Dust from car brakes is more damaging to your lungs than diesel exhaust. Here's what can be done

Dust from your car brakes are polluting the air and is worse than exhaust fumes while electric vehicles are not as green as you think; all you need to know.

As cities worldwide tighten restrictions on diesel emissions, a lesser-known form of air pollution is growing unchecked—brake dust. While exhaust fumes have long been recognised as a health hazard, new research suggests that the microscopic particles released when vehicles brake, may be even more harmful to human lungs. With the rise of heavier electric vehicles, which lead to increased brake wear, the urgency to address this issue has never been greater.

Why Your Car’s Brake Pads Might Be a Bigger Health Hazard Than Diesel Emissions.(Photo by iLexx on Getty Images)

What is brake dust and why should we worry?

Every time a vehicle slows down, friction between brake pads and discs produces tiny airborne particles. These particles, known as brake dust, make up a significant portion—up to 55%—of all traffic-related fine particles in urban areas.

Unlike exhaust emissions, brake dust remains largely unregulated, despite its potential impact on respiratory health. A recent study conducted by researchers at the University of Southampton examined how different types of brake pads affect human lung cells.

A new study found that 50% of lung cancer patients are non-smokers. Experts say air pollution is contributing to the rise in lung cancer cases.(Shutterstock)

Their findings, published in Particle and Fibre Toxicology, reveal a troubling reality: brake dust from copper-rich brake pads, commonly used in modern vehicles, can cause more inflammation and cellular stress than diesel exhaust.

The copper connection: A hidden culprit

Brake pads come in various compositions, including low-metallic, semi-metallic, non-asbestos organic (NAO) and ceramic. Among these, NAO and ceramic brake pads—both containing high levels of copper—were found to cause the most significant harm.

Originally introduced as a replacement for asbestos, copper in brake pads helps conduct heat efficiently. However, the study found that when lung cells were exposed to brake dust from these pads, copper accumulated in the cells over time, triggering inflammatory responses and altering metabolism in ways that could lead to long-term health problems.

Air pollution can inflame breathing passages, decreasing the lung's working capacity and causing shortness of breath, pain when inhaling deeply, wheezing and coughing. (Freepik)

One of the most concerning discoveries was that copper-rich brake dust activated a cellular mechanism known as “pseudohypoxic HIF signalling”. In layman's terms, this means that lung cells reacted as if they were deprived of oxygen, despite oxygen being present—a false alarm that could contribute to conditions like lung disease and even certain cancers.

Regulation vs reality: Are we doing enough?

Some US states, such as California and Washington, have already introduced restrictions on copper in brake pads. However, these regulations were originally intended to protect aquatic life, as copper from road runoff can be toxic to fish.

This new research suggested that limiting copper in brake pads may also have unexpected benefits for human health. Despite these findings, brake dust remains largely overlooked in air quality regulations.

Governments worldwide have focused primarily on reducing vehicle exhaust emissions, with little attention given to non-exhaust pollutants like brake dust, road debris and tire particles. As urban populations grow and vehicle traffic increases, addressing these overlooked pollutants may be crucial to public health.

What about electric vehicles?

The transition to electric vehicles (EVs) has been heralded as a solution to air pollution but there’s a catch—EVs tend to be heavier due to their batteries. Heavier vehicles require more braking force, leading to increased brake dust emissions.

India is among a handful of countries that support the global EV30@30 campaign, which targets to have at least 30% new vehicle sales be electric by 2030.

While EVs use regenerative braking to slow down without relying on traditional brake pads, they still require conventional braking for sudden stops and emergencies. According to study co-authors James Parkin and Matt Loxham, “The zero-emission label for EVs is not entirely accurate. While they eliminate exhaust emissions, they can generate even more non-exhaust pollution due to their weight.” This means that brake dust will remain a significant concern, even in a world dominated by electric cars.

The road ahead: What can be done?

Given the health risks associated with brake dust, researchers urge policymakers to take action. Possible solutions include -

• Developing Copper-Free Brake Pads: Investing in alternative materials that do not pose health risks.
• Improving Filtration Systems: Encouraging the use of dust-catching brake technologies to minimise airborne particles.
• Stronger Air Quality Regulations: Expanding emission controls to include non-exhaust sources like brake dust and tire wear.
• Promoting Regenerative Braking: Encouraging advancements in EV technology to reduce reliance on traditional brakes.

As awareness grows, consumers can also play a role by choosing vehicles with low-emission braking systems and supporting legislation that prioritises cleaner air. For years, the fight against vehicle pollution has focused on reducing tailpipe emissions however, research now suggests that brake dust may be just as dangerous—if not worse—for our health.

With urban air quality already under strain, it is time for policymakers, manufacturers and consumers to recognise and tackle this hidden threat before it becomes an even bigger problem. In a world striving for cleaner transportation, the solution to air pollution is not just about what comes out of the tailpipe—it is also about what is left behind when we hit the brakes.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.