The Known Unknowns : Why Air Quality Parameters Impacting Public Health and Well-being Are Too Visible to Ignore

The Known Unknowns : Why Air Quality Parameters Impacting Public Health and Well-being Are Too Visible to Ignore

Dr. Iyad Al-Attar

We live in an era defined by a paralyzing paradox: while we are awash in information, we frequently find ourselves wrestling with deep uncertainty. On complex global issues-ranging from long-term climate modeling to shifting geopolitical landscapes-progress is often stalled by “known unknowns,” those intricate variables we realize we do not yet fully understand.

Air quality, however, is a critical exception. It is not a mystery we are still trying to solve; it operates almost entirely in the realm of the “known unknowns.” To ignore the reality of air pollution today is no longer a gap in knowledge. It is a failure of will.

Figure 1: Scanning Electron Micrograph (SEM) illustrating the heterogeneous morphology of particulate matter.

For decades, atmospheric scientists and epidemiologists have rigorously cataloged the primary agents of atmospheric degradation, leaving no mystery regarding what is impacting our health and well-being. At the forefront of this crisis is Particulate Matter (PM), specifically PM2.5. These microscopic specks of dust (Figure 1), soot and liquid droplets are the signature of combustion, pouring from vehicle exhaust, industrial and power generation stacks (Figure 2), and the burning of solid fuels. The true danger of PM2.5 lies in its scale; to understand the threat, one must visualize particles often thirty times smaller than the width of a single human hair (Figure 3).

While larger particles might be filtered out by the body’s natural defenses, these ultrafine particles act as a biological Trojan horse, bypassing our protective barriers entirely. Alongside these solids, the gaseous pollutants have been mapped with equal precision. We see nitrogen dioxide as the fingerprint of urban traffic, creating localized health emergencies at busy intersections. We track sulfur dioxide, the classic signature of burning coal and heavy oil responsible for historical “killer smogs.” We also monitor ground-level ozone, an invisible irritant formed when sunlight cooks a chemical soup of other pollutants on hot days. We know exactly what these are, where they come from, and how to measure them with excruciating precision—from high-tech satellite arrays down to low-cost sensors on neighborhood lampposts.

The urgency of this crisis stems from the fact that these parameters are “too visible to ignore,” a visibility that manifests in both literal and biological ways. In many global cities, air quality is no longer just a forecast or a number on an app; it is a texture. It is the acrid brown haze that smudges the horizon, the yellow filter over the sun, and the grit on the windowsill. When PM2.5 levels spike, the very air becomes opaque. The most basic “known known” is this: when you cannot see the building across the street due to smog, you do not need a scientific study to tell you something is profoundly wrong.

Yet, the most insidious visibility is the one we cannot see with the naked eye: the biological impact. The science here is ironclad. The human lung is a permeable barrier designed for gas exchange, not a filtration media or an impenetrable shield. Because PM2.5 particles are so minuscule, they do not just sit in the lungs; they traverse the membrane of the alveoli, the deep air sacs, and enter the bloodstream, traveling throughout the body.

Figure 2: Emissions from a thermal power plant.

This translocation drives systemic inflammation, linking polluted air directly to ischemic heart disease, stroke, lung cancer, and Chronic Obstructive Pulmonary Disease (COPD). The toll is visible in the heartbreaking data on acute lower respiratory infections in children, and in emerging research connecting chronic exposure to cognitive decline and adverse birth outcomes. We are not guessing about these connections; they are painfully visible in hospital admission spikes during high-pollution events and in the reduced life expectancy statistics of heavily polluted regions.

If the health arguments are not “visible” enough for policymakers, the economic data provides a multi-trillion-dollar glare. Organizations like the World Bank and the World Health Organization have calculated the cost of inaction, revealing that air pollution acts as a massive, continuous tax on economic well-being. This cost is measurable in lost labor productivity when workers are too sick to work, and in the soaring healthcare costs required to treat preventable chronic diseases [1-3]. It is even visible in agriculture, where ground-level ozone interferes with photosynthesis, literally stunting plants and lowering crop yields. Far from being a niche environmental concern, air pollution is a thoroughly documented drag on global development.

Why, then, does the problem persist if the variables are so well known? For too long, we have allowed the illusion of complexity to delay action, framing air quality as an unfortunate, unavoidable byproduct of modernity that must be traded off for economic growth. The weight of the evidence now proves that framing to be undeniably false. Clean air is the prerequisite for sustainable economic growth and fundamental human well-being. By allowing pollution, a country is not choosing growth; it is choosing to choke its own productivity.

We must confront a chilling ethical inconsistency: if a person were to intentionally administer a toxin to another, it would be prosecuted as a violent crime. Yet, when industry and policy allow for the slow-motion poisoning of entire populations through poor air quality, it is often dismissed as a “cost of doing business.”

The only difference between an acute act of harm and chronic exposure is the speed of the delivery. Whether the damage occurs in an instant or over a decade, the result is the same. We can no longer tolerate the “slow-motion” exception. If we have the tools to stop the poisoning, our failure to use them is not a tragedy of fate-it is a failure of justice.

Figure 3: Scanning Electron Micrograph (SEM) of a human hair

The Mandate for Clean Air

We possess the technology to monitor air quality in real-time, the means to transition away from combustion, and the policy frameworks to regulate emissions effectively. In the 21st century, pleading ignorance is no longer a valid defense for any government or industry.The data is undeniable: we know what is in our air, the damage it inflicts on our bodies, and the trillions it drains from the global economy. As the environmental bill comes due and the science remains settled, the metrics are in plain sight. This leaves us with only one true “known unknown”: human will. The question is no longer what we must do, but how swiftly we will choose to act on a reality that is visibly, painfully clear. The time for deliberation has passed.

A Failure of Justice

We must now confront a chilling ethical inconsistency: if a person were to intentionally administer a toxin to another, it would be prosecuted as a violent crime. Yet, when industry and policy allow for the slow-motion poisoning of entire populations through poor air quality, it is often dismissed as a “cost of doing business.”

The only difference between an acute act of harm and chronic exposure is the speed of the delivery. Whether the damage occurs in an instant or over a decade, the result is the same. We can no longer tolerate this “slow-motion” exception. If we have the tools to stop the poisoning, our failure to use them is not a tragedy of fate—it is a failure of justice.

References:

[1] World Bank & Institute for Health Metrics and Evaluation. (2016). The cost of air pollution: Strengthening the economic case for action. World Bank. https://openknowledge.worldbank.org/handle/10986/25013

[2]World Bank. (2022). The global health cost of PM2.5 air pollution: A case for action beyond 2021. World Bank. https://openknowledge.worldbank.org/handle/10986/37452

[3] World Health Organization. (2024). WHO COP29 special report on climate change and health: Health is the argument for climate action. World Health Organization. https://www.who.int/publications/i/item/9789240090001

Dr. Iyad Al-Attar is a highly accomplished mechanical engineer, air quality consultant, and Visiting Academic Fellow at Cranfield University, specializing in air quality and filter performance for gas turbines. His foundational work is complemented by his current research at the University of Oxford, which addresses the critical inclusion of air quality as a rudiment of sustainable urban development, focusing on human-centered air quality sensing and appropriate filtration. He is the correspondent of Mahabahu

Mahabahu.com is an Online Magazine with collection of premium Assamese and English articles and posts with cultural base and modern thinking.  You can send your articles to editor@mahabahu.com / editor@mahabahoo.com (For Assamese article, Unicode font is necessary) Images from different sources.