Second Hand Smoke

There are around 7,000 different chemicals in cigarette smoke. Some of those which are known to be hazardous to your health include:

Tar: A collection of solid particles that go straight into the lungs of smokers when they inhale. When it settles out of the smoke, tar forms a sticky brown residue that stains a smoker's teeth and fingers. It's also responsible for the brown colour of walls and ceilings in buildings, such as in pubs, where there has been a lot of cigarette smoking. Tar is a complex mixture of chemicals, many of which are known to cause cancer. The tar content of a brand of cigarettes is listed on the packet. But don't think that a low-tar cigarette is necessarily less harmful because there are many other harmful chemicals within the cigarette.

Arsenic: A potent poison that is a carcinogen and also damages the heart.

Benzene: A cyclic hydrocarbon used as an industrial solvent and that is also a carcinogen. Cancer Research UK states benzene in cigarette smoke is the culprit in up to half of all deaths from leukaemia caused by smoking. A smoker inhales about ten times more benzene than a non-smoker.

Formaldehyde: There are many sources of formaldehyde inside and outside our home environment, and smoking is just one of them. Formaldehyde is also a carcinogen and places where people smoke tend to have much higher levels of this chemical.

Cadmium:A heavy metal found in batteries, but most of the cadmium in our bodies comes from cigarette smoke. Cadmium is a carcinogen and also damages the kidneys.

Acrolein: A gas with a very irritating smell and one of the most abundant chemicals in cigarette smoke. Recent experiments suggest that acrolein is a carcinogen with the ability to damage DNA. Researchers believe that acrolein plays a major role in lung cancer.

Polycyclic hydrocarbons (PAH): A group of powerful carcinogens, related to benzene. One PAH, called benzopyrene, is probably the most widely studied of the tobacco smoke toxins and is known to damage a tumour suppressor gene, which would normally protect against cancer.

Metals: Nickel, lead, cobalt and beryllium are inhaled in tobacco smoke. They are also carcinogens.

Acetaldehyde:This is the chemical that causes hangover symptoms. It also causes cancer.

Hydrogen cyanide: One of the best-known poisons, cyanide damages the airways and makes carcinogens more potent by increasing the lungs' exposure to them. Cyanide is not a carcinogen.

Carbon monoxide:An odourless, colourless gas which is a product of burning, carbon monoxide makes up 3-5% of cigarette smoke. It binds to red blood cells in place of oxygen and therefore results in oxygen deprivation that can be harmful, particularly to those with heart or lung disease.

Nitrogen oxides:Also found in car exhausts, nitrogen oxides damage lung tissue.

Also known as environmental tobacco smoke, second-hand smoke is the smoke emitted from smoking cigarettes, cigars, and pipes to which non-smokers nearby are exposed. There are two types of second-hand smoke; the mainstream, which is the smoke the person smoking exhales, and the sidestream, which is the smoking coming from the burning end of a cigarette, pipe or cigar. Sidestream smoke actually has higher concentrations of toxic compounds than mainstream smoke. Sidestream smoke tends to contain smaller particles, which are the ones most likely to travel deep into your lungs when inhaled. In a smoke-filled room, 85% of second-hand smoke is of the sidestream variety, putting the health of the non-smokers present at risk. However, passive smokers are still less at risk than the smoker who is actually inhaling the smoke directly.

There is no risk-free level of exposure to second-hand smoke. The health problems it can cause are many:

• Second-hand smoke triggers asthma attacks in many and makes the condition worse in the long term.
• Asthmatic children of all ages suffer more from attacks if their parents smoke. A severe asthma attack may put a child's life in danger.
• If you had asthma as a child and ‘grew out’ of it, it is likely to reappear if you take up smoking as an adult.
• It can cause sore eyes, throat and lungs - a common effect of smoke exposure.
• In general, children whose parents smoke are more likely to get sick. And often second-hand smoke can cause lung problems and can make children more prone to bronchitis, wheezing and coughing.
• Children whose parents smoke around them are more likely to get an ear infection. They also tend to have fluid in their ears and may need surgery to correct this.
• Exposure to second-hand smoke has been linked to a 25-30% increased risk of heart disease and a 20-30% increased risk of lung cancer.
• Research shows that chemicals in second-hand smoke affect the brain in ways that interfere with breathing control linked to sudden infant death syndrome (SIDS). Babies who die of SIDS often have more nicotine in their lungs than babies who die of other causes.

The problem of third-hand smoke came to notice in 2009 with a publication in the journal Paediatrics. Lead author Jonathan Winickoff, a paediatrician at Dana-Farber/Harvard Cancer Centre in Boston explained 'Third-hand smoke is tobacco smoke contamination remaining after a cigarette has been extinguished.' Ever noticed how the hair and clothes of a smoker smell of smoke? You are smelling third-hand smoke contamination, which is a complex mixture of toxins which build upon carpets, soft furnishings, and furniture, as well as on clothes, for days after a cigarette has been put out. Even if the smoker has been smoking outside, they bring third-hand smoke back indoors with them. Tests carried out by scientists at the University of California, Berkeley, showed significant levels of various toxins on materials that had been exposed to cigarette smoke. Third-hand smoke builds up over time, with each cigarette, cigar, or pipe of tobacco adding to the toxic deposit.