The EPA has issued a list of pesticides that will be screened for possibly disrupting the human, as well as animal, endocrine system. The list, released Wednesday, focuses on “endocrine disruptors” which are chemicals that can negatively impact hormones produced by the endocrine system. The system regulates all biological processes in the body – specifically, growth, metabolism and reproduction.

“Gathering this information,” said EPA Adminstrator Lisa P. Jackson, “will help us work with communities and industry to protect Americans from harmful exposure. Endocrine disruptors can cause lifelong health problems, especially for children.”
The endocrine, or hormone, system is found in all mammals, birds and fish. It is made up of glands, hormones that are produced by the glands and receptors in different organs that respond to the hormones.

The EPA will have the makers of 67 pesticide chemicals test their products this summer to see if their chemicals are responsible for disrupting the endocrine systems.

The testing will be done through the Endocrine Disruptor Screening Program (ESDP) set up by the EPA, which commonly relies on companies to test their own products.

The list of all 67 chemicals can be found here. The EPA stresses that this list is not a definitive collection of known endocrine disruptors. The chemicals selected were chosen because there is a high potential for human exposure through food and water, residential activity or agricultural pesticide application. Many of the chemicals found on the list are present in commonly used lawn treatments, insect sprays, solvents and other household products.

“These pesticide chemicals were picked because we wanted to start with ones that more people might be exposed to,” says EPA spokesperson Suzanne Ackerman. “They were not selected based on which ones are considered most dangerous. We won’t know that until we have them tested.”

Several chemicals on the list, though, have been flagged for health concerns. Atrazine, for instance, has been banned in the European Union. Atrazine is among the most common, if not the most common, herbicide used in the United States.

Other recognizable chemicals on the testing list, include diazinon, malathion, carbaryl and permethrin. Diazinon has been banned for household use in the U.S., but remains available for agricultural use as an insecticide. Permethrins turn up on flea collars for dogs, which some health groups consider too toxic for household use.

Endocrine disruptors work in several ways. Sometimes, the chemical mimics a natural hormone, tricking the body into over-responding to the stimulus. The endocrine disruptor can also block the effects of a hormone from certain receptors. In other cases, the chemical can stimulate or inhibit the endocrine system, causing the overproduction or underproduction of hormones. Sometimes, as in the birth control pill, a chemical intentionally inhibits the endocrine system.

Impaired endocrine function can result in lowered fertility and other health conditions.

The direct connections between human diseases of the endocrine system and the system’s exposure to environmental contaminants, are still not clear, according to the EPA. This is why the establishment of the screening program is considered an important step.
Copyright © 2009 | Distributed by Noofangle Media

Recent research on potatoes showed that low levels of herbicides, which did not result in obvious damage to the plants above ground, negatively affected their underground growth, reducing yields.

Oregon researchers with the Environmental Protection Agency tested the herbicides to assess a plant’s resilience to exposures that would be assumed to be safe; levels that weren’t concentrated enough to wilt the plant’s foliage or cause any obvious signs of damage.

Seven different herbicides were tested and applied at certain times in the plant’s development – and found to affect the size and number of the potato tubers produced, according to a news release about the study by the American Society of Agronomy.

Potatoes were chosen for the project because scientists suspected that their plant structure  would provide an easy way to check on the effects of herbicide exposure a during a plant’s  reproductive cycle.

Oust, an herbicide authorized for use in ditches and road right-of-ways, was found to have a significant effect on the potato plants, causing deformed tubers and reduced yield, said lead researcher Dr. Thomas Pfleeger, a plant physiologist with the EPA.

That finding had implications for real world practices because the low levels of Oust applied simulated what can happen when a pesticide drifts into agriculture areas. If the drift occurs at a sensitive time in the plants development, the fruit of the plant can be affected, Pfleeger said.

Previous work with low levels of pesticides on cherry trees, simulating accidental or “drift” exposures, also found damage to the trees ability to reproduce and bear fruit the following season, he explained.

The takeaway message?

“People who are applying pesticides have to be very careful. They can go long distances and cause problems. And you can’t always see the damage,” he said.

The experiments also have relevance for EPA labeling practices. Currently, pesticides are tested on pre-emergent and seedling plants, to gauge their effects. Pfleeger says the Oregon experiments suggest that testing during a plant’s reproductive cycle should also be part of the chemical registration process.

Asked if the tests also raise questions about pesticide use in general, and other potential “unseen” effects, he responded that the threat to the produce-buying public would be nominal: “It’s pretty hard to get away from pesticides. They’re pretty much everywhere.”

The research by the U.S. EPA’s Western Ecology Division has been printed in the latest issue of the Journal of Environmental Quality, a peer reviewed publication put out by the American Society of Agronomy.

The article notes that American agriculture’s dependence on herbicides – a multi-billion dollar industry that annually dumps about 500 million pounds of herbicides on the land at last count – is worth evaluating because  of “potential risk are non-targeted crops, rare and endangered plant species, native plant communities, and organisms that are dependent on natural plant communities for food and shelter.”

Copyright © 2009 Green Right Now | Distributed by Noofangle Media