This information is directly from the www.quitnow.info.au website for the benefit of the health of employees.

'Tar' describes the particulate matter which, generated by burning tobacco, forms a component of cigarette smoke. Each particle is composed of a large variety of organic and inorganic chemicals consisting primarily of nitrogen, oxygen, hydrogen, carbon dioxide, carbon monoxide, and a wide range of volatile and semi-volatile organic chemicals.

In its condensate form, tar is a sticky brown substance that is the main cause of lung and throat cancer in smokers. Tar can also cause unsightly yellow-brown stains on fingers and teeth.

Cigarette companies use words like 'light', 'extra light', 'ultra light', 'mild' and 'special mild' on the packaging of cigarettes which have been tested by machines to contain less tar and nicotine than regular brands. Many people assume that 'light' cigarettes are not as harmful.

However smokers of 'light' cigarettes breathe more deeply, smoke more often and inadvertently cover up the ventilation holes in the filter with their fingers, absorbing the same amounts of dangerous chemicals from so-called 'light' cigarettes as they would from a 'regular' brand.

Every cigarette results in dangerous deposits of tar in the lungs of smokers.

All of the tar does not remain in your lungs permanently. Some of the tar is exhaled when you breathe the smoke out, and some is coughed up. Tar that is absorbed by the lungs can cause lung cells to die. Cigarette smoke paralyses or destroys the 'cilia' - which are fine hairs that line your upper airways and help to protect against infection.

When cilia are damaged, tar is able to penetrate further into your lungs, where it can do even more damage.

Immediate health effects from damage to your lungs include coughing and shortness of breath (or tightness in the chest). Damage to your lungs caused by smoking can lead to other complications such as emphysema.

Yes. Cilia that are paralysed (and not destroyed) can recover. Chest and lung conditions which are exacerbated by smoking can also improve, such as asthma and chest infections.

The sooner you stop, the better your chances of recovering.

Cigarette smoke is estimated to contain over four thousand compounds, many of which are pharmacologically active, toxic, mutagenic and carcinogenic. There are also 43 known carcinogens in tobacco smoke.