hogg@utcsri.UUCP (John Hogg) (04/04/85)
An article in Tuesday's Toronto Globe & Mail announces that tin-based
anitfouling may be extremely toxic. While this should be no great
surprise (what do you use it for, anyway?) the degree of toxicity is
such that restrictions on its use in this country are being considered.
James Maguire of Environment Canada has stated that tributyl tin (TBT)
can kill young fish at levels of 5 parts per billion. These levels are
exceeded in some harbours and narrow channels; in a Toronto Harbour
water sample there was "10 times the TBT needed to kill young trout."
There were also high levels at Port Hope, Ont., the Welland Canal, the
Detroit River and the St. Marys River at Sault Ste. Marie.
Mr. Maguire is not certain how TBT kills, but it appears to attack the
enzyme system and has produced effects such as swelling of the brain.
There are reports that France and Britain plan to restrict the use of
TBT because it is killing oysters at concentrations lower than 1 part
per billion. (Europe, are you there? Have you heard anything about this?)
So, this is something else to consider when you select your bottom gunk
this year. The Sikkens antifouling which I lauded in an earlier message
is TBTF-based. I certainly would recommend that sailors in reservoirs
not use TBT paints; those in other fresh waters should probably also
think hard.
--
John Hogg
Computer Systems Research Institute, UofT
{allegra,cornell,decvax,ihnp4,linus,utzoo}!utcsri!hogg