As wildfires rage more frequently, the makeup of the air we breathe is shifting — bringing new and poorly understood risks. Particulate matter (PM) pollution, long associated with vehicles and industrial activity, is increasingly coming from sources that are harder to control. One study shows that wildfire smoke may be 10 times more harmful than other types of pollution sources, especially in the case of children.[1] Another toxicological study suggests that wildfire smoke particles may be more harmful than equivalent amounts of typical ambient PM2.5.[2] This raises a crucial question: how should we compare wildfire smoke with top air pollutants such as cigarette smoke and car emissions, and what does that mean for our health?

PM Emission Factor

A key tool scientists use to compare air pollution sources is the particulate matter (PM) emission factor — a metric that quantifies how much PM is released per unit of fuel burned. It’s widely used to model air quality, predict exposure, and estimate health impacts. In particular, it enables side-by-side comparisons between sources like wildfires, cigarettes, and vehicles — and the results might surprise you.

A PM emission factor (EF) measures how much particulate matter is released for every kilogram of fuel burned — whether that fuel is wood, tobacco, or gasoline. Expressed in grams per kilogram (g/kg),[3] it’s a helpful way to quantify and compare the pollution footprint of activities like driving a car, smoking a cigarette, or the large-scale combustion of a wildfire.

By translating pollution into comparable numbers, PM emission factors make the invisible visible. Whether it’s a smoldering forest or an idling truck, this metric helps clarify what’s more polluting in the air we breathe.

How Wildfires, Cigarettes, and Cars Stack Up

Now that we’ve defined what a PM emission factor is, we can use it to put wildly different sources of pollution — like wildfires, cigarettes, and vehicle exhaust — on equal footing. The differences in emissions per kilogram of fuel are striking, and they offer a new perspective on which sources are dirtiest.

It might be shocking to see that a single cigarette produces ~150–300X more PM than a gasoline car, per unit of fuel burned. And wildfires? They can produce ~200–400X more–and there’s no catalytic converter or filter tip to stop it.

CO-based PM Normalization

The raw emission factors already tell a compelling story — but we can take the comparison a step further by normalizing particulate matter to carbon monoxide (CO), a byproduct of incomplete combustion. This PM₂.₅-to-CO ratio helps account for factors like fire size, fuel type, or engine load, making it easier to compare how “particle-rich” different sources are.

In a 2022 study published in Atmospheric Chemistry and Physics, scientists found that wildfires emit 15–19 times more PM₂.₅ per unit of CO than motor vehicles.[4] In other words, for every gram of CO released, wildfire smoke carries far more particulate pollution — suggesting greater potential for toxicity and health risks.

Not Just More PM — Worse PM

Emission factors help quantify how much PM pollution is released — but that’s only part of the story. Wildfire smoke isn’t just higher in PM; it’s composed of especially hazardous particles. Increasingly, research shows that wildfire smoke is more toxic than other pollution sources for several reasons:

• Particle size: Wildfire smoke is dominated by super-fine particles (predominantly 0.1–0.3 μm), small enough to penetrate deep into the lungs and enter the bloodstream.
• Chemical reactivity: These particles are chemically reactive and can carry toxic or carcinogenic compounds.
• Persistence and spread: Smoke lingers in the atmosphere, travels vast distances, and penetrates indoor spaces.
• Widespread exposure: Unlike cigarette smoke, which primarily affects the smoker and nearby individuals, wildfire smoke can impact entire regions — especially vulnerable groups like children, the elderly, and those with respiratory or cardiovascular conditions.

At first glance, cigarette smoke and wildfire smoke may seem comparable — both contain fine particles and harmful chemicals. But their sources and exposure patterns differ dramatically. Cigarette smoke largely comes from a single, well-characterized source: burning tobacco. Wildfire smoke, by contrast, arises from complex fuel mixtures — wood, grass, and even plastics, electronics, and construction materials — especially in wildland-urban interface (WUI) fires. This makes its toxicology far more complex and more harmful.

The health risks speak for themselves. Wildfire smoke has been linked to:

• Heart attacks and strokes
• Asthma flare-ups
• Cancer and neurological effects
• Cognitive decline and dementia
• Premature death

What Can Be Done?

By combining emission factors with knowledge of particle composition and size, researchers can better assess real-world health risks — and identify interventions such as filtration or public health guidance.

• Mitigate wildfires and risks through better land use, policies, and technology implementation.
• Improve indoor air quality with effective filtration, especially during wildfire season.
• Enforce and update emissions standards for all sources.

Final Thoughts

Whether it’s the tailpipe of a diesel truck, the tip of a cigarette, or a blazing forest, combustion sends PM into the air, harming human health. Wildfire smoke, in particular, is changing the game: it’s more widespread, more dangerous, and harder to control. Emission factors shed light on why — helping quantify how much more particulate matter wildfires produce compared to other sources. But they do more than measure the problem. In a changing world, they remind us that protecting clean air will require smarter tools, appropriate interventions, and renewed urgency.

References

1. Aguilera, R. et al. “Fine Particles in Wildfire Smoke and Pediatric Respiratory Health in California” Pediatrics (2021). https://publications.aap.org/pediatrics/article-abstract/147/4/e2020027128/180791/Fine-Particles-in-Wildfire-Smoke-and-Pediatric
2. Aguilera, R., Corringham, T., Gershunov, A. et al. “Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California.” Nature Communications 12, 1493 (2021). https://doi.org/10.1038/s41467-021-21708-0
3. Urbanski, S.P., O’Neill, S.M., Holder, A.L., Green, S.A., Graw, R.L. Emissions. In: Peterson, D.L., McCaffrey, S.M., Patel-Weynand, T. (eds) Wildland Fire Smoke in the United States. Springer, Cham. (2022). https://doi.org/10.1007/978-3-030-87045-4_5
4. Jaffe, D. A., Schnieder, B., and Inouye, D.: Technical note: Use of PM2.5 to CO ratio as an indicator of wildfire smoke in urban areas, Atmos. Chem. Phys., 22, 12695–12704 (2022). https://doi.org/10.5194/acp-22-12695-2022,

The post What Pollutes More? Wildfires, Cigarettes, or Cars appeared first on Metalmark.

Smart Air Cleaning Deployment: Chariho Middle School piloted Tatama air cleaners and sensors that operate independently of HVAC.

Pilot Findings: Tatama reduced fine particles and VOCs with potential energy savings of as much as 57% per classroom.

Background
Chariho Regional School District, which serves approximately 3,000 students across the towns of Charlestown, Richmond, and Hopkinton in southern Rhode Island, is nationally recognized as a Green Ribbon School District for its commitment to sustainability. To address indoor air quality (IAQ) challenges and improve energy efficiency, the district partnered with Metalmark Innovations to pilot the Tatama ceiling-mounted air cleaning system, designed to maintain or improve IAQ while reducing HVAC energy consumption.

Challenge
K–12 schools must improve air quality while reducing energy use—a challenge as outdoor air becomes less reliable and concerns about airborne disease transmission persist. Traditional HVAC systems rely on outdoor ventilation, which is:

• Energy-intensive: Drives up to 50% of HVAC load
• Poor at filtration: Misses some key pollutants
• Thermal comfort first, not clean air: HVAC airflow can work against pollutant removal

Schools need efficient indoor air solutions that don’t depend on high ventilation or major retrofits.

Solution
Metalmark Innovations deployed Tatama units and sensors at Chariho Middle School in Rhode Island.

Goal: Validate whether or not smart, localized, low-touch air cleaning could improve IAQ and reduce HVAC ventilation load—leading to measurable energy savings.

Results
Cleaner Air, Fast

• Up to 34% reduction in sub-0.5 µm particles in just 5 minutes.
• Up to 5X more effective than ventilation alone for particulate matter ( PM₁.₀ and PM₂.₅).
• Targets the size range of respiratory aerosols of diseases (e.g., COVID-19, flu, measles).
• Tatama significantly reduced volatile organic compound (VOC) levels, independent of other factors.

Opportunity for Major Energy Savings

Tatama’s air quality improvements create an opportunity to reduce outdoor air ventilation. Modeling shows that reducing ventilation rate from 25% to 10% could lower heating energy use by up to 57% per classroom:

• Annual savings: Up to 13 MMBTUs and 990 kg CO₂-eq
• Minimal Tatama energy use: ~211 kWh per year

Customer Feedback

“ It’s quiet. Our air cleaner is up inside the ceiling so we don’t notice any noise. ”

“ The air purifier that was in my classroom from last year is bulky and big. I didn’t even realize the Metalmark was in my room. ”

“ I did not have any respiratory illness this year. ”

“ The people from the company that came to check the cleaner were always very nice and pleasant. They were also very informative and helpful. ”

The post CASE STUDY: Cleaner Air and Lower Energy Use in Rhode Island Schools appeared first on Metalmark.

We’ve got mitochondria hacks, NAD boosters, senolytic stacks, hyperbaric chambers, and $2,000-a-month biohacking protocols — and still, most of us are breathing air that’s killing brain cells faster than our anti-aging regimens can save them.

While the biotech world races to slow cellular decay, wildfire smoke and super-fine pollution particles are making us foggier and sicker. The irony? Many of the world’s most optimized humans are running on dirty air.

We talk about “don’t die” as a bold ambition — a mantra popularized by anti-aging entrepreneur Bryan Johnson. But if longevity is the goal, then clean air isn’t optional — it’s infrastructure. And the healthspan revolution needs to start inhaling like it means it.

The Air Problem No One in Longevity Tech Wants to Talk About

Thanks to climate change, wildfire smoke has become a dominant source of fine particle pollution (PM₂.₅) across much of North America — not just in the West. NOAA’s smoke day maps show how these events now blanket major population centers from New York to Chicago to Atlanta, turning regional events into nationwide exposure risks. But most of the particles in that smoke are smaller and super-fine: between 0.1 and 0.3 microns. That’s the same range that slips through your typical filters, including some HEPA ones, evades indoor air sensors, and is capable of crossing the blood-brain barrier.

These particles aren’t just respiratory irritants. They’re neuroinflammatory. They’re chemically reactive. They accelerate cognitive decline and elevate dementia risk. And they’re increasingly present in the indoor air we breathe, even in our techiest wellness fortresses.

The Mismatch Between Anti-Aging and Air

Longevity influencers talk about sleep staging, mitochondrial efficiency, and blood plasma exchange. But very few are investing in or talking about their air. That’s a blind spot — because even the most finely tuned body is still breathing 22,000 times a day.

And the science is catching up: researchers have linked even short-term PM exposure to changes in cognition, inflammation, reaction time, and performance. That’s not a long arc toward disease. That’s your focus during your next meeting.

Rethinking What We Measure — and What We Design For

Our current air quality metrics — like PM₂.₅ mass concentration — are 20th-century tools trying to address a 21st-century problem. Particle count, size distribution, chemical reactivity, and biologically relevant exposure are what we need to track and study.

And we need to design systems for performance: air that supports mental clarity, immune readiness, and metabolic stability. That means technologies capable of removing particles in the submicron range without creating harm, filters that regenerate instead of clogging, and smart systems that adapt to real-time indoor conditions — especially during smoke events — and sensors and data systems that actually reflect the particles and exposures that matter most indoors. Otherwise, all our longevity gains will be undermined by the simplest, most frequent input we take for granted.

The bottom line: clean air is a prerequisite for living long — and living well.

The post We’re Chasing “Radical Longevity” — While Breathing Like It’s 1950 appeared first on Metalmark.

The latest cover story of the Cardiology Magazine by the American College of Cardiology explores the complex and evolving understanding of how wildfire smoke and extreme temperatures affect cardiovascular health. Long-term, cumulative exposure to smoke has been linked to increased mortality rates and chronic diseases. Similarly, short-term exposure — such as during a wildfire event — has been associated with spikes in emergency room visits for cardiovascular conditions and increased mortality risks. However, these short-term outcomes were not consistently observed across wildfire events in the cited study. Even the long-term associations between particulate matter from smoke and mortality are not always clear-cut. Taken together, these mixed findings raise important questions about how reliably we can assess the health risks of smoke exposure.

This discussion reminded me of a paper led by Dr. Yaguang Wei at the Harvard T.H. Chan School of Public Health, which caught my attention when it was published in 2023. The researchers found that exposure to PM2.5 and NO2 was associated with increased risks for certain types of cancers. Of real interest to me was that the study also pointed to a negative relationship between PM2.5 levels and at least one type of cancer. Even more puzzling, the researchers noted that “at exposure levels below the newly updated World Health Organization Air Quality Guideline, we observed substantially larger associations between most exposures and the risks of all cancers.”

These are merely two examples.

Why the Unexpected Results?

The smoke study authors suggest that increased public awareness and protective behaviors — such as mask usage and staying indoors — may have helped reduce exposure and therefore risks during one fire event. They hypothesize that these behaviors, along with contextual factors like public health advisories and school closures, could help explain the differing health outcomes between the fire events studied. Another proposed explanation is the “depletion of the susceptibles” effect: individuals most at risk may have already experienced outcomes during the earlier fire, reducing the likelihood of similar outcomes during a subsequent exposure. These factors could certainly help explain some of the variations observed — though school closures, for example, seem unlikely to directly reduce cardiovascular risk.

Still, could there be other explanations? Here’s a theory worth pondering:

1. Commercial particulate matter (PM) sensors, frequently employed in epidemiological research, generally fail to detect particles smaller than 0.3 microns (PM0.3). Meanwhile, these particles are abundant in wildfire smoke and other critical pollutants.
2. Although prevalent, these tiny particles typically contribute minimally to standard PM2.5 mass measurements (μg/m³).

These measurement gaps may be distorting the data — potentially contributing to the inconsistent results observed across studies. In my recent article for International Filtration News, “The 0.3-Micron Blind Spot in IAQ: Far-Reaching Implications for Airborne Pathogen Transmission and Climate Adaptation,” I raised concerns about the health significance of PM0.3. These super-fine particles often go undetected by standard sensors, yet they can penetrate deeply into the respiratory system, posing risks that may be underestimated or entirely missed due to current measurement limitations.

Facing the Unknown with Better Awareness

The immediate solution doesn’t rest on technological advancement — although developing improved sensor technology remains essential. More urgently, widespread education on current sensor limitations can make a significant difference. Increasing awareness of these gaps empowers public health officials, researchers, and communities to better interpret air quality data and effectively address the implications for public health, especially in wildfire-prone regions.

Key Takeaways

• Wildfire smoke can significantly impact cardiovascular health, though some findings have been inconsistent.
• Limitations in PM sensor technology may be contributing to these conflicting findings.
• Education about these limitations is essential for informed public health action.

Recognizing the limitations of how we currently measure air pollution is essential — not just for refining future research, but for improving the public’s ability to interpret and act on air quality information today. This isn’t about claiming to have the answers — but rather about acknowledging a critical gap that deserves closer scrutiny. I hope researchers and academics will take this challenge seriously, and explore whether the limitations in our sensing methods might be contributing to the conflicting health data we continue to see. With better awareness and communication, we can bridge the gap between data and action to better protect public health.

The post What If Our Air Quality Data Is Missing the Most Harmful Particles? appeared first on Metalmark.

For years, our understanding of air quality has revolved around broad categories of particulate matter (PM): coarse particles (PM₁₀), fine particles (PM_2.5), and ultrafine particles (PM_0.1). However, within this framework lies a critical oversight — the 0.3-micron gap. This largely unrecognized size range is at the heart of three major blind spots affecting air quality monitoring, airborne disease transmission, and climate adaptation in today’s world.

The Overlooked Tiny Particles with Big Consequences

Traditional air quality metrics assume that PM_2.5 primarily consists of particles between 1 and 2.5 microns, but real-world measurements tell a different story. In indoor environments, the actual size distribution of airborne particles skews heavily toward much smaller sizes — often below 0.3 microns.

Yet, despite their predominance, these tiny particles remain largely undetected by commercial air quality sensors and are inadequately filtered by most HVAC systems. This would be of little concern if this gap didn’t have real-world consequences, especially as we contend with the twin threats of airborne infectious diseases and worsening wildfire smoke exposure.

The Relevance of <0.3 Micron Particles for Pathogen Transmission

Recent studies have demonstrated that infectious aerosols exist in a broad range of particle sizes, including concentrations below 0.3 microns. Pathogens such as SARS-CoV-2, influenza, and other respiratory viruses have been detected in these super fine particles, which can remain suspended in the air for extended periods, increasing the risks of airborne transmission. Unlike larger droplets that settle quickly, these tiny particles can be inhaled deeply into the respiratory system, reaching the alveoli where they may cause infection.

Simultaneously, scientific studies have shown that exhaled breath aerosols contain multimodal particle distributions, with a significant fraction in the 0.08–0.3 micron range. These particles can carry viable viruses and are small enough to evade gravitational settling, increasing the potential for long-range airborne transmission. Research has also detected substantial amounts of SARS-CoV-2 RNA, for example, in particles smaller than 0.3 microns, reinforcing the concern that current air filtration and sensor technologies may be missing a critical vector of disease spread. The failure to account for these particle sizes in air quality monitoring and filtration leaves schools, hospitals, and workplaces vulnerable to outbreaks of airborne diseases.

The Relevance of <0.3 Micron Particles for Wildfire Smoke

Wildfire smoke is one of the most pervasive sources of sub-0.3 micron particles, capable of traveling thousands of miles and infiltrating indoor spaces. These super fine particles pose significant health risks, as they can penetrate deep into the lungs and enter the bloodstream, causing inflammations, and exacerbating respiratory and cardiovascular conditions. Meanwhile, standard air quality sensors are simply blind to particles in this size range, leading to potential underestimation of indoor smoke exposure. Additionally, conventional air filters, including many used in HVAC systems, struggle to capture these particles effectively, leaving indoor environments vulnerable to smoke infiltration during wildfire events.

Blind Spot #1: Measurement Limitations

Due to the physical limitations of the baseline technology, most commercial air quality sensors and even industrial PM detectors cannot “see” particles smaller than 0.3 microns. These limitations unfortunately cannot be easily overcome by data, AI, or software. This means that despite their widespread use, these sensors could be providing a misleading picture of indoor air quality. During one of our recent school-based air quality studies, high-resolution scientific instruments detected a dominance of sub-0.3 micron particles in the presence of students and staff. In the meantime, commercial sensors reported “healthy” air (consistent PM_2.5 <5 µg/m3), unable to account for implications of occupancy concentration and risks of superfine particles.

This oversight has implications: when sensors fail to represent highly relevant particles for airborne disease transmission or pollution exposure, researchers and decision-makers are left with incomplete data that could lead to incorrect conclusions. The result? A false sense of security about indoor air quality.

Blind Spot #2: Filtration Efficiency at Its Weakest

Air filters used in commercial buildings, including schools and hospitals, are least effective at capturing particles in the 0.1–0.3 micron range. This size range happens to be where some of the most concerning airborne threats — such as viruses and wildfire smoke — are concentrated.

Most HVAC systems rely on MERV-rated filters, which are tested for their ability to capture particles 0.3 microns and larger. However, this means there is no standard measure of how well these filters capture smaller particles. Even widely recommended MERV 13 filters may not be sufficient for mitigating the associated risks. Without better filtration technology, many buildings remain vulnerable to poor air quality.

Blind Spot #3: The Testing Gap for Super Fine, Organic Aerosols

While air filters are tested per standards using inorganic particles such as salt aerosols with sizes >0.3 µm, real-world pollutants have very different composition and size distribution. Wildfire smoke, for example, is composed of over 90% organic matter, which behaves differently from inorganic salts. In turn, they can quickly degrade filter performance. This means that even filters that perform well in standardized tests may be significantly less effective when exposed to actual environmental conditions. Without updated testing protocols that better reflect these real-world challenges, our current filters may be offering far less protection than presumed.

Why This Matters More Than Ever

As airborne diseases continue to challenge public health and wildfires become more frequent, these overlooked particles pose an increasing threat. Even in schools, hospitals, and workplaces that have air quality sensors and advanced filtration systems, these technologies may not be providing the level of protection people assume and need. To bridge this gap, we should be demanding:

• Better Air Quality Sensors: Commercial sensors must be improved to detect sub-0.3 micron particles, ensuring that public health and facility management decisions are based on more representative data.
• Stronger Filtration Standards: MERV ratings should include efficiency metrics for particles below 0.3 microns and consider real-world organic aerosols.
• More Research & Revised Public Health Guidelines: More research is necessary to address gaps in understanding the 0.1–0.3 micron particle size range and their associated health risks. This consideration should also be included by researchers and standard makers, and regulators.

The Path Forward

The 0.3-micron blind spot represents a critical gap in our approach to air quality, health, and climate adaptation. Without addressing it, we risk underestimating exposure to harmful airborne pollutants and pathogens, leaving communities vulnerable. By advancing detection technologies, improving filtration standards, and refining public health strategies, we can build a more resilient and health-conscious approach to air quality in the 21st century.

It’s time to stop overlooking what we can’t easily see.

Sources:
https://issuu.com/indamedia/docs/international_filtration_news_issue_2f9d5cd56618cf/s/71091993
https://www.mdpi.com/2073-4433/14/12/1729

The post The 0.3-Micron Blind Spot: The Hidden Gaps in Air Quality, Virus Transmission, and Climate Resilience appeared first on Metalmark.

I normally wouldn’t write about this, but a recent note from an industry insider made me realize it’s worth explaining why this is significant. Metalmark’s Everglades(TM) filter, already rated MERV 13, has now been independently tested and confirmed as MERV 11A — a key validation of its long-term performance.

That might sound like just another technical certification, but in the world of air filtration, it carries real weight — especially as air quality regulations tighten and building standards evolve.

What Does MERV 11A Mean?

Many people are familiar with MERV (Minimum Efficiency Reporting Value) ratings, which measure how well a filter captures airborne particles of varying sizes. A higher MERV rating generally means better particle filtration, with MERV 13 capable of capturing fine particulate matter, including allergens, bacteria, and wildfire smoke.

However, standard MERV ratings don’t always tell the full story. Many filters perform well in initial lab tests but degrade significantly once they’re exposed to real-world conditions — dust, humidity, and continuous use. That’s where MERV-A testing, part of ASHRAE 52.2 Appendix J, comes in.

ASHRAE 52.2 is the industry standard for measuring filter performance, and Appendix J introduces a more rigorous testing process that accounts for efficiency loss over time. Filters that achieve a MERV-A rating (such as 11A) have demonstrated their ability to maintain efficiency even after prolonged exposure to airborne contaminants, ensuring reliable, long-term performance.

Why This Matters

For buildings prioritizing indoor air quality — whether schools, healthcare facilities, commercial offices, or homes — having a filter that holds up over time is critical.

The Everglades filter is not only MERV 13 for excellent filtration but also verified as MERV 11A, meaning it provides consistent, reliable performance over its lifespan. This distinction is increasingly important as industry standards evolve to address long-term air quality challenges.

Notably, ASHRAE Standard 241, which focuses on controlling airborne infectious aerosols, now requires a minimum MERV-A 11 rating for filters used in infection risk management strategies. This reinforces the importance of filters that maintain efficiency over time, rather than those that lose effectiveness as they accumulate contaminants.

Everglades not only meets but exceeds this threshold, making it a future-ready solution for buildings aiming to comply with emerging air quality standards. Being the only filter with enhanced filtration for wildfire smoke with low energy use and only a handful of commercially available MERV-A rated filters on the market, Everglades is setting a new standard for durable, high-efficiency air filtration.

Setting a New Standard

As concerns over indoor air quality, airborne pathogens, and environmental pollutants grow, filters that maintain performance over time will be essential for meeting new industry requirements. So, this is indeed more than just another certification — it’s validation that Everglades is built to perform when it matters most.

The post Why Metalmark’s Everglades Filter Being Rated MERV 11A Matters appeared first on Metalmark.

ASHRAE recognized the challenge with their new Standard 241, which advocates for the use of air cleaners, like Metalmark Tatama, in combination with outdoor air ventilation for meeting indoor air quality targets and controlling the spread of infectious aerosols. 

Contact Metalmark to Learn More About Tatama

The limitations of ventilation were also made obvious over the summer with the wildfire smoke cloud that brought unprecedented air pollution to a large swath of the U.S. – areas that were hundreds and even thousands of miles from the fires themselves. The threat is forecast to continue throughout the year and the coming annual wildfire seasons. This is the new normal. 

Yet another barrier to ventilation is that day-to-day outdoor air in urban areas is often unhealthy to breathe. The American Lung Association says that over a third of Americans live in areas with unhealthy air. 

Air pollution, often referred to as the silent killer, is becoming an even more pervasive environmental threat impacting communities globally. There are many causes of air pollution. Transportation emissions often come to mind first. As mentioned previously, in recent years, another trend has been on the rise around the world: wildfire smoke. In the US and Canada, for instance, wildland fires have resulted in miserable outdoor and indoor air quality across both countries. Data from the US EPA shows that wildfire smoke accounts for about 3x that of PM 2.5 emissions from transportation sources! More broadly, this air pollutant is raising concerns about a public health crisis across the globe because smoke particles can trigger acute health problems such as heart attacks, especially for those with chronic conditions, as well as lead to long-term issues such as dementia. 

Below, we’ll address how breathing polluted air affects our health and some of the environmental and climate consequences of common solutions for treating indoor air quality (IAQ).

Understanding Indoor Air Quality

IAQ is influenced by the composition of airborne particles and gases within enclosed spaces as a result of various sources such as building materials, occupant respiration and activities, cleaning products, outdoor pollutants infiltrating indoors (e.g., natural events such as wildfire smoke), and more. 

Even though wildfires have caused severe damage to properties and communities directly impacted by such disasters, recent research shows that wildfire smoke can be 10 to 100 times more lethal than the fire itself. For example, according to a report from the National Bureau of Economic Research analysis, wildfire smoke contributes to 16,000 deaths annually.  Economically, wildfire smoke is a growing burden, with its total annual cost in the U.S. estimated at $394 billion to $893 billion. This includes $117.5 billion to $202.5 billion in healthcare costs linked to wildfire smoke exposure and driving illnesses like asthma, respiratory, and cardiovascular issues.

These figures highlight the far-reaching and devastating consequences of wildfires beyond just the flames.

The Health Impact of IAQ

Recent studies suggest that polluted air affects our health in multiple ways, from respiratory issues to cardiovascular and even causing DNA damage and mental health problems.

Professor Francesca Dominici, a leading data scientist at Harvard University’s Chan School of Public Health (HSPH), focusing on public health, has been working on analyzing the healthcare records of Americans, especially those linked with exposure to fine/airborne particles. In the study, “Long-term Effect of Fine Particulate Matter on Hospitalization with Dementia”, (Lee et al., 2019), researchers found that a longer exposure to fine particles increased hospitalization for Alzheimer’s disease. 

Furthermore, a longitudinal study of over 1.2 million Californians shows that breathing in wildfire smoke particles, in particular, increases the risks of dementia by 21%. What’s more, this effect is more pronounced with smoke than other PM pollutants. These findings are consistent with those of other research and highlight the need to take measures to mitigate air pollution, especially in the ever-neglected indoor environment. 

So, how does air quality affect health? HSPH’s Professor Marc Weisskopf suggests that fine particles not only damage our cardiovascular system but can also reach the brain and affect our immune system and health in general. Direct physiological studies in mammals demonstrate that smoke can cause long-lasting inflammation in the brain, specifically targeting the hippocampus—a region critical for learning and memory. Studies on mice exposed to smoke showed that this neuroinflammation can persist for over a month, leading to potential long-term neurological effects, including behavioral changes and cognitive impairments.

The situation gets worse in tightly insulated environments, such as those of highly energy-efficient buildings, if air quality is not treated properly. When polluted air becomes trapped indoors, it adversely affects the cognitive performance of occupants. The effects could be felt in the form of anxiety to lower accuracy and ease of problem-solving.

Let’s look at these impacts in greater detail:

Pulmonary Problems: Long-term exposure to air pollution can trigger respiratory issues, including asthma, bronchitis, and other lung diseases. Fine particles can irritate the respiratory duct, resulting in coughing, difficulty breathing, and sneezing. It can also lead to chronic illness, such as reduced lung function and increased risks of lung cancer.  

Cardiovascular Complications: Research shows that air pollution affects the cardiovascular system, including triggering heart attacks and strokes. The toxic pollutants can lead to inflammation in arteries that results in complications like abnormal heart rhythms. 

Brain Disorders: The latest research corroborates that long-term exposure to fine particles can increase the chances of Dementia–such as Alzheimer’s disease–Parkinson’s, and other neurocognitive diseases.

According to the US EPA, people spend around 90% of their time indoors, and indoor exposure to air pollutants is, therefore, highly consequential.

Vulnerable Population

Children, the elderly, and individuals with pre-existing health conditions are susceptible to polluted air, and protecting their health should be a top priority.

How to Mitigate the Effects

Addressing IAQ concerns requires proactive measures to ensure a healthy indoor environment. While we cannot directly control the outdoor environment, we can effectively manage indoor air impurities by implementing the following strategies:

• Control Indoor Sources: Identify and address sources of indoor air pollution, such as smoking and vaping, choices of building materials and furniture, and volatile organic compounds (VOCs) from paint, finishings, and cleaning products. Utilize exhaust fans to remove pollutants at their source.
• Keep Indoor Spaces Ventilated when Possible: If outdoor air quality is reliably clean, implement proper ventilation and filtration systems or open windows to allow fresh air to enter and stagnant air to exit. 
• Use Air Cleaners: Invest in air cleaners equipped with high-efficiency particulate air (HEPA) filters to capture and remove airborne pollutants effectively.

Air Cleaning and Climate Impact

With increasing threats from outdoor sources, such as wildfire smoke, and indoor sources like airborne viruses, it is essential for commercial buildings—including schools, hospitals, and offices—to implement proper air cleaning measures.

Most traditional HVAC systems in these commercial spaces operate sub-optimally, especially given the demand for improved IAQ. Upgrading to advanced air cleaning systems with higher ventilation effectiveness is crucial. This shift involves moving beyond theoretical air change rates or efficiency metrics to adopt solutions with proven ventilation equivalent efficiencies. Air cleaning technologies must not only filter contaminants entering the HVAC systems but also enhance the overall quality of air cleaning.

Improving IAQ is not only a matter of health; it tightly intersects with climate and energy considerations. HVAC systems drive about 40% of building energy use, contributing to massive greenhouse gas emissions. By investing in air-cleaning technologies that enhance air cleaning and reduce the dependence on ventilation, buildings can reduce HVAC energy use by as much as 50%, thereby decreasing their overall energy consumption.

Concluding Thoughts

While air pollution is a pervasive threat to health, taking preventive measures and improving facility management practices can help. More specifically, addressing IAQ problems requires comprehensive and innovative solutions for treating indoor air pollutants effectively, safely, responsively (to data), and energy efficiently.

The post The Silent Threat: How Poor Indoor Air Quality Affects Health appeared first on Metalmark.

Challenge

BioMed Innovations embarked on a search for innovative solutions to enhance indoor air quality in their offices. Despite experimenting with a variety of air purification methods, they struggled to identify a truly effective solution. A notable challenge was the odors permeating their offices from the adjacent medical waste processing plant, an issue that persisted even after the installation of a state-of-the-art, high-efficiency HVAC system.

Solution

In BioMed’s office space, spanning roughly 1,000 square feet, Metalmark installed a unit of their unique air cleaning system, which features the company’s patented self-renewing capabilities. This installation represented a significant step towards improving the indoor air quality within BioMed’s facilities.

Results

To quantify air quality impact, Metalmark implemented a comprehensive data collection strategy, capturing multi-point, high-definition data at 15-second intervals. A baseline was established over a three-week period, which was then compared to data from the subsequent three weeks during which the Metalmark air system was operational. The sensors and other air sampling confirmed a swift and sustained improvement in the air quality within the office space throughout the duration of the operational period of the Metalmark system. The specific improvements included:

• 67% reduction in non-ideal PM_2.5 levels
• 29% reduction in TVOCs
• 38% reduction in bacteria

Equally significant, the employees who occupied the space noted a perceptible enhancement in their subjective work experience. This positive feedback further underscores the effectiveness of the Metalmark air cleaning solution. One employee shared their experience as follows: “ We had an immediate change in our office air quality when the machine came in and an immediate change as soon as it left. Even the drivers have made comments about it. And these are guys who are pretty oblivious to different smells.”

In addition to its air cleaning capabilities, the Metalmark system features a filter renewing mechanism, which helps to extend the lifespan of the onboard filter by up to 10x that of standard HEPA filters. Rigorous independent third-party testing has confirmed that the Metalmark system neither generates ozone nor emits harmful byproducts. As a result, it offers exceptional air cleaning performance that is both hassle-free and cost-effective, while also being climate-friendly. 

The post CASE STUDY: First Self-Renewing Commercial Air Cleaner Installation Reduces PM_2.5, VOCs, and Airborne Bacteria appeared first on Metalmark.

We’ve been using conventional air filters for decades in HVAC (Heating, Ventilation, and Air Conditioning) systems to heat, ventilate, and cool our indoor spaces. These filters remove particulate matter and various air pollutants that can be harmful to our lungs. But are these conventional air filters prepared to handle and remove the particulate matter created by wildfires? That’s what we’re here to talk about today. 

Challenges of Filtering Wildfire Smoke 

How Do Air Filters Work? 

Traditionally, air filters act like a very fine strainer, stopping dust, pollen, and other pollutants from passing through. The finer the filter, the smaller particles can be trapped. However, this comes with a trade-off: a very fine strainer will cause a restriction in airflow. If such a fine filter is installed into the air purification system or HVAC, the pressure drop will increase the energy consumption of the system. 

The ideal indoor air filter would be a type of “mesh or strainer” with high efficiency AND low back pressure. This can be achieved by introducing a charge onto a filter’s fiber. Polymer electret filters carry an electric charge and are very popular in HVAC systems. They provide notable initial efficiency and a low-pressure drop. However, the drawback is the rapid decay of their charges in the presence of smoke. 

The Impact of Wildfire Smoke on Filters

Wildfire smoke particles can be transported large distances from wildfire locations and easily penetrate our homes. It has a very complex composition, being made up of hundreds of volatile organic compounds and chemicals plus large amounts of particulate matter 2.5 (PM_2.5). Multiple studies show that most of these particles are in the submicron range, and contain many organic, carbon-based compounds. This results in very different interactions between these types of particles and filter fibers. 

A recent study by scientists at Metalmark Innovations tested several air filters with pine needle smoke, to simulate the wildfire submicron particles of the real world. The researchers used particle counters and scanning electron microscopy (SEM) to understand how the air filters and smoke particles interacted with one another.

Gaps in Measuring Efficiency & Current Air Filters Testing Standards

Testing and rating air filters in the US is normally done based on ASHRAE standards. Filter media and filters are assigned a value based on the MERV system (Minimum Efficiency Reporting Value) on a scale from 1 to 20, with higher numbers meaning better filtration efficiency. To assign a grade or rating, test filters are typically challenged with inorganic salt particles of various sizes based on the standard test protocols. The filter’s ability to trap these particles determines its rating. 

What’s in most residential and commercial HVAC systems is largely MERV 8 filters. During COVID-19, public health recommendations advocated for MERV 13. And, it’s generally accepted that the same grade would be highly effective for smoke removal. 

The researchers behind the study came to an important realization: the standards used for testing filter efficiency need to be more comprehensive when it comes to wildfire smoke. Most filters are tested based on inorganic salt particles in the range of 0.3-10 μm. There are two problems with this type of measurement. 

First, the size of smoke PM is usually below 0.3 μm (typically 100-200 nm). Second, the chemical composition of smoke particulates is very different from inorganic salts. They contain large amounts of chemicals (organic compounds). As it turns out, this matters to the filtration efficiency outcomes of filter media. The trends observed with the pine needle smoke particles in this study were different from established patterns seen with inorganic particles. 

This challenges the conventional expectations of measuring an air filter’s effectiveness, and it suggests that existing rating systems for filters aren’t capturing important data on wildfire smoke filtration capabilities. 

Challenges in Measuring Wildfire Smoke

Another issue with understanding wildfire smoke is that current PM measurements focus on PM_2.5 sensor values reported in mass concentration. Small particles below 300 nm contribute very little to the total mass, even at very high concentrations. 

For example, the mass concentration of 10 μg/m³ (considered healthy air) of 2 μm diameter particles contains about 1.6 particles per mL of air. In contrast, the same mass concentration of 100 nm particles contains ~12,740 particulates. And during a “smoky” day, we can have billions of tiny toxic particles in just 1 mL of air!

Because wildfire smoke is becoming a more prevalent threat to human health, accurately understanding and measuring smoke particles and applying the knowledge toward rating an air filter is of incredible importance. 

Learnings About Filter Media

Take a look at the SEM image below. 

SEM image of pine needle smoke accumulation on fiber media, forming “pearl strands”.

The Metalmark study indicates that for common HVAC filters, made with electret media, smoke “deactivates” their charges. All that was left after testing was a “coarse mesh strainer.” 

So, Which Filter Media Worked Best? 

• MERV ratings of filters do not translate for smoke well. 
• Not surprisingly, high MERV 15-16 microglass, a high-quality material used for high MERV, HEPA, and ULPA filtration, worked best.
• Microglass media were the most efficient at removing wildfire smoke from the air. However, these filters slow down the airflow and increase energy use in HVAC systems.
• The efficiency of electret filters for salts dropped significantly when exposed to smoke or aging (as much as 95% less effective). However, this behavior is drastically different from testing with smoke. In general, electret media maintained lower than expected efficiency against smoke than their MERV ratings suggest.  

Recommendation

Metalmark is actively addressing the pressing issue of indoor air quality compromised by escalating wildfires. To do this, the team is engaging in further research and technological advancement to improve air filtration systems. 

The Tatama air cleaner by Metalmark stands out as a solution to wildfire smoke pollution in the Western United States. Made with HEPA-grade filters, these air cleaners were specifically designed to capture an array of pollutants that include the small size and organic compounds of wildfire smoke.

The self-renewing system periodically removes accumulated pollutants caught in the filter to extend the filter lifetime upwards of 5 years. The Metalmark’s technology was named winner of the US EPA’s Cleaner Indoor Air during Wildfires Challenge.

A Path Forward for Wildfire Smoke Filtration 

The air we breathe inside our homes, schools, and offices is crucial to our health, and we need top-notch indoor air quality (IAQ) solutions to tackle the challenges posed by these increasingly intense fires.

It’s not just about keeping the air clean though– we’re talking about a holistic approach. We want solutions that not only prioritize our health, but also align with climate resilience, energy efficiency, and green building standards. 

All of this is to say that we need IAQ solutions that go beyond the basics. With more wildfires on the horizon, the amount of particulate matter floating around will likely get worse. Smart air filter choices and continued research will make our indoor spaces healthier while contributing to the bigger picture of a sustainable and resilient future.

The post Are Air Filters Filtering Wildfire Smoke as Well as We Thought? appeared first on Metalmark.

Many others have adopted ventilation as the quickest, easiest path to healthy indoor air quality . For example, in their 2020 book Healthy Buildings, Joseph Allen and John Macomber wrote, “We give the economic evidence demonstrating how even just one building factor – ventilation – can lead to significant enterprise-wide gains, and show you how to create and capture this value.” They further point to the evidence that increased ventilation can improve the health and performance of students and employees.

Ventilation is certainly the only way to deal with elevated CO2 levels; no air purifier can remove CO2. 

However, as climate change accelerates and wildfires become more intense, the limitation to  ventilation as a one-size-fits-all approach to IAQ is becoming apparent. 

First, even if outdoor air were as perfectly clean and fresh as in Florence Nightingale’s time (and it wasn’t always so clean even then, with the abundant burning of coal in furnaces and factories), we hear from many facility managers that it is expensive to ventilate. In our increasingly hot summers, up to 27% of a commercial building’s energy use goes to air conditioning. Heating can be even more expensive, and can account for up to 45% of a building’s energy use in the winter months. This “ventilation penalty” is considerable. That’s a lot of money and carbon flying out the window. 

And what if, aside from reducing CO2, opening the windows and HVAC vents was actually making the indoor air less healthy? 

The American Lung Association says that over a third of Americans live in areas with unhealthy outdoor air. Typically, indoor pollution levels are at least 50% as high as outdoor ones.

This past summer the Midwest and East were blanketed by thick smoke from Canadian and Western wildfires. New research by Metalmark shows that wildfire smoke consists primarily of extremely small particles — .3 microns or smaller. According to a 2020 article in Nature, these tiny particles are especially dangerous, given their ability to pass through the lining of the lungs and into “essentially all organs. Compared to fine particles (PM2.5), they cause more pulmonary inflammation and are retained longer in the lung. Their toxicity is increased with smaller size, larger surface area, adsorbed surface material, and the physical characteristics of the particles.”

Metalmark’s research also found that typical IAQ monitors measuring PM2.5 particles won’t detect these dangerous particles. And typical HVAC MERV filters rated 8-14 can’t filter most of them out. 

And a recent study from Harvard T.H. Chan School of Public Health based on Medicare data from millions of people aged 65 and older, found that long-term exposure to supposedly “safe” levels of PM2.5 and NO2 over 10 years led to elevated levels of breast and endometrial cancers. They were only looking at PM2.5; imagine what they would have found if they could have studied PM1.0 and ultra-fine PM.01. There may be no “safe” level of air pollution.

In 2023, ASHRAE released Standard 241, which for the first time acknowledged that healthy indoor air can be achieved through various combinations of ventilation and air purification. While focused primarily on reducing the indoor threat from pathogens such as COVID, its approach is equally useful in dealing with other harmful PMs, from day-to-day pollution to wildfire smoke. It introduced the idea of equivalent clean airflow, which it defines as “the theoretical flow rate of pathogen-free air that, if distributed uniformly within the breathing zone, would have the same effect on infectious aerosol concentration as the sum of actual outdoor airflow, filtered airflow, and inactivation of infectious aerosols.” 

It also introduced ECAi, the “required equivalent clean airflow per person for infection risk mitigation.”

Only HEPA filters, like those used in Metalmark Tatama, remove virtually all particles and pathogens.

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