Air Pollution Myths That Are Putting Our Health at Risk

At the recent French-Speaking Pneumology Congress held in Marseille, France, between January 24 and 26, 2025, Olivier Brun, a pulmonologist at the Hospital Center of Perpignan in Perpignan, France, and a member of the Occupational, Environmental and Iatrogenic Pulmonary Pathologies Group of the French-Speaking Pneumology Society, addressed five widespread misconceptions about air pollution.

1. Pollution Is Not That Bad

Approximately a decade ago, estimates suggested that air pollution caused between 3.3 and 4.2 million deaths worldwide, 500,000 in Europe, and 48,000 in France, according to Brun.

These figures from 2015 to 2017 were alarming. However, in 2019, researchers discovered a calculation error that underestimated the true impact of air pollution, leading to revised — and far higher — estimates. In 2021, a Harvard study identified additional uncounted deaths, raising the global estimate to 8.7 million deaths worldwide, 800,000 in Europe and 67,000 in France.

By 2023, these numbers were revised upward, as an American report revealed that fine particulate matter (PM) is the leading factor in reducing life expectancy, surpassing tobacco, alcohol, armed conflict, road accidents, AIDS, and malaria. Air pollution is a major contributor to global mortality rates, noted Brun.

2. The Worst Is Over

Images of the Great Smog of London in 1952 might suggest that the worst air pollution was in the past. This disaster marked a turning point in the recognition of pollution as a serious threat.

While there has been a general decline in pollution levels in France, caution is still needed. Not all trends are downward; for instance, ozone levels continue to rise because of climate change. France consistently performs poorly and is often condemned for exceeding the regulatory thresholds. In the 2021 ranking of European countries, it is one of seven countries where the three pollutants exceed the standards.

Moreover, global pollution levels continue to rise. Air pollution knows no borders, and despite renewable energy expansion, fossil fuel consumption (oil, coal, and gas) has reached record levels.

These figures show no signs of slowing down. Global oil demand has reached unprecedented levels. The International Energy Agency had forecasted that it would average 102.2 million barrels per day in 2023, an all-time high. In recent years, global coal demand has plateaued at record levels.

We have shifted from visible and odorous pollution (such as sulfur dioxide and soot) in the mid-20th century to less visible pollution (like carbon monoxide, ozone, and lead) between the 1960s and 1980s and now to invisible and odorless pollutants (such as nitrogen dioxide and microparticles) today.

3. Pollution Causes Just a Respiratory Issue

One might assume that respiratory diseases are the most affected by air pollution, a notion that has often been emphasized in the past. However, when we examine the data, respiratory diseases do not rank in the top three. Cardiovascular and metabolic diseases associated with ultrafine particles have a far greater impact. In 2022, in terms of deaths attributable to diseases related to PM2.5 (particles of 2.5 μm), lung cancer and chronic obstructive pulmonary disease ranked fourth and fifth, while childhood asthma came sixth, with a lesser impact from PM2.5. Ischemic heart disease topped the list, closely followed by stroke and diabetes.

Pollution peaks garner media attention, but the thresholds remain arbitrary. In France, PM10 levels > 100 µg/m are deemed hazardous, whereas Indonesia classifies “very poor” air quality only > 350 µg/m.

Between 2005 and 2022, European Union mortality linked to PM2.5 exposure dropped by 45%, nearing its “Zero Pollution” target of a 55% reduction by 2030. However, long-term exposure to low pollution levels is a critical concern.

4. Pollution and Climate Change Are the Same

Some argue that air pollution and climate change are “twin problems,” but this analogy is not entirely accurate. They are not true twins — the link between climate change and air pollution is not that straightforward. While they share common origins, such as fossil fuels and intensive agriculture, the gases involved in each issue are not the same. For instance, fine particles, which are the main contributors to the health effects of air pollution, are not greenhouse gases by definition.

As proof, the concept of “planetary boundaries,” developed in 2009 and now widely recognized, clearly distinguishes between pollution and climate change. However, their interaction is undeniable. They fuel each other in a snowball effect, with worrying consequences for health and the environment.

The good news is that solutions to combat both pollution and climate change often overlap. This is referred to as cobenefits: Reducing polluting emissions also helps mitigate global warming.

For example, the UK’s action plan Air Pollution: Action in a Changing Climate, 2010, stated, “Many of our activities, especially transport and energy generation, contribute to both local air pollution and global climate change, so it makes sense to consider how the linkages between these policy areas can be managed to best effect.” The plan highlights that cobenefits related to air quality and climate change can be achieved through actions such as promoting low-carbon vehicles, using renewable electricity sources, implementing energy efficiency measures, and reducing agricultural nitrogen demand. At the same time, the plan emphasizes the importance of avoiding policies that aim to address climate change but inadvertently harm air quality and vice versa.

5. We Know Everything About Air Pollution

While considerable progress has been made in understanding air pollution, uncertainties remain.

First, gases such as sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide, and benzene are well understood, even at the nanometer scale, whereas PM10 and PM2.5 have been less studied. Scientists classify them by size and weight, but their oxidative potential and composition are not fully known.

Second, pollutants are classified into primary (direct emissions) and secondary (atmospheric reactions) categories. Air chemistry is complex; substances such as ammonium nitrate have been documented, but others, including potential “tertiary” pollutants, remain unidentified.

Third, pollutants interact with each other. Cocktail effects suggest that the combined impact may far exceed the individual effects.

Finally, over 350,000 chemicals, including plastics, pesticides, and pharmaceuticals, have been introduced since the preindustrial era, permeating our environment. Their long-term health and ecological impacts remain unknown. Even regulated substances, such as pesticides and microplastics, may pose hidden risks.

Brun emphasized, “On one hand, we must exercise to prevent cardiovascular disease and obesity, but on the other, we must avoid inhaling too many pollutants. Patients are confused. However, the studies are clear: The benefits of regular physical activity far outweigh the negative effects of pollution, with an estimated benefit ten times greater than the latter. A person switching from a car to a bicycle for their daily commute could gain a year of life.” 

Precautions are vital in polluted areas: Avoid high-intensity exercise in heavily polluted environments where the risks may outweigh the benefits. Pollution levels vary between main roads and side streets. The optimal outdoor exercise times are early morning or nighttime and indoors when ozone levels peak.

This story was translated and adapted from Medscape’s French edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.