YP Perspective Global Disease and Air Quality in a Changing Climate by Kim Frauhammer Through the lens of the current global pandemic, a look at some of the existing challenges, such as environmental degradation, decreasing air quality, and climate change, that continue to put the human population at risk. 2020 has already been a year to remember, defined by the Seasonality of the Virus novel Coronavirus and its far-reaching effects on our health With how expansive this virus has proven to be, examining and economy. This global pandemic has restructured our all methods of transport is vital to understanding the future lives, while existing global challenges that continue to put the of global diseases. According to the U.S. Global Change human population at risk remain. Environmental degradation, Research Program, a set of “vulnerability factors” determine decreasing air quality, and climate change continue to expose whether someone is at risk for adverse health outcomes: the human population to higher risks of illness and loss of exposure, sensitivity, and adaptive capacity.1 The climate and resources. COVID-19 has provided us with a unique window environment are a part of all three. The virus first emerged into identifying these underlying risks and highlights the and spread rampantly during the Northern Hemisphere benefits between preserving the future of not only our Winter and there is scientific evidence to point to why. health, but our environment as well. Humidity is the greatest factor. em • The Magazine for Environmental Managers • A&WMA • August 2020 YP Perspective In the midlatitudes of the Northern Hemisphere (broadly be - Recent research from Harvard University cites that people tween 30 and 60 degrees), the atmosphere cools down as the who live in areas of poor air quality are more likely to die Earth is tilted farther away from the sun during the winter. from COVID-19. 5 The study examined over 3,000 counties This colder air typically contains less moisture than its summer across the United States with long-term exposure to fine par - counterpart. This is because water does not evaporate as read - ticulate matter (PM 2.5 ) and the virus-related death counts cor - ily in colder air as it does in warmer air. 2 As temperature in - responding to those counties. The study found statistically creases, so does the energy of water molecules, eventually significant results showing that an increase of 1 µg/m 3 of becoming so energetic they evaporate and change from a liq - PM 2.5 was associated with an 8% increase in the mortality uid to a gas phase, becoming water vapor in the atmosphere. rate. This phase change does not happen as frequently in the win - ter, leading to drier air. 3 A similar study done in China showed that there was also a compelling link between higher air pollution levels and mor - Liquid droplets we emit from sneezing, coughing, or even tality rate of the SARS (“Severe Acute Respiratory Syn - breathing can remain in the dry air longer, creating favorable drome”) virus that swept across Asia in 2002. 6 The study conditions for the spread of viruses like the one that causes cites that patients from regions with a high air pollution index COVID-19. The minute water particles we spray into the air (API) had a mortality rate double that of patients from re - float in the dry air of winter for us to breathe. 4 gions with low APIs. These studies represent the increased sensitivity of people to suffer severe impacts from a virus due Disease and Air Quality to poor air quality. Understanding the seasonality behind the spread of viruses is only one environmental aspect determining our exposure. According to the National Climate Assessment, over 100 Figure 1. Human-caused and natural emissions of air pollution. Source: National Climate Assessment. 7 em • The Magazine for Environmental Managers • A&WMA • August 2020 YP Perspective Natural processes also result in the formation of these pollutants. Sea salt, elemental carbon, dust, and smoke are all exam - ples of naturally occur - ring components of PM. It is estimated that wild - fires comprised roughly 40% of direct PM 2.5 emissions in 2011. 7 However, human-related activities, including pre - scribed fires and land management practices, also formed part of this 40%. The U.S. Clean Air Act has made significant progress toward cleaner and more breathable air in our country. 8 A study from 2009 shows life expectancy across the United States increased by five months between 2000 and 2008 due to reductions 9 in PM 2.5 . However, all these pollutants have shown a slight increasing trend since 2016 and Figure 2. NO 2 levels during COVID-19 pandemic. Source: NASA 11 there are still many areas within the United States whose levels of these million people in the United States today live in areas where pollutants exceed federal air quality standards, putting the air pollution exceeds health-based air quality standards. 7 citizens that live in these areas at an increased risk for health Two common air pollutants that adversely affect humans are complications. 10 ground-level ozone (O 3) and particulate matter (PM 2.5 and PM 10 ). These impact the respiratory and cardiovascular sys - As people stayed home in early 2020 due to COVID-19 and tems, leading to health complications, shortness of breath, commuting became walking from the bed to the couch in hospital visits, and even premature death. It is estimated that slippers instead of driving miles in a smog-emitting car, many about 200,000 Americans die from those air pollution-re - cited the dramatic improvements in air quality. On April 9, lated causes each year, despite all the pollutants being de - NASA released satellite images revealing significant reduc - fined as within the U.S. Environmental Protection Agency tions in air pollution over the major metropolitan areas of the (EPA) standards. Northeast United States (see Figure 2). 11 In India, the nor - mally haze-clogged skies were replaced with magnificent The State of Air Pollutants Today views of the Himalaya Mountain Range, a sight not seen in 12 O3 and PM primarily originate from emissions from human- years. These achievements show that widespread action on related activities such as highway vehicles, stationary fuel a global scale to improve air quality is possible, even if the combustion, and industrial processes (see Figure 1). 7 These current circumstances are not sustainable. pollutants are also extremely sensitive to meteorological factors such as temperature, wind speed, and precipitation. EPA air monitor data from 2015–2019 was compared to em • The Magazine for Environmental Managers • A&WMA • August 2020 YP Perspective 2020 data from the same period by county during the time of 2020 stay- at-home orders in Colorado (see Fig - ure 3). PM emissions revealed great contrast, with one county seeing as much as a 40% decrease, while a neighboring county saw a 40% in - crease. O 3 was less dramatic. With fewer cars on the road, data across the state east of the Rockies largely varied on a range from negative to positive 5%, with zero change in Denver County. This unique situation of staying at home shows a need for reductions in other aspects of society to achieve dramatic long-term de - creases in pollutants. A Changing Climate’s Effect on Air Quality According to the National Climate Assessment, many factors contribute to increased PM and O 3 emissions. As the globally averaged tempera - ture increases, we will not see a blanketed effect of this increase throughout the entire world, rather a quilt of extremes with various squares affecting various regions (see Figure 4). The West and Southwest United States are two areas that are pro - jected to see higher temperatures and decreased precipitation due to climate change. 13 This leads to a pro - longed and more severe wildfire sea - son, as well as more frequent droughts. PM emissions from wild - fires and drought-related dust there - fore increase. 14 PM can then travel hundreds of miles in the wind to other parts of the United States, de - creasing air quality. This drier and hotter climate is also expected to re - sult in twice the area of forest burned in the United States due to wildfires, leading to more smoke-related PM. 7 Figure 3. Percent change in Colorado PM 2.5 (top) and O 3 (bottom) median concentrations by county during stay-at-home order Meteorological conditions continue compared to 2015-2019. to influence air quality. O 3 is formed Source: EPA Air Quality System and AirNow data. through photolytic chemical reactions Credit: Holli Williamson and Clement Cros, Spirit Environmental, LLC driven by the sun, which results in in - creased O 3 formation in regions with em • The Magazine for Environmental Managers • A&WMA • August 2020 YP Perspective Figure 4. Climate change effects across the United States. Source: National Climate Assessment 13 increased temperature. O 3 formation also favors low humid - Other viruses such as Lyme disease or malaria, which are ity and stagnant air, allowing the O 3 to “cook” in the atmos - vector-borne illnesses carried by ticks and mosquitoes, could 15 19 phere. Conversely, O 3 and PM can be brought out of the have the ability to reach regions they never have before. air to the ground by rain and snow. Revisiting the quilt analogy, the wet and humid region of the tropics is expected to expand, creating a larger favorable Persistent weather patterns causing stagnant air over one environment for mosquitoes carrying malaria. Similarly, area for a prolonged time lead to a piling up of PM or O 3 increased precipitation across the northeastern United States emissions near the ground that leads to negative health im - has expanded the geographic reach of ticks and Lyme pacts.