Fungicide irreversibly damages immune system

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Fungicide " irreversibly damages immune system "

15:30 09 April 02

NewScientist.com news service

http://www.newscientist.com/news/news.jsp?id=ns99992145

A chemical used widely as an agricultural fungicide causes irreversible

damage to human tumour-fighting cells, new research reveals.

Triphenyltin, or TPT, has been detected in fish and ocean sediments. And it

has previously been shown to cause tumours in rodents.

A team led by Margaret Whalen, a biochemist at Tennessee State University in

Nashville, exposed human killer T cells - a type of immune cell that destroys

cancerous and other abnormal cells - to TPT. They then measured the cells'

potency against isolated human leukaemia cells.

After one hour of exposure, the killer T cells lost between 50 and 60 per

cent of their destructive powers. But, more importantly, after the killer

cells were placed back in a solution without TPT they did not regain their

prior lethality. " Despite the fact that the compound is no longer there, they

are still unable to kill the leukaemia cell, " Whalen says.

Whalen says it is not clear yet whether there is a real health risk to people

working with the chemical. She suspects that agricultural workers are exposed

to lower levels in the field than those she used in the lab. " But it's hard

to know what real-life levels of phenyltins are, " she says.

The next step will be to check for TPT in the blood of people who use it

regularly, such as agricultural workers.

Whalen's team presented their research at a meeting of the American Chemical

Society in Orlando, Florida.

 

Mark Schrope, Orlando