Unit Content
This unit will tackle some of the Mathematics content relative to the climate impacts and climate related health impacts that can affect poor and African American populations who reside in urban environments.
Disproportionate Impact of Climate Change on Vulnerable Populations
A review of the literature shows an increasing number of studies linking historical redlining practices to dire health impacts for vulnerable populations.12 13 14 15 16 Historical redlining was the practice of denying access to federal loans and investment opportunities to an area that was predominantly African American. The term is derived from actual red lines that were drawn on maps to identify the neighborhoods as hazardous. This unit will cover specific environmental impacts that affect African American populations who continue to live in parts of metropolitan areas that were deemed undesirable, remain disinvested and are more likely to experience the disparate health outcomes associated with poverty and climate change.
As stated in the Fourth National Climate Assessment, “People who are already vulnerable, including lower-income and other marginalized communities, have a lower capacity to prepare for and cope with extreme weather and climate-related events and are expected to experience greater impacts.”17 We have seen this with climate-related events like the wildfires impact on the elderly and low-income populations in California or the impact of Hurricane Katrina on low-income and African American residents.
Low income and African American populations were, historically, more likely to be redlined into areas that were deemed as “undesirable”.18 While redlining has since been made illegal, many of those areas still face disinvestment and are more likely to be in close proximity to industrialized transportation systems, industrial centers, oil and gas refineries, less green space, and more risk related land covers.19 20 People of color are more likely to live in an urban heat island21, and this unit will explore the concept further in the Rising Temperatures and Urban Heat Islands section. Conversely, these populations are often neglected in climate change conversations, and adaptation and mitigation efforts, resulting in an even further impact on health outcomes.22 New explorations of pollution inequity are also on the forefront of climate justice conversations. These conversations are centered around the difference between the environmental health damage caused by a particular racial group minus the damage experienced. It is possible that African American and Black Hispanic ethnic groups experience more environmental health damage based off of the consumption of goods and services by Non-Hispanic whites.23 This unit will cover 3 climate related impacts that have disparate impacts on some African American subgroups: (1) rising temperatures, (2) air pollution and (3) ragweed pollen.
Rising Temperatures and the Urban Heat Island Effect
With African American populations being among the vulnerable populations that are more likely to live in an urban heat island24, the topic and understanding of daily temperature and its trends are of extreme importance to the students at Pittsburgh Lincoln. Increased anthropogenic contributions to greenhouse gasses certainly contribute to the higher temperatures in urban environments, but there are other contributing factors that are certainly worth noting in more detail.
Besides greenhouse gasses, there are other components and processes that reflect and absorb heat from the sun to create the temperature, such as albedo. Albedo is a surface’s ability to reflect or absorb radiation/heat from the sun. The ability of matter on earth’s surface to absorb heat and reflect heat is dependent on how light or dark the surface is. Lighter surfaces reflect heat better (making the temperature cooler) while darker surfaces absorb it (making the temperature hotter). For example, snow cover on a surface will reflect heat better than asphalt. This is of particular importance for this unit because it informs how the surface areas in urban environments contribute to rising temperatures that have several impacts, including an increase in respiratory illness and asthma severity.
Earth’s surfaces have an ability to either reflect or absorb radiation from the sun. However, in urban areas, many dark surfaces such as buildings and asphalt pavements absorb a high percentage of heat from the sun.25 They do not have as much reflectivity as green space. The dark surfaces also cannot absorb rainwater, and this causes a problem with the natural cooling system of the earth. Water evaporating from soil helps cool the earth, and so in urban spaces the paved surfaces prevent this from happening. Subsequently, temperatures are increasing at higher rates in comparison to rural areas that have more green space. 26 27
First gaining attention in 1833, this effect is now commonly characterized as the heat sink effect or urban heat island (UHI) effect.28 29 30 In addition to dark pavement areas and decreased evaporation function, there are other variables that exist within a causal sequence to contribute to the UHI effect. For example, the industrialized transportation systems and factories in urban areas emit waste heat and CO2 during operation. These types of emissions are called anthropogenic heat release (AHR) because they are caused by human activities. Because the air and surfaces in cities are hotter, the indoor environment is hotter, resulting in higher usage of air conditioners, ejection of waste heat from buildings, increased energy utilization and contributing to even more AHR.31
A 2021 research brief ranked the top 20 hottest metropolitan areas, using an index score rating that took into consideration the following characteristics of the cities: (1) albedo, (2)percentage of greenery (3) population density, (4) building height, and (5) average width of streets and irregularity of the city. The top 5 cities New Orleans, Newark, New York, Houston, and San Francisco.32 While Pittsburgh was not on the list, we certainly have our issues with rising temperatures as do most metropolitan areas. This unit can be applied to many metropolitan areas, as 85% of people are living in metropolitan areas in the US.33
Last year, Danielle Dozier, news staff for a local news station (WPXI) in Pittsburgh, interpreted the National Oceanic and Atmospheric Administration’s (NOAA) climate normals assessment, and published that “Pittsburgh is getting warmer and wetter.” According to Dozier, the results show that Pittsburgh’s average temperature is 0.5 degrees warmer based on the 30 year normal from 1991-2020.34
Urban Heat Islands and Air Pollution
There are different types of pollution that include water, land, and air pollution. It is important for students to understand their impacts. This unit will introduce the topic of air pollution and encourage students to think about the indicators of what makes a good air quality day versus a bad air quality day. To help students understand this, it is important to note and explain that there are many indicators or criteria for air pollution and air quality. They include U.S EPA criteria contaminants: carbon monoxide, lead, ozone, particulate matter, nitrogen dioxide and sulfur dioxide35 Federal government websites like Airnow.gov give detailed information on the pollution criteria that are high for the day. Using this information, students with asthma can become more aware of times that they may need to exercise vigilance and care to manage the condition.
The urban heat island effect combined with air pollution creates a compounded health crisis, especially for vulnerable and marginalized populations, and people who have asthma. The adverse effects of poor air quality include many respiratory illnesses including asthma. Poor air quality has also been linked to school absenteeism and poor academic outcomes.36 In the American Lung Associations’ 2020 “State of the Air” report, Pittsburgh was found to have ozone and daily long-term fine particle matter (PM 2.5) levels that were considered failing.37 Because these are the pollutants of concern for Pittsburgh, PA, this unit will mostly cover these two. These two pollutants are exacerbated by emissions, but sunlight and temperature also have an impact on how they are formed.
Nitrogen oxide gasses can be naturally occurring, but are also emitted when fuel is burned at high temperatures by vehicles or other industrial sources. Volatile Organic Compounds (VOC) are human made chemicals that are emitted as gasses from certain solids or liquids, like paint, cleaning supplies, and pesticides. These gasses react with sunlight and high temperatures to create the majority of ground level ozone, or smog, that we experience.
When ozone levels are high are at ground level, it has serious health impacts for individuals with pre-existing respiratory conditions, especially asthma. Individuals who are disproportionately impacted include African Americans and children. 38
Another U.S EPA criteria contaminant is particulate matter, or PM. PM 10 and PM2.5 are small, inhalable particles that form in the air as a result of chemical reactions with the gas emissions from power plants, automobiles, and industries. PM2.5 is also called fine particulate matter because of its size is smaller than PM10. PM2.5 consists of particles that are generally 2.5 micrometers in diameter. It can include dust and soot, and can have serious health consequences when inhaled. Ground level ozone and airborne particles are the two contaminants that pose the greatest health risks.39
Ragweed Pollen and Hay Fever
North American pollen seasons are getting worse as a result of climate change. The reason: longer growing seasons and higher pollen counts.40 In 20ll, a study showed a longer duration of the ragweed season for specific latitudes. In that study, the authors identified a delay in frost season in the fall and a ragweed season was between 13-27 days longer than it had been in 1995 (see Figure 1). Due to climate change, the temperatures that used to be considered spring time temperatures are starting earlier and summer temperatures are lasting longer into the fall.41 In Pennsylvania, the ragweed pollen season starts in mid-August and lasts until mid-September when the temperatures begin to decrease to 60°F. With more extreme temperatures due to the urban heat island effect, the extended growing season is likely greater in metropolitan areas
Figure 1-Changes in the length of the pollen season from 1995-2015 42
The longer season exacerbates a major health issue for the estimated 10-30% of the population that suffers from hay fever, and the 300 million people affected by asthma.43 Nationally, allergies account for over 13 million doctor and medical facility visits in a year.44 Allergy symptoms and asthma are major causes of disruptions to learning and school absenteeism, and they are more prevalent in urban areas than they are in rural areas.45 46
Allergy symptoms occur when the body’s immune system views a substance as a threat. When the immune system recognizes a foreign substance as potentially harmful, it will create antibodies to attack it, resulting in an allergic response that can include sneezing, watering eyes, and shortness of breath. The antibody that the immune system creates against allergens is called Immunoglobin E (IgE), although there can be different allergen specific variants. People who have allergies have high levels of the antibody IgE, and whether or not a person develops these antibodies is based on genetics and environment.
Ragweed pollen, is one of the most common aeroallergens in the United States, and can trigger allergies and asthma attacks. It is produced by the ragweed plant, Ambrosia artemisiifolia. It’s 17 species grows throughout the United States, but especially in the Eastern and Midwestern States. The weed can produce up to 1 billion pollen grains. Ragweed pollen season typically begins mid-August, when nights are growing longer. With the aid of certain weather elements like windy, warm, or humid days, the pollen can be released from the plant and travel far distances and into the atmosphere. On the contrary, rain and colder temperatures (50˚ F or below) can slow down the release of pollen.47
Another factor that impacts the rise in respiratory allergies due to ragweed are the heightened CO2 levels from human induced emissions. The CO2 levels result in higher temperatures and more ragweed pollen is able to be produced physiologically by the ragweed plant than the same plant at lower temperatures. Some questions still remain about whether the pollen’s allergenicity, the allergic potency per mass of pollen, is increasing. 48
Increasing allergies have direct impacts on educational outcomes and health. It is not uncommon for students to make multiple requests to grab tissue for runny noses and after sneezing, or to see students holding moistened paper towels on their eyes to attempt to relieve eye irritations. It is also not uncommon for students to miss school due to allergies and asthma. The content of this unit is especially relevant to my school as it is located in the city of Pittsburgh, listed as 10th out of 100 on the 2020 Asthma and Allergy Foundation of America’s list of “Most Challenging Places to Live with Allergies.”49
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