By Kim Robson:
As global climate change takes hold of our planet, warmer temperatures are bringing about an unexpected consequence: increased risk of certain illnesses. From asthma and Lyme disease to mold and parasites, warmer temperatures are great for these pathogens, but not so great for us. Let’s discuss a few of these growing health concerns.
The CDC is monitoring upward trends in numbers of tick-borne disease. Spokesperson Rebecca Eisen, a research biologist from the National Center for Infectious Diseases, says, “Since the late 1990s, the number of reported cases of Lyme disease in the United States has tripled and the number of counties in the northeastern and upper Midwestern United States that are considered high-risk for Lyme disease has increased by more than 300 percent. One explanation for this trend is that the ticks that can transmit Lyme disease have expanded their geographic range and are now being found in places they weren’t seen twenty years ago.”
Cases of tick-borne disease are found most often around the northeastern United States, but at least one case of tick-borne Lyme disease has occurred in every state, according to the Center for Disease Control. Hot spots include
- New Hampshire
- New Jersey
- New York
- West Virginia
Maine, Vermont and Pennsylvania have the highest rates of Lyme cases. Wisconsin, Minnesota and parts of Michigan are also experiencing an increase in cases in recent years. Be diligent about doing tick checksafter outdoor activities, and take steps to prevent ticks in your backyard.
In addition to Lyme disease from ticks, we’ll also need to watch for other insect-carried diseases from mosquitoes or fleas. Insects will hatch earlier in the season and range further north and to higher elevations. The longer growing season increases the amount of time humans will be exposed. Vector-borne diseases found in the U.S. include spotted fever rickettsiosis, ehrlichiosis and babesiosis; mosquito-borne West Nile virus, malaria, dengue and chikungunya virus; and flea-borne plague.
There are a number of reasons why warmer temperatures will exacerbate the suffering of those with asthma:
Ground level ozone, the main ingredient of smog, occurs when fossil fuel pollutants and natural emissions from vegetation or wildfires react chemically with sunlight. Ozone exposure can cause shortness of breath, aggravate respiratory illnesses such as asthma, and lead to premature death.
Increased precipitation and moisture outdoors makes the indoors damper, increasing the chance of indoor mold and dust mites which exacerbate asthma and bronchitis. Rodents, which trigger allergies and carry pathogens such as hantavirus, could be driven indoors by extreme precipitation.
Waterborne viruses such as norovirus, rotavirus, and giardiasis love warmer temperatures. Air and sea surface temperatures, precipitation and runoff, coastal flooding, hurricanes and storm surge all affect the growth, spread and severity of the pathogens and toxins that cause water-related illnesses.
Algae and Seafood
Rising temperatures, heavy rainfall, and runoff containing nitrates (from fertilizer and sewage treatment plant discharges) promote the growth of cyanobacteria. These blue-green algae produce toxins that can cause liver and kidney damage, gastrointestinal illness and neurological problems, especially in children. During these “red tides,” which can last for months or years, one must avoid the following: swimming or boating,inhaling the air near the pollution, drinking polluted water, or eating contaminated seafood. Algae blooms in the ocean can cause respiratory distress and eye irritation, especially in people with pre-existing respiratory diseases.
Vibrio bacteria, which may contaminate shellfish and recreational waters, are more prevalent when sea surface temperatures and sea levels rise, especially along coasts. They can cause eye, ear and wound infections, diarrhea and death.
The pathogens E. coli, Salmonella, and Campylobacter all thrive in warm, wet conditions. Eating food contaminated by these pathogens can cause diarrhea and other gastrointestinal issues and may even be life-threatening. Warm and wet conditions also prompt the growth of molds such as mycotoxins on crops; this also can cause illness or death if consumed. Untreated sewage or manure in floodwaters or runoff may contaminate irrigation water and, ultimately, crops.
What We Can Do
While climate change is a global issue, its effects on health will vary across geographic regions and populations. CDC’s Climate and Health Programis helping state and city health departments prepare for the specific health impacts of climate change that their communities will face and they recommend actions that communities can take to protect their populations from health risks.