Water Quality with Russel Barsh, August 10, 2007 · 13 August 2007, 22:31 by Julie Loyd
SUMMARY: Russel Barsh gave a day long workshop on freshwater chemistry and using a spectrophotometer. Pollutants can be natural as well as human caused. In San Juan County, a county-wide systematic testing program has yet to be instituted. High levels of Cadmium, a toxic heavy metal, have been found. It’s likely that it leaches from rocks rather than being primarily human-caused, although it is a byproduct of electronics industries. Arsenic is likely here too, but we didn’t test for it because toxic gases are released during the testing process. Nitrates in our “pristeen” waters come from human, animal, and especially bird manure. Phenols are petroleum derived substances that can mimic estrogen. Surfactants, found in soap, pull oils into water, and so they can destroy fatty tissue like fish eggs. They come from soaps and wetting agents which are put into pesticides and herbicides to make them spread better.
Russel ran about thirty tests from about ten samples. Cadmium was indeed present all across the island. There was no lead or mercury, except in one plumbing system. Some wells, including one on the mountain, had chlorides, which could be from salt or from other chlorine compounds. Brita water filters, if properly activated, removed much of the cadmium and chlorides from contaminated water. (This isn’t a product endorsement, it’s just the kind a lot of people here use.)
What follows are notes from the workshop. If you want to skip them, read the summary above and the test results above.
Present: Winnie A*, Linda E*, Sue B*, Dorn C*, extended G* family, Tom H*, L* family, Chuck L*, Madrona M*, Glen R*, R* family, Tillie S*, Gretchen W*, Bob W*, and probably others.
CAFFEINE:
In very large quantities, caffeine will interfere with the nervous system. In small aquatic animals it may be lethal. Plants don’t take it up, so running caffeine contaminated water through a bioswale doesn’t help. It lasts about six months in water.
NATURAL ORGANIC TOXINS:
The thing that makes the environment less toxic than it could be is that plants’ most effective defense molecules are heavy and oily, and don’t dissolve in water. For example, Alder trees have incredibly toxic phenols, but they’re insoluble in water. Alders in the water turn it brown with the tannins but the phenols have to be eaten by an insect to be released. Humans, however, design poisonous things specifically to dissolve in water.
SURFACTANTS
Organic chemists divide the world into two chemical systems, the aqueous and the oil/grease/petro world. Alcohols and surfactants are two classes of chemical that can bridge the gap.
Years ago, we worried about phosphates in detergents because they fertilized algal slime at the expense of other aquatic organisms. So we shifted to surfactants, which have a different and probably worse negative effect. They pull oil into water. Aquatic animals with fatty tissue can be fatally damaged. For example, a fish egg is a bag of oil. With a sufficient concentration of surfactants, it’ll pop.
In Washington, the current surfactant maximum is 5ppm (parts per million). Routinely in the streams on Orcas, Russel’s found 3, 4, or 5 ppm. Surfactants are used in soaps, and as a wetting agent in herbicides, pesticides, and fertilizers to cause better penetration. They probably cause more problems than the pesticide or other chemical they’re transferring. The ones we’re using now are linear alkyl benzoates or LAS, a simple molecule with a couple of Carbons and Oxygens at one end, which is lipophilic, that is, oil loving. They look like a jellyfish with long trails. One end is lipophilic, the other hydrophilic, or water loving. What’s at the end of the jellyfish determines the type, like sulfur. Depending on the length, the half life of a surfactant is anywhere from six hours to several years. Short chain surfactants, by the time they get out of a septic tank, are gone. Others last for years.
CADMIUM AND OTHER HEAVY METALS:
Most metals are toxic. The Washington Dept of Agriculture keeps a list of fertilizers. Zinc is used by plants and animals in small quantities, comes off of boat antifouling paint, lumber treatment, concrete pilings. Sometimes combined with Arsenic. Very heavy metals such as Lead, Cadmium, and Nickel are as far as we know never good for plants or animals.
Iron: Barsh has found 15 – 20 ppm in bogs in SJC, it’s toxic at that level. In small concentrations it’s necessary to life.
Copper: is a problem in many places because we use so much of it.
Molybdenum: is used by plants in reproduction and in nitrogen fixing. Found in fertilizer as a contaminant because the fertilizers are smelter ash.
Cadmium: EPA only recommends, not prescribes. Now, allowable Cadmium up to 5 ppm, but research shows it’s toxic at 5 ppb, a thousand times less than the State standard. Two teams are looking at Cadmium in SJC. USGS was asked to look at eelgrass dieoffs. They noticed the sediments had high levels of Cadmium, 2 – 5 ppm, a problem for animals. Maybe it’s coming from upwellings, Cadmium that was deposited and redistributed by underwater events. Barsh’s team with Ruth Harper and Jack Bell were looking at freshwater systems. Maybe it’s coming from industry (dry cells, batteries, brake pads, PVC pipe plasticizer). No correlation found. Both teams now wonder if it’s part of a natural process.
Cadmium and other heavy metals, Lead, Zinc, Uranium, Vanadium, are big electromagnetically sticky balls, don’t dissolve in water well. If water is slightly acidic, then the metal can dissolve, and if the acidity drops, the ions drop out of solution. The ions stick to certain things on the substrate, clay. Microscopically, clay is a sheet of glass with a lot of surface area, and a sticky chemistry. So the heavy metals are bouncing back and forth from water to clay depending on pH. Turbidity carries little clay life rafts which ferry heavy metals. The other thing that does this is charcoal, that’s why charcoal is used in filters. To clean out a charcoal filter, pour acid through it and the metal will come out.
In our wetlands, the sediments become enriched with heavy metals. Over 100’s of 1000’s of years, the silty, alkaline substrate becomes that grey shale that we have all over the islands. That ends up in the hills. Since rain is slightly acidic, the heavy metals are released and flow back downhill.
Oysters live at the edge of our wetlands since they like seeps, so they’d soak up heavy metals. Ruth and Russel are sampling at the stream to wetland zone, and at the oyster zone. May end up sampling up the streams.
Arsenic: Mountain Lake on Orcas has high Arsenic levels. Higher places have more airborne contamination, spread by rainfall. Low places have more terrestrial contamination. In this county we have both. PCBs come from fires, goes into atmosphere with the gases and ash, the highest concentrations are at mountaintops. SJC only has 3 years of testing results for heavy metals, has found arsenic in about a third of the wells.
Lead: Possibly the heavy use of Lead arsenate in orchard spray until the 60’s is a problem but we don’t know how to source that. Arsenic and Lead move differently: Lead goes straight down while Arsenic can be in solution.
1 ppb of Lead is the limit in drinking water. But 1 ppb in other products gets into the environment, and if we eat things like tuna or salmon, we’ll get more than 1 ppb. Lead atoms block ion channels which is how the nervous system functions. A neuron has receptor sites set to respond to a certain signal molecule that locks in by shape, so it has protein landing sites. The heavy metal molecule will sit in a receptor site and never leave. That’s why it’s accumulative.
The nice thing about Lead is that it’s so heavy, it takes a lot to pull it off the substrate. Mercury by comparison is able to combine chemically with some organics in water. Methylation helps it dissolve better. Then creatures in the water can drink it and it accumulates faster. Cadmium is relatively light, and is one of the ones that shifts between being in solution or the substrate with small changes in the acidity of the water. Thus the rocks, substrate, water, life forms, will all have different levels of contamination picked up through different pathways. Ruth, Jack, and Russel, for each site, take water samples and silt samples to get total vs. dissolved metal loads.
PHENOLS and PLASTIC:
The phenols are petroleum derived.
Russel took some skin lotion off a shelf and used it as a horrible example: Look at nice innocent “Suave skin therapy cucumber with aloe” ingredient list. The stearates are surfactants, to make things miscible.
Everyone should test their water now and then keep testing over the years looking for trends.
Bob: What’s the best way to get rid of plastic?
All: Do not burn it! That’s the worst!
Russel: Bury it if you have small amounts, it will eventually break down. Best thing is to not have it. Recycled plastic used to go to China but now might end up in a landfill.
TOXICOLOGY
Barsh and Vicki H* are pressing the county to do a professional assessment of the most commonly available products used in the county, and provide information in stores about the lowest impact surfactants. There are about 12 home pesticides in common use in SJC, all using one of 3 compounds called perethrins. Perethrins are a natural defense in trees that have been modified for mass production and to be more deadly. At the level of a few ppm, two of these pesticides will start killing fish. The third is ten times more toxic.
The National Library of Medicine has about 70,000 of the 240,000 potentially toxic chemicals in the environment. You get a search window, write in what’s on the label, it’ll give you the formula, structure, physical properties, with a navigation button, “toxicology,” giving a bibliography.
Toxicity terminology: LD50 = 50 mg means lethal dose is 50 mg or LC50 = 1 ppm, lethal concentration. The 50 is a %, half the organisms die at the LC50. Depends on weight, age, gender of person. Sometimes it’s expressed as mg/kg, milligrams per kilogram of body weight. It doesn’t talk about cumulative. We now have 10’s of 1000’s of toxic molecules floating around but these toxicology numbers are based on individual doses, not synergies.
Amounts are microgram, mg, 1/1000 of a gram; µg, a millionth, and picogram, pg, is a billionth. There are about 3 grams in a teaspoon. 10 parts per billion, if the room were filled with peas, one of them would be that one part. But Lead is toxic at one part per billion. Dioxins are poisonous at even smaller levels than that.
We metabolize some metals and that’s why they’re not toxic at low levels. But the heavy metals can’t be moved once they’ve settled in. Nickel, zinc, and copper, look similar from the point of view of a body, and so the body might make a copper protein using zinc instead.
Some organotoxins mimic receptor sites instead of blocking them. Misrecognizing proteins is a problem. There are estrogenic compounds in hops, soy, and anything that’s been in plastic.
BIOACCUMULATORS:
The Japanese no longer import oysters from WA, which have 2 ppm Cadmium in them, they’re hyperaccumulators. They’re using oysters in Long Island to bioaccumulate toxins.
Geoducks and some other native shellfish, however, don’t bioaccumulate Cd. Nobody’s studied our native Olympic oysters. Other Cadmium bioaccumulators include mustards (which also accumulate nickel) and agarica mushrooms like portabellas. Phytoaccumulation is planting things on a “hot” site, you harvest it, burn it, smelt the ash and recover the metal. They’re doing this routinely in the Europe, but not West of the Mississippi.
Some plants at Hanford will accumulate the heavy radioactive metals. One of the tumbling plants is escaping, rolling out of Hanford carrying radioactive waste elsewhere.
Crabs are detrital feeders. They’ve only been tested for PCB’s, it’s not known if they are bioaccumulators of metals. Otters will move toxins up the system. The rate of accumulation of metals varies with which one. Lead is slow. The faster ones are Cadmium and Mercury, they enrich through the trophic system.
A metal will sit surrounded by proteins like a basketball. Some bioaccumulators fold melanothyanins around the heavy metals and carry them around.
TESTING ORGANICS:
Organic testing is problematic because they’re hundreds of thousands of compounds. They can come from anywhere. There’s no way to decide which ones to test for. You can do a test to see if they’re there.
PAH are Polyaromatic hydrocarbons, connected benzene rings like chickenwire. The bigger the chickenwire (like 200 rings) the more problematic in your body because they wrap around proteins like DNA and block signalling and transcription. Luckily, as they get heavier, they have trouble dissolving in water. The lightest one has two rings, phenanthrene, it’s in the tar, but probably doesn’t come out later on. Similar in structure to a lignin, but it’s a coal tar, not a wood tar. It’s found in chipseal that the county puts on the roads.
A chromatophore is a group of bonded atoms that pick up a particular wavelength, identified by its particular brand of absorption. The benzine ring absorbs 254 µm (nanometers, a billionth of a meter), ultraviolet. Our eyes function down to about 350 µm. Double conjugated carbon bonds resonates at 212 µm
Benzine, tolulene, are particularly nasty because they are reception blockers on proteins, will fill up receptor sites so the protein can’t function. Proteins work by lock and key shapes and then doing something to the key; fold, separate, whatever. The larger chickenwire things will wrap around them and prevent them from functioning. They break down eventually because they’re made out of the same materials that we are; light and heat will get at them, they’re far less persistent than metals. Eventually some bacterium will turn it into food.
Russel drew pictures. A biphenyl looks like sunglasses, it’s got 2 carbon rings with a join at the corners. It’s a common basic structure, in tannins and tea. But replace one H with Cl and you get PCBs. Bubble chlorine through tea and you’ll get PCB’s. If you put tea in water which still has its Cl in it you get a halomethane.
Friday Harbor Water has been on the edge of exceeding their trihalomethane levels, because they bubble Cl through before removing all their organic compounds. When saturating a biphenyl with Chlorine; there are 10 receptors, you can have 10 congeners or variations. If you break the bond between the rings and put an Oxygen atom where the bond was, you get flame retardants, PCDE. If you put Bromine, you get a PBDE, a flame retardant. Bromine is like Chlorine. Cl is more abundant, Br is more toxic. Br compounds have a longer half life. When you burn it the Br is released, you get a veil of bromine gas which is poisonous and suffocates the fire. It also breaks down naturally over time, releasing the Bromine.
AQUIFERS:
W* is basically a big sandbox. Down to the clay, there are 10 to 20 feet of sand. Metals are immortal and the organics break down over time.
Rock doesn’t filter out bacteria like sand does. Turbid water in a rainstorm will infiltrate through the cracks and carry it to the wells.
Bob W*: On Sandy Point on the south side, almost all the wells are high in chlorides. Every winter our windows get plastered with salt from the wind. That salt is on the surface of the ground, in a few years you have a ton.
Barsh: It depends on what’s on the surface and where your well is. On Cowlitz at the exposed bluffs you can see strata, clay, sand, and silt. Drilled wells are below the clay.
Bill C*n told a prospective buyer of a parcel that W* water comes from Mt. Baker. Actually, it doesn’t.
To see whether surface water goes to the aquifer, they use a labeled stable isotope of something small and light like heavy water, and look for isotopic signals. Many plants and animals actually slightly favor heavy isotopes though they are used the same.
TESTING PROCEDURE:
Unfortunately, every test is specific, so you have to run a combination of them.
You’re measuring such small amounts that the testing process has to be exacting. Load the glass in the same way each time to avoid thickness affecting it, don’t put fingerprints on, scrub the glass out with HCl to burn things off and rinse with ultra-pure water. Using a disposable pipette to transfer water, send the sample through a syringe filter to remove bacteria.
The larger spectrophotometer will generate light from 200 to 1000 nm (not µm as the first draft had it). You tell the smaller one what you’re looking for and it will generate the appropriate frequency.
TNC POND WATER BY THE BEAVER DAM:
Barsh: We see about 750 ppb Cadmium around here so that’s what we’ll test for. Use gloves and a dedicated disposable pipette to put 10ml of water in the jar. This will be the reference, before any chromatophores have been attached to the molecules. It remembers this as a baseline. On the menu, pick out Cd and it tells me to put the cubule in.
Brand it with a chromatophore. Since it’s pH sensitive, it has to have a buffer of 1 ml of buffer, specific to this particular reaction, sodium citrate. There’s a manual with all the pre-programmed recipes. Next add an indicator. 1, 2 pyridyl azo naphthol. This instantly turns it orangey yellow. Now add 1/2 ml surfactants, to emulsify the heavy indicator. Shoot it twice to see if it’s a stable reading as the chemical reactions take place, or there was a bubble. You have a window of 1 minute unless the protocol says different. With Chloride test the window is 2 minutes.
First reading: .12ppm Cadmium Second reading: .13ppm or 130 ppb which is high according to the EPA. 10 – 50ppb starts to show effects.
Interference: Whatever else is in the sample might interfere with the reading. With Cadmium, manganese, silver, and nickel will have a synergistic effect and drive the reading up. Second source of error is instrument or experimental error. With ultra-pure water, 50ppb is not uncommon. So, we can subtract 50 out, and get our final reading of 80ppb. On the other hand, the manganese test is reliable, since putting clear water through results in a zero reading.
A road drains into TNC swamp, so let’s check for phenols. First test with a blank, this should be done before each test instead of using one for all the tests. The reagent is amino antipyrene, which will attach itself to every phenol carbon ring as a chromatophore. The phenolic test is accurate, but we have to remember that some naturally occurring substances are phenols. Since the more complex PAH’s are ring rich, this is a good test for petroleum based contamination. Put 10ml of sample water into cubule. Add amino antipyrene using one of those presized little spoons. First test: .14 ppb phenolics, or 140 ppm, it is within the order of magnitude of 100 ppm. Zero is good, found in high altitude ponds. This reading is typical for the county, most of it is between .1 and .2. At this level, it’s bad news for some microorganisms but probably not for us, unless it’s a specific phenolic like dioxin that affects us.
Surfactants test: Shoot a baseline. To the next sample, I add a buffer. Surfactants are a blob with a phosphorus or carbon blob in it, a carbonate or sulfonate. I add an indicator, it’s toluene, a toxic chemical. Many of the reagents used to test for toxic chemicals are themselves highly toxic, in this case it’s worse than the surfactants. Our noses are capable of smelling toluene at 2 ppb. The toluene puddles at the top in a dark blue layer. The protocol calls for shaking it 1 minute and letting it sit for 5 minutes.
To test for Mercury, the indicator has to be mixed up fresh each day. 1/2 ml of a ketone with a sulphonyl group on it: thio-michler’s solution. Add then wait a minute for the reaction.
At the end of the testing, put the sample into a hazardous waste bucket filled with vermiculite. Keep track of what you put in the bucket because hazmat people can dispose of it cheaply if they don’t have to test it to see what it is.
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