Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Storm runoff and sewage treatment outflow contaminated with household pesticides

03.02.2010
Pyrethroids, among the most widely-used home pesticides, are winding up in California rivers at levels toxic to some stream-dwellers, possibly endangering the food supply of fish and other aquatic animals, according to a new study by researchers at the University of California, Berkeley, and Southern Illinois University (SIU).

Pyrethroid insecticides, commonly used in California to kill ants and other insect pests around the home, have been found in street runoff and in the outflow from sewage treatment plants in the Sacramento area. The insecticide ended up in two urban creeks, the San Joaquin River and a 20-mile stretch of the American River, traditionally considered to be one of the cleanest rivers in the region.

Although the pyrethroid levels were low – around 10-20 parts per trillion – they were high enough to kill a test organism similar to a small shrimp that is used to assess water safety.

"These indicator organisms are 'lab rat' species that are very sensitive, but if you find something that is toxic to them, it should be a red flag that there could be potential toxicity to resident organisms in the stream," said study leader Donald P. Weston, UC Berkeley adjunct professor of integrative biology.

Fish would not be affected by such low levels, Weston said, but aquatic larvae that the fish eat, such as the larvae of mayflies, stoneflies and caddisflies, could be, and should be studied.

Weston first began looking at pyrethroid levels in streams bordering farm fields in 2004, and reported levels in some creek sediments high enough to kill the shrimp-like amphipod, an organism used by the U.S. Environmental Protection Agency as an indicator of the health of freshwater sediment. He subsequently found even higher pyrethroid levels in the sediments of urban streams, contributing to the California Department of Pesticide Regulation’s decision in August 2006 to re-evaluate some 600 pyrethroid products on the market, a process that is still underway.

The new study is the first published work to document toxic levels in the water column as well as in the sediments at the bottom of streams.

"This work opens a whole new can of worms and will probably substantially expand that re-evaluation," Weston said.

Weston's study, conducted with Michael J. Lydy (LIE-dee) of SIU in Carbondale and funded by the Surface Water Ambient Monitoring Program of the California Environmental Protection Agency, appears online today (Tuesday, Feb. 2) in the journal Environmental Science & Technology.

Pyrethroids have been around for decades, but seldom were used until organophosphates like chlorpyrifos and diazinon were banned for homeowner use in 2001 and 2004, respectively. Since then, pyrethroid insecticide use has skyrocketed, while studies in urban streams have found levels toxic to sensitive "indicator" species in California's Central Valley as well as in Texas and Illinois. The crustacean Hyalella azteca, for example, is paralyzed and killed at levels of 2 parts per trillion.

The main sources appear to be readily available insecticides applied around the home by the homeowner or by professional pest control firms to control pesky ants, Weston said. Of the varieties of pyrethroids marketed, however, one – bifenthrin – was found most often in the rivers and creeks in the Sacramento area, and pest control companies in California use four times as much as homeowners do, he said.

He noted that in some areas, pest control companies heavily market monthly or bimonthly sprayings outside the home to control ants.

"I question whether most people need routine insecticide treatment of their property, which results in residues on the lawn, in the garden and around the house that, when it rains, go down the storm drains and out into the creeks and rivers," Weston said. "Average homeowners, when they hire pest control companies to regularly spray their property to cut down on ants, don't realize that those same compounds end up in the American River at toxic levels."

The study found, surprisingly, that pyrethroids were present in effluent from sewage treatment plants at concentrations just high enough to be toxic to the test organisms, but well below levels found in urban runoff. Farm runoff, however, only occasionally contained pyrethroids at toxic levels, although some agricultural runoff did contain toxic levels of organophosphate insecticides.

The new study was conducted in the Sacramento-San Joaquin Delta area last winter, one of the driest in the past 10 years. As a result, water flow in the American River, which is controlled by dam releases, was at very low levels, and provided little dilution of pyrethroids entering the river in storm runoff. Preliminary tests this season, with water flow twice what it was in 2009, show that "the pyrethroid toxicity we found last year is somewhat diminished, but nevertheless still continuing," Weston said.

The paper, "Urban and Agricultural Sources of Pyrethroid Insecticides to the Sacramento-San Joaquin Delta of California," is online at Environmental Science & Technology.

Robert Sanders | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Solar Collectors from Ultra-High Performance Concrete Combine Energy Efficiency and Aesthetics

16.01.2017 | Trade Fair News

3D scans for the automotive industry

16.01.2017 | Automotive Engineering

Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs

16.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>