THERE is much discussion at the moment of the issue of medicinal cannabis. The reason for most coverage is about the sad cases of children with uncontrollable fits or people with brain tumours ("Cannabis may be returned to mother of epileptic girl", The Herald, April 9). Unfortunately, the confusion about what is medicinal cannabis pervades these discussions, spreading serious misinformation about the miracle cures from cannabis. Misinformation about THC (Tetrahydrocannabinol) in particular is very worrying. THC is the part of cannabis plants that is hallucinogenic, giving users the chemical highs they seek. These can be good highs or quite the opposite. I worked for decades as a youth worker with a special interest in youth health matters. I encountered hundreds of children and young people suffering from the serious side-effects of cannabis, with varying levels of THC in it.

It is important that the public understand that medicinal cannabis contains almost no THC, if any at all, and so will not cause hallucinations in the users. It is other elements of the cannabis plant that offers some help, to some patients, with a very limited range of medical conditions.

CBD for medicinal purposes (commonly called cannabis oil) again does not contain THC. One caller to Radio Scotland's Call Kaye programme this week said he buys his CBD online, always a very unsafe source of such products. He claimed that he could also get higher THC-strength CBD. So he clearly was not buying medicinal CBD.

Although our Government has announced that it will allow the use of medicinal cannabis in very specific cases, for a very limited range of medical conditions, the medical profession who take the Hippocratic oath “to do no harm” are as yet, quite understandably, reluctant to prescribe medicinal cannabis, until sufficient research is completed and adequate training is offered to ensure the safest possible use of this drug, especially on children.

Public education about medicinal cannabis is urgent, because very powerful campaigners for legalising all cannabis products are constantly riding on the back of sad cases of children and others with medical conditions that might or might not be relieved by medicinal cannabis.

The often-quoted success story of legalising cannabis in the United States is a myth. As always, the drive for legalising cannabis in the US is driven by money – money to be saved in police enforcement and the billions of dollars per year to be gained in taxes, plus of course massive profits for this industry. It has nothing whatsoever to do with public health benefits. Once the cannabis-driven deaths start to emerge, a very different news story will dominate our media.

Max Cruickshank,

117 Ascot Court, Glasgow.

I ALMOST had to look at the date when I read the article on the back page (“Water plan was hatched in rowing boat on the ocean”, Herald Business, April 8). Ionised water, indeed.! Water is naturally composed of H+ ions and OH- ions. These are balanced and associate with each other. If one adds a solute like salt then this dissociates into Na+ and Cl- ions. They can be separated by electrolysis but normally reach an equilibrium of neutrality. There is nothing unusual in aqueous salt solutions. When Jamie Douglas-Hamilton was rowing across the Indian Ocean he would have sweated a lot, and says he consumed 10-13 litres of liquid a day. Sweat does not just contain water and if he was only consuming water to rehydrate then he was in serious danger of his electrolyte balance being compromised. When he added some sea water the increase in energy came from the salt in the water. Not ionised water – a meaningless term.

His company appears to be selling alkaline aqueous solutions as rehydration liquids. There is nothing wrong with that and I wish him well but please don’t veer into the fruitloopery of describing it as something “special”. We have enough trouble trying to educate our young with real science without confusing them with pseudoscience.

Colin Gunn,

259 Kingsacre Road, Glasgow.