Using more than 500 billion data points, Dyson’s first Global Air Quality Connected Data project examined the indoor air quality data from more than 3.4 million connected Dyson air purifiers.
All countries’ monthly average indoor PM2.5 level exceeded WHO long-term exposure guidance for at least 6 months in the year. In New Zealand, this was true for all but one month of the year.
Two-thirds of countries experienced higher annual average indoor PM2.5 levels compared to outdoor in 2022.
Colder months were generally the most polluted in all geographies, with highest levels of pollution detected in New Zealand homes in May, almost 2 x higher than indoor pollution detected in February.
In an average 24h period, the most polluted time (PM2.5) fell between 6pm and 1am, coinciding with times when people are usually in their homes, and therefore exposed to these higher pollutant levels.
NEW ZEALAND, 11.01.2024 Today, Dyson unveils the results of its first Global Connected Air Quality Data study, which uses more than 500 billion data points from more than 3.4 million connected Dyson air purifiers worldwide, 11,844 of which were in New Zealand. The project studies indoor air quality information from 2022 to 2023 to landscape air quality in real homes across the world, to a granularity never before seen. Whilst data is based on homes with Dyson purifiers and as such is not nationally representative, the volume of data reaches into the tens of billions of data points and paints a picture of indoor air quality in cities and countries globally beyond the scale that has been achievable to date.
From a wealth of data, this project focuses on two types of pollutants – PM2.5 and Volatile Organic Compounds (VOCs). PM2.5 refers to particles as small as 2.5 microns in diameter; a typical human hair measures around 70 microns in diameter. 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 – pollens, pet dander and dust. VOCs are gas pollutants including Benzene and Formaldehyde which can be emitted from activities like cleaning or cooking as well as from products including deodorants and body sprays, candles, furniture and furnishings.
“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
PM2.5 levels exceeded WHO guidelines
The majority of countries studied exceeded outdoor PM2.5 levels for six months or more. While this was not the case for New Zealand, all countries’ monthly average indoor PM2.5 level exceeded WHO long-term exposure guidance for at least 6 months in the year. In New Zealand, this was true for all but one month of the year. The indoor annual average PM2.5 levels in New Zealand in 2022 was 6.85μg/m³., which exceeds the WHO guideline limit for the average PM2.5 exposure (<5μg/m³).
Highest levels of indoor PM2.5 pollution was detected in the colder months, with May showing the highest levels (8.46μg/m³). This was almost 2 x higher than indoor pollution detected in February (4.46μg/m³), which was the month with lowest pollution in New Zealand.
“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
Highest indoor pollution detected in the evening
In most countries studied, indoor PM2.5 levels were highest during the evening and night-time hours, coinciding with the time that the majority of people spend in their homes, rather than being out at work, school or elsewhere.
This was reflected in the New Zealand results, with highest levels of PM2.5 and VOCs pollution in homes in New Zealand were detected from 6pm-1am, which is consistent with the global findings. This coincides with times when people are usually in their homes and therefore exposed to these higher pollutant levels. Levels were lowest at 1pm, with over a 50% increase in VOCs pollution from during the day to during the night. New Zealand featured in the top 20 (number 18) of VOCs rankings of countries surveyed globally (39 countries). Indoor PM2.5 levels in New Zealand were 2.5 times as high at 8pm compared to 5am. Highest levels of PM2.5 were detected at 10pm (6.885μg/m³) whereas the lowest levels were at 5am (3.215μg/m³).
Exposure is the measure of air pollution concentration over time, which within the air quality research community is a key consideration – a spike of air pollution (a very high level for a short period of time) isn’t necessarily worse than prolonged exposure to ‘poor’ or even ‘fair’ air quality. Therefore, data from Dyson Purifiers suggests that this longer, more polluted period may account for increased exposure to PM2.5 in homes.
PM2.5 annual averages: a surprisingly global picture
When looking globally at the data from Dyson connected purifiers throughout 2022, there are some surprising results when ranking countries on their average PM2.5 level. Whilst India and China occupy the top two spots, likely due to the relationship between indoor and outdoor air quality, Romania ranks 6th, Italy 8th and Poland 9th and Austria 10th. The UK (22nd) outranks the United States (26th), Canada (27th) and Australia (28th), but Germany and France rank higher, at 17th and 18th respectively. Indoor PM.5 annual averages in all countries studied exceeded the WHO annual guideline for PM2.5 (5 µg/m3) – India by 11 times, China by 6 times, Turkey and UAE by 4 times, and South Korea, Romania, Mexico and Italy by 3 times.
At a city level, the top five cities by average annual PM2.5 are all in Asia – Delhi, Beijing, Shanghai, Shenzhen and Busan, followed by Istanbul, Dubai, Seoul, Mexico City and Vienna. Similarly to the country-level data, every city studied exceeded the WHO long-term or annual exposure guideline for PM2.5 (5 µg/m3) – even Sydney, which takes last place in the rankings, registered an annual average PM2.5 level of 6.78 µg/m3. Delhi homes exceeded the WHO guideline by 14 times, Beijing by more than 6 times and Shanghai more than 5 times. Osaka, Los Angeles, Paris, Tokyo, Amsterdam, Munich, Taipei and Dublin homes all experienced double the WHO annual guideline for PM2.5.
Low uptake of Auto mode globally
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 monitor and adjust to pollution events. In New Zealand, just 3% of Dyson purifier owners spend more than three-quarters of the time in Auto mode, with the majority changing the settings manually.
Notes
About the study
The Dyson Global Connected Air Quality Data project analyses more than half a trillion data points to paint a picture of the air quality in real homes around the world, understand user behaviours and compare indoor and outdoor air quality. The total global sample size in New Zealand is 11,844. The indoor air quality studied is based on the location of Dyson Purifiers in homes and as such is not nationally representative.
Indoor air quality data is taken from Dyson Purifiers that are connected to the MyDyson app and in monitoring-only mode – that is, not actively purifying the space. Whilst this reduces the sample size for the calculation, Dyson data scientists can be confident that it is an accurate representation of air quality in real homes, without the impact of Dyson Purifiers actively cleaning the air.
From a wealth of data, Dyson data scientists have focused on PM2.5 and VOC data, analysing the measurements from 1st January to 31st December 2022. Data is collected by the machines every 1 minute, which is time-averaged into averages by hour, day, month, season and year depending on the calculation in question. For all the mean estimates, we consider the 99% credible interval to ensure accurate, statistically significant spatial and/or temporal comparisons.
Outlier machines have been removed as part of data cleansing. For example, machines that are showing extremely high particle pollution in a region where this trend is not reflected across the board, may have a blockage in the sensor which might skew the data readings. These types of outliers have also been removed. A machine “in Auto mode” is determined by it spending >75% of each day in the year in Auto mode. This allows for ~6 hours of the day on manual, which would account for it being used manually in heating or cooling mode.
Machines are not all on for 24 hours a day, for every day of the year. As such, machine data is weighted in line with the proportion of the given time-frame that each machine is on, connected to the MyDyson app and recording data. For example, if a machine is only connected to the MyDyson app for 6 months of the year, the machine would be weighted less than a machine connected year-round.
Outdoor air quality data is sourced primarily from OpenAQ, and from the World Air Quality Project in Shenzhen, Fukuoka, Osaka, Amsterdam and Taipei.
Countries studied: Australia, Austria, Belgium, Canada, China, Czechia, Denmark, Finland, France, Germany, Greece, Hungary, India, Indonesia, Ireland, Israel, Italy, Japan, Malaysia, Mexico, Netherlands, New Zealand, Norway, Philippines, Poland, Portugal, Romania, Saudi Arabia, Singapore, South Korea, Spain, Sweden, Switzerland, Thailand, Turkey, UAE, UK, USA, Vietnam
Cities studied: Amsterdam, Bangkok, Beijing, Berlin, Bristol, Brussels, Busan, Chicago, Cologne, Copenhagen, Delhi, Dubai, Dublin, Fukuoka, Hanoi, Hong Kong SAR, Istanbul, Jakarta, Kuala Lumpur, London, Los Angeles, Lyon, Madrid, Manchester, Manila, Marseille, Melbourne, Mexico City, Milan, Mumbai, Munich, New York, Osaka, Paris, Rome, Seoul, Shanghai, Shenzhen, Stockholm, Sydney, Taipei, Tokyo, Toronto, Vienna
About Dyson
Dyson is a global research and technology company with engineering, research, development, manufacturing and testing operations in Singapore, the UK, Malaysia, Mexico, China and the Philippines. Having started in a coach house in the UK, Dyson has consistently grown since it was established in 1993. Today, it has a global headquarters in Singapore and two technology campuses in the UK spanning over 800 acres in Malmesbury and Hullavington. Since 1993, Dyson has invested more than £1bn in its Wiltshire offices and laboratories that house the early-stage research, design and development of future Dyson technology. Dyson remains family-owned and employs 14,000 people globally including a 6,000 strong engineering team. It sells products in 84 markets in over 350 Dyson Demo stores, 50 of which opened around the world in 2021 including a new Dyson Virtual Reality Demo Store.
In 2020, Dyson committed an additional £2.75bn in the business to conceive revolutionary products and technologies, and has global teams of engineers, scientists and software developers focused on the development of solid-state battery cells, high-speed electric digital motors, sensing and vision systems, robotics, machine learning technologies and A.I. investment. Since inventing the first cyclonic bagless vacuum cleaner – DC01- in 1993, Dyson has created problem solving technologies for haircare, air purification, robotics, lighting and hand drying.
In 2019, Dyson launched a national air quality education initiative in partnership with Little Scientists Australia, a not-for-profit program for early childhood educators and teachers. As part of the project, Dyson donated 100 purifying fans to early learning centres across Australia which educators used to provide air science education through hands-on practical demonstrations, while cleaning the air that they and the children breathed. During Australia’s bushfires in 2020, Dyson donated $600,000 worth of products including purifiers and vacuums to bushfire-impacted Australian communities to support relief efforts. This included 400 Dyson Pure Cool purifying fans being sent to Government schools impacted by bushfire smoke pollution in the ACT.
In 2022, Dyson conducted a pioneering citizen science study measuring children’s exposure to air pollution on their commute to and from school in Melbourne’s inner west. Students wore Dyson’s air quality backpack to collect air quality data on the move. The study, titled ‘Breathe Melbourne’ is led by Deakin University in collaboration with Dyson. It aim to equip, empower and educate children as air quality scientists, raise community awareness and collect valuable data to help tackle inner-city air pollution.
The James Dyson Foundation, Dyson’s charitable arm, introduces young people to the exciting world of engineering, encouraging them to think differently, make mistakes and realise their engineering potential. To better educate children on the impacts of pollution and encourage them to think of solutions, the James Dyson Foundation developed a free reaching resource for classrooms around the world – ‘Engineering Solutions: Air Pollution.’ Designed using Dyson engineers’ expertise in air science, it supports teachers to bring to life one of the most pressing problems facing the world.
