Pesticides: a quick fix, but at what cost?

Professional Horticulturist Chip Osborne speaks on pesticides. Photo by Courtesy of Louise Yarmoff

Sustainable Marblehead hosted a webinar on March 29, during which horticulturist Chip Osborne discussed the dangers of using pesticides and promoted moving toward an organic approach.

“We have to remember that pesticides treat symptoms, they do not solve problems,” said Osborne.

With 50 years of experience working in the horticulture industry and 37 years operating a family business, Osborne Florist and Greenhouse on Ocean Avenue, Osborne has seen products come to the market that were removed six months later because they were too dangerous to use. He said the registration process is very flawed.

Osborne, along with Pat Beckett, created a Marblehead Pesticide Awareness Committee in 1997.

In discussing the issue at hand, Osborne stressed, “my goal is not to scare or frighten anyone, it’s basically to point out what happens at the federal level and private industry regarding those pesticide products that are so liberally used on public spaces and residential landscapes.”

The born-and-raised Marbleheader highlighted problems with how pesticides are evaluated.

According to Osborne, the Environmental Protection Agency (EPA) evaluates manufacturers’ data and then looks at it under the model of a risk assessment protocol.

“If risk outweighs the benefit, it does not come to market. If the benefit outweighs the risk, it will come to market,” Osborne said. “Benefit can be economic to the registrar, looking at the levels of exposure and acceptable hazard. So the EPA was created to oversee this level of hazard and risk versus benefit.”

Osborne said the EPA looks for acute toxicity. It finds the lethal dose of a product, which is determined by administering gradually stronger doses to test animals. The amount that kills half of the test subjects is known as the lethal dose, or LD50.

“The values are then extrapolated to the human population by way of a 150-pound male, not a woman, not a pregnant woman, not an infant, toddler or child,” said Osborne. “So, think about that. A 150-pound male is a benchmark for extrapolation of the LD50, and something called a half-life.”

The half-life of a chemical refers to the amount of time necessary for 50 percent of the chemical to disintegrate. Depending on how much of the chemical is used, pesticides often last much longer than commonly believed. According to Osborne, a pesticide application sign cautioning residents to keep off the grass for 48 hours would need to be amended to 10-70 days just to account for the chemical’s half-life.

“That’s 10 to 70 days for half of it to go away. So, does this sign in 48 hours do any good? No. This is legislative. This is political. This is a sign that is put on there because of the state’s failure,” Osborne stated. “They had to come up with something, so they put this sign on there, but all of us in the industry know that it has not done any good.”

In addition, Osborne explained that many of the pesticides that the EPA classifies as lower risk with acute exposures are actually higher risk at low dose exposure and can cause endocrine disruption, attention deficit hyperactive disorder, and asthma.

“We know now that pesticides can cross the placental barrier, they are in umbilical cord fluid. If a pregnant woman is exposed in the first, second, or third trimester, different effects can be had on the fetus, depends when the exposure was, so it can be very subtle and it can be very low dose,” said Osborne.

According to Osborne, many people who purchase pesticide products at local retailers believe they are safe to use simply because the products are made available to them.

“The reality is that the EPA registration numbers should be no assumption of safety,” said Osborne. “So, in Marblehead, a lot of what is happening nationally is attributed to the early work we did in Marblehead 25 years ago.”

“We’re advocates, we created an awareness to education,” he added. “We taught organic lawn care classes in Marblehead to hundreds of people back in the late 90s, early 2000s, and we work with the Board of Health, and we got this done to this point.”