The air pollution problem in Delhi NCR is well documented. And it continues to be so, with the air quality hovering around “severe” on most days. At this time, to ignore the fact that the air quality inside our homes is not bad, would perhaps be categorized as living in denial. British technology company Dyson has conducted a study of the air quality inside the homes in Delhi NCR, and the results do not make for pretty reading.
For this test, Dyson and SGS China, studied the contents in the filters that captured the dirty air and pollutant particles in air purifiers installed in homes. The purifiers were in use for a period of 3-5 months, Dyson says. The results say that formaldehyde, dust mites, mould and bacteria are the four serious issues with air quality inside our homes. It turns out that the average quantity of formaldehyde to be 169.1 mg/kg, while the maximum value in a home was found to be 649 mg/kg. Many everyday household items can emit formaldehyde, including pressed wood products, antiseptics, cleaning agents, carpets, cigarettes, cosmetics as well as paints and varnishes. These tend to stay indoors for longer as the items that emit these pollutants tend to do so over an extended period of time, and not just a few days.
“The present study provides a snapshot to the so-called safer havens for the general public. There are very few studies in India which have talked about bioaerosols (bacteria, moulds, dust mites etc.) and Volatile Organic compounds in indoor microenvironment which are extremely harmful to human health. Especially the young children and elderly, who are indoors for the maximum time are the most affected by the indoor air pollution. The health effects can range from mild symptoms like fatigue, dizziness, watering of eyes to severe respiratory disorders and cardiovascular diseases,” says Dr. Priyanka Kulshreshtha – Joint Secretary- Society for Indoor Environment (SIE).
Dyson’s research says the maximum value of dust mite number was 610 pcs, while the average dust mite number was 292 pcs, from the filters they tested. At the same time, the dust mite allergen concentration was found to be 98.00 ng/g, while the average was 41.48 ng/g. Dust mites feed on dead skin cells and can contain highly allergenic proteins. These, when inhaled, can be the reason for allergies and worse still, conditions such as asthma.
In the bedrooms, the most common sources of pollution include wood furniture, paints and furniture foam, for pollutants such as formaldehyde and volatile organic compounds (VOCs). In the living room, the polluted outdoor air streaming in, furniture, flooring and also any plants can emit pollutants including VOCs and pollen. Things become worse in the kitchen, because the process of cooking food emits large quantities of fumes and odors, while cleaning products are the reason for benzene emissions while damp areas give rise to mould which releases spores into the air.
“The air pollution inside our homes can be as bad, if not worse than the outside air. Indoor pollution can be made worse due to indoor sources. These potentially harmful pollutants are as small as PM 0.1 and remain suspended in indoor air,” says Dr. Sandeep Nayar – Director & HOD, Centre for Chest & Respiratory Diseases, BLK Hospital.
Dyson used a standardized test process for every filter it analyzed. For each carbon particle sample, 2 grams of sample was selected to test for VOCs and formaldehyde. These then underwent patented tests undertaken by SGS China (HPLC-DAD and HS-GC-MS), says the company, and adds, For tests conducted on HEPA filters, dust was collected from each filter which was further split into 10mg samples for microscopic analysis to determine presence of pet hair, mould, bacteria, etc. “Further to this, dust mite concentration was determined by enzyme linked immunosorbent assay method. Bacterial concentration & mould concentration was determined by culture counting method and flat colony counting method. DNA extraction was subsequently used to determine bacteria community analysis,” they say.
“Our whole-room air purifiers use intelligent sensing technology to detect indoor particles and gases. They have been engineered to react automatically, drawing air through an advanced filtration system, capturing pollutants and projecting purified air throughout the whole room. We continue developing new testing methods like the POLAR test to verify the effectiveness of machines to automatically react and purify a whole room evenly,” says Abi Stringer, Design Engineer, Research Design and Development, Dyson.
The State of Global Air 2019 published by the Health Effects Institute (HEI) reports that there were 1.2 million deaths in India in 2017 because of air pollution.