Eco Experts: Safer Water Pipes and Natural Home Cooling Questions Answered

Also find out solutions to reducing electromagnetic fields and learn how silkworms produce silk.


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Safe water pipes

We are about to replace 800 feet of water piping from our well to our farmhouse and are wondering if we should look for an alternative to polyvinylchloride (PVC) pipe. We have found lots of alarming information about the dangers of PVC, but no viable alternatives.

—Dale Williams, via e-mail

The plastics industry considers PVC itself to be inert. When used, however, PVC pipe must be joined together with toxic glue, which can leach into your water supply. In some areas it is illegal to use PVC pipe for potable water.

Copper pipe is the best choice for incoming water. It is the most expensive choice, but the only alternative is galvanized pipe, which is more expensive to install and doesn’t last as long. In the long run, copper is most healthful and economical.

Keeping cool naturally

Now that the weather is getting warm again, I would like to know how to keep cool without using an air conditioner. I want to save energy but, more importantly, I want to breathe natural air that hasn’t been cooled through a machine.

—Sandra Stone, via e-mail

Consider cooling your home with means that are in harmony with your climate. Natural cooling systems prevent heat gain at the source and make use of shade trees, the cool temperature of the soil, flowing waters, open windows, and your home’s northern exposure.

First, minimize the amount of heat created within your home. The three major sources are waste heat given off by lights and appliances, radiant heat from the sun shining through your windows, and outside-air heat conducted through your windows, walls, and ceilings.

To minimize these heat sources, use energy efficient appliances and lights; do your baking and ironing in the evening when it’s cooler; shade windows with vegetation or interior window coverings; close draperies, shades, or radiant shields on windows and skylights to block direct sunlight and hot air drafts; and insulate the attic, floors, crawl spaces, basement, and exterior walls.

Fans can also help reduce the need for air conditioning. A whole-house fan in your attic (or in an upstairs window) can pull cool air inside and blow warm air out. Small fans, such as ceiling fans, keep air moving throughout the house.

Electromagnetic fields

I am building a new house and am very concerned about reducing electromagnetic fields (EMFs). I have already had all the wiring enclosed in metal conduit, but I still have several concerns. Where should I place the main power breaker panel and electric meter? Should I check for a faulty ring main? Is it safe to use electric heat in the floor? Also, I am wiring every room for stereo speakers. Do I need to shield the speaker wire and, if so, will foil in the wall act as a shield?

—Joe Melton, Louisville, KY

The best general advice I can give to anyone who is concerned about EMFs is to get a gaussmeter (about $250), which is a device that measures EMF levels. EMFs are unpredictable. Something that seems threatening may not cause a problem, and ordinary household objects are not necessarily benign.

To answer your specific questions, I called engineer Michael Neuert of Neuert Electromagnetic Services in Santa Rosa, California. He warns that both the breaker panel and the electric meter have strong fields. Both should be at least eight to ten feet from high-use areas in your house. Remember that EMFs pass right through walls, so consider placement carefully. If you have already installed the breaker panel and electric meter within ten feet of a high-use area, it is possible to block them with a custom-designed Mu-metal (nickel-iron alloy)?shield.

A faulty ring main is a problem with the wiring connections. After you have established all wire connections, turn on some lights to get the system going, then use a gaussmeter to check the wires in the walls at a distance of one foot. If your gaussmeter indicates anything higher than a “zero” reading, call an EMF expert to help you determine and solve your particular problem.

As for using electric heat in the floor, Neuert explains, “Electric wires in the floor are like putting an electric blanket on the floor.” Electric blankets are at the top of every list of high-EMF sources to avoid. Instead, consider radiant systems that use hot water.

Speaker wire is of lower voltage than your house’s main electrical wires, but if you’re concerned about that voltage you can shield speaker wire with aluminum foil. The simplest method is to wrap the wire with foil, but this might not pass inspection from the building department. A better option is to fold twenty-four-inch foil over the wire and staple it to the studs. Make sure that any metal shielding is grounded.

It is important to keep in mind that the power of EMFs decreases with distance, so a temporary fix for some problems is to simply arrange your home so that you spend most of your time at a safe distance from EMF sources.

Is silk eco-friendly?

I am designing some home accessories and want to use a hemp/silk blend fabric. Is silk considered a natural fiber because silkworms produce it?

—Michelle Kozin, via e-mail

Silk is made by the domesticated silkworm (Bombyx mori), which is no longer found in the wild. Though more than thirty countries produce silk, China still produces half of the world’s supply. The Chinese silk industry is based on family farm production. Each year twenty-four million cases of silkworm eggs are distributed to twenty million households, where they are raised primarily by women and children to supplement family income.

Extra light is introduced to force continuous rather than seasonal breeding, and eggs may be artificially induced to hatch. On its month-long journey to the moth stage, the worm sheds its skin four times as it grows through five stages. In the fifth stage, the worm spins a single strand of silk and wraps it as a cocoon around itself as protection from birds and lizards. Cocoons of good size are kept for breeding. The rest are processed for silk harvest.

To harvest silk, the cocoons are cleaned of twigs and leaves, then steamed for three minutes to kill the pupa. They are submerged in boiling water to soften the sericin glue that binds the thread together, then dried and exported to spinning factories.

DEBRA LYNN DADD is an internationally known expert on healthy home environments and author of Home, Safe Home (Putnam, 1997).