Mitch Kennedy, ND
In the April issue, Dr. Kennedy began his three-part series discussing global warming and its effects on health. That first column covered the science behind how human activities are changing the climate of the globe. Here, part two of the series provides some of the health implications caused by global climate change.
Unequal Temperature Distribution
One thing we keep hearing in the media is that global temperatures will rise. The misperception is that this will be uniform. In fact, the areas of the globe near the equator will warm the least, and the areas near each pole will warm the most. A five-degree increase globally may translate to one degree at the equator and 12 degrees at the poles. Obviously, this distribution favors rapid melting of the ice floes and fewer days of permafrost in northern climates. It also portends longer growing (and allergy) seasons.
At first glance, this may be interpreted as a good thing. However, many infectious disease organisms are killed or forced into dormancy due to hard frost. Migratory species that visit their winter grounds may become potential vectors for the transmission of diseases, whereas the animal would not normally be exposed during their migration.
Other diseases, such as malaria and dengue fever, are confined to specific geographies by the temperature changes due to elevation. For example, malaria is endemic to low-lying areas of tropic temperature, but cannot spread to higher elevations because of the colder temperatures. If it gets warmer on the mountain, malaria can take hold. In Africa, some cities were intentionally built at higher altitudes to avoid malaria. Now they are at risk as the climate changes.
Most infectious organisms are more adaptable than the predator species that keep them in check. Therefore, shifts in weather patterns that favor infectious diseases often work against the predators that would normally control their spread. This is true for insect vectors and the bird species that eat them as food. Hatching dates for new chicks have traditionally corresponded to a time when food was available for them, i.e., hatching dates for caterpillars and mosquitoes, etc. With a decrease in the number of frost days, these insects hatch sooner than the chicks. This results in starving chicks and an overpopulation of insects.
More Frequent Extreme Weather Events
As the climate warms, weather events are becoming more frequent and more severe. For example, heat waves have increased dramatically. Across Europe in the summer of 2003, a record-breaking heat wave caused more than 39,000 deaths due to heat stroke, heat-related dyspnea, asthma and electrolyte imbalances.
Then, in 2006, European temperatures climbed into the triple digits: Bordeaux, 102 degrees; Turin, Italy, 104 degrees; Bosnia, 104 degrees. Even cities with moderate-to-cool climates set new temperature records: London, 97 degrees; Brussels, 93 degrees.
The European Union was poorly equipped to deal with the sudden weather events, just as the U.S. was and still is poorly equipped to deal with disasters such as hurricanes Katrina and Rita. New Orleans and the Gulf Coast are still reeling from the by-products of these hurricanes. Dust, mold, bacteria and spilled chemicals coat the houses, yards and belongings of the people that lived there. Long-term remedial measures may require replacement of the soil and houses, and treatment of a growing list of respiratory ailments and cancers.
In summary, there are four major concepts:
1) A warming climate extends life span of diseases and vectors
2) Rising temperatures allow disease to spread to higher elevations
3) Extreme weather events tax our healthcare system emergency response and cause acute disease outbreaks due to lack of sanitation
4) Extreme weather events also create long-term health risks due to mold, bacteria and pollution.
Next issue’s column will provide a list of suggestions for NDs and their patients to slow the process and limit the damage.
Mitch Kennedy, ND has a family practice in Avon, CT, and is the first ND with clinical privileges at the University of Connecticut, a teaching hospital. Before graduation from Southwest College, Kennedy earned an international reputation as a leader in pollution prevention, showing industries around the world how preventing pollution saves money.
