Forecasting illness: the weather-health connection

Human biometeorology

Bart's curiosity about the relationship between weather and human health—the study of human biometeorology—was piqued several years ago by his patients' comments and complaints. He paired up with a meteorologist, Denis Bourque, and together they began sifting through the existing research, much of which comes from Germany and the Netherlands. In fact, the German national weather service issues weather-related public health warnings based on a set of biometeorologic phases known to cause distress in weather-sensitive patients.

Beyond the ozone and pollen warnings and the UV index issued by North American forecasters, the German warnings alert migraine and arthritis sufferers, for instance, to weather patterns that might affect their conditions. In one year, the German biometeorological forecast telephone line received 1.3 million calls, Bart says.

Bart and Bourque have developed a similar set of biometeorologic phases for North America which they call MediClim^TM phases. However, they are finding it difficult to elicit interest in the project due to the lack of conclusive scientific proof of the weather-health connection.

In what ways does weather affect health?

We already know that atmospheric conditions affect our bodies. We shiver when we're cold and our ears pop when adjusting to airplane cabin pressure during takeoffs and landings. If our bodies react to the environment in these ways, then we might also experience more subtle reactions to changing atmospheric conditions. Because of the number of parameters involved—temperature, solar radiation, barometric pressure, humidity, wind, etc.—it is difficult to prove that a specific parameter is affecting our bodies.

Here's some research on weather and health:

• Asthma and thunderstorms
• Several studies have shown that a greater number of emergency room visits by asthma patients during thunderstorms is due to an increased number of spores in the atmosphere—the result of those spores being split by lightening.
• Labor and tornadoes
• - A study from Bowling Green University shows that more women go into labor before a tornado hits, when there is a rapid decrease in atmospheric pressure.
• Cold and heart attack
• - Studies have shown a connection between cold weather—during which blood supply to the heart wall is decreased—andheart attack andangina.
• Seasonal affective disorder - It is well documented that decreased sunlight during the winter months can lead to fatigue and depression.

Other connections, less conclusively proven, include a suspected rise in the number of cases of sudden infant death syndrome (SIDS) during cold weather, and a higher incidence of breast cancer in U.S. urban areas with more sunlight.

Weather and migraine

As parents of a child who is a chronic migraine sufferer, my husband and I are firm believers in the weather-health connection. Our son has suffered from debilitating migraines for the past eight years. After eliminating or accounting for all of his known triggers, it became obvious that approaching weather fronts, and frequently, rapidly departing ones, correspond to the onset of his attacks. We now call him our "barometer boy."

He is not alone. Dr. Seymour Diamond, executive chairman of the National Headache Foundation and director of the Diamond Headache Clinic in Chicago, says that although the research has not yet proven that weather makes a difference in the incidence of migraine, as a clinician he believes it does. "Whenever a front comes through or there's a big change in the weather, the number of phone calls we receive from patients dramatically increases," says Diamond. In fact, fifty percent of patients report that weather changes influence their migraines.

Why does this happen? While there is no statistical proof, Diamond cites the 1969 research of an Israeli scientist who noticed that a change in the number of small air ions and the ratio of positive to negative ions alters with changes in barometric pressure. These same changes may affect the body's serotonin levels—a chemical that has been linked to migraines.

What's a migraine sufferer to do? Diamond suggests that migraine sufferers pay attention to weather forecasts. When a weather system you may be sensitive to is forecast, avoid all other migraine triggers and keep your abortive medication handy. He also recommends that you speak to your physician about other measures that may be appropriate in your case.

Weather and joint pain

There is much debate about the effects of weather on arthritis and joint problems. No cause and effect relationship between weather and joint pain has been proven, and it is not known exactly how weather might effect some physiologic change that could cause increased pain. That means little to anyone who experiences joint pain that seems suspiciously weather-related.

"There's no question that the majority of people who have arthritis or joint problems in general feel worse with weather changes," says Dr. Thomas Sculco, director of orthopedic surgery at the Hospital for Special Surgery in New York. "In a cool, damp climate, the muscles are probably a little more irritable and prone to spasm. Also, the blood supply to the muscles may be diminished. Those who have had surgery or a joint injury will feel changes in barometric pressure in the affected joint. It's not known why," Sculco says.

Some patients find they can relieve the pain, he says, by warming the area, perhaps by wearing leg warmers if the knee is affected. Anti-inflammatory medications can also be helpful. Many arthritis sufferers who found their pain exacerbated by cold, damp conditions have made the move to warmer, drier climates.

The forecast for biometeorology

The weather-health link is getting some attention, albeit not very much in the grand scheme of medical innovation. "If MediClim^TM could prevent one patient visit per person per year, a tremendous amount of money could be saved and put back into research," Bart says. "I'm as sure as I can be that the effects of the atmospheric environment on human behavior and health will become a major issue. I hope [human biometeorology] becomes a small but respectable part of every physician's and social worker's training."

In the meantime, if you feel that the weather affects or aggravates your medical condition, speak with your health care provider. Keep a diary outlining your symptoms, the weather conditions on the days when they occur or worsen, and any other pertinent information that will enable you and your health care provider to make a diagnosis and develop a treatment plan.