mercury

USGS claims that mercury and selenium are accumulating in the Colorado River

A study conducted by the U.S. Geological Survey (USGS) claims to have found “relatively high -compared with other large rivers” concentrations of mercury (Hg) and selenium (Se) in the food web along the Colorado River between Glen Canyon Dam and the Grand Canyon, The study was done in the summer of 2008, but curiously, results were just published in the journal Environmental Toxicology and Chemistry in August 2015. Perhaps they were taking advantage of publicity associated with the toxic spill from the Gold King mine in Colorado earlier this month.

USGS Hg Se study map

Some excerpts from the press release:

“The study, led by the U.S. Geological Survey, found that concentrations of mercury and selenium in Colorado River food webs of the Grand Canyon National Park, regularly exceeded risk thresholds for fish and wildlife. These risk thresholds indicate the concentrations of toxins in food that could be harmful if eaten by fish, wildlife and humans. These findings add to a growing body of research demonstrating that remote ecosystems are vulnerable to long-range transport and bioaccumulation of contaminants.”

“The study examined food webs at six sites along nearly 250 miles of the Colorado River downstream from Glen Canyon Dam within Glen Canyon National Recreation Area and Grand Canyon National Park in the summer of 2008. The researchers found that mercury and selenium concentrations in minnows and invertebrates exceeded dietary fish and wildlife toxicity thresholds.”

“Although the number of samples was relatively low, mercury levels in rainbow trout, the most common species harvested by anglers in the study area, were below the EPA threshold that would trigger advisories for human consumption.”

See full paper: http://onlinelibrary.wiley.com/doi/10.1002/etc.3077/epdf

From the paper:

“Sampling occurred from 12 to 28 June 2008. At each site, we collected representative basal resources (organic matter and primary producers), macroinvertebrates, and fishes. Basal resources included fine benthic organic matter, seston (suspended organic matter), epilithon (benthic biofilm), attached algae (Cladophora sp.), and epiphyton (diatoms attached to Cladophora). We collected fine benthic organic matter from sandy depositional habitats using a Ponar dredge (0.052 m2 ) deployed from a boat.”

As far as I can determine, the study analyzed fewer than 25 samples of each group along 250 miles of river. That is indeed a very low number upon which to form conclusions.

“In the present study we found no significant differences in Hg and Se accumulation among sites throughout the Grand Canyon.”

“There is a well-documented antagonistic interaction between Se and Hg, whereby Se protects animals from Hg toxicity when Hg:Se molar ratios are approximately 1 or less. The Hg:Se molar ratios were typically much lower than 1 in the present study, ranging from 0.04 (rainbow trout) to 0.38 (fathead minnow) among fish species. Assuming that Se and Hg in prey are equally transferred to consumers, this large excess of Se in this system suggests that the risks of Hg toxicity could be considerably lower than the Hg wildlife risk values alone would indicate.”

From the press release:

“The good news is that concentrations of mercury in rainbow trout were very low in the popular Glen Canyon sport fishery, and all of the large rainbow trout analyzed from the Grand Canyon were also well below the risk thresholds for humans,” said one of the study authors.

“We also found some surprising patterns of mercury in rainbow trout in the Grand Canyon. Biomagnification usually leads to large fish having higher concentrations of mercury than small fish. But we found the opposite pattern, where small, 3-inch rainbow trout in the Grand Canyon had higher concentrations than the larger rainbow trout that anglers target.”

Regarding mercury: “Airborne transport and deposition — with much of it coming from outside the country — is most commonly identified as the mechanism for contaminant introduction to remote ecosystems, and this is a potential pathway for mercury entering the Grand Canyon food web.” Selenium is derived from “irrigation of selenium-rich soils in the upper Colorado River basin contributes much of the selenium that is present in the Colorado River in Grand Canyon.”

The paper abstract notes that “consistent longitudinal patterns in Hg or Se concentrations relative to the dam were lacking.” That would seem to cast in doubt the proposed source of selenium from upstream irrigation of agricultural land. The “relatively high” concentrations they were talking about in fish are 0.17–1.59 ppm Hg and 1.35–2.65 ppm Se.

END

Hype about Mercury in the oceans

“A new paper by a group that includes researchers from the Woods Hole Oceanographic Institution (WHOI), Wright State University, Observatoire Midi-Pyréneés in France, and the Royal Netherlands Institute for Sea Research appears in this week’s edition of the journal Nature and provides the first direct calculation of mercury in the global ocean from pollution based on data obtained from 12 sampling cruises over the past 8 years. The work, which was funded by the U.S. National Science Foundation and the European Research Council and led by WHOI marine chemist Carl Lamborg, also provides a look at the global distribution of mercury in the marine environment,” says the press release.

 What made headlines in the press is this: “Analysis of their results showed rough agreement with the models used previously—that the ocean contains about 60,000 to 80,000 tons of pollution mercury. In addition, they found that ocean waters shallower than about 100 m (300 feet) have tripled in mercury concentration since the Industrial Revolution…..” “Tripled” is what the press picked up, but most sources did not print the rest of the sentence: …” and that the ocean as a whole has shown an increase of roughly 10 percent over pre-industrial mercury levels.”

But “tripled.” Wow. How much is that? According to the researchers, the tripling amounts to a concentration of 0.6 parts per trillion in the upper ocean (that means it changed from 0.0000000000002 to 0.0000000000006, less than one molecule of mercury per liter of water). Are instruments so refined that they can even measure such a small amount? And, how do they know how much mercury was in the oceans in pre -industrial times?

As it turns out, the researchers could not actually measure mercury present in pre-industrial times. Rather, “The group started by looking at data sets that offer detail about oceanic levels of phosphate, a substance that is both better studied than mercury and that behaves in much the same way in the ocean… By determining the ratio of phosphate to mercury …the group was able to estimate mercury in the ocean that originated from natural sources such as the breakdown, or weathering, of rocks on land.” In other words they made a very big assumption.

The researchers also said that current mercury concentration is lower than that reported in several previous papers.

Let’s look at the bigger picture. The following is from a fact sheet published by the Science and Public Policy Institute:

Mercury (Hg) is an element that has existed (and will continue to exist) naturally since the earth was formed 4.5 billion years ago. The oceans alone contain millions of tons of mercury. [So called “pollution mercury” even at 80,000 tons is small compared to the naturally-occurring millions of tons.]

There are two major forms of mercury emitted during fossil fuel combustion:

1. Oxidized, which is water soluble and can be washed out of the air into rivers, lakes, and streams.

2. Elemental, which is not water soluble and moves around in a global mercury cycle.

A small fraction (about one one-thousandth) of the oxidized mercury that ends up in waterways may be changed into an organic form called methylmercury (MeHg) which is the kind of mercury with which EPA is concerned. This type of mercury can be eaten by tiny organisms that are then eaten by small fish, resulting in possible bioaccumulation in larger fish eaten by humans.

Methylmercury is not emitted directly from fossil-fuel-fired power plants. It is produced and

accumulated within the biosphere by a myriad of mercury transformation processes that do not depend upon the amount of inorganic mercury emitted from man-made sources. The natural cyclical production and destruction is controlled by environmental factors and ecosystem processes that are largely beyond human control or intervention.

A new estimate by scientists from the National Center for Atmospheric Research shows that mercury emissions from forest fires in the lower 48 U.S. states and Alaska amount to about 44 tons per year. This is of similar magnitude to the total mercury emissions from U.S. power plants. When estimates of all natural sources are considered, including geothermal events under oceans and lakes, US power plants may account for as little as 0.002% of the entire annual world mercury emissions budget.

Another SPPI report examines the safety of eating fish and concludes:

“The preponderance of the latest scientific literature strongly suggests that at historic

consumption levels we have always been, and will continue to be, safe from the fish we eat.

All sectors of the U.S. population, especially pregnant women, children and the elderly, should

continue deriving critically needed nutrition from fish. There is no sound scientific evidence to suggest that the American public, especially infants and young children, have been exposed to harmful levels of mercury.”

It’s just another phantom menace so scare the people so they demand that government save us.

First Image of Planet Mercury

NASA’s Messenger exploratory vehicle achieved orbit around planet Mercury on March 17, and has now sent back the first close-up image of the planet.

Mercury1

From the image, Mercury looks much like our moon.  A continuous mapping program will begin April 4.  You can keep track of progress here.  Messenger’s orbit is highly elliptical around Mercury, varying from 124 miles to 9,300 miles above the surface.

Why explore Mercury?  According to NASA:

The importance of Mercury, beyond that we know so little about this planet, is that it offers a chance to examine another outcome of the processes that also produced Earth, Venus, and Mars. Learning how Mercury ended up the densest planet (after correcting for internal pressures) will tell us much about planetary formation. Discovering how Mercury has sustained a magnetic field while larger bodies either have lost an earlier field (as Mars did) or have no present field or a record of a past field (Venus) will help us to understand magnetic field generation in our own planet.

Mercury also has the thinnest atmosphere among all the terrestrial planets and an incredibly wide temperature range. In fact, temperatures vary from nearly the highest in the solar system (at the equator) to among the coldest (in the permanently shadowed areas where ice deposits seem to lurk). Documenting the nature of Mercury’s tenuous and changeable atmosphere and the composition of its mysterious polar deposits – thought by many to consist of water ice – will give us new insight into the volatile materials in the inner solar system.

On its sunny side, Mercury can reach a scorching 700 K (about 800°F). But because it has virtually no atmosphere to hold in that heat, temperatures drop to about 90 K (about -300°F) on the dark side.

How Many Haz-Mat Suits Do You Need to Change a Lightbulb?

Congress, in their wisdom, has mandated that the phase-out of incandescent light bulbs is to begin with the 100-watt bulb in 2012 and end in 2014 with the 40-watt. They use too much energy you see. The government is encouraging us to use eco-friendly green lighting such as Compact fluorescent light bulbs (CFL) or LEDs (light emitting diodes).

HazmatThe U.S. Department of Energy has a “Change a Light Bulb Program” in which they encourage us to replace incandescent light bulbs with more-energy-efficient, but much more expensive compact fluorescent bulbs. The Environmental Protection Agency (EPA) has a similar program.

Compact fluorescent light bulbs contain mercury vapor which can be hazardous to our health. Therefore, the EPA recommends you take the following steps if you should break one in your home:

Before Cleanup

Have people and pets leave the room, and avoid the breakage area on the way out.

Open a window or door to the outdoors and leave the room for 5-10 minutes.

Shut off the central forced-air heating/air conditioning (H&AC) system, if you have one.

Collect materials you will need to clean up the broken bulb:

Stiff paper or cardboard

Sticky tape (e.g., duct tape)

Damp paper towels or disposable wet wipes (for hard surfaces)

Glass jar with a metal lid (such as a canning jar) or a sealable plastic bag(s)

Cleanup Steps for Hard Surfaces

Carefully scoop up glass fragments and powder using stiff paper or cardboard and place debris and paper/cardboard in a glass jar with a metal lid. If a glass jar is not available, use a sealable plastic bag. (NOTE: Since a plastic bag will not prevent the mercury vapor from escaping, remove the plastic bag(s) from the home after cleanup.)

Use sticky tape, such as duct tape, to pick up any remaining small glass fragments and powder. Place the used tape in the glass jar or plastic bag.

Wipe the area clean with damp paper towels or disposable wet wipes. Place the towels in the glass jar or plastic bag.

Vacuuming of hard surfaces during cleanup is not recommended unless broken glass remains after all other cleanup steps have been taken. [NOTE: It is possible that vacuuming could spread mercury-containing powder or mercury vapor, although available information on this problem is limited.] If vacuuming is needed to ensure removal of all broken glass, keep the following tips in mind:

Keep a window or door to the outdoors open;

Vacuum the area where the bulb was broken using the vacuum hose, if available; and

Remove the vacuum bag (or empty and wipe the canister) and seal the bag/vacuum debris, and any materials used to clean the vacuum, in a plastic bag.

Promptly place all bulb debris and cleanup materials, including vacuum cleaner bags, outdoors in a trash container or protected area until materials can be disposed of properly.

Check with your local or state government about disposal requirements in your area. Some states and communities require fluorescent bulbs (broken or unbroken) be taken to a local recycling center.

Wash your hands with soap and water after disposing of the jars or plastic bags containing bulb debris and cleanup materials.

Continue to air out the room where the bulb was broken and leave the H&AC system shut off, as practical, for several hours.

Cleanup Steps for Carpeting or Rugs

Carefully scoop up glass fragments and powder using stiff paper or cardboard and place debris and paper/cardboard in a glass jar with a metal lid. If a glass jar is not available, use a sealable plastic bag. (NOTE: Since a plastic bag will not prevent the mercury vapor from escaping, remove the plastic bag(s) from the home after cleanup.)

Use sticky tape, such as duct tape, to pick up any remaining small glass fragments and powder. Place the used tape in the glass jar or plastic bag.

Vacuuming of carpeting or rugs during cleanup is not recommended unless broken glass remains after all other cleanup steps have been taken. [NOTE: It is possible that vacuuming could spread mercury-containing powder or mercury vapor, although available information on this problem is limited.] If vacuuming is needed to ensure removal of all broken glass, keep the following tips in mind:

Keep a window or door to the outdoors open;

Vacuum the area where the bulb was broken using the vacuum hose, if available, and

Remove the vacuum bag (or empty and wipe the canister) and seal the bag/vacuum debris, and any materials used to clean the vacuum, in a plastic bag.

Promptly place all bulb debris and cleanup materials, including vacuum cleaner bags, outdoors in a trash container or protected area until materials can be disposed of properly.

Check with your local or state government about disposal requirements in your area. Some states and communities require fluorescent bulbs (broken or unbroken) be taken to a local recycling center.

Wash your hands with soap and water after disposing of the jars or plastic bags containing bulb debris and cleanup materials.

Continue to air out the room where the bulb was broken and leave the H&AC system shut off, as practical, for several hours.

Future Cleaning of Carpeting or Rugs: Air Out the Room During and After Vacuuming

The next several times you vacuum the rug or carpet, shut off the H&AC system if you have one, close the doors to other rooms, and open a window or door to the outside before vacuuming. Change the vacuum bag after each use in this area.

After vacuuming is completed, keep the H&AC system shut off and the window or door to the outside open, as practical, for several hours.

Now isn’t that easy? Strangely enough, while DOE and EPA are encouraging Americans to use CFLs, they are discouraging school children in Southeast Asia from using CFLs. The EPA says, “Just as there are no safe uses of mercury and mercury-containing equipment in schools, there are no safe uses for these products in homes, either. Tell your parents about the toxic effects of mercury, and encourage them to remove all mercury products from your home.” (Source: see Section 3.4.2, page 17). It is not clear to me just why the EPA is concerned with school children in Southeast Asia.

The EPA’s current permissible exposure to elemental mercury via inhalation is 0.3 µg/m3. A broken bulb can put 200 to 800 µg/m3 into a room. If CFLs were not important to the EPA in its war on carbon dioxide, the EPA would probably ban them as unsafe.

Maybe we should skip CFLs and go to the more eco-friendly LED (light emitting diode) lights. They contain no mercury. But, according to a study of LEDs from the University of California, Irvine, LEDs ” contain lead, arsenic, and a dozen other potentially hazardous substances…”

Isn’t it ironic that the eco-friendly, green lighting systems are not only more expensive, but hazardous to our health. It’s time for the feds to stop micromanaging the type of lighting we use and give us back our old-fashioned, and much safer incandescent light bulbs.