THAT’S THE WAY THE COOKIE CRUMBLES (15 page)

Would you believe that the Roman Empire crumbled due to a lack of sugar, and that an extreme fondness for sauerkraut brought the British Empire to its knees? I’m not sure I believe it, but I have come across a fascinating, albeit contentious, theory that supports this take on history. In those early times, most Romans had a sweet tooth, but they didn’t know about sugar. So they boiled down grape juice to make a sweet syrup called “sapa,” which they added to wine and to various foods. Because experience had taught them that it enhanced the sweetness of the finished product, they used lead vessels for this task. The Romans were unaware of the chemical nuances of the procedure, but we now understand that acids — such as those found in grape juice — leach lead from containers. Indeed, we sometimes refer to lead acetate as “sugar of lead.”

One of lead’s amazing characteristics is its extreme toxicity. Regular intake in the milligram range can have catastrophic consequences. Stomach cramps, weakness, headaches, irritability, loss of appetite, anemia, high blood pressure, and kidney problems are all classic symptoms of lead poisoning. These are nasty enough, but perhaps the most insidious aspect of lead is that it can be devastating over the long term at intakes too low to cause overt symptoms. Scientists have connected mental confusion and impaired judgment with chronic low-level exposure.

The Roman ruling classes suffered the effects more acutely because they drank more sweetened wine, usually from lead-based pewter mugs, and they had access to water delivered through lead pipes. Our word
plumbing
actually derives from the Latin
plumbum
, meaning “lead,” and that is also why this element’s chemical symbol is Pb.

The Romans used lead to make water pipes, hence the derivation of the word. So, we can easily see why historians link Caligula’s orgies, the poor military decisions made by Roman emperors, and Nero’s fiddling while Rome burned (in short, the fall of the empire) with lead exposure. While this may sound fanciful, archeological evidence does exist to bolster the lead-poisoning theory.

In part, lead is toxic due to its chemical resemblance to calcium. Calcium is essential for myriad biochemical reactions, and it’s one of the main building blocks of bone. When lead is present in the system, our bodies can mistake it for calcium and incorporate it into bone, where x-rays can detect it readily. Remember how lead shields always stymied Superman’s x-ray vision? Archeologists have x-rayed some ancient Roman skeletons and found abnormal levels of lead. And abnormal levels of lead may also have caused the sun to set on the British Empire. George III was king of England during the American Revolution, and some historians have suggested that it was his inept handling of the situation that led to the loss of the colonies.

George was not only inept, but he was also close to being insane. His madness has been widely attributed to porphyria, a disease of faulty hemoglobin production. It is generally an inherited condition, often characterized by purple urine — and we know that George exhibited this symptom. But lead poisoning can also cause similar symptoms. And how was George exposed to lead? Being of German ancestry, he loved sauerkraut. His cooks prepared it in lead pots — almost exclusively for the king’s consumption, since sauerkraut was not a delicacy favored by the members of his royal court. It is conceivable that George alone suffered the serious effects of lead poisoning.

The question of whether lead played a part in the downfall of the Roman and British Empires may be just an academic one. But the question of whether our own lives are under attack by this stealthy intruder is one of great practical importance. Peeling paint and crumbling walls may not sound like weapons of war, but they can mount a pretty effective assault on health. Lead carbonate was the main white pigment used in paint up until about 1950, and it was still in general use until 1980, when it was finally phased out. Concern was mounting, because lead from paint was finding its way into people’s bodies, particularly the bodies of young children in poor neighborhoods who had a fondness for putting flakes of peeling paint into their mouths. One milligram of lead from paint, ingested daily, can cause poisoning. Paint dust will accumulate on a windowsill as one opens and shuts the window. A child who touches this and then sucks his or her thumb can take in dangerous amounts of lead. And here is the really scary finding. The poisoning may not make itself immediately apparent. Indeed, it may show up only years later as aggressive behavior, learning disabilities, poor speech articulation, hyperactivity, or a subtle drop in IQ.

A study carried out at the Children’s Medical Center in Cincinnati showed that lead can damage a young child’s ability to learn and reason at exposures far less than those deemed safe by the U.S. government. There is no threshold effect for adverse reactions. Researchers tested blood lead in 276 children from infancy, and they administered an IQ test at age five. They noted a decreasing trend in the children’s IQ, beginning at half the level health authorities deem acceptable. The effect may be lifelong, because early lead exposure can change the brain’s hard wiring.

Millions of children in North America have high blood levels of lead, and they don’t necessarily live in old, dilapidated buildings. Some parents have inadvertently made their children sick by engaging in home renovations that generate lead-laden dust. Some children have put paint flakes from old, peeling playground apparatus in their mouths. In one documented case, a family purchased a Victorian farmhouse in upper New York state and began renovating it. Soon, the family’s ten-year-old dog began shaking and twisting. When the family told the vet that they had been stripping paint, he suspected lead poisoning. Blood tests confirmed that the dog and every family member had elevated levels of lead. All were treated with calcium disodium ethylene diamine acetic acid (EDTA) to eliminate the lead, but the dog died of kidney failure.

Although such drugs can rid the blood of lead, any lead deposited in the brain remains there forever, permanently impairing mental performance. And it is not only children who are affected. One of my colleagues — ironically, an analytical chemist — experienced this tragic phenomenon firsthand. When dust from renovations to the stately old residential building in which he lived drifted into the apartment he and his family inhabited, the trouble started. At first, the dust merely presented an annoying cleaning problem, but soon his wife and mother-in-law began to experience symptoms consistent with lead toxicity. The lead-filled dust became a life-changing nightmare.

We have to take lead pollution seriously. Only properly equipped and trained contractors should renovate houses that contain lead paint. A program designed to screen the blood of children in underprivileged areas may be the best tool to identify problem homes. Massive federal funding will be needed to remove the paint, and in some cases even the surrounding soil, of any house that harbors lead paint chips. Experts will have to evaluate children’s nutritional status; an adequate calcium and vitamin C intake significantly reduces lead absorption, but it is precisely these nutrients that poor children lack. Communities must monitor drinking water and install filters if lead levels rise above ten parts per billion. Now that we have banned lead in gasoline, paint, water-pipe welds, and food-can solder, we need to study other potential sources of contamination — such as the lead weights we use to balance car tires. The quantity of lead that these weights shed each year can exceed fifty kilograms per kilometer of road. As the weights wear out, they generate lead dust that people can inhale, and people or their pets can track the dust onto carpets where babies crawl.

Nero fiddled while Rome burned, possibly because he suffered from lead poisoning. Modern chemistry has given us ways to monitor lead in our environment as well as techniques to deal with the problem appropriately. Sweeping paint dust under the carpet is tantamount to fiddling while lives — especially children’s — burn.

Lead may even have affected Beethoven, one of the world’s greatest composers. As I already noted, lead is so toxic that even ingesting it in small amounts can cause a wide range of symptoms. These include abdominal pain, nausea, slowed reflexes, weakness, vertigo, tremors, loss of appetite, depression, confusion, irritability, anxiety, and, in children, learning difficulties. And guess which symptoms Beethoven suffered from? From the age of twenty, the composer constantly complained of stomachaches, digestive problems, depression, and irritability. Doctors found themselves at a loss for an explanation. But now, we may finally have one. When Beethoven died, at the age of fifty-six in 1827, a young music student clipped a lock of his hair as a souvenir. The student’s descendants passed the memento down, until it was finally sold at auction in 1994.

The buyers decided to subject the hair to chemical analysis to see what they could discover about the great man. Did he die of syphilis, an explanation that was widely reported? If so, his doctors would have treated him with mercurial drugs, and these leave traces in the hair. The scientists who analyzed Beethoven’s lock of hair found no mercury residue. Neither did they find opiate residues, demonstrating that Beethoven took no pain killers and struggled through his various ailments unassisted, fighting hard to keep his mind clear for writing music. But the scientists did report one surprising finding: there were high levels of lead in the composer’s hair. They found about sixty parts per million — roughly one hundred times the amount in an average person’s hair today.

How the composer slowly poisoned himself we can only guess. Perhaps he often drank from lead mugs, which were common at the time. Even today, some people may be exposed to the lead that leaches out of improperly glazed pottery or the lead-crystal decanters in which alcoholic beverages are sometimes stored. Maybe Beethoven’s drinking water flowed through lead pipes. Maybe he was somehow exposed to lead-based paints. We will probably never solve this mystery, but there is a good chance that plumbing silenced one of the greatest composers in the world. And there’s another Beethoven mystery that will never be solved. How did he compose his brilliant pieces given the fact that for most of his life he couldn’t hear a sound? Ludwig van Beethoven, as you may have heard, was deaf.

Dioxin is the most toxic substance we humans have ever produced. I’m going to have some for supper today. And so will you. You can’t avoid it. But it won’t be your last supper — not on account of the dioxin, anyway. Still, any chemical that possesses such remarkable toxic properties and that is so pervasive and persistent in the environment merits our scrutiny. While you certainly won’t succumb to any acute effects of dioxin after eating your meal tonight, the jury is out on whether you’ll be having fewer meals in the long run because of the chemical. It is the issue of long-term exposure to extremely low doses of dioxin that we need to address.

The term
dioxin
, as used by toxicologists, actually refers to a number of substances that share certain molecular features. They contain chlorine atoms attached to carbon atoms that are linked to each other in structures known as aromatic rings. We consider polychlorinated biphenyls, for example — the notorious PCBs — to be dioxins when it comes to discussing toxicity. And a discussion of this brand of toxicity is fascinating. It takes us all the way from Charles Darwin’s living plants to Belgium’s dying chickens.

Darwin’s interest in evolution inspired him to undertake a number of experiments with plant reproduction. In the course of these investigations, he discovered that growth and reproduction are governed by plant hormones, molecules that cruise through the plant delivering chemical signals. The first such hormone that scientists managed to isolate, in 1928, was auxin. A flurry of agricultural research ensued, as scientists sought to increase crop yields by boosting auxin levels in plants. As they usually do when experimentation first isolates an active and potentially useful chemical from nature, chemists went to work and synthesized a number of compounds with molecular structures similar to that of auxin. They hoped that they could improve upon nature. Two synthetic auxins, with the rather imposing names of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) looked interesting. Indeed, these chemicals proved useful in promoting root growth in certain plants and in preventing strawberries from falling before they ripened. But it was in the war against weeds that the chemicals would really shine.

Both 2,4-D and 2,4,5-T caused such rapid growth in broad-leaf weeds that the weeds essentially grew themselves to death. Lawns and golf greens quickly benefited, and people frolicked in weed-free splendor. Then, during World War II, the U.S. military had an idea. Trees are broad-leaf plants. Could this chemical growth stimulation cause trees to shed their leaves, just like weeds? If so, then they could spray 2,4-D and 2,4,5-T from the air as defoliants, thereby exposing the enemy’s hiding places. Experiments conducted in Florida showed that the idea was workable, but the war came to an end before the military had a chance to implement the defoliation plan.

Then came Vietnam. The jungles afforded plenty of hiding places for the Vietcong, so defoliation seemed an attractive military maneuver. Experts concocted a special blend of 2,4-D and 2,4,5-T, and the military shipped it to Vietnam in large orange-colored barrels. Eventually, they sprayed forty-two million liters of this chemical — dubbed Agent Orange — over the Vietnamese countryside in what came to be called Operation Ranch Hand. Those in command didn’t worry much about exposing personnel to the chemicals, because the only health problem that had ever cropped up was a rare skin disorder known as chloracne. This had come to light in 1953, when a German physician noted several cases among workers who produced trichlorophenol, the chemical used to make 2,4,5-T. The physician examined the problem in a very thorough fashion, and he discovered that the culprit was a contaminant in the trichlorophenol, a contaminant called TCDD, a specific dioxin.

Although those in command in the U.S. Air Force were aware of this problem, they didn’t think it particularly important. After all, the American servicemen involved in spraying Agent Orange were not contracting chloracne. But, as the spraying went on, so did research into the effects of 2,4,5-T. Research that, in 1969, produced a bombshell: 2,4,5-T caused birth defects in mice. Actually, 2,4,5-T itself wasn’t the problem; as with chloracne, the culprit was a contaminant, dioxin. Birth defects are a far more serious problem than acne; so, all of a sudden, dioxin became a hot research topic. Scientists soon determined that they were dealing with an extremely potent substance. A millionth of a gram could kill a guinea pig. Arsenic and cyanide seemed like candy by comparison. This was the most toxic synthetic substance they had ever seen.

But then the story took a strange turn. Rabbits, mice, and monkeys proved to be two hundred times less sensitive to dioxin than guinea pigs were, and hamsters were almost immune, being two thousand times less sensitive. This was remarkable species specificity. Where did humans fit in? Well, no one has, as yet, answered that question adequately; no human has ever died of an acute dose of dioxin, even though some people have been massively exposed in chemical plant accidents. But what about long-term, low-dose exposure? This is a much bigger worry. The researchers who were conducting the animal tests learned that, despite its reduced effect on some species, dioxin is the most potent carcinogen ever tested on animals. It caused cancer in every species they tested, and it did so at a lower dose than any other substance. Furthermore, dioxin is remarkably stable and fat soluble. This suggested that it builds up in the environment, and in humans.

When the researchers released these findings, authorities took immediate action to reduce dioxin exposure. Since they believed that the only significant source was 2,4,5-T, they ensured that use of this substance was greatly curtailed. (Its confrere, 2,4-D, was never contaminated with dioxin and is still used as a weed killer.) But, much to everyone’s surprise, dioxin levels in the environment did not drop. There had to be another source of these nasty chemicals. And there was. People wanted white toilet paper, white tissues, and white writing paper. Manufacturers complied by bleaching pulp with chlorine. We didn’t know that this created dioxins. We were also producing an ever-increasing amount of garbage, which we burned in incinerators. Waste often contains substances — such as polyvinyl chloride (PVC), a common plastic — that furnish the chlorine that combines with combustion products to yield dioxin. Metal smelters and cement kilns also contributed to airborne dioxins. Winds carried the chemical to every corner of the world. It settled on oceans and grazing fields and was detected in the fat of fish, cattle, hogs, and poultry. And, worst of all, in the fat of humans.

Then scientists discovered that dioxins in test animals not only acted as carcinogens, but they also affected the endocrine and immune systems. So it really wasn’t surprising that the Belgians panicked in 2001 when their chickens began to die due to dioxins in their food. Apparently, some unscrupulous manufacturers had mixed transformer oil with the animal fat used to make chicken feed. The authorities quickly remedied the situation, but the bad taste of dioxin remained in people’s mouths.

Talking about leaving a bad taste in one’s mouth, how about those comments about dioxin, attributed to a physician, that are circulating on the Internet? The physician warns the public that dioxins can leach out of the plastic containers we use in microwave ovens, and he raises the prospect of cancer. The good doctor cites the example of the foam containers that were removed from fast-food restaurants a few years ago. But he’s muddled the facts.

Let me try to figure out how this story got started. Dioxins are molecules that contain chlorine, so we need a source of this element if the dioxin is to form. We also need some high-temperature incineration products of organic matter to combine with the chlorine. Indeed, if we incinerate chlorinated substances, then dioxins will form. PVC is a commonly used plastic. We use it to manufacture fabrics, tubing, and various kinds of containers. If we incinerate PVCs, then dioxins can form, but in order for this to happen, the temperature must be quite high — higher than the temperatures achieved with a microwave oven. And, furthermore, the containers we use in microwave ovens are almost always made of polyethylene or polypropylene, not PVC. These two substances do not contain chlorine and therefore cannot create dioxins. The physician’s statement that foam containers were removed from fast-food restaurants because of the dioxin problem is completely false. Those containers were blown with freon, a greenhouse gas — that is why the restaurants stopped using them. Nothing to do with dioxins. In fact, the restaurants started dishing up their fast food in paper containers, and guess what? The chance of dioxin contamination with paper products is greater than with foamed polystyrene; we have to bleach paper in order to make it white, and we often do this with chlorine. I remember that a few years ago people were up in arms because traces of dioxin had been found in toilet paper. But this posed no real danger — except to toilet paper eaters. In any case, you can see how those who fail to understand the whole story can blow a kernel of scientific truth way out of proportion.

Finally, here is some good news about dioxins. Levels in the environment have been dropping. The pulp and paper industry has switched processes, and now its plants release virtually no dioxin. Regulations have forced operators to run their incinerators at high temperatures, minimizing dioxin release. Studies have revealed that chemical industry workers exposed to dioxins do have an increased incidence of cancer, but only the most heavily exposed fall into this category. Workers with lighter exposures — those who have twenty times more dioxin in their bodies than members of the general public — do not have elevated rates of cancer.

Still, we have lingering concerns. A 1976 accident in Seveso, Italy, released huge amounts of dioxin. Afterwards, the exposed men of Seveso fathered a disproportionate number of girls, a fact that suggests a hormonal effect. Without a doubt, we must keep reducing our contact with dioxins. Since about ninety-five percent of our exposure comes from animal fat, switching to a low-fat diet helps. So, while you will still be having dioxins for supper tonight, you’ll consume less if you boost your vegetable intake and cut down on the meat. Bon appetit!