Air Pollution: Covid's Impact On Our Atmosphere

The COVID-19 pandemic has had a significant impact on various aspects of human life, and air pollution is no exception. While the pandemic led to a temporary reduction in pollution levels due to decreased human activity, the long-term effects of the virus on air quality are more complex. The pandemic has highlighted the vulnerability of specific groups, such as those living in industrial areas or from minority backgrounds, to the combined effects of air pollution and COVID-19. Furthermore, the pandemic has also influenced policy decisions and public awareness regarding air pollution and its health implications.

COVID-19 and air pollution: Wildfires and respiratory-tract infections

Air pollution is a well-known environmental health hazard, and it has been linked to a range of respiratory issues, including asthma, chronic bronchitis, and other respiratory diseases. The COVID-19 pandemic has brought a unique set of challenges regarding air pollution and its impact on human health, especially when considering the confluence of the pandemic and wildfires in the western United States in 2020.

COVID-19, Wildfires, and Air Pollution

During the COVID-19 pandemic, the focus on air quality and its impact on respiratory health became even more critical. Wildfires, a significant source of air pollution, often cause smoke and ash to be released into the atmosphere, which can have detrimental effects on human health. The COVID-19 pandemic and the western US wildfires of 2020 created a "perfect storm" of respiratory hazards, with a study linking exposure to wildfire smoke to more severe cases of COVID-19 and deaths.

The US Environmental Protection Agency (EPA) has recommended strategies to mitigate the impact of indoor airborne transmission of COVID-19, including the use of evaporative coolers and whole-house fans to increase ventilation. However, it is crucial to avoid using these devices when outdoor air pollution is high, especially in areas affected by wildfires, to prevent further health risks.

COVID-19, Respiratory Tract Infections, and Air Pollution

The COVID-19 pandemic has also had an interesting impact on the prevalence of other respiratory viruses. Studies in China, for example, observed a significant reduction in respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus A and B (FluA and FluB), and human metapneumovirus (MPV) infections during the pandemic compared to pre-pandemic years. However, there was an increase in rhinovirus (RV) infections, especially after the reopening of schools.

The multifaceted non-pharmaceutical interventions (NPIs) implemented during the pandemic, such as social distancing and lockdowns, likely contributed to the decrease in the spread of these respiratory viruses. However, as restrictions ease, a resurgence of these viruses is possible, and ongoing monitoring is necessary to prepare for potential outbreaks.

In conclusion, the COVID-19 pandemic has highlighted the critical interplay between air pollution, wildfires, and respiratory health. The pandemic, coupled with the western US wildfires, likely exacerbated the respiratory health of many, especially those already vulnerable to the effects of air pollution. Additionally, the pandemic's impact on the prevalence of other respiratory viruses underscores the complex dynamics between infectious diseases and public health interventions.

Air pollution and neurological disorders: Parkinson's, Alzheimer's, and dementias

Air pollution has been linked to a higher chance of developing neurological disorders, including Parkinson's disease, Alzheimer's disease, and other dementias. Hospital admissions data from 63 million older US adults, collected over 17 years (2000-2016), was analysed along with estimated PM2.5 concentrations. The results indicated a correlation between air pollution and neurological disorders.

Parkinson's Disease

An abstract from Neurology Today mentions that air pollution may increase the risk of Parkinson's disease. This is supported by a study with data from 10-year long exposures that found a relationship between CO, PM2.5, and an increased likelihood of developing Parkinson's disease.

Alzheimer's Disease

While there is no direct mention of a link between air pollution and Alzheimer's disease, a new biomarker has been discovered that can track cognitive decline in Alzheimer's disease.

Dementias

Several studies have found a link between air pollution and dementia. An NIH-funded study led by Drs Boya Zhang and Sara Adar from the University of Michigan examined the links between different types of PM2.5 air pollution and dementia. They analysed data from over 27,000 adults aged 50 and older, collected between 1992 and 2016. The study found that 15% of participants developed dementia during the follow-up period, and those who did were more likely to be non-White, have less formal education, less wealth, and live in places with higher levels of PM2.5. Overall, higher PM2.5 exposure was linked to an increased risk of dementia, specifically from PM2.5 produced by agriculture and wildfires.

Another study, with data from 63 million older US adults, also found a correlation between PM2.5 concentrations and dementia.

These studies add to a growing body of evidence that air pollution can have effects beyond the lungs, impacting the body and brain in ways that are still being understood.

While the COVID-19 pandemic caused a decrease in air pollution levels due to reduced human activity, the subsequent increase in wildfires across the western US in 2020 led to a confluence of air pollution and respiratory-tract infections. A study linked exposure to wildfire smoke with more severe cases of COVID-19 and deaths. As such, the overall impact of the pandemic on air pollution and its related health effects is complex and still being understood.

Air pollution and noncommunicable diseases (NCDs): respiratory, cardiovascular, and more

Air pollution has been identified as a significant risk factor for noncommunicable diseases (NCDs), impacting not only the respiratory and cardiovascular systems but also other organs and biological systems.

Respiratory Diseases

Air pollution can affect lung development and is linked to various respiratory diseases, including emphysema, asthma, and chronic obstructive pulmonary disease (COPD). Urbanization and outdoor air pollution are associated with increased asthma prevalence and severity, particularly in children from low-income urban areas. Research has also linked specific air pollutants, such as ozone and PM2.5, to asthma-related changes in children's airways. Additionally, long-term exposure to PM2.5, PM10, and nitrogen dioxide has been associated with chronic bronchitis in women. Furthermore, exposure to wildfire smoke has been connected to more severe cases of COVID-19 and deaths, building upon the established link between air pollution and respiratory tract infections.

Cardiovascular Diseases

Short-term exposure to higher levels of outdoor air pollution has been associated with cardiac problems. Air pollution exposure is linked to oxidative stress and inflammation in human cells, which can contribute to the development of chronic diseases and cardiovascular issues.

Neurological Disorders

Air pollution has also been associated with an increased risk of developing neurological disorders, including Parkinson's disease, Alzheimer's disease, and other forms of dementia. Studies have found a relationship between exposure to air pollutants, specifically CO and PM2.5, and a higher likelihood of developing Parkinson's disease.

Other Health Effects

Air pollution has been linked to bone damage, particularly in postmenopausal women, and an increased risk of osteoporosis. Additionally, air pollution affects almost every organ in the body and increases the risk of various health problems, including lung cancer, heart disease, strokes, and cognitive development issues in children.

Air pollution and environmental regulations: EPA deregulation and climate change

Air pollution is a significant environmental health hazard, affecting lung development and implicated in the development of emphysema, asthma, and other respiratory diseases. It also impacts many other organs and systems, including the cardiovascular system, and has been linked to an increased chance of developing several neurological disorders.

In March 2025, the US Environmental Protection Agency (EPA) announced the biggest deregulatory action in its history. Administrator Lee Zeldin stated that the EPA would undertake 31 actions to advance former President Trump's executive orders. These actions included reconsidering the Biden-Harris electric vehicle mandate, the Biden administration's Risk Management Program rule, and the 2009 Endangerment Finding. Zeldin argued that these rollbacks would not negatively impact health or the environment but would reduce the cost of living for Americans.

However, experts disagree, stating that the impacts of climate change on human health and the environment are already evident, and that upending the 2009 Clean Air Act would be detrimental. The 2009 Clean Air Act determined that planet-warming greenhouse gases endanger public health and welfare and has been central to the fight against climate change. The EPA's deregulatory actions also included reconsidering the Mercury and Air Toxics Standards, which targeted coal-fired power plants, and the mandatory Greenhouse Gas Reporting Program.

In May 2025, the Senate voted to overturn an EPA rule that limited seven hazardous air pollutants, marking the first time in the Clean Air Act's 55-year history that Congress has weakened this environmental law. This rule required industrial facilities, such as chemical plants and oil refineries, to maintain strict pollution controls. The Trump Administration had attempted to revoke this rule during his first term, but it was finalized under the Biden administration. Despite opposition from environmental advocacy groups, Republican lawmakers have continued to push for its revocation, arguing that it disincentivizes companies from adopting new technologies to reduce pollution.

Air pollution and COVID-19 death rates: Harvard study and Louisiana's industrial corridor

Air pollution has been linked to a wide range of adverse health effects, including respiratory and cardiovascular issues, neurological disorders, and even bone damage. The COVID-19 pandemic has brought a new dimension to the impact of air pollution on human health.

A recent Harvard study found a correlation between long-term exposure to air pollution and higher COVID-19 death rates. This study, focusing on fine particulate pollution (PM 2.5), revealed that small increases in exposure can lead to large increases in the risk of death from COVID-19. The findings underscore the intuition that air pollution damages our lungs, making it more difficult to withstand the virus's attack.

Louisiana's industrial corridor, from Baton Rouge to New Orleans, presents a stark illustration of this link. Here, communities face both high levels of air pollution and some of the worst COVID-19 death rates in the country. Kimberly Terrell from the Tulane Environmental Law Clinic delved deeper into the data, confirming that the parishes with the highest per capita COVID-19 death rates in Louisiana coincide with areas of elevated long-term PM 2.5 levels.

The situation in St. John the Baptist Parish and its neighboring communities is particularly concerning. Reserve and LaPlace, both within the industrial corridor, are pollution hotspots, and St. John has one of the highest COVID-19 death rates in the nation. The adjacent St. James Parish shares a similar story, with residents facing a disproportionate impact of the virus and the burden of air pollution.

The interplay between air pollution and COVID-19 death rates in Louisiana highlights the urgent need to address air quality issues. While regulations like the Clean Air Act have improved air quality since the 1970s, air pollution continues to plague many communities, disproportionately affecting people of color and low-income areas. The health implications are dire, and the COVID-19 pandemic has only served to exacerbate the problem.

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