Donate to Science & Enterprise

S&E on Mastodon

S&E on LinkedIn

S&E on Flipboard

Please share Science & Enterprise

Technology Funded to Assess Superfund Site Contamination

Rolf Halden (Arizinoa State University)

Rolf Halden (Arizinoa State University)

Researchers at Arizona State University in Tempe and University of Florida in Gainesville received funding to develop a device to measure toxic sediments with greater precision, accuracy and sensitivity. ASU’s Rolf Halden (pictured right) and Florida’s Nancy Denslow will test the device, and also evaluate health effects on two marine organisms and assess remediation efforts underway at a Superfund clean-up site on Lake Apopka in Florida.

The three-year, $830,000 grant from National Institute of Environmental Health Sciences, part of NIH, will fund further development of the device, known as the in situ sampling/bioavailability determination tool or IS2B. The device, for which a patent has been filed, can simultaneously measure contaminant levels in bulk water and pore water — the fluid occupying spaces between sediment particles.

Halden says half of the IS2B’s tubular body is buried in sediment while the other half of the device is exposed to bulk water. Pumps in the IS2B device draw in samples of bulk water and sediment pore water and push the samples through an array of filters and adsorption media at, respectively, high and low flow rates.

The IS2B’s design, Halden notes, allows a broad spectrum of contaminants — in some cases at sub-nanogram per liter levels — to be detected and accurately measured, including some chemicals that escape current sampling technologies. The device will permit measurements of a chemical’s effects on living matter, including its ability to cross an organism’s cellular membrane.

Lake Apopka is the third largest lake in Florida, and once a haven for migratory birds, vacationers, and fishermen. The lake became contaminated 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 DDE, a byproduct of DDT’s breakdown.

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. Soon after the accident, some 90 percent of the lake’s alligators disappeared and large numbers of migratory birds were poisoned, likely from consumption of contaminated fish. Many migrant farm workers lost their jobs when area citrus farms were shut down, or contracted a variety of diseases believed to be related to the contamination.

In the study, five contaminants will be evaluated for their effects on two marine organisms: Lumbriculus variegates, a species of black worm, and Pimephales promelas, also known as the fathead minnow. Contaminant exposure in fish will also be examined using DNA microarray analysis, allowing for a determination of health effects that may not be predicted solely on the basis of exposure levels to parent compounds.

The findings will be used to establish mathematical relationships between pollutant concentrations in bulk water, pore water, worms and fish. These results are then expected to be applied to IS2B-derived data to predict existing health risks. The study will also monitor the effectiveness of two remediation approaches: granular activated carbon and deep tilling of contaminated sediment.

Read more: Antibody-Based Biosensor Aids Environmental Cleanups

*     *     *

1 comment to Technology Funded to Assess Superfund Site Contamination