Tanzania: Cigarette Smoking Is Deadly, Can''t We Stop It?

Source from:  Tanzania Daily News 11/18/2014

Puffing out a cloud of cigarette smoke. Smoking shortens the lives of smokers.

TOBACCO is a plot worthy of the universe - a fatal radioactive poison which has affected humanity since time immemorial. It has taken a painstaking search through thousands of courtordered documents to uncover exactly why tobacco firms are unwilling to remove this deadly radioactivity, despite knowing how dangerous their products are to consumers for more than 30 years now.

The Director General of the Tanzania Atomic Energy Commission (TAEC), Prof Iddi Mkilaha, says that by their own admission, cigarette companies create doubt about the health charge without actually denying it.

According to him, this is a strategy that the tobacco industry has used effectively for decades, using smoke and mirrors to deflect mounting evidence about the deadly harm caused by their products.

Prof Mkilaha says that as politicians and the public debate the merits of putting cigarettes in plain packaging to deter new young smokers, this particular example should serve as a timely reminder of how big tobacco firms operate when faced with the possibility of falling profits.

Before delving into the main plot of this real-life drama, it is worth taking a step back to understand some of the basics about radioactivity and cancer, says the professor.

"For many, the word 'radioactive' is likely to conjure up emotive images of nuclear power plant catastrophes and mushroom clouds. But it is not all the stuff of disaster movies.

Lowlevel background radiation is constantly present in the natural environment, both from cosmic rays from outer space and from radioactive material found throughout nature - in the soil we tread on, the water we drink and the air we breathe," says Prof Mkilaha.

He adds that low levels of radiation are safe, even some of the essential elements that make up our own bodies - such as potassium and carbon - have radioactive versions, which add to our background radiation dose. But higher, concentrated doses of radiation can be dangerous.

And longterm exposure to abovenormal levels of radiation can be deadly. "It is no coincidence that Marie Curie - who coined the phrase 'radioactivity' - died from plastic anaemia, a disease of the bone marrow that is now known to be linked to radiation poisoning.

She did much of her work in a shed, with absolutely no safety measures and she even carried radioactive material around in her pockets," he says.

Prof Mkilaha says that one of the earliest links between radioactivity and cancer was made in a small US town called Orange in the 1920s.

According to him, women working in a watch factory in the New Jersey town painted the dials with glow-in-thedark radioactive paint. They frequently licked the tips of the brushes and inadvertently took in the radioactive element in the paint - radium.

Many of these women later developed cancer of the jawbone or mouth and the use of the deadly radioactive paint was stopped. A TAEC recent report says that back in 1964, two scientists from the US-based Harvard School of Public Health published a landmark study that revealed that a radioactive element called polonium in cigarettes could be 'significant' in the development of lung cancer.

The report insists that tobacco leaves used in making cigarettes contain radioactive material, particularly lead-210 and polonium-210. The radionuclide content of tobacco leaves depends heavily on soil conditions and fertiliser use.

Soils that contain elevated radium lead to high radon gas emanations rising into the growing tobacco crop, says the report. Radon rapidly decays into a series of solid, highly radioactive metals (radon decay products). These metals cling to dust particles, which in turn are collected by the sticky tobacco leaves.

The sticky compound that seeps from the trichomes is not water soluble, so the particles do not wash off in the rain. There they stay, through the curing process, cutting and manufacture into cigarettes.

Lead- 210 and Polonium-210 can be absorbed into tobacco leaves directly from the soil. But, more importantly, fine, sticky hairs (called trichomes) on both sides of tobacco leaves grab airborne radioactive particles.

For example, phosphate fertiliser, favoured by the tobacco industry, contain radium and its decay products (including lead-210 and polonium-210).

When phosphate fertiliser is spread on tobacco fields year after year, the concentration of lead-210 and polonium-210 in the soil rises.

When you smoke a cigarette, research indicates that radioactive lead-210 and polonium- 210 are present in tobacco smoke as it passes into the lung.

The concentration of lead-210 and polonium- 210 in the tobacco leaf is relatively low. However, this low concentration can accumulate into very high concentrations in the lungs of smokers.

As it passes into the lungs, the smoke impacts the branches of the lung passages, called bronchioles, where the branches split. Tar from tobacco smoke builds up there and traps lead-210 and polonium-210 against the sensitive tissues of the bronchioles.

Studies show that filters on ordinary commercial cigarettes remove only a modest amount of radioactivity from the smoke inhaled into the lungs of smokers. Most of what is deposited is lead-210, but polonium- 210 (whose half life is about 138 days) quickly grows in as the lead-210 (half life is 22.3 years) decays and becomes the dominant radionuclide.

Over time, the concentration of polonium-210 directly on tissues of the bronchioles grows very high and intense localised radiation doses can occur in the bronchioles.

Puff by puff, the poison builds up to the equivalent radiation dosage of 300 chest X-rays a year for a person who smokes one and a half packs a day.

This type of radiation is basically a Helium atom. Once inside it won't get out and it does a lot of damage due to being highly ionizing (it knocks electrons off other atoms). It's not penetrating, so it is of no harm if it's outside since it can't get in; but once smoked, it is in and won't get out.

In addition, polonium- 210 is soluble and is circulated through the body to every tissue and cell in levels much higher than from residential radon. The proof is that it can be found in the blood and urine of smokers.

The circulating polonium-210 causes genetic damage and early death from diseases reminiscent of early radiological pioneers: liver and bladder cancer, stomach ulcer, leukemia, cirrhosis of the liver and cardiovascular diseases.

Although polonium may not be the primary carcinogen in cigarette smoke, it may nonetheless cause thousands of deaths a year. And what sets polonium apart is that these deaths could be avoided with simple measures.

The tobacco industry has known about polonium in cigarettes for nearly 50 years. By searching through internal tobacco industry documents, manufacturers even devised processes that would dramatically cut down the isotope's concentrations in cigarette smoke. But Big Tobacco consciously decided to do nothing and to keep its research findings secret.

In consequence, cigarettes still contain as much polonium today as they did half a century ago. The more you smoke, the more radiation you have in your body and it builds up. Hence, tobacco is the single greatest cause of preventable death globally.

Tobacco use leads most commonly to diseases affecting the heart, liver and lungs, with smoking being a major risk factor for heart attacks, strokes, chronic obstructive pulmonary disease (COPD) (including emphysema and chronic bronchitis) and cancer (particularly lung cancer, cancers of the larynx and mouth and pancreatic cancer).

It also causes peripheral vascular disease and hypertension. The effects depend on the number of years a person smokes and on how much the person smokes. Starting smoking earlier in life and smoking cigarettes higher in tar increases the risk of these diseases.

Also, environmental tobacco smoke or second-hand smoke (passive smoking), has been shown to cause adverse health effects in people of all ages. In contrast, a 1999 review of tobacco smoke carcinogens published in the Journal of the National Cancer Institute states that "levels of polonium-210 in tobacco smoke are not believed to be great enough to significantly impact lung cancer in smokers."

The complexity of tobacco smoke leads to some confusion about the mechanisms by which it causes lung cancer. Among the multiple components of tobacco smoke, 20 carcinogens convincingly cause lung tumors in laboratory animals or humans and are, therefore, likely to be involved in lung cancer induction.

TAEC says that a large number of studies have shown that stopping smoking can greatly reduce the risk of smokingrelated cancers, compared to continuing to smoke.

And the earlier you stop, the better. Cutting down is a good start, but the big benefits come from quitting. The evidence for the health benefits of cutting down the number of cigarettes you smoke is mixed.

Some studies have shown that reducing your cigarette consumption, compared to carrying on smoking the same amount, has benefits for lung cancer risk and overall survival. But other studies found benefits only with quitting completely. However, if you reduce the amount you smoke you may be more likely to stop smoking in future.

So, although you only experience the full health benefits if you stop smoking altogether, cutting down can be a good first step if you find it too difficult to quit completely in one go.

Every year we humans smoke about six trillion cigarettes, enough to make a chain that would easily reach from the Earth to the Sun and back and then do the whole trip again, just for good measure.

By 2020, says the TAEC report, cigarettes will be killing about 10 million people each year worldwide. "They have already knocked off 100 million people in the 20th Century and if we don't come to our senses, they could kill one billion in the 21st Century," says the report. Enditem