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Professor disputes science in chicken litter testimony

Published on 21 September, 2006, Last updated at 02:36 GMT

By Trish Hollenbeck

A Cambridge-educated professor who has performed extensive research on arsenic chemistry criticized the science done on the part of plaintiffs in a case that claims arsenic in chicken litter has caused cancer in Prairie Grove area residents.

University of British Columbia Professor William Cullen testified Wednesday that sampling attic and air conditioning filter dust, as was done in the case being tried this week in Washington County Circuit Court, is not a recognized or legitimate sampling method.

Cullen, who has a doctorate degree in chemistry from the University of Cambridge, has done research on creating compounds or classes of arsenic never before made. He also has looked at how arsenic compounds transform in the environment.

He is just one of the defendants' expert witnesses put on the stand this week to try to poke holes in the theory of plaintiffs who claim the degradation of roxarsone - a feed additive made by Alpharma and Alpharma Animal Health - in chicken litter spread as fertilizer has caused their son's leukemia.

Michael and Beth Green and their son, Blu, are suing the companies in the first trial for a multi-suit case involving several other plaintiffs who claim a similar theory. The Greens are asking for about $ 900, 000 in compensatory damages.

Cullen testified that he is unaware of any literature that supports looking at air conditioning filters, and there are required procedures put out by the Environmental Protection Agency to determine inhalation levels from house dust.

He also discussed a study where a researcher looked at household dust arsenic levels in Ottawa, Canada. The range was 1. 7 to about 80 parts per million. Soil levels were 1. 7 to about 10 parts per million of arsenic.

Defendants' lawyer Rod Adams asked about concentrations being higher inside the home than outside.

" This is not an unusual phenomenon, " he said.

One household dust sample taken by plaintiffs' testers found 66. 9 parts per million of arsenic in the Greens ' home. The soil was lower.

The Ottawa study, he said, used well-established protocols, and samples had to be related to surfaces people came into contact with.

Samples from the filters in the Green case, he testified, cannot be compared to any samples taken by any legitimate means.

Other household dust taken in the Green case and put forth by a plaintiffs' expert, he said, did not show exceptional arsenic levels.

He also talked about the lab testing of the dust samples that separated arsenic species and, according to O'Connor, showed the presence of roxarsone.

He said the testing did not establish the presence of roxarsone in the samples, and was critical of the way the testing was done.

Although the lab did use a chromatograph to separate forms of arsenic, he testified, there is another test performed to detect various species of arsenic that was not done in this case.

Just using the first method, he said, is a " little bit unreliable" or can be wrong.

He discussed another test that could have been done, repeating the procedure to make sure what was thought to be roxarsone graphed at the same level again.

" That experiment is easy to do, " he said, " because they clearly had the samples. "

He also testified that he has not seen any scientific literature that indicates a risk to humans from transformation of roxarsone.

He said roxarsone changes to a certain degree when spread on fields. He changed his opinion - from the one he gave in a deposition - about a study that looked at sunlight and its role in degradation. He told plaintiffs' attorney Clayton Davis that he had since found that there were different conditions in the experiment, including no real sunlight.

Billy Clay, a veterinary toxicology and agronomy consultant from Stillwater, Okla., also testified, primarily about chicken litter. He talked about there being no requirement before 2004 to report how much litter was spread in Arkansas.

He said he did not know how much roxarsone was fed to chickens in the Prairie Grove area.

Plaintiffs' attorney Jason Hatfield went through feed tickets for one grower, Randy West, in the Prairie Grove area during different months in 1999, showing each group delivered contained. 005 percent of roxarsone.

The total amount of feed with roxarsone delivered to West was 301, 060 pounds, based on Hatfield's listing in court.

Clay also testified that he raised chickens and did not feed them roxarsone.


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