A recent study has revealed that humidity in Delhi’s air could lead to an underestimation of pollution levels by up to 20%, particularly concerning fine particulate matter (PM1). The research, conducted by scientists from the University of Birmingham, UK, highlights the impact of moisture absorption on pollution measurements.

The study, published in the journal npj Clean Air, explains that fine particulate matter tends to absorb water from the humid air, especially during winter. This process, known as hygroscopic growth, causes the particles to swell, which in turn reduces the efficiency of air quality sampling devices. As a result, PM1 concentrations may be underreported, leading to a misleading assessment of Delhi’s pollution levels.

PM1 refers to airborne particles with a diameter of less than 1 micron, which pose severe health risks as they can penetrate deep into the respiratory system and bloodstream. The underestimation of PM1 pollution could have serious implications for public health policies and pollution control measures in one of the world’s most polluted megacities.

The researchers emphasize the need for improved air quality monitoring techniques that account for hygroscopic growth to ensure more accurate pollution data. This study bridges a crucial gap in the understanding of Delhi’s air pollution and calls for further advancements in monitoring technology.

With Delhi consistently ranking among the most polluted cities globally, this new insight underscores the urgency of refining air pollution measurement methods to protect public health and improve environmental policies.