Can artificial rain lessen air pollution in Delhi? Experts question effectiveness

Delhi and its surrounding National Capital Region (NCR) have been grappling with “very poor” pollution levels for the past ten days, raising serious health concerns for its residents. In response to this alarming situation, some residential societies, including the prominent DLF, have implemented an unconventional method to tackle the dust concentration: sprinkling water from the top of high-rise buildings, an initiative they refer to as “artificial rain.”
This experiment, recently reported widely in the media, attempts to mimic the natural cleansing effects of rain on air quality. However, it introduces a pertinent question: can this method effectively reduce dust particles and overall pollution?
The idea of using firefighting systems for water sprinkling, as seen in DLF’s high-rises, aims to mimic these cleansing properties of natural rain. However, the effectiveness of such a method remains questionable. While natural rainfall can cover large areas and provide prolonged exposure to water, artificial sprinkling systems have numerous limitations.
Experts say natural rainfall contributes to air quality improvement mainly through processes like scavenging and washout, which help remove pollutants from the atmosphere temporarily. Despite being called nature’s cleanser, rain is not an infallible solution, as it can also cause pollutants to aerosolize, potentially re-emitting some of them back into the air. They are not only less efficient but may also have any limited impact dissolved by the dynamic and open nature of ambient air systems.
Previous attempts to apply similar techniques, such as those conducted by the Central Pollution Control Board (CPCB) at ITO in Delhi as per the National Green Tribunal’s (NGT) order, did not yield positive results.
This underscores the complexity of controlling pollution in an open environment and suggests that while creative, the water sprinkling initiative may not be the ultimate solution to Delhi’s protracted pollution crisis.