If you buy only one fruit or vegetable organic, make sure it's this: apples. Year after year, the nonprofit Environmental Working Group has listed apples as the No. 1 most contaminated produce. Eighty percent of apples sampled by the USDA tested positive for a chemical called DPA (or diphenylamine), which farmers use to prevent the skin from darkening. While it extends the shelf life of apples, it has the potential to be a serious carcinogen. And since the DPA is sprayed on apples after they are harvested, its concentration is highest when consumers buy them. Buy organic, or at the very least, wash apples thoroughly and peel them before eating.

It may be sold in some health food stores, but be wary of burning incense sticks inside your home. Recent studies have shown that burning incense can be just as harmful to your health as smoking cigarettes. Of the 64 toxins identified in incense sticks, two of them have been found to be "highly toxic," according to the journal Environmental Chemistry Letters. Since incense sticks are unregulated, there's no way of really knowing what's in that package when you buy them. If you want to scent your home, consider all-natural methods like essential oil-based sprays or simply opening a window.

Do you know what the No. 1 most recycled product is? It's not what you might think: It's car batteries. Almost all of the car battery is recyclable. Sixty percent of it is lead, which can be recycled and used for other metal products. The three pounds of plastic is also reclaimed and used in the manufacturing of new batteries. And the sulfuric acid inside is safely captured and recycled in new batteries. If you replace your battery at a dealer or auto shop, your battery is recycled. If you have any old car batteries at home, take them to any auto shop, and it'll recycle them free of charge for you.