Confessions of a Greenpeace Dropout: The Making of a Sensible Environmentalist (56 page)

The roots of these plants have specialized nodules, which are designed to provide a home for the nitrogen-fixing bacteria. There the bacteria produce nitrogen compounds, some of which are shared with the plant. In turn the plant provides some of its sugars to the bacteria, which they use for energy. These plants are commonly called
nitrogen-fixers,
even though it is actually the bacteria that do the specialized work. Nitrogen fixers are capable of colonizing mineral soil when the organic layer has been washed away by flooding or burned off by fire. Nitrogen-fixers such as alfalfa, peas, lentils, and beans are often used as rotation crops partly because they replenish nitrogen in the soil.

Dr. Norman Borlaug is known as the father of the Green Revolution for his work in India and Pakistan in the 1960s, where he developed improved varieties of wheat, thus saving millions of people from starvation.
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He estimates that the nitrogen fertilizer made from synthetic ammonia is responsible for the survival of nearly five billion of the nearly seven billion people on earth today. In other words, without the nitrogen we harvest from the air there would only be enough natural nitrogen in soils, compost, and manure to feed about two billion people.
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This is a sobering point. It highlights both the fact that it would not be possible to have a population of seven billion if Fritz Haber had not invented a way to make ammonia, and the fact that we now depend on this process. Extreme greens might argue the world would have been better off if there were only two billion people. They may have their opinion, but the fact is there
are
nearly seven billion of us and unless we wish to see a calamity like no other we must recognize the importance of the Haber-Bosch process for our continued survival.

For the life of me I do not understand how nitrogen harvested from the atmosphere can be characterized as “artificial” or “unnatural.” The nitrogen in the atmosphere is entirely natural and not artificial in any way. It is true that through science we learned how to synthesize ammonia from the nitrogen in the air. But we also learned to produce (synthesize) steel by blending iron with other metals, yet organic farmers are happy to use a steel hoe for weeding their fields. One can only conclude the ban on “synthetic” nitrogen in organic farming is either a kind of superstition or an illogical rule based on faulty information about the origin of the nitrogen.

The story of phosphorus use as a fertilizer is not quite as fascinating as that of nitrogen. Phosphorus comes from phosphate rocks of sedimentary origin. These were laid down in ancient seas and are mined in a number of countries, chiefly the United States, China, and Morocco. Phosphorus is a constituent of DNA and the phospholipids, which form all cell membranes, and is thus central to the existence of life. Organic farmers use phosphate rock as a fertilizer, despite the fact that it is an inorganic mineral.

Potassium has a source that is similar to the source of phosphorus; it is mined from massive potash deposits that are also of sedimentary origin from ancient seas. The province of Saskatchewan in Canada produces nearly 25 percent of the world’s potash from huge underground deposits. These were formed when the North American prairies were a great inland sea. Organic farmers use mined potash as a fertilizer even though it is an inorganic mineral, like phosphate rock.

It is time consumers recognized that the premium they pay for foods marked “organic” is not doing them any good from a nutritional standpoint, or any standpoint, for that matter. This was made clear in an independent 2009 study, funded by the UK Food Standards Agency and carried out by the London School of Hygiene and Tropical Medicine. It concluded, “There is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority.”
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While organic farm groups routinely dispute this, they do not supply any evidence to back their claims.

My conclusion on the issue of fertilizer application is that the so-called synthetic nitrogen fertilizers are obtained from the atmosphere and are therefore perfectly natural, that “organic” growers actually use quite a number of inorganic and synthetic substances, and that eating foods labeled “organic” has no nutritional benefits. In addition, more land is required to grow the same amount of organic food as conventional food and therefore there is a serious environmental downside to these production methods.

Pesticides

In the same way that human health and longevity has been greatly improved by modern medicine, crop and livestock health has been greatly improved by the use of pesticides and through veterinary science. Indeed the use of medications in agriculture is at least as important as fertilizer and genetics, which in combination have increased yields up to five times during the past hundred years.

Most of us think nothing of taking medicine to cure an infection or a disease. We don’t think of it as taking pesticides in relatively large doses, right into our bodies. Many human medicines are designed to kill pests, otherwise known as bacteria, parasites, and viruses, in our bodies. The term
pesticide
comes from pest, as in pestilence (the most famous of which was the Black Death, or Great Pestilence, which killed about one-quarter of the human population in the 14th century), and
cidium
, from the Latin meaning “a killing.”
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Pests, diseases, weeds, and vermin are all categories of biodiversity that can destroy our food and our health, and we’d rather they didn’t exist.

The general term for a substance used to kill living things is
biocide
, the literal meaning of which is “to kill life,” in other words, a poison. In medicine we use the term
antibiotic
(anti-life), which means exactly the same thing as biocide. Pesticides are used to kill living things that we judge as harmful. More specific terms for pesticides are: fungicide, herbicide, insecticide, rodenticide, algicide, germicide, and spermicide, depending on the category of living things one is trying to kill. The main reason chlorine is the most important element for human health is precisely because it is toxic to many of the pests and diseases that can harm us. It turns out that poisons, also known as medicines and pesticides, are essential for our survival.

Why is it that we generally wish to take pesticides (medicine) to cure disease yet many of us fear the slightest residue of pesticides on our food? Are the chemicals we use to kill crop pests and cure livestock more dangerous than the medicines we take? Is there any evidence that pesticide residues on food damage our health? The answer to the last two questions is no, therefore the answer to the first one is that the fear of agricultural pesticide residues is largely irrational. Of course, as with many medications, it is possible to overdose, but the amount of pesticide residues on our food is thousands of times lower than any amount that would harm us.

In the 1990s, the Cancer Research Institutes of the U.S. and Canada collaborated on a multiyear study of all scientific publications about the connection between cancer in humans and pesticide residues on food.
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They could not find a single piece of evidence connecting the two. And yet they concluded 30 percent of human cancer is caused by tobacco consumption, from a perfectly natural plant, and 35 percent of cancers are caused by poor diet, mainly too much fat and cholesterol, which are also natural substances.

The concern that pesticide residues may do harm often causes parents to avoid or buy fewer fresh fruits and vegetables for themselves and their children. The authors of the article pointed out the irony of the fact that one of the best ways to stay healthy and prevent cancer is to eat lots of fresh fruits and vegetables. So, the people who listen to the scare campaigns about pesticide residues are liable to adopt eating habits that put them at higher risk of getting cancer than they would have been had they ignored the campaigners and eaten more fresh fruits and vegetables.

Dr. Bruce Ames received the U.S. National Medal of Science in 1998 for his lifelong research into the causes of cancer.
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He developed the Ames Test, which is used to determine the relative carcinogenicity of various chemicals. For much of his life he has worked to live down the legacy of this test.
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What he found was that many otherwise harmless substances, if administered in huge doses, resulted in tumors and mutations in bacteria, rats, and mice. This led to the conclusion among many scientists and activists that these substances were therefore carcinogens and should be banned. They tended to forget the first rule of toxicology: the poison is in the dose.

Take simple table salt, sodium chloride, for example. It is essential for our health. It regulates the electrolyte balances in our bodies, and without it we would die. Yet it is possible to take too much salt and if you overdose on salt it can kill you. Many chemicals behave in a similar fashion. At low doses they are essential, beneficial, or harmless, while at higher and higher levels they become harmful and even fatal. It is a matter of degree.

For me, Dr. Ames’s most interesting work involved comparing the relative carcinogenicity of a number of synthetic pesticides with a number of natural pesticides. Largely because plants can’t run from danger or swat flies they produce natural pesticides to ward off predatory bacteria, insects, and fungi. The chemicals they produce are either toxic or extremely unpleasant to the pests that want to attack them.

Dr Ames administered large doses of a number of common synthetic pesticides and a similar number of natural pesticides extracted from plants. He found the synthetic and natural pesticides had virtually identical effects. At high doses about 50 percent of both the synthetic and natural pesticides produced tumors in white mice. He then calculated the doses of the synthetic and natural pesticides we would be exposed to by eating a typical diet of conventionally grown fruit and vegetables.

When synthetic pesticides are applied to crops there is a period of time required after the final application before the crop can be harvested and consumed. During this time the pesticide biodegrades so that at the time of harvest there is an undetectably low or negligible level of pesticide on the food. This is not the case for the natural pesticides, however. The plants keep producing these defensive chemicals right up until they are harvested. Dr. Ames estimated that when the food from these crops is consumed it contains about 10,000 times as much natural pesticide as synthetic pesticide residue. In other words, there is about 10,000 times as much risk of getting cancer from the natural pesticides as from the synthetic ones. And this risk is very close to zero in the first place. To quote Dr. Ames, “The effort to eliminate synthetic pesticides because of unsubstantiated fears about residues in food will make fruits and vegetables more expensive, decrease consumption, and thus increase cancer rates.”
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For centuries farmers used nicotine from tobacco plants as a natural pesticide. Organic farmers continued to use nicotine to kill insect pests until very recently. Nicotine is one of the most poisonous examples of a natural pesticide and it has now been banned even for organic farming. Some synthetic pesticides developed in the 1950s and 1960s have also been banned, as they too are very poisonous compared with the synthetic pesticides in wide use today. The lesson is that it is not so much whether a chemical is natural or synthetic that determines the risk of using or ingesting it. It is the nature of the specific chemical, how much of it we are exposed to, and how it affects living tissues.

Everyone has heard of DDT, the insecticide that became the subject of controversy in the 1960s, partly due to Rachel Carson’s influential book,
Silent Spring
.
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Whereas DDT had originally been used to control mosquitoes and other insects that are responsible for the spread of typhus and malaria, after World War II it came into widespread use as a way to control insect pests in agriculture. As a result of the concern about DDT’s impact on wildlife, many countries, beginning with Hungary in 1968, banned the chemical’s use in agriculture. The U.S. Environmental Protection Agency banned DDT in 1972. Additional bans followed around the world. DDT was even discontinued for use in malaria control by the World Health Organization and USAID. This decision proved to carry a high cost in terms of human lives.

The movement against mass aerial spraying of DDT initially focused on the use of DDT to kill insect pests on farms. Euphemistically known as “crop dusting,” in the 1950s and 1960s, the aerial spraying of food crops with insecticides and other pesticides became widespread. Some of these chemicals, including DDT, are known as
broad-spectrum
poisons. DDT, for example, is deadly to all insects, not just the target insects that prey on food crops. It addition, DDT does not break down or biodegrade quickly. And it tends to accumulate up the food chain. Such chemicals should be used sparingly, and only when there is no substitute that is more selective, breaks down quickly, and does not bio-accumulate.