Ashe About Your Health: Smoking, regardless of the substance, is one negative health habit that should be avoided

Cancer is the number two killer in the U.S., after heart disease. You just can’t escape it. Or can you? Well, if you focus on the big picture, you really can prevent a large portion of the cancer deaths. All you have to do is eliminate tobacco. UCLA took a step in that direction with the chancellor’s recent announcement that UCLA will become a tobacco-free campus on Earth Day, April 22, 2013. That means no more tobacco use of any kind anywhere on campus.

According to the World Health Organization, tobacco is the single greatest cause of preventable deaths worldwide, causing an estimated 22 percent of cancer deaths, 70 percent of lung cancers and a hefty chunk of other types of cancer. It is also the cause of a host of other painful, debilitating and disfiguring diseases like emphysema.

According to the 2011 UCLA Freshman Profile, 5.4 percent of incoming students smoked cigarettes at least occasionally, and a 2009 UCLA Student Affairs Information and Research Office survey reported that 19 percent of transfer students were smokers. So, speaking as a physician, and as the director of a student health center, I welcome the chancellor’s news.

On Tuesday, voters in Colorado and Washington passed ballot initiatives that made the possession of small amounts of marijuana legal. In California, marijuana can be grown, sold, bought and used only medicinally. But we all know that that’s not what always happens.

Tar released when tobacco leaves are burned causes most of the cancer, most of the damage, genetic and otherwise, to the tissues that are chronically exposed to it. There’s carbon monoxide in cigarette smoke too, which does a lovely job on your coronary arteries.

Funny thing is that when you burn pretty much any organic material, specifically any plant leaf ““ whether it’s tobacco, cannabis, cloves, oregano or banana leaves ““ the chemical combustion of the organic material results in smoke that contains tar.

You want to know if smoking marijuana can give you cancer? It can. How much does it take? No one really knows. The fact that cannabis is still classified as a “Schedule 1″ drug by the FDA, meaning it’s totally illegal to grow, buy or use it for any reason, and has no “recognized or legitimate medical applications” suggests no one has been able to really study it well. There are only rough estimates as to the equivalency of damage caused by whatever quantity of weed people smoke to a given number of cigarettes.

Smoking anything is simply awful for your body, for your health, and if you expose others to your secondhand smoke, to theirs too. All this is preventable.

Dr. David Baron is the executive director of the Arthur Ashe Student Health and Wellness Center.