Climate Change in Washington - Human Health

Human Health

Impacts on infectious diseases
The West Nile Virus is a serious disease linked to climate change in the US that is transmitted by mosquitoes. It favors periods of drought and heavy rain, which are likely to become more common as increased average temperatures in Washington State result in rain replacing snowfall during the winter, resulting in drier summers (chance of drought, particularly east of the Cascades). The mosquitoes will also survive longer because the warmer winters will not eliminate as many bugs as it usually does. Documentation of the West Nile Virus is just beginning in Washington State, but Colorado has been grappling with cases of it since 2002. Total costs there have been estimated at $120 million or $670 million (P. 58), both as of 2006. Louisiana has been battling cases since 2001, with total costs of $190 million by 2006. In the hopes of avoiding these costs, the Washington Department of Health currently spends $246,000 per year on surveillance for the virus and Epidemiological follow-up and testing on suspected human cases (P. 59)

Dengue fever is an infectious disease also carried by mosquitoes and caused by any of four related dengue viruses. It is also called "break-bone" fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking. Health experts have known about dengue fever for more than 200 years. An epidemic in Hawaii in 2001 was a reminder that many locations in the United States are susceptible to dengue epidemics because they harbor the particular types of mosquitoes that carry the dengue virus. Worldwide, 50-100 million cases of dengue infection occur each year. This includes 100-200 cases in the United States, mostly in people who have recently traveled abroad. Many more cases probably go unreported, because some health care providers do not recognize the disease. During the last part of the 20th century, many tropical regions of the world saw an increase in dengue cases. Epidemics also occurred more frequently and with more severity. In addition to typical dengue, dengue hemorrhagic fever (DHF) and dengue shock syndrome also have increased in many parts of the world. Globally, there are estimated to be several hundred thousand cases of DHF each year.

Recent Article from New York Times: As Earth Warms Up, Tropical Virus Moves to Italy
Published: December 23, 2007.
Aided by global warming and globalization, Italy suffered the first outbreak of a tropical disease in modern Europe.

Impacts on respiratory illnesses, (such as asthma and allergies)
Washington's asthma prevalence is among the highest in the nation, costing the state over $400 million yearly. 400,000 adults and 120,000 children currently suffer from it in WA. Though increases in average yearly temperatures is the hallmark of global warming, human activities are the cause of greenhouse gases like emissions from cars, power plants, and airborne particles from human caused forest fires. Global warming has a "direct" effect on respiratory illnesses because increased CO₂ levels stimulate pollen production, which stimulates allergies. More frequent flooding in WA State will increase the growth of fungus, also exacerbating allergies. Increased carbon dioxide levels have already and will continue to increase the level of pollen output in the state. In 2001 when carbon dioxide levels were 370 parts per million the pollen output for a common ragweed was twice the level of output that plants used to give out at 270 parts per million, which was the level before the industrial revolution. One possible scenario for the coming years is that pollen count could increase to 20 grams per cubic meter. This would cause a serious increase in the need for medication for allergies and exacerbate the effects of global warming on the economy.

Impact on heat-related illnesses
Heat-related deaths will increase as average yearly temperatures increase. More frequent days over 100 °F (38 °C) will cause several problems for humans, including heat cramps, heat exhaustion, and heat stroke. The amount of heat waves has increased in the state of WA over the past 20 years. The average cost for each mortality from heat related deaths is $6,250. These occur when the human body is so overwhelmed by heat that it no longer can combat the extreme level of heat. Urban settings will see even worse conditions. At night, heat levels can remain dangerously high. This is because buildings and roads absorb heat during the day and release this heat at night. Studies of heat-related mortality in eastern WA had highs of 107 °C in 2006. Hospital charges for heat-related admissions in 1998 was roughly $6250 per patient.