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It’s Not Just Pollen: Confronting the Role of Particulate Matter in Asthma

Op-Med is a collection of original articles contributed by Doximity members.

Spring arrives in Virginia with an explosion of life. Flowers bloom, trees blossom, and people statewide flock to porches and patios to emerge from their months-long retreat indoors. Truly, there is no sweeter time to be in the Old Dominion. But the arrival of spring marks the arrival of another issue: pollen. This time of year, we can expect itchy noses, watery eyes, and, most importantly, an increase in asthma attacks. Sadly, due to the effects of climate change, Virginia is slated for its worst allergy season in recent memory this year. With Central Virginia and the Tidewater already considered among the worst places to live for asthma, this year’s pollen burst is getting well-deserved media coverage across the state as physicians prepare for the springtime wave of asthma exacerbations. But it isn’t just pollen that’s to blame for the asthma attacks in our backyard — it’s also fine particulate matter (those particles ranging from 0.1 to 2.5 µm in diameter) produced from industrial activities like mining, natural gas, and more.

Indeed, particulate matter is an equally important driver of asthma outcomes: So-called PM2.5 deposits preferentially in the terminal bronchioles and alveoli, leading to increased inflammation, airway reactivity, and finally bronchospasm. Alarmingly, a 2020 report on air quality showed that the vast majority of Virginia’s cities and counties have annual PM2.5 concentrations at levels above the WHO recommended limit (5g/m3 annually). This is estimated to have contributed to 230,000 annual asthma attacks and 7,000 new cases of asthma in our state alone, with a combined $282 million in health-related costs. Socially vulnerable communities unsurprisingly bore the brunt of these effects, with a 61% increase in PM2.5 attributable all-cause mortality in the most vulnerable census tracts compared to the least vulnerable. 

As clinicians, we are obligated to understand not only the mechanism of disease but also the treatment. As asthma therapies improve at a dizzying pace with the advent of new biologic therapies, we must not forget that sometimes the best approach to healing is to tackle the problem at its root. Below, I describe the main sources of PM2.5 — and the inspiring efforts underway to confront them.

“Clean” Natural Gas is Polluting Our Own Backyards

One of the main sources of PM2.5 is natural gas. And according to the U.S. Energy Information Administration, 54% of Virginia’s energy production in 2022 derived from such gas. In the past decade, Virginia has transitioned away from coal power plants to industry-dubbed “clean” natural gas. This is a less harmful choice, but a harmful one nonetheless: combustion from this gas leads to the formation of hydrocarbons and nitric oxide byproducts that decompose to create fine particulate matter. 

In Virginia, the majority of these natural gas plants are located near the major population centers. However, their emissions easily travel downwind, affecting the air in the rest of the state. Socially vulnerable communities are most likely to face the harmful effects, as historically redlined city districts are considerably more likely to be near industrial power plants. And yet, utility companies continue to push for gas-powered plants. 

Perhaps the highest profile example of this issue comes from Chesterfield County, a large suburb of Richmond. Here Dominion Energy has proposed the development of a natural gas-burning plant that would become the state’s largest “peaker plant,” or site for electricity production during peak hours. One estimate suggests that emissions from this plant would be equivalent to adding 120,000 cars to the road in the Richmond metro area. This means more emissions and more asthma attacks right in our backyard. 

Motor Traffic Emissions Have Important Effects on Asthma Rates

Another critical contributor to PM2.5 is motor vehicle emissions. The combustion of gasoline leads to organic and elemental carbon byproducts as well as nitrogen oxides that can form smaller particles in the atmosphere. In Virginia, vehicle-related PM2.5 concentrations are highest in urban areas and along the major interstate corridors, according to one analysis. However, motorized vehicle combustion is ubiquitous in all but the most remote areas of our state. The same group cited above proposed that this contributes to approximately 2,600 annual asthma exacerbations in our state. 

Over the past several years, there has been a concerted effort among Virginia lawmakers to curb vehicle emissions, especially among the gravest offenders (medium and heavy-duty vehicles). In January, Virginia adopted the California motor vehicle emission standards mandating that all vehicles meet emission standards by 2027 and that all vehicles sold after 2035 be zero-emission vehicles. 

However, the effective level of PM2.5 is additionally influenced by emissions from adjacent states mixing into our atmosphere. Virginia is the only southern state to adopt the vehicle standards listed above. Thus, surrounding states will continue to spread emissions without concerted regional efforts to attack this issue. 

Coal Dust Affects Communities from the Appalachian Mountains to the Atlantic Ocean

Another form of industrial PM2.5, and one of the least publicized, is the spread of coal dust throughout Virginia. Adjacent Kentucky, West Virginia, and Pennsylvania are all among the top five coal-producing states, making Virginia the largest handler of coal exports in the U.S. From neighboring mines, coal is loaded into open-air cars and shuttled through the state to the coast. These open trains deposit coal dust along the way not only in chunks, but as fine particles that irritate airways, leading to lung irritation and asthma attacks. The problem is so pervasive that one railroad official for BNSF Railways conceded that nearly 500 pounds of coal is lost from each train car per trip. 

Disturbingly, the effects of coal dust don’t end when the journey does. As just one example, Lambert’s Point, a historically Black neighborhood in Norfolk, has battled for years against pervasive coal dust from the adjacent Norfolk Southern Coal Export Terminal (the nation’s largest). Here, mountains of coal lie uncovered, waiting to be loaded for transportation. Meanwhile, winds lift and transport minuscule bits of coal into surrounding communities. 

The ubiquity of coal dust, and its resultant health effects, has not gone unnoticed. The Sierra Club recently proposed a rule whereby the Environmental Protection Agency would regulate the dispersal of coal dust by requiring all rail cars transporting coal to be covered. Additionally, the Virginia Department of Environmental Quality is currently studying coal dust distribution in the Tidewater region with the hopes of extending this data to understand the impact on local health outcomes. Clearly, this is a problem that demands to be tackled.

Virginia’s Health Professionals are Becoming Critical to Environmental Advocacy 

As an individual, it can be daunting to consider the scale of the issue. What can one clinician do to combat this billion-dollar industry? The short answer is that we must all work together to unite our expertise, our voice, and the trust our communities have in us to fight the spread of these harmful pollutants in our air. 

Fortunately, there are a number of organizations, such as Virginia Clinicians for Climate Action, that are doing just that. In addition, health professionals can become a key part of our state’s environmental advocacy ecosystem. Advocacy can look like supporting the landmark 2020 Virginia Clean Economy Act, or penning op-eds, as I myself have done, critiquing decisions like Virginia’s withdrawal from the Regional Greenhouse Gas Initiative. 

Though the industry is intimidating, the opportunity for attacking the root of asthma in Virginia is out there. So the next time you find yourself cursing the number of asthma cases in your clinic, remember that we all have the choice to change the status quo. I look forward to fighting alongside you!

How will you join the fight against the root causes of asthma? Share in the comments! 

Dr. Matthew Scott is a third-year internal medicine-pediatrics resident in Richmond, VA. He is passionate about advocacy, engaging with his community, and his newborn daughter. Dr. Scott is a 2023–2024 Doximity Op-Med Fellow.

Image by Feodora Chiosea / Getty Images

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