Issue August 15, 1998 Ð PRESS RELEASE Ð The Lancet


DEAD FISH, ESTUARINE WATER, AND MENTAL DIFFICULTIES
(pp532-39)

In this weekÕs Lancet, Professor Glen Morris Jr and coleagues from the University of Maryland and Johns Hopkins University report a clinical syndrome in human beings resulting from exposure to certain stretches of estuarine water in the USA.

In autumn, 1996, in the Pocomoke River and nearby estuaries on the east shore of the Chesapeake Bay, Maryland, commercial fisherman noticed unusual skin lesions and erratic swimming behaviour in fish. In August, 1997, large numbers of fish died, and a toxic dinoflagellate called Pfiesteria piscicida and other similar dinoflagellate species were found in the water. In autumn, 1996, fishermen working on the Pocomoke estuary began experiencing headaches, diarrhoea, weight loss, skin irritation, and memory problems. Professor Morris and colleagues assessed these complaints.

The investigators assessed 24 people who had had direct contact wit the affected waterways during periods when fish were dying or were seen with Pfiesteria-associated lesions. The investigators collected data on exposure history and symptoms, did medical and laboratory assessments, and carried out neuropsychological tests. Morris and colleagues found that people with high exposure to affected waters weres significantly more likely than controls to experience headache, skin lesions, and neuropsychological symptoms (eg forgetfulness and learning difficulties), confirmed by abnormalities on neuropsychological testing. Risk of illness was directly related to degree of exposure. By 3-6 months after cessation of exposure test scored had returned to within normal ranges.

ÒPeople with environmental exposure to waterways in which Pfiesteria toxins are presentÓ, conclude the researchers, Òare at risk of developing... difficulties with learning and higher cognitive functionsÓ. The investigators acknowledge that Òmechanisms responsible for the observed neuropsychological symptoms remain to be definedÓ. 

Contact: Professor Glen Morris Jr, University of Maryland School of Medicine, Baltimore, Maryland, USA; tel +01 410 706 4580; fax +1 410 706 4581; e=mail jmorris@umppal.ab.umd. edu

Please mention The Lancet as the source of this material
   
QUOTE: ÒWe have moved from public controversy to hard scientific data,Ó said Dr. J. Glenn Morris Jr., who headed the medical research team. ÒThis puts the spotlight on the human health issues, where it belongs.Ó