Pesticides are designed to kill. Of course, they are designed to kill the insects, the fungi, the rodents, and the weeds that compete for our food supply, that carry disease, or that tarnish our green space. But they can also kill people. And, unfortunately, that isn’t a rare occurrence. The World Health Organization estimates that there are roughly three million cases of pesticide poisoning worldwide every year, and close to a quarter-million deaths! Astoundingly, in some parts of the developing world, pesticide poisoning causes more deaths than infectious disease. How? Certainly, people do die from a lack of proper protective equipment, or because they can’t read the instructions about diluting the chemicals properly. But the real tragedy is that the main cause of death due to pesticides is suicide!
Believe it or not, about a million people in the world do away with themselves every year. More than three-quarters of these are in Third World countries, where life can be so miserable that the alternative seems more attractive. In Sri Lanka, suicide is the number-one cause of death among young people, and in China, more young women kill themselves than die from other causes. Pesticides are the weapons of choice. In rural Sri Lanka, pesticide poisoning is the main cause of death reported in hospitals. There are wards devoted to patients who have tried to kill themselves with organophosphates, one of the most toxic classes of pesticides. In 1974, when paraquat was introduced in Samoa, suicide rates went up, sharply. They dropped back down in 1982, when paraquat was taken off the market. In Amman, Jordan, poisonings fell way off when parathion was banned. Obviously, if the use of the most toxic pesticides could be curtailed in these countries, many lives would be saved. Sadly, though, these chemicals are often completely unregulated. Some of the most toxic ones are readily available in stores, and will be sold to the illiterate farmer who has virtually no chance of using them properly. Pesticide companies, in some cases, pay their salespeople on commission, so it is in their interest to push product even when it may not be necessary. In Sri Lanka, pesticides are advertised on radio to the public, often painting an unrealistic picture of magical, risk-free crop protection. Some sort of joint effort by pesticide manufacturers and governments is needed to keep the most toxic pesticides out of developing countries.
In North America, our pesticide regulations are far more stringent, and farmers must be licensed to use these chemicals. That doesn’t mean we don’t have problems. In North Carolina, for example, roughly 100,000 migrant workers are employed on tobacco, vegetable, fruit, and Christmas-tree farms. Many of them live in dilapidated housing next to the agricultural fields, and their homes and bodies are contaminated with pesticides. Metabolites of organophosphates commonly show up in their urine. This is not surprising, given that access to showers and clean clothes after working in the fields is limited. Even though there may be no immediate effects of such exposure, sufficient studies have suggested ominous links—between pesticide use and neurological problems, developmental delays, Parkinson’s disease, and cancer—to cause concern. What’s the answer? Elimination of agricultural pesticides is simply not an option. But providing workers with safe housing, clean clothes, showers, and above all, pesticide safety training certainly is.
Of course, working in the fields of North Carolina is not the only way to be exposed to pesticides. Garden-supply stores sell a wide array of such products. They are all “registered,” meaning that they have undergone extensive safety evaluation. Risks should therefore be minimal, if the products are properly used. That, though, is a big “if.” An often-quoted study at Stanford University found a link between Parkinson’s disease and domestic pesticide use. People with as few as thirty days of exposure to home insecticides were at significantly greater risk; garden insecticides were somewhat less risky. Because of the large variety of products available, the researchers were not able to zero in on any specific ingredients. Another study, this one at the University of California at Berkeley, compared pesticide exposures of children diagnosed with leukemia to a healthy control group matched for age and socioeconomic status. The families of children with leukemia were three times more likely to have used a professional exterminator. During pregnancy, exposure to any type of pesticide in the home coincided with twice as much risk. But—and an important “but”—there was no association between leukemia and pesticides used outside the house! Yet I have often seen activists who oppose “cosmetic” lawn-care chemicals use the leukemia argument to demonize this practice.
Pesticides cannot all be lumped together, in terms of their safety profile. There are tremendous differences between the various insecticides, which differ extensively from herbicides and fungicides. And one must always remember that associations cannot prove cause and effect. Physicians should realize this, one would think. Apparently, not all do. In a letter to a medical publication, a doctor chastised the federal government for allowing people to be exposed to dangerous substances on their lawns, and buttressed the argument with this example: “A boy was removed from a day care three years ago because his parents noticed the lawn was being treated with pesticides and the child began to suffer health problems and recurrent pneumonias. He developed acute lymphoblastic leukemia.” The simple-minded message, of course, is that the spraying caused the leukemia—a gigantic, and inappropriate, leap of faith.
Great caution must be used with insecticides in the home, and I believe that their use during pregnancy should be totally avoided. But using insecticides inside a house presents a completely different scenario from occasionally spraying a lawn with fertilizer and weed killer. Different chemicals, different exposures, different risks. When contemplating the use of pesticides, always remember that, while there may be no completely safe substances, there are ways to use substances safely.