Rising nut allergies and saving energy in the office.

What's behind the startling explosion in nut allergies among children? Is it changes in the kids, the nuts or the processing?

--Lynne Whetzel, Ithaca, NY

Recent research does in fact show that the incidence of nut allergies among American and British children has tripled within the last two decades. No one knows exactly why, but because the phenomenon seems to be occurring only in developed countries, some environmentalists believe that pollution and synthetic chemicals might be to blame. An allergic reaction happens when the body's immune system overreacts to a perceived threat, and researchers believe there may be an as-yet undiscovered link between exposure to various chemicals, pollutants and food additives and an overall rise in immune system disorders.

Parents of children suffering from nut allergies must constantly check the ingredients on food labels. Nuts andnut oils are used in an increasingly wide range of processed foods, including many of the chips and cereals preferred by kids today. The ubiquity of snack foods makes it difficult for kids to avoid nuts and nut oils, even if they know they are allergic.

Nut allergies can start early on and usually do not disappear in adulthood. From the second trimester of pregnancy on, the unborn fetus can recognize allergens to which the mother has been exposed, and may at this early point begin to develop sensitivities that can lead to allergic reactions following birth. Pregnant women with a history of allergic reactions can minimize the risk to their children by avoiding certain known allergens, especially tree nuts (cashews, almonds, pecans and walnuts) and peanuts. Breast-feeding mothers should also avoid foods that contain these allergens, as they can be transmitted via breast milk.

Symptoms of nut allergies can range from mild reactions like watery eyes, an itchy throat or a runny nose to severe reactions like eczema, hives, nausea and vomiting. In extreme cases, allergic reactions can lead to anaphylaxis, a life-threatening condition hastened by the body's release of toxic amounts of histamine into the blood stream.

The Fairfax, Virginia-based Food Allergy and Anaphylaxis Network and the Farnborough, England-based Anaphylaxis Campaign are working to raise awareness about and conduct research on this issue. CONTACT: Anaphylaxis Campaign, www.anaphylaxis.org.uk; Food Allergy and Anaphylaxis Network, [phone], www.foodallergy.org.

What can be done to make office buildings more energy-efficient? So many leave thousands of lights on at night!

--Deborah, Baltimore, MD

Office buildings are indeed the top energy guzzlers among commercial buildings in the United States, head and shoulders above retail and service establishments and even manufacturing facilities. The U.S. Department of Energy says that office-building owners spend an average of $1.34 per square toot annually on electricity. Lighting comprises 44 percent of all usage, office equipment accounts for about 23 percent, and heating/cooling systems use most of the remainder.

Building managers can make a big difference by installing energy-efficient systems, from heating and cooling to lighting and waste disposal. Individuals can have an impact by simply turning off lights and shutting down dormant machinery during non-working hours.

According to Advanced Energy, a North Carolina-based nonprofit group that analyzes energy use, replacing older fluorescent tubes with newer, more efficient compact fluorescent bulbs can save as much as 30 percent on electricity, g And installing occupancy sensors can save five percent. Furthermore, building managers can save up to 15 percent on electricity bills by programming thermostats to trigger warming and cooling as needed during the workday while hibernating at night and on the weekends.

Any heating and cooling equipment older than a decade is also probably ripe for an upgrade to a newer, more energy-efficient system. The federal government's Energy Star program rates the energy efficiency of lighting, office equipment and heating/cooling systems from a wide range of manufacturers. CONTACT: Advanced Energy, [phone], www.advancedenergy.org; Energy Star, (888)STAR-YES, www.energystar.gov.

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