Nowadays, everyone around the world is familiar with the dangers of climate change as one of the most visible environmental concerns, where temperature is rising, polar glaciers are melting, and sea levels are rising. Over the past few years, the frequency and strength of natural disasters, such as floods, droughts, hurricanes, and tsunamis, more than doubled, killing thousands of people in affected areas. With the rise in mortality rates caused by those extreme events, climate change does not only threaten human safety, but it also directly and indirectly affects the human health.
In some areas, especially in Northern Latitudes, people are less prepared to cope with excessive temperatures. Moreover, young children, pregnant women, elders, and people with certain medical conditions are less able to regulate their body temperature, and can therefore be more vulnerable to extreme heat. As the planet warms up, heat wave attacks increase, leading to increase in deaths in certain areas due to the exposure to excessive heat. In 2003, more than 70,000 excess deaths were recorded after the heat wave that attacked Europe. Exposure to extreme heat can lead to heat stroke and dehydration, as well as respiratory, cardiovascular, and cerebrovascular diseases.
Higher temperatures also affect air quality as the levels of ground-level ozone and other pollutants rise in the air. A new study found that breathing ground-level ozone can trigger coughing, throat irritation, and congestion. Excessive exposure to ozone can worsen bronchitis and asthma, and can also inflame the linings of the lungs, leading to lung tissue damage.
Particulate matters—a term used for extremely small particles and liquid droplets suspended in the atmosphere—may be created by human activities, such as burning fossil fuels to produce energy, and can be formed in the atmosphere from chemical reactions of gases, such as sulfur dioxide, nitrogen dioxide, and volatile organic compounds. Some of this particulate matter, such as dust, wildfire smoke, and sea spray, occur naturally. Climate change can increase the severity of wildfires, where the wind can carry particulate matter from the wildfire smoke for a very long distance. Inhaling these particles can lead to lung cancer and chronic obstructive pulmonary disease.
Researchers found that plants are growing earlier and faster, which produces more airborne allergens. They linked this to increasing levels of carbon dioxide in the air, in addition to the warming temperatures. Higher concentrations and longer intense pollen seasons play a large role in the rise of allergy-related illnesses and asthma attacks.
Changes in the climate will also influence the spreading of vector-borne diseases that are transmitted by mosquitoes, ticks and flees, such as malaria, dengue fever, and Rift Valley fever, changing their geographic range. Increasing rainfall patterns and higher frequency of floods will create more standing water for insects to thrive and breed; insects also grow faster in warmer climates. Malaria kills around 600,000 people every year, mainly African children under 5 years old; however, in recent years, and with the continuous rise in temperature, mosquitoes can spread into new areas, so communities of higher altitudes are at higher risk of developing malaria.
Warmer oceans and other surface waters could increase water contamination with harmful pathogens, chemicals, biotoxins, and toxicants, resulting in increased human exposure to water-borne illnesses and cholera outbreaks. Fresh water contamination can also occur through the release of chemical contaminants previously locked in melting polar ice sheets, in addition to floods. This threatens fisheries and directly affects agricultural productivity, crop failure, and lack of clean drinking water, leading to intensifying malnutrition and starvation.
Climate change and high temperatures affect food safety and nutrition, where they increase cases of salmonella and other bacteria-related food poisoning, because bacteria grow more rapidly in warm environments. These bacteria can cause gastrointestinal distress, and in severe cases, death.
People in developing countries may be the most vulnerable to health risk globally, but climate change also threatens health in wealthy nations. World Health Organization (WHO) researchers are expecting that, between 2030 and 2050, climate change will cause approximately 250,000 additional deaths per year, whether from malnutrition, malaria, dengue fever, or heat stress. Researchers are, thus, developing strategies to raise the communities’ awareness to provide and disseminate information about the threats that climate change impose on human health while cutting down carbon emissions.
*Published in SCIplanet printed magazine, Summer 2017 Issue.
References
health2016.globalchange.gov
climatehotmap.org