Wendy Gordon, General Manager, National Geographic's TheGreenGuide.com

It's back to school time, which brings the return of those nasty colds that travel from kid to kid through the entire class. Did you know the average American uses 50 pounds of tissue paper per year? That equals a lot of felled trees if every pound comes from virgin pulp.

That fact drove me to start buying recycled-content paper products. I've learned with time to look for the highest content of "post-consumer waste," or PCW:

Marcal products are entirely recycled, and although they contain a relatively low level of PCW content, that brand is the one most commonly found in conventional grocery and drug stores.

Natural food stores will provide you with a greater selection of products with a higher PCW content, offering brands like Seventh Generation, Earth First, and -- at Whole Foods only -- 365.

If you're really dedicated to the cause, online retailer Green Earth Office Supply sells a Finnish brand of toilet paper called Heron's, which is 100 percent PCW and even comes without the pesky, albeit recyclable, cardboard roll.

For a complete list of recycled-content (and chlorine-free) paper products, you can download thegreenguide.com's Paper Products Smart Shopper's Card.

Wendy Gordon, General Manager, National Geographic's TheGreenGuide.com

With severe to extreme drought conditions affecting parts of the U.S. and Australia, as well as elsewhere, I for one am eager to find ways to reduce my water footprint, not just my carbon footprint.

There are numerous ways to save water, but here's one simple that hadn't occurred to me until I read it in the Green Guide: Switch from liquid detergents to powders. Laundry liquids are mostly water (up to 80 percent). While the double and triple compact concentrates reduce that amount, it still costs energy and packaging to bring this water to the consumer.

So we can all save three ways by using powder detergents to wash clothes. The same holds for dishwashing detergents, when there's a choice, choose dry powders. For other water saving tips, check out thegreenguide.com.

Wendy Gordon, General Manager, National Geographic's TheGreenGuide.com

A new friend (whose wife just had a baby) was recently telling me about all the things they were doing to keep environmental contaminants out of their home. He asked me if I knew which houseplants were most effective at reducing indoor air pollutants. I didn't know the answer off-hand but was curious to find out.

I came upon a wonderful book by Dr. B.C. Wolverton, How to Grow Fresh Air. What I learned is, while plants can't cure major indoor pollution problems on their own, as noted in a recent Tip of the Week, they are an ideal antidote to the minor contamination introduced into our indoor environments through everyday household products and building materials.

Plants produce oxygen, add precious moisture and remove toxins from the air through the tiny openings in their leaves. In fact, as few as 15 houseplants in an average-size home can offer a significant reduction in the number of indoor contaminants.

This is not just folklore. In the 70s, the National Aeronautics and Space Administration, faced with the task of creating a life-support system for planned moon bases, began extensive studies on a fundamental question -- just how does the earth produce and sustain clean air? The answer of course is through the living processes of plants. Now, 30-plus years later, we know a great deal about the cleansing power of house plants. And powerful they are. Just consider the indoor air quality problems many commonly available and beautiful houseplants can help to remedy:

Formaldehyde: The Boston fern (Nephrolepi exalta "Bostoniensis"), Florist's mums (Chrysanthemum morifolium), the Gerbera daisy (Gerbera jamesonii) and the Dwarf date palm (Phoenix roebelenii) are all highly effective at reducing indoor levels of formaldehyde, a contaminant present in many household items (including particleboard, carpet backings, some grocery bags, facial tissues, paper towels and permanent-press clothing) and released by gas stoves.

Toluene/Xylene: Add an Areca palm (Chrysalidocarpus lutescens), the Moth orchid (Phalenopsis) and the Dwarf date palm to your indoor greenery, all of which are effective at removing xylene and toluene, harmful volatile organic chemicals which can be emitted from gasoline, adhesives, ceiling tiles, computer screens, paints, inks used in photocopiers, stains and varnishes, and upholstery among other common household products and materials.

And it's not just our material things. Our breath contains bioeffluents -- such as ethyl alcohol, acetone, methyl alcohol and ethyl acetate -- that also contribute to poor indoor air quality, particularly in a crowded classroom. The beautiful peace lily is remarkably effective at addressing these problems.

Other hardworking and beautiful indoor plants include bamboo palm (Chamaedorea), Chinese evergreen (Aglaonema), English Ivy (Hedera helix), the indoor dracaenas (Dracaena "Janet Craig," D. marginata, D. massangeana and D. warnekii), and the snake plant or mother-in-law's tongue (Sansevieria trifasciata laurentii).

When choosing houseplants, remember that many (including some of those above) can be toxic if ingested, so be extra careful if you have young children or pets in your home. Staff at the local garden center should be able to advise you on nontoxic choices; contact your local poison-control center for guidance (the phone number is listed in the front of your telephone book).

For a beautiful and authoritative reference to the cleansing power of particular houseplants, order How to Grow Fresh Air (Penguin Books, 1996, $18) from our online book store. And get more tips and advice on how to reduce or eliminate indoor air pollutants in your home at thegreen.guide.com.

My youngest was considering what he wanted to do the summer between his junior and senior years in high school. He’d thought he’d stay home, get a job and play lacrosse, in the hopes that this might put him in a position to be recruited for a college team. It seemed he was all set, but then he and a couple of friends started thinking about something altogether different: traveling far from home and volunteering.

Their imaginations took them to the farthest points on the planet, and involved some fairly outlandish job ideas, so with a bit of gentle steering from mom, they began to explore what their real options might be. My husband and I were ok with their traveling to a far away country as long as it was a relatively stable one (they were only 17), and as long as the organization they worked for was legitimate.

My son and his friends studied volunteer programs in Asia, Africa and the Americas, primarily through internet searches and word of mouth. At the same time, we asked a lot of friends with older kids and also a number of teachers about programs they’d researched and what they knew about them. The kids then contacted the ones they were most interested in. They settled on an agency that ran an orphanage in Llasa, Tibet and were in need of teachers.

The program they chose was geared for college kids and adults, so it did little to coddle the volunteers -- or his anxious parents. There were no pretty brochures or thick packets of forms sent to us to prepare them for the trip, just what the organization provided on their web site.

Ok, I admit it. I am kind of looking forward to my son starting school in the Fall. It's not that I don't love our camping trips and days at the beach, it's just that juggling work and play is hard and the hours he is in school make it much easier for me to balance things. To be able to really sink into being with him when we are together. What I am not looking forward to is the idea that he will be spending over five hours in a day in a potentially toxic environment.

The pesticides and cleaning agents that are commonly used at most schools have been shown to impair learning as well as reduce overall health and well-being. Furthermore, the lack of proper ventilation increases the risk of allergies and life threatening diseases such as asthma and cancer associated with exposure to many of these contaminants. If that's not enough incentive for you to consider greening your child's school:

• K-12 schools account for 7 percent of all energy used by commercial buildings, costing a total of $6 billion every year, and schools account for a large percentage of the over 1 billion trees worth of paper that is thrown into landfills each year in the United States.
• Being green can save money and help improve test scores. Purchasing Energy Star appliances and light sensors can save up to 50% on energy costs. Reducing garbage can save your school thousands of dollars per year.

Now that you're inspired, here are a few steps to start with: