EMBARGOED FOR RELEASE August 14, 1998
Contact: Jennifer Donovan
Phone: 410/706-7946
Pager: 410/407-6873
For the first time, researchers have published scientific data documenting novel, serious but reversible neuropsychological effects of exposure to Pfiesteria-infested water.
"It is a new clinical syndrome with a distinctive neuropsychological profile," says Lynn Grattan, PhD, first author of a paper published in the August 15 issue of the international medical journal, The Lancet. A neuropsychologist and associate professor of neurology at the University of Maryland School of Medicine, Grattan performed neuropsychological evaluations of 24 people exposed to Pfiesteria toxins in Maryland waterways last summer. J. Glenn Morris Jr., MD, MPH, the report's senior author, calls the publication a landmark, the first peer-reviewed scientific documentation that there is a clinical syndrome resulting from exposure to the toxins produced by Pfiesteria and Pfiesteria-like dinoflagellates. "We have moved from public controversy to hard scientific data," says Morris. "This puts the spotlight on the human health issues, where it belongs."
A professor of medicine, epidemiology and preventive medicine at the University of Maryland School of Medicine, Morris headed a state-appointed medical team that examined people who complained of symptoms after exposure to Pfiesteria-infected waters. During August 1997, massive fish kills associated with Pfiesteria occurred in the Pocomoke River and adjacent waterways on the eastern shore of the Chesapeake Bay in Maryland. Some people who had contact with the water reported a variety of symptoms including fatigue, headaches, respiratory irritation, diarrhea, weight loss, skin rashes and memory problems. Exposure and symptom histories were taken, and medical, laboratory and neuropsychological tests were conducted on people with varying levels of exposure. Performance on the neuropsychological tests was compared to a group of controls matched for age, gender, education and occupation. No consistent physical or laboratory abnormalities were found, the scientists report. However, those with high levels of exposure scored significantly lower than unexposed controls on some of the neuropsychological tests. Difficulties with memory, new-learning ability, and some forms of attention and concentration were seen in people whose other neuropsychological test results were normal. Repeat testing after 10 to 12 weeks showed significant improvement in most of the people affected. Six months after exposure, everyone had returned to normal performance levels on the neuropsychological tests. "Moderate to high exposure to waters containing Pfiesteria toxins causes neuropsychological problems in otherwise normal people, and as far as we can tell, the effects appear to be reversible," Grattan concludes. "Further prospective studies are needed to determine if everyone returned to his or her original level of cognitive ability." A Centers for Disease Control and Prevention grant, with support from the Heinz Family Foundation and other federal funding, are enabling University of Maryland and Maryland Department of Health and Mental Hygiene researchers to continue to monitor effects of long-term chronic exposure to Pfiesteria or related toxins; to identify, evaluate and treat new cases; and to develop methods for exposure prevention. A number of ongoing neuropsychological, neurologic, molecular and environmental research studies also are under way. "It is important that we aggressively develop models and methods for understanding and managing the human health effects of exposure to this group of emerging, marine-based pathogens," Grattan says. Co-authors on The Lancet paper are: David Oldach, MD, Mark Lowitt, MD, C. Lisa Kauffman, MD, and J. Richard Hebel, PhD, University of Maryland School of Medicine; Trish M. Perl, MD, MSc, and Patricia Charache, MD, Johns Hopkins University School of Medicine and School of Public Health; Martin Wasserman, MD, JD, and Diane L. Matuszak, MD, MPH, Maryland Department of Health and Mental Hygiene; Curtis Dickson, MEd, and Colleen Parrott, RN, MS, Somerset County Health Department; and Ritchie C. Shoemaker, MD, Pocomoke City, Md.
www.oea.umaryland.edu/Media/OMRhome.htm
RSS