YOUNG people put themselves at risk of getting mouth and throat cancers by smoking dagga and the hubbly bubbly pipe. This is according to research announced recently.

The cancer develops in the mouth area and is caused by the human papilloma virus . Professor André van Zyl says if one smokes dagga there is a fourfold chance that one will get HPV-positive oro-pharyngeal cancer or throat cancer.

"You will get the cancer because the cannabis will modify the immune system.

It also modifies the immune system in the throat area where you are breathing the cannabis in. This is the same area that the HPV virus will target, your tonsil and throat area.

"So cannabis will cause the immune system to change and make it easier for HPV to attach and once it attaches it is easier for it to become an infection. Then it will lead to the cancer. That is why cannabis is such a big danger," Van Zyl says.

He says research shows that HPV is spreading fast among young people because when they smoke dagga, they are also likely to engage in risky sexual behaviour.

But he says statistics do not reflect the reality of dagga usage among young people as most of these cases go unreported. He makes an example of Western Cape.

"The percentage of users were mostly coloured in Western Cape, followed by white, third Asian and fourth, black. Most children will say no, even if they are using it. So we assume there is a huge under-reporting of this problem in our schools," Van Zyl says.

The problem doesn't end there for these youngsters. The hubbly bubbly is also fast becoming a concern as more and more young people are starting to use it.

Much like dagga, the hubbly bubbly can also cause mouth and throat cancer. The hubbly bubbly is more dangerous because it is smoked in larger quantities for a longer period of time.

"The studies that we believe are correct are those that have gone to the hubbly bubbly that have examined the smoke and analysed what toxins are coming through," Van Zyl says.