Will Parson / Chesapeake Bay Program

Rising to the Challenge
A New Climate Reality in the Potomac River Region
Potomac Conservancy

Part 3A

People, Health, and Justice


The climate crisis isn’t an environmental issue. It’s a life-or-death issue. In Part 3a of our climate series, we look at how the warming atmosphere and rising waters are wrecking our health and exacerbating inequalities in our community.

Published August 30, 2021
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The rapidly heating climate is an emerging public health crisis for the communities of the Potomac River region.

We take a look at how climate-driven changes in our environment are impacting public health and how we can better plan to protect ourselves from the consequences of heat stress, air quality, vector-borne diseases, water quality, and health care inequities.

Dan Thombs

Milder winters, wetter weather, deforestation, and urban sprawl are creating the ideal climate for ticks

You consult your veterinarian about the best tick protection for your dog. You tuck your pants into your socks while hiking through tall grasses and diligently do a tick check after each woodland excursion. Unfortunately, when it comes to the war on tick-carried diseases, the climate crisis is on the side of the disease.

Lyme disease is the most prevalent vector-borne disease in the United States and has become even more rampant over the past decade. The pathogen responsible is a bacterium called Borrelia burgdorferi which is transmitted to humans via tick vectors. Lyme disease is characterized by the bullseye that arises at the site of the tick bite. If left untreated, it can progress to cause migraines, fever, fatigue, and skin rashes. Severe cases lead to joint pain, numbness in hands and feet, heart palpitations, or nervous system failure.

In the Northeast United States, the deer tick is the main vector of Lyme disease and is mainly carried by the white-footed mouse (though birds and other small mammals can also act as reservoirs.) While white-tailed deer do not carry the bacterium, they play an essential role in the life cycle and spread of deer ticks.

While white-tailed deer do not carry the bacterium, they play an essential role in the life cycle and spread of deer ticks.

Recent scientific studies have indicated that climate change is increasing the prevalence of Lyme disease in areas like the Potomac River region. Why?

The climate-driven temperature and precipitation changes in our region are creating a fertile habitat for deer ticks to thrive.

Typically, about 20% of tick populations die off each winter, either from freezing to death or from large, seasonal temperature swings (studies conflict). Mild winters can actually propagate tick populations, meaning we can expect to see more ticks come springtime. Consistent 70-90° F days support tick reproduction and can lead to an increase in population size.

Ticks also thrive with moisture, so populations will rise as the climate gets wetter in both winter and summer.

Moreover, forest fragmentation and urbanization have allowed for a population explosion of host “edge species” that thrive at the border between forests and human-made environments and have brought ticks right to our doorsteps.

A recent study found that in a warming scenario of 3.6° F the number of Lyme disease cases in the U.S. will increase by 20%.

Reported cases of Lyme Disease by Year, United States, 1998-2019

View Source

What are possible solutions?

Local counties need to reduce the amount of fragmented landscapes by encouraging the protection and creation of larger forests that can draw tick host species away from our backdoors.

Other nature-based solutions include encouraging natural predators of tick host species, such as owls and black rat snakes.

Public health officials, policy-makers, and professionals must raise public awareness of the increasing danger of Lyme disease and improve their preparedness and response protocols.

Climate-driven triggers are increasing rates of asthma and severe allergies

Global rates of asthma and allergens rose 8% from 1997-2007 and 19% between 2007-2017. Research ties the increasing rates to the way the warming climate is changing the behavior of allergens.

Within the Potomac River watershed, multiple climate-related factors are contributing to making asthma suffering worse and more common.

Hotter, longer summers and increased atmospheric carbon dioxide levels provide plants the opportunity to produce more pollen over a longer growing season.

Extreme heat can trigger asthma symptoms by causing people’s airways to constrict. A recent study showed that Asthma patients experienced a 112% increase in airway constriction when hyperventilating warm air as opposed to a 38% increase when hyperventilating room temperature air.

“Thunderstorm asthma” is a phenomenon still under investigation, but sufficient evidence supports the hypothesis that strong storms trigger asthma attacks because more pollen grains are present in flowing, humid air.

Increased flooding is causing fungal spores (from mildew, molds, rusts, and yeasts) to become more prevalent – especially in low-lying flood prone areas often occupied by communities of color.

With asthma attacks and allergen numbers being driven by so many aspects of climate change, how can we protect ourselves?

Increased flooding is causing fungal spores (from mildew, molds, rusts, and yeasts) to become more prevalenT.

What are possible solutions?

Urban planners should consider solutions that reduce the amount of air pollutants and allergens afflicting the public. For example, buffer zones could be established between residential or recreational areas to reduce toxic exposure to air pollutants like ozone.

Health departments could also create early warning systems in which allergy-prone individuals are alerted to risky conditions like thunderstorms during our pollen season.

You know, public health costs are tremendous in lower resource communities because of higher rates of chronic diseases. So investing in communities of color to mitigate these extreme weather events, which are becoming more and more frequent, will ultimately be worth it for municipal governments as it will help save money on the back end.

Abel Olivo

Abel Olivo Executive Director, Defensores de la Ceunca (Defenders of the Watershed)

Heat Stress, Air Pollution, and Water Quality

The deadly heatwaves seen in the Pacific Northwest earlier this summer should be seen as a warning to our local area.

In the Potomac River watershed, the number of extreme heat days expected to exceed 95°F will continue to rise throughout the century. By 2050, the Potomac region is expected to experience about seven heatwave events per summer, lasting upwards of ten days or more.

Extreme heat can result in a number of illnesses, including heat cramps, fainting, heat exhaustion, heatstroke, and even death; all of which (except for heat cramps) arise from the inability of our bodies to regulate their internal temperature when air temperature and humidity are at extremes. This means that those already less able to regulate their body temperature – like the elderly, children, and the infirmed - are more at risk, as are those without access to shade or air conditioning – like people experiencing homelessness or living in neighborhoods with less tree canopy and vegetation (which tend to be lower-income neighborhoods.)

What are possible solutions?

Counties and states can help cool our cities and keep people safe by strengthening urban forestry programs; passing land use ordinances to increase tree canopy, green streets, and other nature-based solutions; and updating building codes to promote green walls.

For safety, governments should also guarantee air-conditioners or cooling devices for every home – which makes the need to switch to renewable energy even more urgent as, ironically, air conditioning’s demand on electricity will accelerate emission of greenhouse gases.

Ozone and Air Quality

More frequent and extreme heat events also promote the formation of smog, a lung-irritant.

“Ground level” ozone (which, as opposed to the stratospheric ozone that shields Earth from the sun’s harmful UV rays, exists in the troposphere where we live) is quite dangerous. Tropospheric ozone reduces lung function, exacerbates bronchitis and emphysema, aggravates asthma by increasing sensitivity to allergens, and inflames and damages the lining of the lungs, sometimes leading to permanent scarring of the lung tissue and even death.

Climate change is increasing the presence of smog in the air we breathe by creating longer, hotter summers in which the chemical reactions that create ozone can occur and by decreasing frequency of the low-pressure weather systems that bring wind and rain, thereby trapping pollution, ozone, and particulates under a lid of hot air.

We do have the capacity to reduce ground level ozone and improve air quality in a warming world – we just need the willpower.

Systemic policy solutions include: phasing out fossil fuel-burning power plants; shifting to renewable energy; investing in high-quality, affordable public transportation that runs on clean energy; and creating mixed-use, walkable, bikeable, and public-transit friendly neighborhoods.

Companies can also contribute to reducing ozone pollution, smog, and GHG emissions by allowing telecommuting as often as possible.

Water Quality

“Dead zones” are areas in bodies of water that do not have enough oxygen to support aquatic life. But the algal blooms that cause these dead zones can also be harmful to human life.

Algal blooms in the Potomac River watershed are caused by nutrients from agriculture and urban industry, most notably nitrogen and phosphorus, making their way into the region’s waters. Some species of algae, like cyanobacteria (commonly known as blue-green algae) release harmful toxins which can threaten the health of both aquatic and human life at high enough concentrations.

Humans can be exposed to cyanobacterial toxins not only through drinking water, but also by eating contaminated fish. Symptoms include skin irritation, kidney and liver damage, gastrointestinal disturbances, and even cancer.

Fifty years ago, the Potomac River was so polluted that blankets of bright green algae coated the water’s surface every summer. Thanks to decades of work, the Potomac has been transformed from “an open sewer calling itself a river” (The New York Times) to a boating and fishing destination. But the water is not yet safe to swim in and the fish aren’t yet safe to eat – and climate change is threatening to reverse all that progress.

Good news! We’re already hard at work on possible solutions.

DC Water’s Clean Rivers Project, which is a massive insfrastructure project designed to capture and clean wastewater before it reenters DC’s rivers, expects a 98% reduction in combined sewer overflow by 2021 – which will reduce nutrients available for algal growth

Projects geared toward restoring river sediments, underwater grasses, and freshwater mussel populations (with aid in water filtration and algal cleanup) are already underway in parts of the Potomac watershed, including the Anacostia River.

A Buzzing Threat: Vector-Borne Diseases

Ticks aren’t the only disease carrying pests to expand their range thanks to warmer and longer summers. Mosquitoes thrive in hot, humid conditions.

In the Washington, D.C. metro areas, bug-bite season now lasts an average of 152 days, an increase of 37 days since 1980. This allows for more infections from mosquito-transmitted viruses like Zika and West Nile.

These viruses are themselves fostered by climate change as higher temperatures can shorten a virus’ incubation period. West Nile virus, which affects the brain and central nervous system of 65% of patients in the US, is the most common mosquito-borne illness in our area.

In 2018, approximately 9% of West Nile cases nationwide occurred in the Potomac River watershed. The virus affected the central nervous system of 75% of individuals infected in our region.

Changes to ecological cycles are bound to affect insect populations and other vectors. In turn, this is likely to change how diseases spread. But humans can control our impact on the environments that we inhabit, and, that is, perhaps the most crucial step in ensuring that we do not accelerate the arrival of another future health crisis.

Maria Cohut

Maria Cohut Medical News Today

Unfortunately, there is no cure to West Nile virus, though symptoms can be managed. And while eliminating standing water as a breeding ground for mosquitos and setting mosquito traps can be effective – these are also just ways of managing a symptom of a larger disease.

In fact, the best solution for all the health impacts described above is to tackle the root causes of climate change. This, of course, means drastically and immediately reducing greenhouse gas emissions and use of fossil fuels.

But it also means dismantling the exploitative systems that both degrade the Earth and place unequal burdens on low-income, indigenous, and communities of color.

Empower Communities!

Systemic injustices have put some communities in our region at greater risk for climate-driven health impacts

Racism and systems of exploitation have placed the largest environmental burdens on communities of color and low-income communities. We can help relieve these health burdens by investing in the power of people.

Your donation will help the Center for Community Engagement, Environmental Justice, and Health (CEEJH) in all of our outreach and engagement efforts. CEEJH offers direct technical assistance to communities impacted by environmental justice and health issues, in addition to providing education and training opportunities for the next generation of Environmental Justice leaders, such as the annual UMD Environmental Justice symposium. Your gift to this fund will allow CEEJH to expand our mission to advance environmental justice in underserved and differentially burdened communities in the DMV region and beyond.”

Dr. Sacoby Wilson

Dr. Sacoby Wilson CEEJH Director

spread the wealth! no climate action without climate justice.

Help support the communities most at risk from the health impacts of the climate crisis with a donation to the Center for Community Engagement Environmental Justice, and Health.

Donate to the Environmental Justice Fund

Explore More of the Report

Part 1

Part 1

Global versus Local Climate Trends

Read Now


Part 2

Part 2

A River Rising

Read Now


Part 3B

The Story Continues

This summer, Potomac Conservancy is rolling out a six-part series to uncover the rich and complicated nature of the climate crisis in our region. Don't miss out! Sign up for e-alerts and we’ll let you know when our next "Rising to the Challenge" story is out.

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Fun fact: Scientists can identify increases in atmospheric carbon dioxide are, indeed, human-made because carbon created by burning fossil fuels has a different isotopic ratio of heavy-to-light carbon atoms than carbon produced naturally by living plants. 

Fun fact: While carbon dioxide is the main culprit, other gasses like methane and nitrous oxide also add to the atmospheric soup of heat-trapping greenhouse gasses. Methane is released from natural gas fracking, the decay of organic waste put in landfills rather than composted, and from livestock and industrial agricultural practices. Nitrous oxide is released during fuel combustion and during the application of fossil-fuel based fertilizers or un-composted manure to fields (U.S. Environmental Protection Agency, 2020a). 

In 2015, the ATMOS Research and Consulting for Kleinfelder published local climate projections by studying historic emission and temperature data at three District sites: Dalecaria Reservoir, the National Arboretum, and Washington National Airport.

Andrew Elmore co-authored a study on the warming waters of the Chesapeake Bay for the University of Maryland Center for Environmental Science.

Learn More at Science Daily

Fun fact: Scientists can use high resolution climate models to tell whether an extreme event was made more likely by climate change – whether it served as a key ingredient in the storm’s formation. This is called “extreme event attribution.”

Fun fact: A rainfall event that is so heavy and unordinary that it only statistically happens once every 100 years

The National Weather Service confirmed an EF0 tornado touched down in Washington, DC and an EF1 tornado touched down Arlington, VA on Thursday, July 1, 2021. The nation’s capital has only experienced three confirmed tornadoes above an EF0 level in the last fifty years (two of which occurred on the same day in 2001).

FACT: According to the U.S. Geological Survey (USGS), glaciers and ice sheets store enough water to raise sea level by about 68 to 70 meters (223 to 230 feet) (Cronin, n.d.).

Thermal expansion is the phenomenon whereby the upper layer of the ocean absorbs heat from the warming atmosphere and expands

Over 400 miles in length, the Potomac River flows with fresh water from the highlands of West Virginia downstream to Washington, DC where it mixes with brackish saltwater and continues on to the Chesapeake Bay, the largest estuary in the world. The Potomac experiences daily low and high tides as far upstream as Washington, DC.

One such effort is underway in Washington, DC where tunnels are being constructed underneath the city’s rivers to divert excess rainwater and reduce sewer overflows into local streams. As part of the $2.7 billion Clean Rivers Project, DC Water has built a 5-mile long tunnel under the Anacostia River with plans to start building another one under the Potomac River in 2023. The plan also includes investments in tree plantings, rain gardens, and other types of nature-based infrastructure.

Living shorelines are a type of nature-based infrastructure that incorporates indigenous vegetation, either alone or in combination with harder materials for structure and stabilization. They restore ecosystems that naturally withstand and recover from the flooding that has become more common because of rising seas, stronger storms and heavier precipitation. Further, living shorelines build habitats that sequester, or store, carbon. According to NOAA, “one square mile of saltwater marsh stores the carbon equivalent of 76,000 gallons of gas annually.

Extreme heat conditions are defined as weather that is much hotter than average for a particular time and place—and sometimes more humid, too.

The heat index is a measure of how hot it feels when relative humidity is factored in with the actual air temperature. Relative humidity is the percentage of moisture in the air compared with the maximum amount of moisture the air can hold. Humidity is an important factor in how hot it feels because when humidity is high, water doesn’t evaporate as easily, so it’s harder for your body to cool off by sweating.

Ozone (O3) is a highly reactive gas composed of three oxygen atoms. It is both a natural and a man-made product that occurs in the Earth's upper atmosphere

(the stratosphere) and lower atmosphere (the troposphere).  Depending on where it is in the atmosphere, ozone affects life on Earth in either good or bad ways.

Stratospheric ozone is formed naturally through the interaction of solar ultraviolet (UV) radiation with molecular oxygen (O2).  The "ozone layer," approximately 6 through 30 miles above the Earth's surface, reduces the amount of harmful UV radiation reaching the Earth's surface.

Tropospheric or ground-level ozone – what we breathe – is formed primarily from photochemical reactions between two major classes of air pollutants, volatile organic compounds (VOC) and nitrogen oxides (NOx).  These reactions have traditionally been viewed as depending upon the presence of heat and sunlight, resulting in higher ambient ozone concentrations in summer months.

Ground level ozone is a secondary byproduct of a chemical relation between human-made nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. Humans are producing an extra 24 million tons of NOX annually through combustion processes from vehicles, power plants, cement factories (which are located adjacent to many communities of color in the Potomac River region), and other industry.

Nutrients—primarily nitrogen and phosphorus—are essential for the growth of all living organisms in aquatic ecosystems. However, excessive nitrogen and phosphorus degrade water quality.

Both nitrogen and phosphorus feed algal blooms that block sunlight to underwater grasses and suck up life supporting oxygen when they die and decompose. These resulting "dead zones" of low or no oxygen can stress and even kill fish and shellfish. Algal blooms can also trigger spikes in pH levels, stressing fish, and create conditions that spur the growth of parasites.

The incubation period is the number of days between when you're infected with something and when you might see symptoms. Health care professionals and government officials use this number to decide how long people need to stay away from others during an outbreak.

Coal ash, also referred to as coal combustion residuals or CCRs, is produced primarily from the burning of coal in coal-fired power plants. 

Coal ash contains contaminants like mercury, cadmium and arsenic. Without proper management, these contaminants can pollute waterways, ground water, drinking water, and the air.

A Superfund site is an abandoned toxic waste site (usually that once supported an oil refinery or smelting or mining activities). In response to attention on sites like these in the late 1970s, Congress established the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980.  

CERCLA is informally called Superfund. It allows EPA to clean up contaminated sites. It also forces the parties responsible for the contamination to either perform cleanups or reimburse the government for EPA-led cleanup work.

When there is no viable responsible party, Superfund gives EPA the funds and authority to clean up contaminated sites.

Frontline communities are those that experience “first and worst” the consequences of climate change. These are communities of color and low-income, whose neighborhoods will be increasingly vulnerable as our climate deteriorates.

Adaptive capacity is the ability of a habitat to support its species and ecosystem functioning as the climate changes. Plants and animals respond to changing climate by adapting, shifting their range, or fleeing completely.

Species that reproduce quickly are able to adapt or migrate more readily than slower growing, long-lived. species – like Maryland’s bald cypress that regularly lives up to 600 years.

Agriculture, development, and past logging operations played a large role in the large-scale loss of eastern hemlock throughout the Appalachian region.

Indigenous to East Asia, the fast-spreading hemlock woolly adelgid insect attaches to the soft, woody plant tissue and sucks nutrients from the sap of eastern hemlocks. Once the insect establishes a population on a hemlock, it can kill the tree within four years. Click on the link to read more about the pesky adelgid.

Coldwater streams make up approximately 2,750 miles of Maryland’s freshwater streams, spanning across Allegany, Garrett, Frederick, Carroll, Washington, Montgomery, and Prince George’s counties. In West Virginia, coldwater streams are found chiefly in the eastern panhandle. In Virginia, coldwater streams meander through the mountains and valleys of the Interstate 81 corridor, stretching across Augusta, Rockingham, Shenandoah, Warren, and Frederick counties up through Berkeley County in West Virginia.

Rainbow trout from the western U.S. and brown trout from Europe were introduced to the region in the late 1800s. They have slightly higher temperature tolerances and, once temperatures reach 68°F, they can out-compete indigenous brook trout. Elimination by competition is already occurring in some streams.

Fun fact: Salamanders are ectotherms, meaning they regulate their body temperatures through their environment. They sun themselves on rocks to warm up and cool off in streams or shaded areas.

Salamanders prefer temperatures between 33°F and 60°F. Their metabolism and heart rate slows when temperatures reach 50°F to survive more extreme conditions.

The opportunity to roam for resources is an important need for animals’ adaptive capacity in the fight against environmental changes.

NatureServe based its research on data from a weather station in Rock Creek Park and then used an ensemble of global climate models from the IPCC’s 5th Assessment Report to project near-future climate conditions in the Park.

In slightly salty oligohaline marshlands, salinity ranges from 0.5- 5 parts per thousand (ppt).

Visit Dyke Marsh or Mattawoman Creek to venture through two of our region’s freshwater marshes, areas of the Potomac River with salinity ranging from 0-0.5 parts per thousand (ppt).

According to a 2016 study in PLoS One, this edge might only be pushed up as far as Indian Head by the end of the century due to the region’s topography and the potential for water to spill out cross-sectionally (widening the river), rather than being pushed far upstream (Cadol et al., 2016).

Visit The American Scientist’s “Spring Budburst in a Changing Climate” for more information on how a warming climate is throwing off the timing of spring. The authors use Henry David Thoreau’s 160-year-old field notes to compare the timing of spring activities between then and now.

Roosevelt Island was transformed back into a “real forest” in the 1930s to mimic the natural ecosystems that covered the landscape before settler-colonial interference. Learn how this island has been transformed time and again – including how it was used as a place of refuge by people who were enslaved.

Source: University of Maryland Center for Environmental Science, 2015; Ding & Elmore, 2015.

www.umces.edu

The Maryland Commission on Climate Change, the Department of the Environment’s Scientific and Technical Working Group (STWG).

Source: “Understanding Virginia’s Vulnerability,” 2015

Every community produces polluted runoff – a type of pollution caused when excess rainwater carries toxins, debris, and litter into nearby streams – but the issue is particularly problematic on farmland. In fact, agricultural runoff is the greatest source of pollution to our region’s waterways. Poor land-use practices on farmland pollute streams with excess nutrients from fertilizers, pest treatments, and animal feces.

In 2018, the United States’ agricultural activity alone emitted approximately 698 million metric tons of greenhouse gasses into the atmosphere: 12.3% as carbon dioxide, 36.2% as methane, and 51% as nitrous oxide (U.S. Department of Agriculture, 2020).

Nitrous oxide is 298 times more potent than carbon dioxide over one hundred years, and is produced as microbes in the soil break down fossil-fuel based synthetic fertilizers and manure that hasn’t been aged or composted before being applied to fields.

Best management practices (BMPs) are conservation measures that improve land health and prevent or mitigate pollution through natural means. BMPs are critically important to restoring water quality in the Potomac River region. Potomac Conservancy helps connect area landowners to available resources to implement BMPs on residential properties with a focus on family-owned farms in the headwaters region.

Learn more at www.potomac.org/lands.

TEK refers to the ever-evolving wisdom gained by indigenous and locally rooted peoples over hundreds of years by means of direct contact with their environment. The U.S. Fish and Wildlife Service explains that, “this knowledge is specific to a location and includes the relationships between plants, animals, natural phenomena, landscapes, human beings, and timing of events that are used for lifeways,” like agriculture or hunting and trapping (Rinkevich et al., 2011).

Source (Aman & Pratt, 2014).

Industrial farming that relies on growing expansive fields of one crop – corn, wheat, soy, as examples – planted year after year, drain the soil of essential nutrients and lack the genetic diversity to fight diseases and pests. Consequently, they require the help of artificial additives.

The Lacandon are the last of the Mayans who escaped the Conquistadors’ forced Christianity by hiding in the heart of the jungle. For the last five hundred years, the Lacandon lived very simply and have kept their borders closed to outsiders. Their population consists of about six or seven hundred people now.

Earthaven Ecovillage is a permaculture community outside of Black Mountain, North Carolina that applies Traditional Ecological Knowledge.