9.1 Health effects

Oral use of smokeless tobacco

In 1985 the International Agency for Research on Cancer (IARC)(5) concluded that:

There is sufficient evidence that oral use of snuffs of the types commonly used in North America and western Europe is carcinogenic to humans. There is limited evidence that chewing tobacco of the types commonly used in these areas is carcinogenic.

Epidemiological studies that did not distinguish between chewing tobacco and snuff provide sufficient evidence for the carcinogenicity of oral use of smokeless tobacco products, as reported in these studies.

In aggregate, there is sufficient evidence that oral use of smokeless tobacco of the above types is carcinogenic to humans.

After a review of the evidence of the health effects of usage of smokeless tobacco in 1986,(6) the National Health and Medical Research Council (NH & MRC) recommended that state and territory governments attempt to restrict availability and advertising of smokeless tobacco products.

The NH & MRC also recommended that the Commonwealth Department of Health liaise with the Department of Industry, Technology and Commerce to put smokeless tobacco products on the prohibited import schedule. The NH & MRC reiterated their conclusions about the health effects of smokeless tobacco to the Australian Health Ministers' Conference in November 1987.(7)

An expert advisory committee to the US Surgeon General reviewed the evidence on the health effects of smokeless tobacco in 1986,(8) and made the following summary statement:

After a careful examination of the relevant epidemiologic, experimental, and clinical data, the Committee concludes that the oral use of smokeless tobacco represents a significant health risk. It is not a safe substitute for smoking cigarettes. It can cause cancer and a number of non-cancerous oral conditions and can lead to nicotine addiction and dependence.

In 1987, a special Study Group appointed by the World Health Organization concluded that:

ð the use of smokeless tobacco caused cancer in humans, the evidence for causality being strongest for cancers of the oral cavity;

ð there was some evidence that the habit also increased the risk of cancer of the nasal cavity, pharynx, larynx, oesophagus, pancreas and urinary tract; and

ð laboratory studies clearly supported the observation that smokeless tobacco use caused a number of pre-cancerous oral lesions and non-cancerous oral conditions, such as gingival recession.

The WHO Study Group also considered that although the evidence relating smokeless tobacco use to other diseases was less conclusive, it might contribute to or support the pathogenesis of coronary artery and peripheral vascular diseases, hypertension, peptic ulcers and foetal toxicity.(1)

Inhalation of smokeless tobacco

The first published account linking any manner of tobacco use with cancer dealt with nasal snuff. Lutschg(9) recounts the work of Dr John Hill, who in 1761 reported on the association of nasal snuff with malignancy:

Whether or not polypusses, which attend Snuff-takers, are absolutely caused by that custom; or whether the principles of the disorder were there before, and the Snuff only irritated the parts, and hastened the mischief, I shall not pretend to determine: but even supposing the latter only to be the case, the damage is certainly more than the indulgence is worth: for who is able to say, that the Snuff is not the absolute cause, or that he has not the seeds of such a disorder which Snuff will bring into action.

With respect to cancers of the nose, they are as dreadful and as fatal as any others... It is evident therefore that no man should venture upon Snuff, who is not sure that he is not so far liable to a cancer: and no man can be sure of that.(10)

Nasal snuff use is now relatively rare. Consequently, it is difficult to observe its effects in large enough populations over long enough time periods for consistent health data to emerge.

A 1964 study showed that extended use of commercially available snuff in England led to changes in the tissues inside the nose. Biopsies showed cellular changes of a pre-cancerous type, but in no case had a malignant neoplasm developed in the patients studied.(11)

The snuff made and used by the Bantu tribes in the Transvaal is strongly carcinogenic and the prime cause of cancers of the upper jaw in that region.(12) There has been a reported case study of a patient who placed snuff in his ear, eventually developing cancer at that site.(13)

Nasal snuff has been included in the Victorian ban on smokeless tobacco on the grounds that it has not been proved to be safe.