Pesticide concentrations decreasing

Oct 20, 2008

The widespread use of pesticides across the United States has been in practice for decades, with little knowledge of the long-term effects on the nation's groundwater.

The results of a new study show that samples taken from over 300 wells across the US have not retained a high concentration of pesticide contamination. The news is a result of a decadal long study to assess the extent of the impact of contaminants on the nation's water supply.

Over the years, frequent research has detected pesticides in ground water around the country, including in aquifers used for drinking-water supply. Over the past few decades, the use of some pesticides has been restricted or banned, while new pesticides have been introduced. One goal of the study was to track the retention of various types of contaminants that would be found in the different pesticides used over the years.

Results for one of the first national studies on the presence of pesticides in groundwater were recently published by the U.S. Geological Survey in the September-October issue of the Journal of Environmental Quality. The study is a part of that agency's federally-funded National Water-Quality Assessment (NAWQA) Program.

"The results of this study are encouraging for the future state of the nation's ground-water quality with respect to pesticides," said Laura Bexfield, who conducted the data analysis. "Despite sustained use of many popular pesticides and the introduction of new ones, results as a whole did not indicate increasing detection rates or concentrations in shallow or drinking-water resources over the 10 years studied."

Original samples were taken from the wells from 1993-1995, and compared with samples taken from 2001-2003. Laboratory analysis was performed using methods that allowed detection of pesticide compounds at concentrations as small as 1,000 times below USEPA drinking-water standards. Of the 80 compounds studied, only six were detected in ground water from at least 10 wells during both of those sample periods. Concentrations of these compounds generally were less than 0.12 parts per billion, or more than 10 times lower than applicable USEPA drinking-water standards.

Characterization of trends in pesticide occurrence and concentrations through time is important in determining how quickly ground-water systems respond to changes in chemical use and in identifying compounds that may pose a threat to water quality before large-scale problems occur. Continuing research is planned to track and understand changes in both ground and surface-water quality across the United States.

Source: American Society of Agronomy

Explore further: California farmers agree to drastically cut water use

Related Stories

Silicon: An important element in rice production

Apr 28, 2015

Silicon (Si) is the second most abundant element of the earth's crust after oxygen. It has long been neglected by ecologists, as it is not considered an essential nutrient for plants. However, research of ...

Predicting pesticide loads more accurately

Mar 27, 2015

The EU wants to further improve the authorization process for plant protection products. The different national procedures for this are supposed to be further harmonized. Fraunhofer researchers have developed ...

Researchers detail new insights on arsenic cycling

Mar 09, 2015

University of Oregon geologist Qusheng Jin initially labeled his theory "A Wild Hypothesis." Now his study of arsenic cycling in a southern Willamette Valley aquifer is splashing with potential significance ...

Researchers connect climate change to food safety

Mar 06, 2015

Climate change can affect our food safety in a number of ways. In a European study, researchers at Wageningen University and Ghent University (Belgium) state that there is often a relationship between long-term changes in ...

Recommended for you

Pipeline that leaked wasn't equipped with auto shut-off

8 hours ago

The pipeline that leaked thousands of gallons of oil on the California coast was the only pipe of its kind in the county not required to have an automatic shut-off valve because of a court fight nearly three ...

California farmers agree to drastically cut water use

May 23, 2015

California farmers who hold some of the state's strongest water rights avoided the threat of deep mandatory cuts when the state accepted their proposal to voluntarily reduce consumption by 25 percent amid ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.