Last month we stated that passive smoking, also called "second-hand smoking," poses serious health risks. We will now look at how smoking not only hurts the smoker but those around him or her as well. It may not suffice to simply quit smoking, we should also try our best to avoid smoke-filled environments.

Passive smoking is the inhalation of the side stream of smoke emitted from tobacco between puffs on the cigarette, and/or inhalation of the exhaled smoke from the smoker. This smoke presents a special problem. It contains more particles of smaller size than the directly inhaled smoke and is often deposited deeper within the tissue of the lung. The pathological changes depend upon the total amount of smoke particles inhaled and the duration and frequency of exposure.

We do not need to be in near proximity to a smoker to be assaulted by this poison. Smoke particles are carried great distances by diffusion, convection, and other modalities. The public relations aspect of the separate "smoking dining areas" in our finer restaurants really is not much safer than the adjacent "Smokers" section, for the air is mixed by central air circulation, often without being filtered. This is also true in air travel. If you watch the wafts of smoke rise and disperse in front of you while you are in or next to the smoking section, it doesn't take much imagination to determine where the smoke will end up. Although the separate sections are an improvement, we should not rely on a possibly inadequate air filter to be the final act of safety.

Unfortunately, there is no "threshold" toxin level that is considered safe. What is clear is that prolonged contact, primary and secondary, determines toxicity. It is thought that there are about 53,000 annual deaths in the US caused by passive smoking, 37,000 of these come from combined cardiovascular disease. Spousal smoking accounts for much cardiovascular disease and pulmonary changes, as well as increased mammary carcinoma. Is it any wonder that our youth are developing pulmonary weakness and disease?

There is a two-fold attack that secondary smoke has upon the tissues of the nonsmokers' body. All the usual carcinogens, fiber and other chemicals have their direct toll on the physiology of the cells, much like they do in the primary smoker. But there is the added effect of the carbon monoxide diminishing the oxygen-carrying capacity of the blood. With reduced oxygen in the blood, there is an obvious decrease in the viability of the cells of the heart and respiratory organs. This low-level deprivation of the brain oxygen levels leads to subtle but permanent brain and vascular changes. In women, these subtle changes are more profound if she is also on the "pill."

The tender tissues of infants and children are the most susceptible to second-hand smoke. Being exposed many hours a day, they develop many pulmonary conditions such as allergies, asthma, chronic bronchitis and cardiovascular problems. Later in life, many develop cancers. Studies have repeatedly shown that children of smokers do not develop physically or mentally to their full potential. Yet, in spite of the scientific proof, people do not want to believe this is true. So it seems logical that a smoke-free school, workplace and home would take this public health burden off of us and give us all a chance to lead healthier lives.

Dr. Devananda Tandavan, MD, is a member of the American Medical Association, the Society of Nuclear Medicine, the International Center of Homeopathy- and more. Send your questions to Hinduism Today, 107 Kaholalele Road, Kapaa, Hawaii 96746 USA.