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Dyson Connected Purifier Data: Singapore ranked 4th globally amongst countries with poorest indoor air quality when compared to outdoor air quality

The largest study of its kind, Dyson’s first Global Air Quality Connected Data project examined the indoor air quality data from more than 2.5m connected Dyson air purifiers

18 January 2024

  • Two-thirds of countries experienced higher annual average indoor PM2.5 levels compared to outdoor in 2022. 
  • Singapore saw average annual indoor PM2.5 levels 36% higher than outdoor PM2.5, placing it 4th globally amongst countries with the poorest indoor air quality when compared to outdoor air quality in 2022.
  • All countries’ monthly average indoor PM2.5 level exceeded the World Health Organisation’s (WHO) long-term exposure guidance for at least 6 months in the year. 
  • Singapore saw indoor annual average PM2.5 levels exceed WHO annual guidelines by 1.8 times, placing it 14th globally amongst countries with the highest annual indoor average PM2.5 levels in 2022.
  • In an average 24h period, the most polluted time (PM2.5) fell between 6pm and midnight, coinciding with times when people are usually in their homes.

Today, Dyson unveils the results of its first Global Connected Air Quality Data project. The project analyses indoor air quality information collected by more than 2.5 million Dyson Purifiers from 2022 to 2023 to landscape air quality in real homes across the world. This is done, to a high degree of granularity, breaking down pollution into gas and particle pollutants, and profiling trends over days, months, seasons and the full year. The data comes from Dyson Purifiers connected to the MyDyson™ app; the volume of data exceeds half a trillion data points and paints a precise picture of indoor air quality in cities and countries globally to help build understanding and awareness of indoor air pollution.

What is PM2.5? What are VOCs?

From a wealth of data, this project focuses on two types of pollutantspollutant – PM2.5, and Volatile Organic Compounds (VOCs). PM2.5 refers to particles as small as 2.5 microns in diameter, 1/25th the diameter of a typical human hair. These particles are invisible to the naked eye, can be inhaled and are an area of increasing scientific and health research. Sources include combustion, – wood burners, or gas cooking and heating – pet dander, ash and dust. VOCs are gas pollutants including Benzene and Formaldehyde which can be emitted from activities like cleaning, or gas cooking as well as from products including deodorants and body sprays, candles, furniture and furnishings. 

According to the WHO, long-term exposure to PM2.5 is a likely cause for respiratory effects, cardiovascular and respiratory mortality and conditions such as lung cancer. Notably, the 2019 annual population weighted PM2.5 concentrations from the WHO Global Ambient Air Quality Database were highest in the South-East Asia Region. 

The United States Environmental Protection Agency (EPA) identifies common household products such as paints, aerosol sprays, disinfectants, cleansers and air fresheners as sources of VOCs. According to the WHO, VOCs such as Benzene have been associated with a range of acute and long-term adverse health effects and diseases, including cancer and hematological effects. 

“Our connected air quality data allows us insight into the real problem of indoor air pollution in homes across the world. This gives us a direct understanding of the challenges Dyson Purifiers face in real environments and the knowledge to engineer ever-better machines to tackle those challenges. But the data we capture isn’t just an engineering tool – on an individual basis, this data is shared back through the MyDyson app in real-time and via monthly reports, to help our Owners improve their air quality understanding.” Matt Jennings, Engineering Director for Environmental Care

We all think of air pollution as being an outdoor or roadside problem. Indoor air pollution research is growing but continues to be underdeveloped. Dyson's findings give us a valuable insight into the real pollution levels in homes across the world, helping us to understand the patterns of pollution daily, monthly and seasonally. The Dyson data is an incredibly powerful education tool and the opportunities for positive impact are boundless – understanding the pollution around us is the first step to reducing our pollution exposure.” Professor Hugh Montgomery, Chair of Intensive Care Medicine at University College London, and Chairperson of Dyson’s Scientific Advisory Board

“Indoor air pollution can be a cause of health problems when left unchecked. Dyson’s study showcases the prevalence of poor indoor air quality in Southeast Asia and dispels the common myth that outdoor air quality is always worse. This can support public understanding of indoor air pollution and is a prompt for clinicians to adopt a holistic view when managing allergic rhinitis, asthma, and bronchitis among other health issues.” – Dr Ong Kian Chung, Respiratory Physician and President of the Chronic Obstructive Pulmonary Disease (COPD) Association of Singapore.

PM2.5 annual average: Singapore exceeds WHO annual guidelines by close to 2 times

  • When looking globally at the indoor air quality data from Dyson connected purifiers throughout 2022, there are some surprising results when ranking countries on their average PM2.5 level. Whilst India, China and Turkey occupy the top three spots, four countries from Southeast Asia, including Singapore, occupied the list of top 15 countries globally with the worst indoor annual average PM2.5 levels.

    With PM2.5 annual indoor average levels at 14.21μg/m³, Singapore exceeds the recommended annual exposure level of 5μg/m³ by 180%. The data also found that monthly indoor PM2.5 levels in Singapore exceeded WHO guidelines across all months in the year, with a low of 11.28μg/m³ in December 2022 and a high of 17.95μg/m³ in April 2022. 

    Meanwhile, PM2.5 average annual outdoor levels were also found to be at 10.46μg/m³ - over 109% higher than the WHO recommended level of 5μg/m³.

VOCs annual average: Europe claims top rankings

  • In contrast to PM2.5, it is European countries that experienced the highest annual average VOC levels according to Dyson Purifiers. Austria tops the list, followed by Romania, Germany, Switzerland, and Poland.

    Southeast Asian countries emerged from 19th position, with Singapore faring worse than neighbouring country, Malaysia, with VOC Annual Average levels of 190.37 parts per billion (ppb) as compared to 171.42 ppb in Malaysia. 

Indoor air quality VS Outdoor air quality: Singapore takes 4th spot

When looking at PM2.5 annual average indoor levels versus PM2.5 annual average outdoor quality levels, the data from Dyson purifiers yielded surprising results. 19 countries globally were found to have indoor air quality poorer than outdoor air quality on average, with Singapore notably taking the fourth spot after China, Austria and Spain. Except for April, July, October and September 2022, monthly average indoor PM2.5 levels in Singapore were poorer than outdoor levels – bringing indoor air quality in Singapore to be 1.36 times worse on average than outdoor air quality.

Low uptake of Auto mode globally and in Singapore

  • Globally, just 8% of Dyson Purifiers spend more than three-quarters of the time in Auto mode – where the machine constantly monitors the air quality and automatically responds to changing pollution levels – suggesting that Dyson machines in homes across the world are not being used to automatically manage the pollution events in homes these connected air quality data insights show. The US leads the way on proportion of purifiers in Auto mode (14%), with Chicago topping the list of cities, followed by New York, Toronto and Los Angeles. 

    Some of the cities with the lowest proportion of machines in Auto mode correlate to those who rank highly in pollution levels on a daily, monthly and average basis – in particular PM2.5 – including Shenzhen (2.2%), Mexico City (2.4%) and Shanghai (3%) which note the three lowest percentages of purifiers in Auto mode. 

    Just over 3% of Dyson purifier users in Singapore use their machines in Auto mode despite high levels of indoor air pollution and seasonal haze.

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Debra Rajwani

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