There's the old saying that a little bit of dirt is good for you. Turns out that's actually true. Studies are now showing that our desire for a totally sterile freakishly clean living environment could be causing problems down the line, leading to immunological problems, and ultimately allergies, asthma, multiple sclerosis, and other diseases. The WSJ has an excellent article on the subject.
Over the past decade I've observed a change in cleaning products, as well as an explosion of new brands and advertising claims. The main selling points these days seem to be one of two things: "Now kills XX% of germs!" or "Biodegradable and phosphate free! Unscented! Hypoallergenic!"
As a kid I remember cleaning products being simpler. Granted they contained things we now know to be toxic and dangerous. But this preoccupation with sterilizing our surroundings seems to have gone a bit overboard, and is now endangering the health of the next generation. Another dimension to this problem is the prevalence of antibiotics used in soaps, shampoos, body washes, hand gels, and of course in our food (a Grist article details the food issue nicely). We are a nation of clean freaks, but our penchant for being beyond squeaky clean (perhaps screamingly clean?) has given rise to two distinct problems: a lack of dirtiness which later causes disease, and the rise of the resistant super bacteria which ALSO causes disease. Double trouble.