logarithms
        t = elapsed time
        τ = time constant

        This paper shows that atmospheric mercury levels are variable over relatively short time periods. In particular, mercury seems to be washed out of the atmosphere by rain. That doesn’t seem to be consistent with residence times of one or two years.

        Similar logic applies for residence times of CO2 in the atmosphere.

        What am I missing?

      • Commiebob

        The rain angle supports the evidence at Cape Point. If it is washed out completely by rain that accounts for the sporadic changes hour to hour and why there are no detectable plumes downwind of ‘major sources’.

        The hazardous broken CFL lamp story doesn’t pass the smell test. People write about mercury as if it is Sarin gas. When I was in kid we played with a cubic inch of mercury, dipped pennies in it and so on. Lots of fun.

        O wait! Maybe that explains why 50 years later my hair has started to fall out, my body feels weaker and I occasionally forget what I started talking about. It was the MERCURY!!

    • Some gold miners use a retort to vaporize the mercury off of their gold. They are then able to recover their mercury. I knew a recreational gold miner back in the early1980s, who used to burn his mercury off inside his motor home. By the end of the 1980s he was dead. Even when I first met him around 1981, I could see that his face had an unhealthy pallor. He was also mildly paranoid back then. I always wondered who had the bad luck to inherit his motor home as it would have been severely toxic.

    • Back in the early 1980s I knew a recreational gold miner who would burn mercury off of his gold in his motor home. When I first met him around 1981, I could see that his face had an unhealthy pallor to it. By the end of the 1980s he had died from mercury poisoning. I always wondered who had the misfortune to acquire his motor home as it would have been severely toxic.

  8. It would be wonderful if we could celebrate all the environmental problems solved in the US. Mercury is solved, lead is almost solved with a very positive trend.

    Instead we have organized lies. Fearmongering aimed at pregnant women.

    When the debate about regulating mercury was in progress, one of the watermelon groups issued a press release about the trend in bans for eating fish because of coal. The Washington State Department of Ecology had issued a warning for the entire state waters. I thought that it was odd because there is only one coal plant in the state.

    I found the study. There are two location where legacy pollution resulted in mercury accumulating in fish. It had nothing to do with coal and the source of mercury had been stopped many years ago. This study and previous studies show a downward trend as you would expect if the source is stopped. Fish were safe to eat.

    The Washington State Department of Ecology warning was purely political.

    • “It would be wonderful if we could celebrate all the environmental problems solved in the US. Mercury is solved”

      One of the major sources of mercury pollution that future generations are going to face is from discarded compact fluorescent lamps (CFLs), which contain mercury. Although each CFL contains a very small amount of mercury, there are vast numbers of them because incandescent bulbs have been demonized by the greenies and replaced by CFLs. . Eventually most CFLs will find their way to garbage dumps, where the mercury in them will doubtless find its way back into the environment.

      Environmental mercury can hang around for a long time. In days gone by when men wore beaverskin hats, the outer layer of fur was removed by rubbing the beaver pelt with mercury (hence the phrase ‘mad as a hatter’). Places where hat-making establishments were sited, two hundred years ago or more, are often still heavily polluted with mercury.One example of this is the Canadian Prime Minister’s official residence, which may explain Canadian foreign policy …

      • Count the number of lightbulbs in your house. Then google the number if homes destroyed on the Gulf (of Mexico) by Katrina. Calculate the number of bulbs destroyed in a single day in a relatively small area. Now imagine a storm like that hitting after a large number of people have converted to CFLs, with all that mercury going into one of the US’s prime fishing areas.

        Buy LEDs.

      • Is a mine where the ore is removed to access the mercury ‘heavily contaminated’ by definition? The mere presence of mercury is not a hazard unless a) it is no longer sitting there and b) it is in a toxic form and c) it entering the pathways to ‘us’ a a rate that presents a health hazard.

        Would we say that the Klondike is ‘contaminated by heavy metals’? It is, you know. Lots of it.

  9. I might have missed something but I don’t see any concentrations mentioned anywhere. I do see a statistic on distance. Is that too complicated for the general public, and inconvenient for the distributing bloggers?

    • I too could not find any information of the amount. Furthermore i get the impression that they migt not have found much methylmercury but only the bacteria.
      And then to make alarm we are told a long story of how toxic the substance is, but no mention of proportions.

      • SF, google minimata disease. Serious neurotoxin. Killed thousands. Particularly harmful to foetal development, which is why pregnant women are warned off things like salmon and tuna. PubMed NCBI has a large database of papers on methylmercury.

      • SF for amount, see my subcomment to TO upthread. Google atmosphere residency time mercury, takes you to a 87 page report from arl.noaa.gov that answers all your questions.

      • It’s traditional in alarmist papers not to give any actual numbers, since people would discover the levels are insufficient to be dangerous in normal circumstances.

    • ristvan,

      I don’t think that there has ever been a well-documented case of methylmercury (MM) poisoning in the US. I conclude that from my own research and a conversation with an EPA representative at a conference in Nevada City (CA) examining the legacy of mercury in the Yuba River (CA) from gold mining. That is in part, because MM is very volatile and has a boiling point the same as water. Americans are not in the habit of eating raw fresh-water fish. The Japanese have a fondness for salt-water sashimi. Cooking apparently removes most of the MM. That explains the large number of Japanese afflicted at Minimata Bay. I did a study on the potential of contaminating the Santa Clara Valley aquifer with mercury from percolation ponds obtaining the water from reservoirs on the Almaden and Guadalupe Creeks in the quicksilver district south of San Jose (CA). I had to find a lab that could do the analysis for me. The head chemist told me that if I had intentions of bringing him any fish, for me to freeze them if I could not get them to him in 24 hours. The EPA does its analysis on raw fish, not cooked fish. They base their recommendations on the MM content of the raw fish. There are only two major studies on the neurological impact of MM on children. They came to different conclusions, but the EPA has decided that the only one to be trusted is the one that showed an effect.

      • Thank you for that Clyde. Now we are reading some common sense. The ‘thousands of deaths’ mentioned above was actually ‘thousands of cases’ from eating very highly contaminated raw fish, not deaths.

        I note that the recommendation about tuna doesn’t warn us about raw vs cooked tuna. Interesting omission.

        I have just finished a design project for producing smoked fish in West Africa to reduce the Polycyclic Aromatic Hydrocarbon (PAH-4) content. Particularly they wanted a low Benzo(a)Pyrene level as the EU limit is 2 ppb.

        When the fish were dried below 85 degrees C (using a pretty clean but not spectacular wood fire) the B(a)P was 1 ppb and the other three were undetectable at a resolution on 1 ppb (LOD). Raising the processing temperature to 140 greatly increased the PAH levels because it is created by heating the fish oil.

        In short, cooking fish, especially frying it, is likely to be hundreds to thousands of time more ‘toxic’ in the sense of carcinogenic than mercury in the flesh as a brain/nerve toxin.

      • Crispin,
        If commercial fish are cooked with steam in a pressure cooker, then the volatile MM may stay with the fish. Thus, things like tuna and salmon that has been canned, may still retain much of the original MM..However, for a more typical situation of fresh fish being grilled, baked, or fried, if the volatiles are removed by a kitchen fan, then the MM content should be much lower than in raw fish.

        Anecdotally, I have in my files a story about a California Fish & Game warden, who was fond of striped bass found in the area of Suisun Bay. He was middle-aged and had eaten striped bass his whole life. Despite stripped bass having elevated MM, because they are at the top of the food chain, the game warden had normal levels of mercury in his blood.

  10. ““We need to understand more about marine mercury pollution,” said Dr Moreau, “Particularly in a warming climate and when depleted fish stocks means more seafood companies are looking south.”

    Will there be any appetite to investigate levels of mercury in marine deposits during periods of glaciation? It appears that the researcher have just admitted a disqualifying bias.

    • Kwikid,

      I gave your link a quick once over. What I didn’t see was any explanation for the transport mechanism. If you are maintaining that a couple PPM difference in partial pressure results in diffusion with the speed you claim, I’m dubious. If there is some other mechanism, then I would expect a back-flow to maintain equal pressure.

      I’d like to point out that when NH CO2 declines suddenly, about May, that coincides with when trees leaf out in NA and Europe. A much simpler explanation is that photosynthesis is kicking in and sucking up the CO2 created in the Spring from decaying leaves and stubble. Similarly, the increase in CO2 in the SH can be explained more simply by the seasonal changes.

      You write well and authoritatively. However, I can’t be as complimentary about your powers of deduction. You are violating Occam’s Razor and not providing a convincing argument as to why your explanation should be preferred over the simpler explanation of seasonal differences created by vegetation. Further evidence for the preference of vegetation controlling the changes is that the greatest CO2 concentrations are to be found in the Eastern hardwood forests of NA and in the Amazon Basin, instead of being uniformly distributed downwind from Asia.

    • There is no transport mechanism identified or imaged, only assumed.

      The Northern Hemisphere images are very different from the images that were available and posted.

      The alleged averages moves the CO2 concentration formation from Ocean and forest/jungle centric emissions to urban centric emissions.

      Which would explain why it has taken NOAA two years to finally let a study using the OCO-2 satellite.



      Note: No atmospheric transport. North Hemisphere CO2 concentration reduces as the season changes to winter while the South polar region CO2 increases as their season changes to summer, primarily over water.

      Also note the odd discrimination that masks high latitude polar CO2 emissions.

  11. After confronting PPM concentrations, there are always the PPBs and PPTs. After that we have PPquads.

    • Just researched this. FDA max allowance for methylmercury in fish is 1ppm. Swordfish and bluefin tuna the biggest problems. Parathesia (numbness, tingling, neurotoxicity) onset is 200 ppb in blood.

      • Just think of all the mercury absorption and environmental damage caused to millions by concerned mothers who liberally dumped Mercurochrome and Merthiolate on every child’s open wounds to prevent “blood poisoning” from staph infection. It was doctors orders that caused them to do that. We won’t even mention the fact that mercury was used to cure syphilis and still is the major component in dental amalgam used in filling cavities.

        My bet is that everyone over 25 walking around today has absorbed far more mercury than 200ppb. I think I’ll apply for early social security disability based on the FDA findings.

      • I grew up in the 1950s, and frequently had a sore throat (until I had my tonsils removed in 1956). EVERY time this happened, my mother ‘painted’ the back of my throat with mercurichrome. Moreover, we used to play with mercury frequently (you could make a penny look silver, like a dime). On top of that, I had a junior high science project that required my melting lead, which I did, in a small apartment, almost daily for three months. I’ve never had any health problems. I last saw a doctor for an illness (bronchitis) in 1983. My older brother is still very health, too.

        I have to wonder about those government numbers.

      • Jtom,
        You missed the remark that organic mercury compounds are much more toxic than elemental mercury. The body excretes simple metallic mercury (even when inhaled). On the other hand, methylmercury accumulates in the body. Di-methylmercury is exceedingly poisonous! There is the classic case of the Dartmouth researcher who was handling di-methyl with double latex gloves. Apparently, one or two drops got past the double barrier and she died a painful death shortly thereafter. The form of the mercury is important both in determining the potential toxicity and the bioavailability.

      • Clyde: According to the government, mercury in any form is poisonous. The most toxic form are organic compounds, which both methylmerc and mercurochrome (merbromin) are. Your argument that methylmercury is more poisonous than merbromin does not change what I said, nor its implication. We grew up frequently ingesting organic compounds of mercury, handling elemetal mercury, and for that matter, eating seafood contaminated with mercury compounds, while living in an area where electricity was produced by the burning of dirty coal, long before the EPA ever came into existence. We also lived two blocks from a huge steel mill (I have not researched what pollutants that were produced at that site). Our exposure to mercury, in whatever form you wish to consider, was as much as anywhere else in the country. There were no health problems associated with it.

        The last time I researched this issue, the only those living along a river in Japan severely polluted with organic mercury (a spill, iirc) had been documented with mercury-induced health issues.

        Again, I have to wonder if the government has overplayed the general danger of mercury. Their restrictions are not limited to methylmercury. Merbromin, for example, is now banned. I have never seen a follow-up study after the ban of various mercury-containing products that suggest a decrease in any health issues theoretically associated with those products.

  12. It appears that lower PH and solar exposures causes the break down of organic mercury compounds into elemental mercury. http://dx.doi.org/10.5562/cca2314 I expect that there is a continuous process where elemental Hg is converted to organic Hg by bacteria and then reverted to elemental Hg by other means. It would be helpful if a researcher could provide the concentrations of organic Hg in the environment over a period of years. Is the levels increasing, remaining stable or decreasing. Commenting on organic Hg in the environment is not helpful research since that fact has been documented for many years.

  13. The report is supposed to have said bacteria CAPABLE of creating methylmercury compounds were discovered. That is a far cry from actually finding methylmercury yet various assumptions and conclusions are drawn AS IF these compounds were found. If you look hard enough I would wager that you could find those bacteria just about anywhere in the world. It does NOT mean there is methylmercury all over the place.
    Just because something can be measured does NOT mean it is valid to assume it will cause harm at any time or place.

  14. I’m guessing that quite a lot of mercury comes from those ‘low energy’ light bulbs we all were forced to buy to save electricity and reduce CO2 emissions, you know the ones, kind of squirrelly shaped, the ones that are meant to last for years? (chortle)

    • In Massachusetts…if you’re a National Grid customer, they will come to your house, do a complete energy evaluation, give you insulation services at 75% off, and change EVERY lightbulb in your house for a CFL bulb, …wait for it…
      For FREE.
      My thinking was that the electric company should be going door to door giving away electric space heaters. But not in the People’s Republic of Mass, especially dealing with a European company. Heck of a business model.
      I did this, because I wanted the insulation discount. After they left, I went around and removed the CFLs.
      My insulation job was quoted at $2400, of which I paid $600 (numbers may be off, it was awhile ago).

  15. too little mercury is also a problem. something the regulators never consider. almost everything has a safe minimum and maximum. water, oxygen, food. too much, death. too little, death.

    • I have been told without evidence that mercury is a necessary trace element for proper brain development. If so, what is it’s function? Because the body has a mechanism for disposing of elemental mercury it seems very likely that it will hang onto what it needs and dump the rest. That we even possess the ability to excrete mercury suggests we are well adapted to handling the certain level we get from the natural environment.

      What is the form of mercury in a CFL and what is the form of it when it emerges from a broken one? No one has mentioned that in the comments I saw above, and I read to the bottom.

  16. Once again there is no consideration given to the inestimable amounts of elemental mercury directly injected into the oceans by submarine hydrothermal vents, which are found in all oceans, especially at the spreading centers such as the Mid-Atlantic ridge which provide the impetus for continental drift.
    http://geology.gsapubs.org/content/27/10/931.abstract
    http://www.eurekalert.org/pub_releases/1999-10/NS-Ssth-061099.php
    https://commons.wikimedia.org/wiki/File:Hydrothermal_vents_map.svg

  17. Not a ppm or ppb figure in sight. This is just rabble rousing rhetoric without them.
    Pracelsus noted the important point ‘It is the dose the makes the poison.’

  18. I wish I could find the study, but a few years ago I read about an 8,000-year-old Amerind settlement next to what is today’s Merrimack River in New Hampshire. The middens comprised large quantities of fish remains, no surprise given the site’s location.

    But what was surprising was the finding that mercury concentrations in the middens were very high, which obviously raises the question of how much humans add to what must be a natural level of Hg in fresh and salt water.

    Anyone know anything about this?

    • Anna K

      There are numerous cases where man or nature has concentrated toxic substances to level where long term exposure result in harm. It is difficult to detect.

      There is a long list of things we did to introduce mercury to our bodies. Every school child of my generation did thing with mercury in science class because it is way cool. It was in many medicines and part of voodoo.

      Put this in context of the times. My first car did not come from the factory with seat belts. Gasoline had lead in it.

  19. @ristvan

    “Wrong. See the arl.noaa.gov report on atmospheric mercury. …. Biggest US source in 1999 was utility coal. ”

    Not wrong! What part of the word ‘insignificant’ do you not understand. Natural sources of mercury are huge. Coal burning is ity bity, tiny whiney.

    There I said man is an insignificant contributor.

    Congrats on being easily brain washed.

    Here the deal. All the significant sources were regulated. That leaves coal as the ‘biggest’.

    There is not a problem.

  20. “Which is why there is danger in breaking a CFL light bulb and why they should not be cast into the garbage.”

    For general information, modern landfills have liners and leachate collection systems so there is no danger.

    If you break a CFL, call the hazmat team, condemn your house, and live in a cardboard box under the freeway. [/sarc]

    I believe the EPA has a good web site that gives practical advice.

Comments are closed.