THERE'S been much talk about the risk of smoking cannabis, and every cannabis smoker knows the risk of being busted.

But there's a far more serious risk involved with buying illegal cannabis. That of quality - the only control is that exercised sometimes by dealers.

Over the years, there have been more and more obnoxious cannabis products, containing who knows what, on the streets, often relatively inexpensive.

We've seen "soap bar" (supposedly Moroccan) containing everything from wax to animal excreta; we've had "Squiggy Black" (supposedly from Pakistan) that I wouldn't like to even think about; and now we have cannabis "bud" containing some sort of ground-up grit, sand or glass.

Cannabis, as we know, is outside of the control of the law, so little can be done.

The health risks from contaminants are doubtless greater than those for pure cannabis - whether or not some smokers are at risk from strong bud, certainly everyone who smokes that contaminated rubbish is at serious risk.

People need to be warned - and I hope I can use your letters page to do it. We cannot just sit and wait for the Government to legalise this popular plant, and allow some sort of consumer protection and taxation on profits - we need to warn people now.

Alun Buffry, Legalise Cannabis Alliance, PO Box 198, Norwich.