A team of ‘human probes’ traverse Shenzhen and Hong-Kong to detect urban air pollution. Sensor data reveals atmospheric boundaries between the two cities: very real divisions... made of nothing but air.

Check out senseable.mit.edu soon for our Breathing Cities Initiative.

Amidst a matrix of towering skyscrapers and dense streets, citizens inhabiting two vertical cities are connected by nothing but air… the breathing, invisible, and interconnected landscapes of Hong Kong and Shenzhen. Is it possible to visualize the ebbs and flows of the cities’ atmosphere? How do humans fit into this binary urban ecosystem? Can we map what people breathe and absorb, showing the dynamics of air pollution? How can these results empower citizens to transform the urban space around them?

Like a tracer running through the veins of the cities, an array of sophisticated human-borne sensors draws a dynamic map of Hong Kong and Shenzhen on the human scale, showing how we live in and move through urban space, breath by breath. Until today, the precision of air quality measurements has been limited by static and sparse ground-based stations. Thanks to the development of miniature, networked sensors, today we can accurately zoom into the individual scale - measuring personal exposure, the main determinant of health.

Particulate Matter (PM10), Carbon Monoxide (CO) and Nitrogen Dioxide (NO2), together with personal data associated with travel – such as spatial position, pace and heart rate – are collected by a team of researchers, as they traverse Hong Kong and Shenzhen in prototypical commuting patterns while carrying measurement instruments. Initial results show that air pollution in Shenzhen is higher than in Hong Kong - in particular the levels of small aerosol particles that have the most adverse effects on human health.

By showing the invisible inequality between these two cities and making it public, citizens can take action - politically, or with their feet, on their daily commutes. The Chinese central government in Beijing coined the slogan ‘One Country, Two Systems’ during the 1980s, at the time of Hong Kong’s sovereignty transfer. Today, ‘One country, Two Lungs’ explores how this divide still persists in one of the less visible dimensions of urban life: distinct but interconnected atmospheres. A living map split by very real divisions... made of nothing but air.

Air Quality Statistics

An urbanizing planet: since 2008, more than half of the human population lives in cities - which amounts to over 3.6 billion people today. This number is projected to swell to 5 billion by 2030.

Air quality worldwide: the World Health Organization estimates its effects at over one million deaths per year.

Hong Kong and Shenzhen: a metropolitan area with over 17 million inhabitants, one of one of the world’s largest and most densely populated urban spaces.

Threats to air quality: emissions from traffic and coal-powered electricity plants on mainland China create pollution, while Hong Kong’s tall buildings sequester stagnant air.

Toxic impact: researchers estimate the financial burden of air pollution to Hong Kong at approx. HK$21.2 billion (USD$2.7 billion) a year due to hospital admissions and lost productivity.

MIT Senseable City Lab :.::

Carlo Ratti, Director & Curator
Assaf Biderman, Associate Director
Yaniv Jacob Turgeman, R&D Lead
Davide Zilli, Project Lead
Marguerite Nyhan, Lead Data Scientist
Rex Britter, Scientific Advisor
Matthew Claudel, Curator
Mike Xia, Hardware Developer

Special Thanks to Sensaris



Otto Ng, Director & Curator
Yip Chun Hang, Director & Curator
Kenneth Cheung, Lead Data Scientist
Tim Tsui, Data Scientist
Angel Li, Travel Manager
Joe Lam, Translator
Lewis Hung, Curatorial Assistant
Ng Kin Mo, Curatorial Assistant
Jason Choi, Curatorial Assistant
Li Yuen Lung, Fabricator
Li Chi Lung, Fabricator
Ricci Wong, Director
Geoff Chan, Director

Download Press materials,

The material on this website can be used freely in any publication provided that:
It is duly credited as a project by the MIT Senseable City Lab. PDF copy of the publication is sent to senseable-press@mit.edu
For more information, senseable-contacts@mit.edu