(Beyond Pesticides, April, 23, 2013) A report released by the Surface Water Ambient Montioring Program (SWAP) has found in California that “detection of pyrethroid pesticides in sediment increased from 55 percent of the statewide samples in 2008 to 85 percent in 2010.” The findings are among the results of the Stream Pollution Treads, or SPoT, monitoring program, an annual assessment of pollution in streams in California. The report also found that stream beds in urban areas have higher levels of pyrethroids that those in agricultural areas.
The SWAP report summarizes results of the 2009 and 2010 annual surveys and compares those results to the 2008 SPoT data. Beyond the 30 percent increase of pyerthriods detected in sediment, the percentage of highly toxic samples increased from 6 percent to 67 percent when toxicity tests were conducted at a colder temperature that more closely matched the normal surface water temperature in average watersheds. These results, according to the report, “suggest that current monitoring may underestimate the occurrence of parathyroid-associated toxicity using the standard protocol.” The report also acknowledges that some pyrethroids, such as bifenthrin, may persist longer than others, and the chronic impacts of these pesticides may be underestimated by some of the sample results.
The report also found that watershed samples in urban areas have a higher concentration of these pesticides. Pyrethriods are in many household insecticides and pet sprays. Pyrethriods are also used in mosquito adulticide programs. The only pesticide that was found in higher concentration on agricultural watersheds compared to urban watersheds is DDT. DDT is highly persistent and has been banned in the U.S. since 1972.
Synthetic pyethroids are synthesized derivatives of naturally occurring pyrethrins. Synthetic pyrethroids are toxicologically similar to the natural occurring pyrethrins, however, pyerthrins have dramatically shorter half-lives and are extremely sensitive to light, heat, and moisture. Pyrethriods are known irritants and can have a high acute toxicity depending on the specific formulation. Pyrethriods have also been connected to multiple symptoms of acute toxicity, asthma, incoordination, tremors, and convulsions.
Pyrethroids have been linked to chronic health problems. Many pyrethroids have also been linked to disruption of the endocrine system, which can adversely affect reproduction and sexual development, interfere with the immune system and increase chances of breast cancer.
Pyrethriods are highly toxic to aquatic organisms. Lobster shrimp mayfly nynmpsh and zooplankton are the most susceptible non-target aquatic organisms and pyethroids can damage the gill of fish.
This is not the first report to find that California has contaminated water. A 2011 report found increased levels of chemical pollution, including pesticides, in California water bodies. According to the report, which gathered monitoring data for 2008-2010, more than half of the state’s water bodies do not meet existing water quality goals and many still need federal pollution control standards. While federal officials maintain that the increases are due to improved monitoring and not new pollution, the data presents a more accurate representation of real world contamination.
Other states beyond California are battling with the issues that surround contaminated water. SGS data indicates that U.S. waterways and groundwater are contaminated with toxic substances, including fertilizers, pesticides, pharmaceuticals, and other industrial chemicals. Chemicals, even those detected at low-levels, are increasingly linked to serious health and developmental effects, well below U.S. Environmental Protection Agency’s (EPA) drinking water standards and levels of concern. According to a Beyond Pesticides report, Threatened Waters: Turning the Tide on Pesticide Contamination, over 50% of the U.S. population draws its drinking water supply from groundwater. Once groundwater has been contaminated, it takes many years or even decades to recover.
For more information on pesticides and water quality please visit Beyond Pesticides’ Threatened Waters page.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.