A recent study highlights the significantly higher oxidative potential (OP) of fine particulate matter (PM2.5) in India compared to Europe. PM2.5, tiny particles with a diameter of less than 2.5 micrometres, can penetrate deep into the lungs and even enter the bloodstream, causing various health issues, including respiratory and cardiovascular diseases. The study, conducted by researchers from India and Europe, revealed that the OP of PM2.5 in Indian cities is five times greater than that in European cities. OP measures the ability of PM2.5 to generate reactive oxygen species, which can cause oxidative stress and damage to cells and tissues. The researchers collected PM2.5 samples from multiple sites in both regions and analysed their chemical composition. They found that the higher OP in Indian PM2.5 is mainly due to the presence of transition metals like iron and copper, which are known to catalyse the formation of reactive oxygen species. These metals are abundant in emissions from industrial activities, vehicular exhaust, and biomass burning, common sources of air pollution in India. In contrast, European PM2.5 had lower levels of these metals and higher concentrations of organic matter, resulting in a lower oxidative potential. The findings underscore the need for stricter air quality regulations and effective pollution control measures in India to mitigate the adverse health effects associated with high OP of PM2.5. This study is crucial as it provides new insights into the toxicological properties of PM2.5 and emphasises the importance of addressing not just the concentration of particulate matter, but also its chemical composition and oxidative potential to protect public health.