Chicken litter trial: Expert says arsenic spread via air into defendants’ home
Posted on Wednesday, September 13, 2006
Chicken litter with arsenic in it was spread in the air to the home of Michael Blu Green, who lived in Prairie Grove when diagnosed with leukemia in the 1990 s.
This was the essence of the testimony given by the plaintiffs ’ expert witness Tuesday as the trial continued for a civil lawsuit alleging arsenic in roxarsone, a chicken feed additive, caused Green’s leukemia via spreading of poultry litter laden with the substance in the Prairie Grove area.
The trial in Washington County Circuit Court is the first one in a multi-lawsuit case alleging that roxarsone that degrades in chicken litter turns into a harmful arsenic that has caused cancer of several plaintiffs.
Devraj Sharma, whose field of study is fluid mechanics, testified that he was asked to evaluate data in order to understand how arsenic found its way to residents.
Michael Blu Green, Sharma said, was exposed to arsenic from roxarsone contained in poultry litter repeatedly and in a large number of locales in and around Prairie Grove via the air, and the duration of this exposure began in the early 1990 s and continued into late spring of 2004. He was diagnosed with leukemia in 1999.
Sharma said he used maps of the Prairie Grove area and information about atmospheric conditions, and measured wind speed and direction. He collected wind information from the meteorological tower at Drake Field in Fayetteville. He set up his own weather station in Prairie Grove to measure the wind every minute for a six-month period. He also reviewed information about chicken litter spreading and arsenic content in homes.
He said he also reviewed studies about degradation of roxarsone, as well as spreader records, poultry feed tickets and data about arsenic in residents’ homes that was compiled by another expert in the case, Rod O’Connor.
Sharma said under cross examination, however, that he did not have any mathematical modeling to show how contaminants from the litter spread from the fields to the Greens’ home. He said, though, that he developed a physical model.
Also testifying Tuesday was William Sawyer, a toxicologist, who said that he ruled out other potential causes of the leukemia, such as insecticides, pesticides, a local galvanizing plant and abandoned gas wells.
“ Prairie Grove has been very well studied, ” he said. “ I have not been able to find any other potential causes. ”
Lab results from the materials found in the homes revealed arsenic and roxarsone, he said. The National Toxicology Program of the Centers for Disease Control, he said, has determined that arsenic causes leukemia in humans and animals, and the Environmental Protection Agency lists arsenic as the number one carcinogen. Arsenic, he said, has no function in the human body. “ It’s been used since the 13 th century to poison people, ” he said, adding that the chemical is dangerous even in low levels.
Richard Clapp, an epidemiologist and Boston University professor, who performed a study about excess leukemia cases in Prairie Grove, did not go as far as to conclude that there was a leukemia cluster in Prairie Grove based upon his work. He does claim that there were more cases of childhood leukemia than would be expected in a 10-year period in a town the size of Prairie Grove.
He testified about the parameters of his study, which were people 0-19 years of age in the Prairie Grove geographic census area when diagnosed with leukemia, and covered the period 1993-2002. These cases were compared to another comparable data set.
Questionnaires were filled out about possible exposures to toxic substances.
There were two leukemia cases in the 10-year period in Prairie Grove in the study.
Two who were diagnosed with leukemia in that period were excluded from the study. Holly Green was excluded because she stayed at a day care in Prairie Grove and did not live there, while Crystal McConnell was not included because she was older than 19 when diagnosed. Both young women died from leukemia.
Asked by defendants ’ attorney Rob Adams, he testified that he did not conclude that there was a leukemia cluster in Prairie Grove based upon his work.
He also admitted that toenail clippings to establish biologically if those in the study had biological markers for toxic exposure were not taken, and that the person to do it was not available.
He also said, responding to Adams, that researchers did not look at any other poultry-producing areas in the country.
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