The innovative design of IS2B allows a broad spectrum of contaminantssome occurring at minute levelsto be detected and accurately measured. These include fully water-soluble to highly sorptive and hydrophobic chemicals, giving the apparatus considerable versatility compared with presently available passive sampling technologies.
According to Halden, previous modeling efforts indicate that the IS2B is capable of sampling bulk and pore water pollutants at sub-nanogram per liter levels. Further, the device will permit measurement of bioavailability (how much of a chemical is present and able to cross an organism's cellular membrane) and bioactivity (a chemical's effect on living matter).
The project underway at Lake Apopka focuses on two traditional and three emerging sediment contaminants (p,p'-DDE and dieldrin; and fipronil, triclosan and triclocarban). The lake became contaminated with these and other chemical toxins as a result of a series of environmental mishaps, including a large spill in 1980 by the Tower Chemical Company, which had been producing dicofol, a mixture of the pesticide DDT and DDEone of DDT's breakdown products.
Both DDT and DDE are reproductive toxicants for a variety of bird species, and are linked with the decline of the bald eagle, brown pelican, peregrine falcon, and osprey. Dieldrin is a chlorinated hydrocarbon pesticide, originally developed as an alternative to DDT. It has been found, however, to stubbornly resist breakdown, remaining in the environment as a persistent organic pollutant. Fipronil is a slow-acting pesticide, while triclosan and triclocarbon are both antibacterial/antifungal agents.
|Contact: Joe Caspermeyer|
Arizona State University