As Maha Ashtami rituals were observed at temples across Ahmedabad and other parts of Gujarat on Tuesday, a two-decade-old scientific study on havan smoke has resurfaced in public discussions. The research, published in 2007 in the Journal of Ethnopharmacology, reported that smoke from sacred fire rituals could cut airborne bacteria by as much as 94%.
The Study and Its Findings
The study, led by Chandrashekhar Nautiyal, Puneet Singh Chauhan, and Yashwant Nene of the National Botanical Research Institute, suggested that ritual smoke might reduce microbial presence in the air and even help protect crops from bacterial infections.
In controlled experiments, researchers burned 1,000 grams of mango wood followed an hour later by 500 grams of traditional havan offerings. Air samples collected in sealed steel vessels showed a 94–96% reduction in bacterial count. The antibacterial effect lasted 24 hours in a closed environment and was still noticeable after ventilation.
The research documented reductions across 14–15 bacterial strains, including pathogens that damage crops such as wheat and rice.
What Goes Into a Havan?
The mixture tested included ingredients such as camphor, sandalwood, sesame, almonds, nutmeg, dried dates, apricots, turmeric, musk, amber, agar, and wood from trees like mango and khejri. When burned, these substances were found to exhibit antibacterial effects under laboratory conditions.
Science Versus Reality
While the findings point to potential antimicrobial benefits, health experts highlight the other side of the story: burning such materials also releases particulate matter and harmful pollutants. In real-world settings, the smoke may irritate eyes and throats, even if it does reduce airborne microbes.
On Tuesday afternoon, Ahmedabad’s air quality index (AQI) was recorded at 74, in the “moderate” category, with PM10 levels at 32 µg/m³ and PM2.5 at 21 µg/m³—about 20% higher than the state average. Public health authorities caution that even moderate air pollution can worsen respiratory problems.
Ritual and Relevance
Havans, rooted in Vedic tradition, are performed with offerings to the fire god Agni alongside mantra chanting. This year’s Navratri spans ten days due to overlapping tithis, with Maha Ashtami carrying special importance. In Ahmedabad, major temples such as Bhadrakali and Bahuchar Mata organised large-scale havans to mark the day.
The 2007 study remains one of the few peer-reviewed investigations into havan smoke. However, with limited follow-up research and changing environmental concerns, experts continue to debate its relevance in today’s discussions on health and air quality.

