Environmental Impacts

persistent-envrio-impacts2.png

Bees in hive

When chemicals that are designed to kill are introduced into delicately balanced ecosystems, they can set damage in motion that reverberates through the food web for years.

  • Honeybee populations are plummeting nationwide.
  • Male frogs exposed to atrazine become females.
  • Pesticides are implicated in dramatic bat die-offs.

Pesticides wreak havoc on the environment, threatening biodiversity and weakening the natural systems upon which human survival depends. PAN works hard to promote agricultural systems that protect and strengthen, rather than contaminate, our natural ecosystems.

Bees, Bats & Frogs Dying Off in Droves

Five great extinction events have reshaped earth in the past 439 million years, each wiping out between half and 95% of planetary life. The most recent was the killing off of dinosaurs. Today, we're living through a sixth great cataclysm. Seven in ten biologists believe that mass extinction poses an even greater threat to humanity than the global warming which contributes to it.

Amphibians were the first to start dying off – in 1998 scientists identified the cause as a type of fungus, with population declines showing a strong correlation to pesticide exposure. A few years later America’s honeybees started dying – populations have dropped by 29% - 36% each year since 2006 (see below).

Bee populations have dropped 30% per year since 2006.

Bats are the most recent victims. In 2006 the first cave floors were found covered with dead bats in the Northeast. Some scientists believe that like amphibians, bats have become more susceptible to deadly disease (in this case, White Nose Syndrome) because their immune systems are weakened by pesticides. A growing body of evidence points towards pesticide exposure – even at so-called “safe levels” – as a key contributor to these and other problems for wildlife.

Mystery of Disappearing Honeybees

Without bees, say goodbye to almonds, peaches - even chocolate. Fully 1/3 of the food we eat depends on bees for pollination. So when the insects suddenly started dying off and abandoning their hives in 2006, scientists, beekeepers and farmers sounded the alarm. Researchers dubbed the phenomenon “Colony Collapse Disorder,” and went to work trying to find a cause.

As scientists unravel the mystery, they are discovering that exposure to pesticides—perhaps acting in synergy with other stressors—is a prime suspect. Most insecticides are inherently toxic to bees, and a recent study found a cocktail of toxic pesticides in the wax and honey of commercial hives. A new class of insecticides called neonicotinoids has been specifically implicated.

Some U.S. beekepers are responding by keeping their hives away from crops where these pesticides are used. Many European countries, including France, Germany, Italy and Slovenia, have already banned neonicotinoids in response to the threat, and beekeepers in these countries report that hives are beginning to recover. Meanwhile, researchers in the U.S. have established a Colony Collapse Disorder Working Group, as farmers and beekeepers anxiously await solutions.

tadpoles

Male Tadpoles Become Females in Contaminated Water

What do you call a weed killer that can give a frog a sex change? Its primary manufacturer, Syngenta, calls it “Aatrex”, but it’s commonly known as atrazine. More than 75 million pounds of the herbicide are used on U.S. farms every year, making it the second most-used pesticide in agriculture. And it contaminates water supplies throughout the Midwest at levels above those found to turn male tadpoles into female frogs in the lab.

In the 1990s, the Syngenta corporation funded Dr. Tyrone Hayes of UC Berkeley to study the environmental impacts of atrazine.When Dr. Hayes discovered ovaries growing in the testes of male frogs raised in atrazine-contaminated water, Syngenta refused to let him publish his findings. Hayes repeated the experiment with independent funding, and today continues research on atrazine’s dramatic impacts on amphibians.

Atrazine’s effect on amphibians is shocking: 10% of male frogs raised in atrazine-laced water developed into females. Genetically, the frogs are still males, but morphologically they are completely female—they can even mate successfully with other males and lay viable eggs.

Switzerland, where Syngenta is based, banned atrazine in 2007. EPA officials are currently reviewing the chemical’s use in the U.S. PAN and our Midwest partners are pressing hard for transparent, science-based decisionmaking without undue influence from Syngenta—the largest chemical company in the world.

Fouled Waterways Endanger Fish & Birds

PelicanSome pesticides seep through the soil into groundwater; others are washed by rain into creeks, rivers, and lakes where they can poison fish and other aquatic organisms. Depending on the type of chemical, contamination can last for days, weeks, months – even decades. 

  • California: Pesticides used by homeowners on lawns poison invertebrates at the bottom of aquatic food chains, upsetting fragile ecosystems statewide.
  • Florida Everglades: Endosulfan runoff from tomato fields threatens the small fish that feed ibises, storks, and egrets.

Pesticide runoff remains largely unregulated, and government agencies have shown little initiative in protecting complex aquatic ecosystems. Fortunately, when tainted runoff threatens a species already listed as endangered, the government can be forced to act. In the pacific northwest, creeks that are home to endangered salmon now require substantial buffer zones from toxic pesticides. The Center for Biological Diversity recently took legal action to force EPA to protect 887 threatened and endangered species from 400 of the most dangerous pesticides.