Smoking is Really Hazardous to Your Health

By now everyone knows that smoking is not a healthy habit, to say the least. I am not sure, however, that many people, especially smokers, know just how deadly smoking really is. Most people associate smoking with lung cancer but how many know that lung cancer is one of the worst forms of cancer, with only a 15% survival rate after five years? How many people think about the connection between smoking and heart disease? These are only the most obvious health problems caused by smoking. There are a whole host of others, as related in this article from Yahoo News.

Fifty years after the first U.S. Surgeon General‘s report in 1964 warned about the link between smoking and lung cancer, research continues to identify more diseases that are directly caused by smoking.

Now, liver and colorectal cancers have been added to the list of cancers for which there’s sufficient data to infer smoking is not merely linked to but actually can cause the diseases, according to the newest Surgeon General’s report released today (Jan 17).

Cigarette smoke contains thousands of compounds, including 69 known to be carcinogens, chemicals that are directly involved in causing cancer. Carcinogens can result in tumors by damaging the genome or disrupting the cell’s metabolic processes.

Smoking is responsible for more than 90 percent of lung cancers. But traces of tobacco carcinogens have been found in other organs as well. For example, pieces of DNA bound to carcinogens have been found in breast tissue and breast milk, according to the report authors, who reviewed new research over the recent years.

“These carcinogens are absorbed systemically. They don’t just stay in the lungs. They are carried through the blood to many organs,” said Stanton Glantz, director of the Center for Tobacco Control Research and Education at the University of California at San Francisco, who was not involved in compiling the report.

In colorectal cancer, tumors often originate in the glands and the cells that cover the inside of the bowel. Carcinogens in tobacco smoke can reach the large bowel through the blood supply and disrupt regular functioning of the cells. These cells then might form polyps, which can progress into malignant, or cancerous, tumors.

Reviewing large previous studies, the researchers found an increased risk of colon and rectal cancer, particularly after smoking for two or more decades. In some studies, smokers were up to twice as likely to develop colorectal cancer as nonsmokers.

The report authors also looked at other cancers such as prostate cancer and concluded that smoking is not a cause for this type of cancer, although it increases risks of dying for those diagnosed with prostate cancer.

Examining breast cancer, the researchers concluded the evidence suggests smoking can cause the disease.

“Even a finding that is ‘suggestive,’ is a pretty strong finding,” Glantz told LiveScience. “If I give a glass filled with clear liquid and say, this might give you breast cancer but I’m not absolutely positive, I don’t think you want to drink the liquid.”

Other new entries in the official list of smoking-caused diseases include Type 2 diabetes, rheumatoid arthritis, erectile dysfunction, macular degeneration that can blind older people, and cleft palate birth defects.

“In addition to carcinogens in the cigarette smoke, there’s a lot of inflammatory agents,” Glantz said. Smoking causes these diseases partly “by triggering inflammatory processes and increasing the general inflammatory environment.”

Looking over the past 50 years of the war on smoking, the report authors warned that the disease risks from smoking by women have risen sharply and are now equal to those of men for lung cancer, and pulmonary and heart diseases.

Since the landmark 1964 report, nearly 21 million people have died prematurely because of smoking or exposure to secondhand smoke, according to the report.

Heart and metabolic diseases attributed to smoking accounted for 40 percent of tobacco-related deaths, the report revealed.

“This is very important. When people think about smoking they usually just think cancer. Most people don’t really appreciate how big the risks of heart diseases are,” Glantz said.

I am glad I never started smoking, though I am not sure if I deserve any credit. Both my parents smoked and it may be that not smoking was my particular way of rebelling. In any case, the experience of growing up surrounded by cigarette smoke has given me such an aversion to the smell of smoke that I cannot stand to be in the same room as someone smoking. I guess that I am lucky not to be tempted into such an unhealthy and addictive habit.

 

 

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The Asteroid that Killed the Dinosaurs

The hypothesis that an asteroid collision was the cause of the extinction of the dinosaurs has been around for several decades now, but recent research has provided new support for the theory.

The idea that a cosmic impact ended the age of dinosaurs in what is now Mexico now has fresh new support, researchers say.

The most recent and most familiar mass extinction is the one that finished the reign of the dinosaurs — the end-Cretaceous or Cretaceous-Tertiary extinction event, often known as K-T. The only survivors among the dinosaurs are the birds.

Currently, the main suspect behind this catastrophe is a cosmic impact from an asteroid or comet, an idea first proposed by physicist Luis Alvarez and his son geologist Walter Alvarez. Scientists later found that signs of this collision seemed evident near the town of Chicxulub (CHEEK-sheh-loob) in Mexico in the form of a gargantuan crater more than 110 miles (180 kilometers) wide. The explosion, likely caused by an object about 6 miles (10 km) across, would have released as much energy as 100 trillion tons of TNT, more than a billion times more than the atom bombs that destroyed Hiroshima and Nagasaki.

New findings using high-precision radiometric dating analysis of debris kicked up by the impact now suggest the K-T event and the Chicxulub collision happened no more than 33,000 years apart. In radiometric dating, scientists estimate the ages of samples based on the relative proportions of specific radioactive materials within them. [Wipe Out: History’s Most Mysterious Mass Extinctions]

“We’ve shown the impact and the mass extinction coincided as much as one can possibly demonstrate with existing dating techniques,” researcher Paul Renne, a geochronologist and director of the Berkeley Geochronology Center in California, told LiveScience.

“It’s gratifying to see these results, for those of us who’ve been arguing a long time that there was an impact at the time of this mass extinction,” geologist Walter Alvarez at the University of California at Berkeley, who did not participate in this study, told LiveScience. “This research is just a tour de force, a demonstration of really skillful geochronology to resolve time that well.”

The fact the impact and mass extinction may have been virtually simultaneous in time supports the idea that the cosmic impact dealt the age of dinosaurs its deathblow.

“The impact was clearly the final straw that pushed Earth past the tipping point,” Renne said. “We have shown that these events are synchronous to within a gnat’s eyebrow, and therefore, the impact clearly played a major role in extinctions, but it probably wasn’t just the impact.”

The new extinction date is precise to within 11,000 years.

“When I got started in the field, the error bars on these events were plus or minus a million years,” added paleontologist William Clemens at the University of California at Berkeley, who did not participate in this research. “It’s an exciting time right now, a lot of which we can attribute to the work that Paul and his colleagues are doing in refining the precision of the time scale with which we work.”

I can’t help wondering if there is any chance that some species of dinosaur might have been intelligence, perhaps even civilized. No fossils suggesting such a possibility have ever been uncovered, but given the haphazard way in which fossils are made and preserved, it is doubtful that that we know of even 1% of all the organisms that existed at any given time. If an asteroid were to kill us off, I wonder if any remains of our civilization would be recognizable after 65 million years. Considering that it seems that quite a few asteroids have passed, and will be passing extremely close by, maybe a far future paleontologist will be wondering what happened to the mammals.

By the way, I have been reading The Peshawar Lancers by S. M. Stirling. The book takes place in an alternate history in which an asteroid or comet struck the Earth in 1878, destroying civilization in the Northern hemisphere. One hundred fifty years later, the descendants of the survivors are finally reaching the levels of technology we had around 1920.