Bengaluru tops other cities in dust mites, fungal counts: Study

Fungal count is also higher compared to other metros

Despite the cleaning done in most Indian homes, they contain a large quantity of allergens and harmful dust particles, a study has found.

Hundreds of housing units, including 44 homes or flats in Bengaluru, had been sampled to determine their level of cleanliness in two separate studies conducted in 2018 and 2021 by FICCI Research and Analysis Centre (FRAC) on behalf of Dyson.

Researchers collected samples from 304 surfaces per house amounting to a total of 25 grams of dust, which was then analysed for pollen and spore count, parasites, dust mite and cockroach allergens in addition to dog and cat allergens. Four locations at each household were sampled, including the family car, a carpet, a sofa and mattresses.

They found that the city’s moderately humid and slightly warm weather resulted in “a higher dust mite concentration than Mumbai and that the total fungal count in Bengaluru is higher than any other region”.

The dust mite allergens count was 6.88 nanograms per gram in Bengaluru, whereas it was a mere 3.58 NG in Mumbai. New Delhi recorded a dust mite allergen count of 14.8 NG per gram.

Bengaluru had the highest fungal and bacterial count of any of the large metros surveyed with a bacterial count of 31.39 billion CFU (colony forming units), compared to 29.06 CFUs in New Delhi and 31.2 CFUs in Mumbai. Bengaluru’s total fungal count also reached 16.93 CFUs, compared to 14.8 CFUs in New Delhi and 16.2 CFUs in Mumbai.

Jonathan McGaughey of Dyson pointed out that residents cleaned the house before researchers could collect the samples. The sample dust also contains a high amount of human skin cells. On an average, a person would lose 28 grams of skin per week.

Can trigger asthma

Dust mites feed on dead skin cells and their faeces contain high-allergic proteins that might trigger asthma and other allergic conditions when inhaled.

Though previous studies highlighted the protective effects of some dust exposure on immunity building, Dr Lancelot Mark Pinto, Consultant Pulmonologist at Mumbai’s P D Hinduja Hospital and Medical Research Centre, said the amount of dust found in random sample sites could cause more harm than good.

He points to the global asthma report, which says 6% of Indian children and 2% of adults have asthma that affects nearly 15 to 20 million citizens. Studies have also revealed that asthma is aggravated in 66% Indians compared to 19% people in Hong Kong.