NATURALLY DANGEROUS: Surprising Facts About Food, Health, and the Environment.
By James P. Collman, Professor of Chemistry, Stanford University
Chapter 6. Nature is Elemental
© James P. Collman, 2003. All rights reserved
Recall from Chapter 6 in Naturally Dangerous that all shell-fish contain
a natural, water-soluble arsenic compound that is not considered toxic. Very
recently, fat-soluble compounds containing arsenic have been discovered in
a North Atlantic fish in the smelt family: "capelin. It is probable that
these natural arsenic containing lipids may exist in other fatty fish and
this has important implications concerning human health and the ocean environment.
It is likely that this lipid would be a source of arsenic toxicity. This discovery
flies in the face of suggestions that people eat fatty fish to obtain essential
omega-3 fatty acids in their diets. So far, three similar arsenic containing
fatty molecules have been discovered in fish. This is an ongoing, but unrecognized
problem. Watch out for more news stories on this issue, which so far has been
reported only in the scientific literature. (Chem. & Eng. News, August
11, 2008, page 10)
Hydrogen sulfide, H2S, is a noxious toxic gas familiar to students who worked in old chemistry laboratories. It has been known for decades that H2S is produced in our body. Two enzymes, cystathioneine-lyase (CSE) and cystathionine-synthase regulate H2S levels in mammals (including humans). CSE is found in the liver and vascular smooth muscle cells, but cystathioinine-synthase produces H2S in the brain. Garlic can be transformed into H2S by enzymes in the body, so that some of its claimed medicinal properties can be traced to H2S.
H2S can have helpful or harmful effects on a range of disorders: hypertension, diabetes, atherosclerosis, neurological problems, and strokes. But possible protocols for using H2S to treat these problems have not been worked out.
Experiments with mice have shown that H2S can reduce their ability to metabolize oxygen, reducing their heart rate and breathing rate, lowering their body temperature, and creating a state of deep hybernation. By flushing the with air, the mice can be restored to normal without apparent behavioral effects. The possibility of using H2S in heart surgery or treating badly injured soldiers is being studied. By studying roundworms (C. elegans) it has been shown that 50 parts per million of H2S can extend their lives by 70 percent. This "fountain of youth" phenomenon seems to be connected to the gene SIR-2, which had previously been related to life span regulation.
These preliminary findings are very exciting and may lead to medical advances.
H2S appears to be another example of a "gasotransmitter" such as
the hormone NO. Your author speculates that H2S may be involved in the hybernation
of certain animals. (Science News, March 8, 2008, Vol. 173, page 152)
Roxarsone is an organic arsenic-based additive used in chicken feed to promote growth, kill parasites that cause diarrhea, and improve the color of chicken meat. Such arsenic additives have been banned from chicken feed by the European Union since 1999, but roxarsone is still added to the feed of about 70% of the 9 billion broiler chickens that are grown annually in the U.S. This organic arsenic compound is not as toxic as the inorganic forms of arsenic, but some of the roxarsone is transformed into these more dangerous inorganic forms of arsenic by bacteria within the chicken and additional roxarsone is turned into the inorganic forms after the chicken excretes it. Some roxarsone and the inorganic forms of arsenic end up in the meat of the chicken; other arsenic from chicken litter contaminates the soil and gets into the ground water. Chicken litter is used to make fertilizer pellets for gardens and lawns, further contaminating the environment. As of January 2006, the EPA lowered the permissible arsenic in drinking water from 50 to 10 ppb. Nevertheless the risk of cancer from 10 ppb arsenic in drinking water is 1 in 2000, which is 50 times higher than that allowed for other carcinogens. But the allowed arsenic in chicken meat remains at 500 ppb. A scientist at USDA has estimated that the intake of inorganic arsenic from eating chicken is between 1.3 and 5.2 micrograms per day, but this amount would be higher for people who ate more chicken. David Wallinga, director of the food and health program at the Institute for Agriculture & Trade Policy found 55% of 151 samples of chicken contained arsenic in an amount between 1.6 and 21.2 ppb. Most of the chicken containing arsenic came from “conventional producers”; but one third of samples from organic suppliers had detectible arsenic. The “good news” is that no arsenic was found in chicken obtained from Tyson and Foster Farms, which have stopped using roxarsone. McDonald’s has forbidden poultry suppliers from using this arsenic additive. (Chemistry & Engineering News, April 9, 2007, page 34)
Anemia is the medical term for a shortage of red blood cells; these tiny cells carry oxygen from the lungs to tissues throughout the body and then back to the lungs to pick up more oxygen. Every heartbeat pumps millions of red blood cells at a speed of about 3 feet per second. Blood cells die before they are 4 months old, but they are replaced with new ones at an amazing rate: 2 million new cells per second! As people age, some individuals fail to produce as many blood cells as they are losing. The resulting deficiency, anemia often reflects poor health. Anemic individuals suffer fatigue, headaches, lower cognitive function, and have pale skin. Anemic people tend to have a shorter life span, a poor quality of life, are more often hospitalized, and require greater health care. In some studies it appears that anemic individuals have a 40 percent higher death rate compared to a non-anemic control group. But it is uncertain whether these deaths were directly related to anemia; some underlying problems may have caused both the anemia and the shorter life span.
Is there a simple test for anemia? A practical test of anemia is to measure the concentration of red oxygen carrying pigment, hemoglobin in the blood, which should be greater than 13.0 grams per deciliter for men and 12.0 for women. Average hemoglobin concentrations in healthy white men and women are greater than 15.0 and 13.0 respectively. Black men and women have slightly lower levels than white men and women. In fact anemia is more common among blacks in all age and sex groupings.
What groups tend to be anemic? Premenopausal women are more likely to be anemic compared with their male counterparts such that about 12 percent of U.S. women between the ages 17 and 49 have anemia, but only 1 percent of men that age are anemic. But the major anemic group is found among the elderly: for instance, after age 85, 26 percent of men and 20 percent of women are anemic.
What causes anemia and can it be treated? In some cases anemia can be explained by the fact that those individuals do not produce enough of the hormone erythropoietin, which stimulates the production of red blood cells. Erythropoietin is made in the kidneys and certain cases of anemia can be traced to a kidney disorder sometimes resulting from diabetes or rheumatoid arthritis or from a chronic infection. In those instances the anemia may respond to injections of erythropoietin, but this can be expensive and must be continued to be effective. In other instances, an anemic patient may have a deficiency of iron or of folic acid or vitamin B12, all of which are required to make hemoglobin. However, in many cases there is no simple explanation for a patient’s anemia. For such anemic patients there is no obvious treatment.
Selenium is known to be an anti-oxidant and there is some evidence that it can lower the incidence of various cancers: colorectal, prostate and lung cancer. Since selenium is known to be an anti-oxidant, it was assumed to be effective in lowering the rate of heart disease. Not so, according to a recent statistical study of more than 1,000 Americans who took 200 microgram selenium supplements daily. These adults were followed for over seven years and compared with other subjects who took placebo pills. Selenium was found to have no effect on the rate of heart disease. Another myth falls to statistical analysis in a double-blinded study. (New York Times, may 23, 2006, page D5, Anahad O’Connor)
When the famous 19th century composer Ludwig von Beethoven was a late teenager, he experienced a serious illness: his personality changed - he became irritable and depressed. Beethoven also suffered chronic abdominal pain and bad digestion. The rest of his life, Beethoven consulted with many physicians searching for a cure for his ailments. He expressed a wish that, after his death, his remains might be preserved and examined to determine the cause of his illness. Beethoven died long ago, at a relatively modest age: in 1827 at age 57. Now scientists have analyzed Beethoven’s hair and bones. These tests revealed large, toxic amounts of lead. The authenticity of the bone samples used in these analyses have been verified by DNA analysis. Earlier work with samples of Beethoven’s hair had also shown lead poisoning. It is uncertain as to from where Beethoven got this toxic level of lead, but these recent studies showed no evidence of other toxic metals, cadmium or mercury. (World Science, December 9, 2005)
Concentrations of atmospheric oxygen over the Earth have risen and fallen in a span of geologic time periods. Until about 2.5 billion years ago Earth’s atmosphere had little or no oxygen. Then organisms began to use green pigments such as chlorophyll in a process known as photosynthesis to convert water into oxygen using sunlight and to take up carbon dioxide forming carbohydrates. Other geologic processes such as the breakdown of newly exposed rocks consume oxygen and reduce its concentration in the atmosphere. Scientists now understand that the concentration of oxygen in the air can have major impacts on the types of creatures that live on the Earth. At the present time, our atmosphere at sea level contains about 20 percent oxygen. All animals require oxygen to extract energy from food in a process called respiration to fuel their actions and to keep mammals warm. Reptiles, which are said to be cold-blooded, require less oxygen because their blood carries oxygen by diffusion, oozing through their bodies and these animals are not very active. But warm-blooded mammals, which pump blood through their arteries, require higher concentrations of oxygen to function. Big mammals need even more oxygen than small ones.
Geologists and biologists are now finding correlations between the concentrations of oxygen in the atmosphere and the sorts of creatures living on earth during particular time periods. Most of the Earth’s significant die-offs have taken place when the concentrations of oxygen in the air were rapidly declining. For example, about 255 million years ago the oxygen concentration was about 30 percent, but this fell to around 13 percent in “just 10 million years”. Large woody trees declined and gave way to small plants such as ferns. As many as 95 percent of the species living in the oceans and about 70 percent of those on land died off. In these low-oxygen periods, most animals lived at sea level, because the oxygen concentration was of course depleted at high altitudes as it is today.
The sizes and types of creatures are also connected to the oxygen concentration. For example more agile, larger reptiles require more oxygen to function; so do flying reptiles, which flapped their wings. Ancestors of the first mammals appeared in the Triassic period, when more oxygen was present. Warm-blooded animals are especially oxygen demanding. A large-brained mammal needs copious fuel, since about one-third of a mammals’ energy supply, derived from food and oxygen, is required by their brain. Pound -for-pound, mammals need three times as much oxygen that reptiles do. Large, “mega-mammals”, need more oxygen than smaller mammals.
As the oxygen concentration in the atmosphere fell from about 23 percent, about 25 million years ago, to the present day 21 percent, very large mammals such as the giant sloth and 15 ton indricotheres (ancestors of today’s rhinos) became extinct. In addition to mass extinctions such as the disappearance of the dinosaurs 65 million years ago, which is traced to the impact of an extraterrestrial object, variations in the concentration of atmospheric oxygen have been a major factor in determining the sort of creatures that lived or died. One measure of this phenomenon is a correlation between the size of insects in different geologic times. For example 300 million years ago immense insects such as, Meganeura, a dragon fly with a wingspan similar to that of a modern hawk prospered in an atmosphere which had a much higher concentration of oxygen than is found today. Biologists have confirmed this idea by growing insects in an elevated or a depleted, artificial oxygen atmosphere. It is interesting that some abnormally large insects produced in the presence of higher levels of oxygen do not live as long as normal insects, perhaps the result of oxygenation of their tissues during respiration. (Science News, December 17, 2005, vol. 168, page 393) For a deeper look at evolution, you might read: The Ancestor’s Tale” by Richard Dawkins (Houghton Mifflin, 2004)
King George III, who ruled from 1760 to 1820, is known to have suffered repeated bouts of mental illness. His mental illness was probably a factor in the loss of the American colonies. Recall the 1995 movie, “The Madness of King George”, page 203 in Naturally Dangerous.
King George’s mental instability has long been thought to have resulted from a hereditary disease, porphyria, which arises from defects in the oxygen carrying pigment, hemoglobin. His symptoms, lameness, abdominal pain, insomnia, periodic mental disturbances, and discolored urine (blue pee) are typical of porphyria. Recent evidence suggests that the root cause of King George’s condition came from arsenic poisoning. Samples of the king’s hair, showed large concentrations of arsenic (17 parts per million). Recall from page 131 in Naturally Dangerous that human hair can be a barometer of exposure to toxic elements such as mercury and arsenic. Arsenic is known to interfere with the synthesis of heme in the body and can trigger porphyric episodes in individuals who are genetically disposed to porphyria. How did King George become poisoned with arsenic? Was it a political plot? The probable cause is thought to have come from a medicine he was taking: emeric tartar (potassium antimony tartrate). In King George’s time, antimony was contaminated with about 5 per cent arsenic. Since he took about 180 mg of emeric tartrate a day, he could have unwittingly received 9 mg of arsenic – not enough to kill him, but plenty for chronic poisoning.
People are advised to eat fish because the omega-3-fats in fish are thought to ward off heart disease and to help brain development. But too much of a good thing can be a bad thing. Even canned tuna contains mercury, especially canned Albacore. Consumers should strike a balance; eat modest amounts of fish depending on the person’s body weight and whether they are pregnant. Infants must be more cautious. The FDA does not require canned tuna to be marked showing that it contains mercury. The amounts of mercury in canned fish can vary widely; some samples contain seven times the average. Large aggressive fish such as swordfish, shark, king mackerel, and tile fish contain more mercury than other fishes such as cod, salmon, and pollock. There is disagreement between the FDA and the EPA over the amount of fish people should consume to balance the value from omeg-3 fatty acids and the risk from mercury. The EPA is more risk adverse. (The Wall Street Journal, August 1, 2005, page A1)
Safe drinking water is in short supply and in the future it will become even scarcer. Oceans and salty seas contain 97 percent of the Earth’s water. Most of the remaining 3 percent fresh water is locked up as ice in glaciers and in underground pools. Only 1 percent of the Earth’s water, mostly as rivers, lakes, aquifers, reservoirs and wetlands is readily available as sources of fresh water. Much of that non-salty water is polluted. Each year polluted water contributes to the death of about 15 million children over the Earth. When fresh water is pumped from a well it is important to know if that water is ancient and therefore will not be replenished or is that water young, indicating that within a few years it will be replaced from rain. Old or “fossil” water must be used with great care because over a long period it will become exhausted. So how do scientists distinguish young from fossil water? The key is to measure the ratios of oxygen isotopes in a water sample. What are isotopes? Your author calls isotopes “nuclear siblings”. Isotopes are forms of the same atom that differ in the number of neutrons in their nucleus. Isotopes exhibit virtually identical chemical properties but show slight differences in the rates of their reactions. For example water containing the heavier isotope, oxygen-18 evaporates more slowly and builds up in the ocean. The common isotope is oxygen-16, which has 8 neutrons in its nucleus, whereas the nucleus of oxygen-18 contains two additional neutrons raising the total to 10. There only about 1 oxygen-18 is present in every 500 atoms of oxygen, but seawater is enriched and snow is depleted in oxygen-18. The ratio of isotopes in water that is measured with an instrument called a mass spectrometer, can be used to determine the relative age of that water. The ratio of oxygen isotopes in a sample is a signature of the age of that water. Fossil water contains much less oxygen-18 because it is derived from the ice ages or other cooler eras. The age of water can also be determined by a different method, by measuring the amount of a radioactive isotope, carbon-14, which occurs in very tiny amounts in water. Carbon-14 slowly disintegrates such that determining the remaining carbon-14 can be used as a “carbon-dating” clock. It is important to know that the huge aquifer under the Sahara desert, lying under Libya, Chad, Egypt, and Sudan contains fossil water. (New York Times, July 26, 2005, page D 1)
A study of 209 boys and girls in Grand Forks, N. D., showed that zinc supplements can help children perform a battery of tasks on a computer. The group was divided into three parts: the first received nothing in their orange juice; the second had 10 mg, and the third 20 mg; they all drank this orange juice every day for 10 to 12 weeks. Those receiving the larger zinc supplement performed better than the lower dose, who out performed those who got no zinc. Sounds good, but remember that in the body zinc competes with another essential element, copper; moreover, these tests on children might be a little unethical. The tests were funded by the Agriculture Department’s Human Nutrition Research Center. (Science News, April 30, 2005, Vol. 167, page 286)
The antibacterial agent, thimerosal, once called mercurochrome, contains ethyl mercury, which has chemical properties similar to a dreaded neurotoxin, methyl mercury. For many years thrimerosal has been added to vaccines to prevent bacterial contamination. A large number of people, mostly parents or relatives of children who have developed autism, a tragic lifelong disorder marked by an inability to form social relationships as well as repetitive behavior. About one-fourth of autistic children develop the disorder abruptly in a period between their first and second birthdays. During this time, just before the child developed autism, he or she received multiple vaccinations. Parents blamed thimerosal. This was logical because ethyl mercury is soluble in the blood and should easily penetrate the blood brain barrier (mentioned in Naturally Dangerous on page 56). The association between thimerosal and autism has generated a large, influential national movement resulting in the removal of this preservative from children’s vaccines in the U.S. in 2001. Thimerosal is still present in adult vaccines, such as the annual flu shots. Upon advance request, an adult can obtain a flu shot free of thimerosal by receiving two children’s shots in succession. Your author does that. The possible relationship between thimerosal and autism was carefully examined by the National Institute of Medicine, an arm of the National Academy of Sciences. This prestigious group found no relationship. Their primary evidence was based on five statistical studies comparing children who had or had not received shots containing thimerosal and evaluated their incidence of autism. The most impressive study was that from Denmark based on the records of 467,450 children born between 1990 and 1996. These records showed that the incidence of autism rose slightly after 1992 when thimeroal was removed from Danish children's vaccines. It is plausible that an anti bacterial agent would reduce autism, because this disorder is known to have a genetic component, but to be triggered by some external factor, possibly an infection. A similar American study is currently underway. The results should be interesting and may be definitive. On the other hand, injecting a blood soluble brain toxin into humans, especially children and old people is unethical; who can say what harm this might do? Arguments such as “the amount of thimerosal in a vaccine is less than the methyl mercury in a tuna sandwich” or in mother’s milk are not valid. The difference between exposure via a food and an injection in the blood stream is very important and tends to discredit the person making such an argument. One of the treatments that have been given to autistic children, based on the belief that heavy metal poisoning is the culprit, can be dangerous, because this treatment can remove vital metals such as zinc and copper from the body. This treatment, advocated by a small number of physicians, is ill advised and should be stopped. (New York Times, June 25, 2005, page 1)
The origin of autism, a tragic neurological disease found in increasing numbers of children, remains elusive. A recent report from the University of Arkansas suggests that autism may be related to oxidative stress. Glutathione, a strong antioxidant that is produced in the body, was found to be reduced in 80 per cent of children afflicted with autism. Blood samples from 90 autistic children were compared with samples taken from 45 children without the disorder. Further studies showed changes in three genes of children with autism; it was speculated that these genetic differences are connected with glutathione metabolism. Autism is thought to have a genetic basis but to be activated by an unknown environmental trigger. Earlier, heavy metals such as the mercury preservative, thimerosal, an antibacterial preservative that had been used in children's vaccines, had been suspected as a trigger for genetically susceptible children, but later studies have discounted this hypothesis. In 2004, the Institute of Medicine issued a report ruling out vaccines as a trigger for autism. Glutathione may also help remove heavy metals from the body. Low levels of glutathione may signify oxidative stress. All these factors are hints, but do not help in understanding or treating this tragic disease. (HealthDay News, April 3, 2005, by Aerena Gordon)
Lead and lead compounds are listed as the number one toxic materials released into the U.S. and Canadian environments from industrial sources. The most recent reports from 2002 say that approximately 95 million lbs of lead and lead compounds were released from industrial facilities into the environment in both countries. Canadian releases were 13 times greater than those in the U.S. Mexico has not yet reported lead releases, but is expected to do so in 2006. Where do these lead contaminate come from? One source, estimated at 10 percent of the total, comes from tin-lead alloys, which are used as solder in the electronics industry. Most of this lead is to be found in consumer products such as cell phones and electronic toys, for example in printed circuit boards. These popular products have a short lifetime and are discarded within a year or even months, usually ending up in a landfill. The disposed lead then leaches into drinking water. This toxic metal poses a severe health risk to humans. The European Union has introduced legislation to ban lead from electronic products by 2006, but the U.S. has so far not acted, probably because of pressure from industry. (Chemistry & Engineering News, 5/30/2005, page 27; Science, Vol. 308, 6/3/2005, page 1419)
On page 126 in Naturally Dangerous you will discover that too much iron can be bad for your health, a condition called hemochromatosis. The Harvard Women’s Health Watch (volume 11, number 2, October 2003 page 1) has additional interesting information about this situation. Approximately 1 in 200 people having hemochromatosis, which means that this is one of the most common genetic disorders in the U.S. (rivaling the Celiac Sprue autoimmune disease). Like Celiac, hemochromatosis can go unrecognized for many years, but because of its life-threatening complications it is important for physicians and their patients to know when to suspect this disorder. Standard blood tests don't include screening for excess iron. Some of the symptoms: fatigue, joint pain, depression, diabetes, and heart and liver problems may be unrecognized with female patients because these could be misinterpreted as aging or menopause. Hemochromatosis is a serious, even life-threatening disease in 25% of the women and 50% of the men who have this disorder. The human body needs very little iron. Only 10% of the iron that is consumed is absorbed, but a genetic disorder resulting from a mutation in a gene called C282Y is usually the cause of hemochromatosis; people who get two copies of this gene absorb too much iron and 40% of these develop hemochromatosis, especially if they consume iron-rich foods, iron supplements, or drink much alcohol. About 1 out of 10 Caucasians (especially those of celtic origin) have this genetic problem; perhaps the early Celts had iron poor diets. Diagnosis in the U.S is poor; it is estimated that it requires and average of nine years and three doctors before a correct diagnosis is achieved. It is advised that anyone having a close blood relative who has hemochromatosis get screened for excess iron. In the future genetic testing will probably be more widely used, but at this time such DNA testing is controversial. Once a person is diagnosed with hemochromatosis, an effective treatment, called phlebotomy, is to donate a pint of blood twice a week for a brief period and then several times a year. It is prudent for such patients to limit their intake of iron-rich foods such as liver, red meat, and iron-fortified products. Warning: vitamin C increases iron adsorption, so avoid vitamin C supplements, but don’t worry about vitamin C-rich foods. Limit alcoholic drinks to two a day for men and one a day for women. Cirrhosis of the liver is a common problem experienced by those suffering hemochromatosis.
Perchlorate, employed in solid rocket fuels, is an oxidized form of chloride. The negatively-charged perchlorate ion is about the same size as iodide, and perchlorate interferes with an enzyme that incorporates iodide into a vital thyroid hormone. Under most conditions, perchlorate is quite stable and very water-soluble so that it can become widely distributed in drinking water supplies. It has been detected in the water supplies of 35 states. Now, based on a small number, 36 samples, from 18 states, perchlorate has been found in human breast milk. This situation is creating a furor and conflicts between the defense industry, the Environmental Protection Agency, and researchers at Texas Tech University, who made these measurements. The National Academy of Sciences’ National Research Council (NRC) has recommended a safe limit for perchlorate in drinking water, at levels up to 24 parts per billion (ppb). The average perchlorate level found in breast milk was reported to be about 10 ppb, but there is a question about whether a safety factor should be included for infants. This issue is another one of “risk versus benefits”, since breast milk is thought to be very healthful. Another strange result found in the Texas Tech study was that some states, such as New Jersey, that have the highest perchlorate levels in mother’s milk, have relatively low levels in that state’s drinking water. The perchlorate contaminant may have derived from fruits and vegetables as a result of contaminated irrigation water. (Peter Waldman, The Wall Street Journal, 2/23/05, page D5)
One page 125 of Naturally Dangerous, compounds of chromium are reported to be helpful and perhaps essential in the metabolism of glucose. Certain chromium compounds sold as dietary supplements have been claimed to have insulin-enhancing properties. It has long been known that the higher charged forms of chromium, called chromium(VI) are cancer causing (carcinogens), but the lower charged forms such as chromium(III) in dietary supplements were not thought to be carcinogenic. Now Australian chemists have shown that chromium(III) can be transformed into chromium(VI) by oxidizing chemicals in the body such as hydrogen peroxide and hypochlorite (the chemical found in bleach and also generated by the body’s immune system). This seems a good reason to avoid these chromium supplements, which have not been rigorously demonstrated to help with sugar metabolism anyway. By the way, all these things are “natural”, but that doesn’t mean they are safe. (Angew. Chem., Int. Ed., 2004, 43, 4504)
Plants from the sea are considered healthful foods. Sushi dishes are often accompanied by seaweed; deep-fried seaweed is a delicacy in some Chinese restaurants. Seaweed contains healthful iodine, but some seaweed contains high concentrations of arsenosugars, carbohydrates that have chemically bonded arsenic. This situation was encountered around a remote Scottish island, North Ronaldsey, where a primitive breed of sheep fed on seaweed were found to have arsenosugars in their urine. Are these substances toxic, to the sheep or to people eating mutton? This is uncertain. Does seaweed in other parts of the World contain arsenic? I don’t know? Remember from page 140 in Naturally Dangerous that all shellfish contain a form of arsenic that is said to be non-toxic. (Chemistry World, February 2004, page 8)
There is confusion about whether people should stop eating fish because they may contain mercury in spite of the fact that fish do have omega-3 fatty acids that protect the heart. Two recent studies, both published in the New England Journal of Medicine, have attempted to sort out this dilemma, but they disagree. One study of 470 American men found no connection between mercury levels in the body and the risk of developing heart disease; another study of 684 European men found those with the highest mercury levels were about 2 times more likely to have a heart attack. Conclusion? More studies are needed. It is interesting that mercury levels were determined from toenail clippings. If you are worried about this problem eat salmon and shrimp, which contain little or no mercury. Predator fish such as sharks and swordfish have more mercury apparently from the small fish they eat. Remember from Naturally Dangerous, page 140, that all shellfish contain arsenic, but in a form that is not thought to be a health risk.
Recent studies have shown that eating products that contain calcium may regulate weight in teen-age girls. Milk is OK, in spite of the fats that it contains. The fear of gaining weight is cited as one reason that many teen-age girls stop drinking milk and switch to diet drinks. Calcium seems to cause the body to make less fat and increases the ability to break down fat. A small study in Hawaii showed that for every 300 milligrams of calcium consumed, a set of girls from 9 to 14 years of age lost 1.9 pounds. Of course calcium intake is also important to support bone growth. The effect of calcium consumption on older people has been less well studied and is less dramatic, but there may also be a positive effect with this group. (San Jose Mercury News, 4/29/03, 4F)
Chromium picolinate is a popular dietary supplement, that has even found its way into diet drinks. Products containing this substance have annual sales of $500 million! A recent scientific paper (PNAS, April 1, 2003, page 3766) reviews two issues: does this supplement have any beneficial effect in terms of reducing body fat, maintaining insulin levels, and controlling glucose concentrations in the blood and do chromium supplements have deleterious effects? The answer to the first question is NO! Statistical studies fail to demonstrate any effects on body composition of healthy individuals taking chromium supplements. Evidence on the second question is mixed. There are isolated reports of deleterious effects of this supplement on humans: anemia, liver dysfunction, and kidney damage, but the significance of these scattered reports is difficult to determine. Some cell culture and rat studies have suggested that chromium picinolate seems to cause oxidative damage and might be mutagenic (genetic changes that are passed on to offspring). However, the significance of these results on humans is also unclear. The recent paper reports on genetic damage that this supplement causes to fruit flies. At levels adjusted to those encountered by patrons of “health food stores”, there is some damage in the sense of sterility and damage in the early stages of the fruit flies life. Extrapolation to human health problems is a big leap. As described in Chapter 3, a 1994 Federal law protects these mineral supplements from the sort of scrutiny given to drugs and food additives. The main risk seems to be in your pocketbook. The only advantage may be a placebo effect on the patrons of health food stores. They should know however, that chromium picinolate is not natural; it is made in a chemistry laboratory!
This unstable tri-atomic form of oxygen is a toxic atmospheric pollutant, but it protects the Earth from ultraviolet radiation (refer to the ozone hole in Chapter 8). Now ozone is being examined by the Food and Drug Administration (FDA) as a food additive to be used in storing and processing many types of food, including meats, poultry, fruits, and vegetables. Ozone works by attacking and damaging the cell walls of harmful microorganisms, thus killing these microbes. The byproduct is ordinary oxygen and no tastes, odors, or flavors are left in the food, unlike other purifying oxidants such as chlorine, which leaves annoying residues. Ozone is very toxic, but it is unstable and therefore short-lived. Ozone has already been approved and is used in the U.S. to purify water and it has been employed for food processing in other countries. It seems likely that the FDA will soon approve the use of ozone to purify foods in the U.S. Other suggested applications are the fumigation of crops so they can be safely stored and to control odor in fish markets. The promotion of ozone as a user-friendly agent comes from the Electric Power Research Institute, in Palo Alto California. Why? Ozone is produced by passing oxygen through an electric discharge. Recall from Chapter 6, that ozone occurs naturally in lightening strikes.
A proposal to partially mitigate global warming is to use gaseous hydrogen in fuel cells in place of burning fuels such as natural gas and petroleum in electric power plants or in internal combustion engines. A fuel cell converts hydrogen and oxygen (from the air) directly into electricity with nearly perfect efficiency. The only byproducts are water and a small amount of wasted heat. Fuel cells have been touted as efficient, pollution-free devices that can provide electric energy in homes and businesses and to power automobiles. Good electrode catalysts are required to make fuel cells practical; recently, very efficient fuel cell catalysts have been developed. It has been proposed that in the future fuel cells will power automobiles that are very energy efficient and produce water, but no carbon dioxide in their exhaust. It would appear that an impending “hydrogen economy” will solve two great societal problems: reducing the major green-house gas, carbon dioxide, and producing energy more efficiently. As with most fantasies, this would be wonderful if it were only true! This seemingly attractive technology has many difficulties.
The gaseous element, hydrogen does not occur in Nature; there are no hydrogen wells anywhere on Earth. If hydrogen is to be used as a fuel, it must be manufactured, shipped, and stored. How would hydrogen be produced? Electrolysis of water is one possible answer. In this process water is converted into hydrogen and oxygen using electric power. Unfortunately this method would result in a net loss of energy, because electrolysis requires more electric power to produce hydrogen than would be created by the most efficient fuel cell using the same amount of hydrogen. Looking at this as a solution for reducing the amount of the greenhouse gas, carbon dioxide is a false premise. More carbon dioxide would be generated by using hydrogen in a fuel cell to generate electrical power than by simply burning the hydrocarbon in a power plant.
The combustion of carbon fuels such as coal, oil, or natural gas in power plants generates most of our electrical energy; the remainder comes from hydroelectric or nuclear power. The two latter energy sources do not produce carbon dioxide as a byproduct. The World does not have excess hydroelectric power sources, except in a few remote locations such as New Zealand. Society is unwilling to build more atomic power plants, although this is one of the few methods by which additional energy can be produced without generating the green house gas, carbon dioxide. Alternative sources of energy such as solar and wind-power are too inefficient or limited to have any significant impact on society’s energy requirements.
The cheapest current method for producing hydrogen is not electrolysis of water, but rather to use a reaction involving oxygen and methane. Unfortunately, the energy in the hydrogen produced by thus process is less than the energy contained in the methane. The overall process: converting natural gas to hydrogen and then using that hydrogen in a fuel cell to generate electrical power would therefore not only result in an overall loss of energy, but it would also produce more carbon dioxide byproduct. This is true even though the fuel cell is 100% efficient!
There are additional troubles with a hydrogen economy. The storage and transport of hydrogen is a serious, unresolved problem. Hydrogen gas has a very low density. A tank of hydrogen, necessarily under pressure, possesses much less energy that an equivalent volume of natural gas or especially of liquid hydrocarbon (gasoline or diesel fuel). Moreover, hydrogen gas destroys welds in natural gas pipelines so that is would be difficult to ship hydrogen through these existing pipelines. There seem to be no viable methods to make hydrogen more dense except to compress it or to cool it to a liquid at very low temperatures. Both techniques are expensive.
However there is hope in using hydrogen to improve the efficiency of vehicles, because the internal combustion engine is inherently less efficient than fuel cells. How would the hydrogen fuel be provided to a fuel cell to propel such an automobile? Some scientists and engineers have suggested that hydrogen could be produced from a tank of natural gas within the fuel cell powered vehicle. This would require a miniature chemical factory within the machinery of the car, bus, or truck. In theory, this complex technology could result in higher mileage than an internal combustion engine using the same tank of natural gas, but it would produce the greenhouse gas, carbon dioxide. A practical, economic system of this sort is still in the future.
Until recently most vaccines contained an anti-bacterial preservative, thimerosal, commonly known as mercurochrome. Thimerosal contains mercury and decomposes to release trace amounts of ethyl mercury, a blood-soluble potential neurotoxin related to the infamous methyl mercury, an established neurotoxin. Both compounds can penetrate the brain blood barrier. At the present time there is a raging argument that thimerosal in vaccines has damaged the brains of immunized infants and that it has contributed to the sharply increased incidence of autism being diagnosed in children. American children receive up to 20 vaccines during their first two years, protecting them against diseases such as pertussis and hepatitis B. Until recently, many 6-month year olds received a total of about 190 micrograms of ethyl mercury through vaccinations. Equally disturbing is the fact that hundreds of thousands of rh-negative pregnant women and their unborn babies are still being given thimerosal containing immunogobulin (RhoGam) injections that are designed to prevent the mother’s immune systems from attacking their fetuses. Thimerosal has recently been removed from children’s vaccines, but in 2002, it was still present in influenza vaccine. I verified this, but took my flu shot anyway, thus balancing the risk of flu versus possible neurological damage. When some pediatricians postponed giving newborns hepatitis B vaccine, because they contained this mercury compound, some of these babies got hepatitis B. This demonstrates a balance of risks.
The question of whether autism is related to earlier vaccination of infants with thimerosal is hotly debated, but is generally discounted. One method to determine this would be to carry out a statistical analysis of children who received vaccines containing thimerosal and those who subsequently received vaccines free of this preservative in order to determine whether the incidence of autism has declined. The results of such an analysis could be a factor in lawsuits filed by parents of autistic children. (New York Times Magazine, November 10, 2002, p. 68)