Air Purifiers in Delhi: A Temporary Solution to Hazardous Air Pollution

Residents of Delhi have increasingly turned to air purifiers as a method to combat the hazardous levels of air pollution plaguing the city. However, experts caution that these devices provide only a temporary measure and may bring additional concerns if relied upon heavily. Air purifiers are designed to filter out particulate matter such as PM2.5, but they do not address the issue of rising carbon dioxide levels in enclosed spaces, potentially posing health risks, especially during sleep.

Priyanka Kulshreshtha, co-founder of the Society for Indoor Environment, emphasized the limitations of air purifiers. «While the capacity of an air purifier is important and some devices are designed for smaller areas while others cover more,» she stated, «there is constant leakage of air through locked doors or windows.» She added, «If a room is well-sealed, the air purifier can manage PM2.5 by trapping it in its filters, but it does not address the CO2 problem.»

The concentration of carbon dioxide outdoors is typically around 400 parts per million (ppm) and 1,100 indoors, according to Kulshreshtha. She warned that during sleep in a closed room, this concentration could rise to 2,000-2,500 ppm, which could be harmful. The expert also highlighted that while air purifiers may be recommended for sick individuals, over-reliance on them could pose problems, particularly for children who might become overly accustomed to filtered air, resulting in extreme exposure when outside.

Shambhavi Shukla of the Centre for Science and Environment noted the inefficiency of purifiers, as pollution spikes when a sealed room is opened. «Air filters work when you close a room completely. But one cannot be inside a closed room for an entire day,» she explained. As a more effective approach, experts suggest the judicious use of ventilators and the timely ventilation of rooms.

Sunil Dahiya, founder and lead analyst of Envirocatalyst, highlighted that only a fraction of India’s population can afford air purifiers and that most Indian homes are not suited for such devices. «A majority of people live in houses that aren’t sealed or isolated from the outside, which means outdoor polluted air will keep entering, reducing the usefulness of air purifiers,» he stated. Dahiya also noted the mental health challenges associated with staying indoors due to pollution.

Addressing both indoor and outdoor air quality remains critical, with experts consistently emphasizing reducing pollutants at the source. The unequal distribution of resources like air purifiers points to broader issues of environmental and social inequality, underscoring the need for systemic solutions to improve air quality for all.