Should we be worried about pesticides in groundwater contaminating the water we drink and the food we eat?
According to many public health and environment officials nationwide, the answer is yes.
In the last year and a half, public interest law firm Earthjustice has filed four federal lawsuits against the Environmental Protection Agency concerning the use of pesticides.
Many of the pesticides at the center of those legal battles are the same pesticides that recently surfaced as cause for concern in the state of Oregon. Of seven pesticides highlighted as contaminating groundwater in Oregon -- three of which are listed as possibly or likely to cause cancer by the EPA -- only two are are not subjects of Earthjustice's pending lawsuits.
"There are several pesticides on the market that pose extreme risks to human health -- through the water, air and food," said Joshua Osborne-Klein, an attorney for the Earthjustice. "Our lawsuits say that the EPA has not fully assessed these risks."
Concerns about groundwater come at the same time as several safety concerns -- whether about tainted peppers or the presence of drugs in drinking water -- that have left many people wondering what else is in our food and water that we don't yet know about.
Used largely to irrigate crops, as well as by more than half of the people in the United States as drinking water, groundwater is a critical natural resource for people throughout the country.
But according to information posted on the EPA's Web site, it is also "highly susceptible to contamination from septic tanks, agricultural runoff, highway de-icing, landfills, and pipe leaks." Contamination from pesticides is among those concerns. According to the U.S. Geological Survey, about 1 billion pounds of pesticides are used in the United States every year.
To prevent contamination, the EPA carries out several programs to ensure both people and the environment stay healthy.
The EPA helps ensure hazardous materials are properly stored, transported and disposed of so they don't leak into groundwater. The federal agency also works with regions and states to ensure drinking water is safe, making certain that laboratories that test water samples are certified by the EPA or the state and have periodic audits to ensure they're up to par.
The EPA also maintains a database, called for in the Safe Drinking Water Act, to monitor contaminants in the water. It also also collects data on contaminants that are believed to be in drinking water, but not yet regulated by health-based standards under the law, and reviews that list every five years.
Still, some say efforts under way are not enough.
"We should be doing a lot more to protect our groundwater," Wenonah Hauter, executive director of Food and Water Watch, told ABCNews.com. "There just has not been a willingness to classify some of the pesticides or to look at the human health effects," she said.
Hauter said part of the problem comes down to politics.
"Especially we've seen it during the last eight years, the manufacturers of these chemicals have some influence over the way that the Environmental Protection Agency assesses them," Hauter said.
"Looking at pesticides has become very politicized. EPA hasn't been doing what they need to do," she added.
Oregon is one state that said it has stepped up its effort to study pesticides. Along with scientists and public health experts from Oregon state departments of agriculture, health and human services, forestry and environmental quality, Janet Fults, a supervisor with the Oregon Department of Agriculture's pesticides division, is working to identify the state's pesticide priorities.
By studying water samples taken by the Oregon Department of Environmental Quality and the U.S. Geological Survey, her coalition observed that seven pesticides appeared routinely: Azinphos-methyl, Chlorpyrifos, Diazinon, Endosulfan, Dacthal, Ethoprop and Simazine.
Concern over those particular seven pesticides came out of a report released this summer by the Oregon Department of Agriculture. In that first state effort to examine pesticide use, Oregon learned that more than 40 million pounds of pesticides and herbicides were used in 2007, especially in soil on potato farms.
A 2006 USGS report on pesticide use likewise found that pesticides were detected in every stream sampled. Of more than 5,000 wells sampled, more than half of shallow wells and a third of deeper wells contained at least one pesticide.
Fults said that EPA support for reducing pesticides in groundwater is minimal. She said it has not given the states a deadline by which to establish their benchmarks and address water quality issues.
"There are so many pesticides that do not have benchmarks," Fults told ABCNews.com. "The EPA expects states to address water quality issues without benchmarks. Oregon is one of them but all of the states are in the same position."
Aimee Code, a water quality coordinator for the nonprofit Northwest Coalition for Alternatives to Pesticides, said that Oregon is one of only three states that has a comprehensive pesticide reporting program. California and New York are the other two states, she said.
"Oregon is rising to the challenge and it's better than holding out and waiting for the federal government to catch up. They are unfortunately years behind," Code said.
But, she emphasized, not all states have the resources, knowledge and capability to tackle pesticide issues in the way that Oregon can.
"There really should be a federal overarching review of these pesticides," she said.
In the meantime, in July, on behalf of a broad coalition of farmworkers, labor unions and environmental groups, Earthjustice filed a suit against the EPA in a federal court in San Francisco over the use of the pesticide diazinon. The pesticide was one of the seven recently identified in Oregon but has been detected in other states across the country.
Osborne-Klein said the chemical was originally developed to be a nerve gas, but after World War II was used as an insecticide, primarily for agricultural.
In 2004, the EPA banned the residential use of the chemical because of the risks it poses to children. However, it continued to allow farm uses of diazinon.
Earthjustice's suit challenges the decision to allow continued use of the pesticide because it can reach nearby communities through runoff and air. It is the most common insecticide detected in surface waters and has been detected in the air near schools at unsafe levels.
"Children are really at risk," Hauter said. "And a lot of these pesticides aren't just found in groundwater, they're also found in food products."
"Consumers need to be really cognizant of the food that they're eating and, as much as possible, buy organically grown or locally grown where you can actually talk to the farmer and look how the food is being grown," she said.