Tuesday, November 2, 2010

Life Lines 19


How fast did it take you to know as a child not to put your hand on a hot pot or pan? I suspect a few seconds and a pained “ow” was sufficient to drive home cause (very hot) and effect (pain). Which is worse, a burn on your hand from touching a hot pot or a tumor in your lungs? The question is idiotic but surprisingly more people are aware of avoiding hot surfaces than avoiding things that produce tumors in the lungs. Why is that? The burn is immediate and millions of cells including nerve cells are involved in the burn that produces the “ouch.” So our brains are very good at recognizing immediate cause and effect. But if you smoke cigarettes you are inhaling some four thousand combustion products of tobacco and several dozen are known carcinogens, agents that induce cancers. These include stuff you never heard of like nitrosamines and anthracenes but some that are familiar like aldehydes. That stuff slaps against the lining cells of your trachea and bronchial tree; and it kills those cells, most of which flatten out into squamous cells. But you don’t feel that. Nor do you feel the seepage of the chemicals of combustion as they dribble down several layers of cells and on rare occasions (about once in 10 to 20 years of smoking a pack a day) they produce a tumor cell. Nor do you feel that tumor cell divide every six months or so and after some 15 or more years it produces a lump about the size of a pea. That will make you cough. So 25 or 35 years may elapse between starting a smoking habit and having a first symptom of cancer. Our brains do not respond to the gene mutations and chromosome breakages that eventually set off a cell to act like a tumor cell.

The first person to realize cancers were diseases of cells was Rudolph Virchow in the 1850s. He formulated the cell doctrine that asserts all cells arise from pre-existing cells. He extended this to cancers because he saw that they were alike in the tumor and he inferred they arose from one initial cell. It took 20 more years to work out cell division and it took a century before the relation between tumors and carcinogens was worked out.

Because most of humanity is ignorant of science they spend their time teaching kids not to play with broken glass, not to swallow yucky stuff in pretty bottles, and other things to which their experience and senses are familiar. But to the big killers, like agents that mutate genes, break chromosomes, deform embryos, and transform cells into tumor cells, we rely on what? Nothing! So we call it fate or bad luck or say stupid things [“You’ve got to die of something”] when we can greatly reduce the amount of harm done by agents in our foods, air, water, and the house we live in that can cause cellular damage.

If we were science literate or cared as much about our health for serious things as we do for relatively minor things, we would demand our schools teach “defensive living” just as we demand it for teaching our teens “defensive driving.” The fault is shared by scientists who prefer to teach science stripped of its values and implications for our lives and by the public which is afraid that learning about biology in a liberal arts context leads to loss of faith, conflict with religious beliefs, or subversive social views about regulating industry. The price we pay for this attitude is a lot of unnecessary illness and death.

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