A pesticide is a chemical used to kill or repel pests—anything from mice to weeds, bugs, fungi, and disease-causing bacteria and viruses (U.S. EPA, 2012
People have been using substances for thousands of years to protect themselves and their crops from pests—from lye to ash, Sulphur, tobacco, soapy water and green lizard gall—all with varying results (University of Minnesota
Chemical pesticides took a giant leap forward in the 1940s, after Paul Müller discovered that DDT killed mosquitoes that spread malaria and fleas that spread typhus (U.S. EPA, 2015-b
). (Müller won the Nobel Prize in Medicine in 1948 for this discovery. It’s amazing to think how far we’ve come.) In 1944, the chemical 2,4-D showed its effectiveness against weeds. By 1952, nearly 10,000 new pesticide products were registered with the EPA (Ganzel
Chemical pesticides enjoyed their heyday of beating back disease and increasing crop production for people around the world, until Rachael Carson’s book, Silent Spring
, showed the world that these successes came with a great price—the destruction of birds and other wildlife because of the biomagnification of these chemicals up the food chain. Silent Spring
helped inform the world about the health impacts of chemical fertilizers and led to the banning of DDT in the United States in 1972.
A farmer spraying pesticides on lettuce in Yuma, Ariz., in 2011 (source: Wikimedia)
Dangers to Humans
Because many of these chemicals last a long time, their effects can on people and wildlife can last for decades. For example, a recent study showed that women exposed to DDT in the 1960s may have an increased risk of breast cancer today. DDT is still used to control mosquitoes in Africa and Asia (Cohn
Pesticides have been linked to asthma, memory loss, loss of coordination, slower reaction times, uncontrollable mood and behavior changes, impaired motor skills, allergies, hormone disruption and cancer. The World Health Organization estimates there are 3 million cases of pesticide poisoning each year and as many as 220,000 deaths, mostly in developing countries (Institute of Neurotoxicology and Neurological Disorders
Three recent, independent studies showed that children whose moms were exposed to organophosphate pesticides while pregnant had lower IQ scores and poorer working memory than other kids. Organophosphate pesticides are similar to the nerve agents produced during World War II and are among the most common pesticides used today (Grossman, 2011, May 16
What Dangers Lurk in Your Food?
Pesticides include the following chemicals: Organochlorines, organophosphates, organosulphers, carbamates, formamadines, dinitrophenols, organotins, pyrethroids, nicotinoids, spinosyns, phenylpyrazoles, pyrazoles, pyrroles, pyridazinones, quinazolines, benzoylureas, and toxic plant extracts—and this is a short list (University of Minnesota
Most of these chemicals did not exist in nature before they were invented by the chemical industry. And although many break down easily and are short-lived, many can persist for decades. And remember, they were designed to kill.
Is it worth the extra expense to buy organic food over conventional?
A Consumers Union research team tested 94,000 samples of more than 20 different crops, grown both organically and conventionally. They found 73% of conventionally grown crops had residue of at least one pesticide. Only 23% of the same crops grown organically had any pesticide residue. More than 90% of apples, pears, peaches, strawberries and celery had pesticide residues. Conventional crops were six times more likely to have residues from multiple pesticides. And the levels of residues found on organically grown crops were consistently lower than conventional samples in all cases (Consumers Union, 2002
Although there may be only small residue amounts on your food when you eat it, how much is too much? Is it worth the risk?
What You Can Do
Knowledge is power. Arm yourself.
Everyone eats different food and has different sensitivities to what we eat. Protect yourself and your family by learning about what you eat.
is a searchable database, courtesy of the nonprofit Pesticide Action Network
, that brings to light the pesticide levels on the foods you eat. I like their Conventional v. Organic comparisons. Spend a few minutes researching your favorite foods, and make adjustments to the fruits and veggies on your table if you need. You’re worth it!
If you want the details, and enjoy diagrams of complicated chemicals, check out this Introduction to Insecticides (University of Minnesota
Join the Pesticide Action Network’s Action Center
, and let your voice be heard to influence decision-makers about laws and regulations that will affect your health.