Bengaluru, the most liveable city, is also a cockroach allergens hothouse. A study has found that city households have more cockroach allergens, as well as high percentage of particle size between 2-20 μm, compared to New Delhi, Mumbai and Hyderabad.The study, conducted by Dyson in association with FICCI Research and Analysis Centre (FRAC), found that “one can also find bacteria, fungi, dust mites, cat and dog allergens in houses...” These findings are part of the study to analyse household dust by collecting samples across Delhi, Mumbai, Hyderabad and Bengaluru, including dust samples from 44 surfaces in 14 households of Bengaluru.
FRAC scientists collected samples from four sources: sofa, carpet, mattress and car. “All these sources are cleaned regularly,” the study quoted.Interestingly, the study looked at 11 different allergens which include particles, human/dog/cat hair and less obvious things like bacterial and fungal count, dust mite allergens and even spore count.
Dyson’s team also took samples from some homes two days after it had gone through a vacuuming session. Approximately 25 grams of ‘dust’ was collected from each source. Pulmonologists and doctors in Bengaluru said it proved that these allergens can lead to a spectrum of manifestations, including allergic rhinitis/rhinosinusitis, asthma and urticaria.
Renowned pulmonologist Dr Satyanarayana Mysore, Manipal Hospitals, Bengaluru, said the Dyson study needs to be repeated as a multicentric study and validated. “Chitinases, the external protein layer of cockroaches, plays a very important role in stimulating our immune system and drive the asthma response further,” he said.
A similar study in 2018 by Dyson had found that in two of three houses in Bengaluru, at least one person was found to be affected by a dust allergy and the total fungal count was higher than in other metropolitan cities. Dr Mysore added that doctors need to educate their patients that absence of symptoms does not mean all is well with the airways.