You've surely known kids whose parents smoke declare their repulsion for the habit. The health risk, the expense, the filth of smoking seem to deter many youngsters from following in the footsteps of mom and dad. Theoretically, anyway. In practice, these same kids may fall prey to the very act they vowed to reject.

How about kids raised in households filled with sugary snacks and drinks, foods packed with fat, salt, and calories, and parents with expanding waistlines? Seems only natural these children, despite good intentions, end up struggling with healthful eating and weight management.

We are what our parents teach us. It's all we know for a good many years. And by the time we are able to make our own independent decisions, it's often too late. Our parents' actions and values are already programmed within us -- and it takes hard work to switch things up.

So here's my plea for this Sunday morning: do your kids a favor and become a positive role model. Don 't just tell your little ones what is right and healthy and virtuous -- show them. Let your behavior be the gold standard now, so that later, it's likely to be what your sweet babies will fall back on.

Here are seven ways to get started:

Feed 'em well
If kids learn healthy eating habits early, they're likely to stick with them. Offer whole grains options (rice, bread, pasta) and snacks that are not in the junk food group. Don't even buy the stuff you may later wish to clear out of your cupboard. Guests at our house are offered two drink options -- water or milk. Why? Because if we have juice (it's loaded with sugar) or soda (also sugary and calorie-laden), our kids just can't hold back. But if we don't have these beverages, they are never an option. Out of sight, out of mind.

Keep 'em moving
Take your kids to the park, get them running around your backyard, take them swimming, organize a kid-friendly football game, invest in a kite. Quiet activities are also good -- and necessary -- but when in doubt about how to entertain your busy little bees, make them move!

Let 'em see you sweat
You need to keep moving too. Not only for your own well-being -- that's obvious -- but so your kids see your physical activity as a staple of healthy living. Teach your kids to do push-ups and sit-ups and do them together. Jump rope, run laps at a local track, ride bikes, or dance. Just don't expect your kids to stay active if your idea of exercise is flipping through TV channels.

No TV
Turn off that TV. Rid your household of junk-food commercials, mind-numbing content, and addictive inactivity. Let TV be a treat -- a small one -- and not an expectation.

No smoking
Need I explain? It's unhealthy, costly, dirty, and a sure contributor to cancer. Try with every ounce of your being to keep this habit away from your impressionable children.

No stress
Some stress is unavoidable. Some is even healthy. But the kind of stress that hurts our tummies, gives us headaches, and threatens our health should be minimized. We must do our best to control our own stress so its effects don't spill over. And we must teach our kids how to cope too. Fortunately, some of the techniques listed above also work for this category -- physical activity, for example, does wonders for lowering stress. We can become experts at deep breathing -- have your kids practice with you. And we can teach a bit of distraction. If homework is making kids crazy, go with them on a short walk where they can regroup and return to the task with a clear head.

No double standards
We simply cannot say one thing and do another. Smoking while preaching the dangers of the habit just doesn't make sense. Saying "no" to sweets with your hand in the cookie jar is downright unfair. Carrying around extra weight and demanding physical fitness is simply ineffective. So make a commitment to yourself and your kids that you will do as you say. It's the only way.

Maryland's air has cancer-causing toxins, and they are far higher than the federal government considers safe, according to Environment Maryland -- an environmental group lobbying to make Maryland the 11th state to follow stricter auto emissions standards.

The group, a spin-off of the Maryland Public Interest Group, has released a report revealing the risk of cancer from air toxins was at least 10 times higher than federal standards in each of the state's counties and Baltimore City.

While California is currently setting the bar for higher auto emissions standards, there is no data at this time to compare Maryland's levels with the rest of the country.

Breast density has something to do with breast cancer. This is not really news. It's clear there is some kind of link, some kind of relationship, some kind of risk related to breast density for both pre- and post-menopausal women. It's just not clear how exactly breast density -- how much fat tissue fills the breast compared to other tissue -- contributes to breast cancer risk. But once it is clear, medical professionals will have a whole new arsenal of power in the fight against this deadly disease.

Cancer News in Context, a regular series of podcast commentaries produced by the Harvard Center for Cancer Prevention, highlights two recent studies that add weight to the fact that breast density is an important tool in breast cancer prediction and identifies two areas that with futher study might help determine why breasts that are very dense are associated with higher risks for breast cancer -- and why density may be as important a factor as age in determining risk.

Currently, mammograms are the chosen method for measuring breast density. But measurement is not required, and there are no national standards for how to measure. Once federal groups issue requirements and direction on how to classify density, women will receive more accurate assessments of their personal risk.

There is also speculation that altering breast density through hormonal therapy may lower risk. Perhaps genetics are the strongest indicator of risk, making short-term solutions ineffective, but perhaps certain interventions can override genetics, helping women protect themselves from breast cancer.

There are many issues that must be ironed out before we really understand how breast density affects breast cancer. There is no doubt that density, when added to other risk factors, will surely help improve the accuracy of prediction. It's one tool, among many, that is poised to open all sorts of doors.