Organics is the latest buzz word for homeowners, municipalities, golf courses and landscape professionals. However, many people don't realize that the use of organics is nothing new. Traditional gardening methods employed organic methods and have been in place for the past 30,000 years, since the invention of agriculture. What is relatively unknown is that the  abandonment of organic agriculture methods began at the end of WWII when chemical pesticides and manufactured fertilizers first became available on a large scale.

There are many reasons why traditional organic methods fell into disuse. One reason was the replacement of draft animals with machines. Horse drawn plows and wagons gave way to tractors and trucks. On many farms the source of manure disappeared and the manures used for fertilizer were bulky and messy to handle. Chemical fertilizer were light weight, easy to apply and did not stink. They contained up to 46% nitrogen (N) as compared with only 5-10% N for manures and  their results at improving crop yields were phenomenal. The increased use of chemical fertilizers were directly responsible for the green revolution. Productivity per unit acre skyrocketed worldwide and fewer people were needed to operate much larger farms. The outcome of using chemical fertilizers was that the United States became the world's largest producer of food. The use of chemical fertilizers and pesticides led to astonishing results. The price of food dropped and a new way of doing modern agriculture came about. In many people's view traditional organic methods were now "old fashioned". Farmers who did not adapt these new methods fell behind and could not stay competitive. By the 1960's organics was all but dead. Everything seemed good. The world would not starve.

Then things started to got bad.

When Rachel Carson published her landmark book, Silent Spring it ushered in the first notions that there were problems with using pesticides. She described how DDT, an insecticide that was developed during WWII, was being overused and how it was leading to problems with the environment. The first signs were observed in birds. DDT is now banned but many people don't realize that DDT actually saved more lives than penicillin! It eradicated mosquitoes that spread malaria in many parts of the tropics. During the 1950's it was used against virtually every insect pest known. After about 20 years, evolution took over and many of these insects became naturally resistance to DDT. More DDT was used but it too became ineffective. Another problem with DDT was that it did not break down in the environment. Levels built up in the soil, entered the food chain and began affecting the reproductive activity of birds.

Many people in the chemical and ag industry rejected the notion that DDT was a threat, but the facts were there. As time went on DDT was phased out and new chemicals was developed. These had lower toxicity to humans and did not persist in the environment. But problems persisted. Many of these pesticides affected beneficial organisms and pests usually developed resistance to them. [To learn more about the History of DDT click here]

Determining Pesticide Toxicity

Toxicity is relative. There is acute toxicity, which means it kills you quickly and there is chronic toxicity, which means it takes a long time to kill. The term LD50 was used to quantify the acute toxicity of any pesticide that was developed. LD 50 stands for the amount of chemical ingested in an animal that will kill 50% of the population. A chemical with a low LD50 is more toxic than one with a high LD50.  LD50's are also determined for how each chemical is ingested, either by contact to the skin, by inhalation or by swallowing. The EPA became the government agency that regulated monitored these values. All values of LD50 measure acute toxicity only. There is far less known about the long term or chronic effects of these chemicals. For example, there is no way of knowing what the effect of a one time exposure to ingesting one gram of 2,4-D is twenty years ago. Unfortunately, the way we learn about these effects is by tragic accidents.

Seveso, Italy
On July 10, 1976, an explosion occurred at a chemical plant where the herbicide 2,4,5-T was being manufactured by Hoffman LaRoche in the town of Meda, Italy. A visible chemical cloud containing an unknown amount of dioxins, a minor by-product of the chemical process, spread over several miles of the populated community of Seveso, Italy exposing more than 30,000 people, aged 20 to 74, to the toxic vapor. Over the next few months there was an alarming number of birth defects in the farm animal population that gave rise to widespread fear over the potential effects on the human inhabitants.

Over the years Italian physicians and researchers examined outcome of the incident. They compared the health conditions of 30,703 "exposed" people, aged 20 to 74, to a larger population of 167,391 individuals, aged 20 to 74, living in nearby non-exposed areas. Between 1976 to 1986, there were no substantial increases in cancer. But in the decade afterwards, a significant rise in many types of cancers and cerebrovascular disease occurred. Cancers usually show a "latency period" between the time of exposure and when a cancer actually develops; this latency period varies from 7 to 40 or 50 years. Thus, the full long-term effects of the disaster are tragic but unclear.