
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, December 24, 1993                   TAG: 9312270286
SECTION: EDITORIAL                    PAGE: A4   EDITION: METRO 
SOURCE: JULIE WATTS
DATELINE:                                 LENGTH: Medium

THE MEDICAL TEXTBOOK MAKES THE CASE AGAINST CIGARETTES

THE PUBLIC has recently been bombarded with grim statistics and warnings concerning the deleterious effects of cigarette smoking. The Roanoke Times & World-News has included reports on this highly charged subject, including denials by cigarette manufacturers of any ill effects caused by smoking. Because the arguments are emotionally charged, most smokers turn a deaf ear to any discussion concerning smoking, and the general public is relatively uneducated as to what smoke is and how the body responds to it.

More than 2,000 components of cigarette smoke have been identified and many are related to the development of disease. Cigarette smoke is an aerosol of solid particles in a gaseous base. The solid particles consist mainly of tar and nicotine, and the major gas component is carbon monoxide.

When an individual is exposed to smoke, some components of smoke are absorbed directly through the oral, nasal and airway mucosa while other components are inhaled into and absorbed through the lungs. Carbon monoxide is a toxic gas present in smoke, which interferes with the delivery and utilization of oxygen that's needed for healthy, growing cells. Carbon monoxide combines with hemoglobin in the red blood cell much easier than oxygen, thus the supply of oxygen to the tissues is decreased. This lowered oxygen level may cause decreased activity tolerance, and an earlier onset of angina (cardiac-related chest pain) in those that experience angina, and it may impair vision, concentration and coordination.

In pregnant women, the hemoglobin containing carbon monoxide also crosses the placenta, exposing the fetus to the toxic gas and a lower level of oxygen, which can interfere with cell growth. As less oxygen is delivered to the tissues, the heart becomes overworked in trying to oxygenate the tissues.

Besides affecting the heart, carbon monoxide causes blood vessels to become more permeable to fluid that creates swelling in the vessel wall. These thickened blood-vessel walls further increase the strain on the cardiovascular system and also may promote the formation of cholesterol deposits leading to atherosclerosis.

Nicotine is the chemical component most often associated with cigarette smoke that's partially responsible for the addiction to smoking. Nicotine is an alkaloid poison that has its major effects on the adrenal glands and the heart. Nicotine causes the release of chemicals called catecholamines from the adrenal glands. These chemicals cause peripheral vascular constriction and cause the walls of the heart to contract more often and more strongly, resulting in an increase in blood pressure, heart rate and cardiac workload. The problem that exists in increasing the cardiac workload is that as the workload increases the oxygen requirements for the heart increase. And yet, there's less oxygen available because of the presence of carbon monoxide gas. This vicious cycle is a major contributor to the development of heart disease and heart attacks.

Nicotine has effects on various other body systems. It causes lung irritation, resulting in increased mucous secretion, and it also causes platelet aggregation that may contribute to blood-clot formation.

The toxic effects caused by nicotine and carbon monoxide are only the tip of the iceberg. Cigarette smoke and its components are known to be carcinogenic. There are also chemicals that act to promote and accelerate tumor growth. Many gases contained in cigarette smoke paralyze the cilia that line the lungs. When the cilia are not functioning, the lung is not cleared of foreign particles. This can result in respiratory infection, chronic cough and diminished breathing capacity.

Other components of smoke have effects on the body as well. For example, tar and hydrocarbons are carcinogens. Phenol is a co-carcinogen and irritant. Indole accelerates tumor growth. Besides carbon monoxide gas, ammonia gas and formaldehyde are present. These two compounds are toxic to the cilia and are also chemical irritants.

The response of the body to cigarette smoke is complex and has been the subject of much research. If we approach this issue less emotionally and educate the public on what they're consuming, our efforts toward a healthier society will be more successful.

\ Julie Watts of Boones Mill is a clinical nurse specialist at Roanoke Memorial Hospital and the Cancer Center of Southwest Virginia.

by CNB