Sir Stephen Holgate’s findings reveal that air pollution is a major driver of multiple non-communicable diseases. It affects every organ in the body, contributing to more than 700 diseases including dementia, diabetes and cardiovascular illness.
His research has reshaped how the UK perceives and manages air pollution and has contributed to measurable policy change, reinforcing the urgent need for coordinated public health action.
Policy changes include the UK’s Clean Air Strategy and public awareness initiatives such as London’s ULEZ that have improved lung growth in children.
Decades of research
Sir Stephen has spent decades uncovering how allergens, viruses and air pollutants drive asthma and related diseases. His research has shaped national debates on outdoor and indoor air quality.
He has become one of the most influential voices in environmental health policy with his landmark reports such as Every Breath We Take and The Inside Story, his leadership of the UKRI Clean Air Programme, his roles as an expert witness in the Ella Adoo-Kissi-Debrah case and Special Advisor to the Royal College of Physicians’ (RCP) on air quality.
He laid the foundation for the advocacy of cleaner air after revealing how air pollutants trigger airway inflammation that worsens lung diseases.
His research demonstrated that short-term exposure to vehicular pollutants, such as NO₂, diesel exhaust, ozone and fine particulate matter, damage the lung’s lining and caused inflammatory symptoms.
His later work revealed poor indoor and outdoor air quality increase the risk of asthma and recurrent wheezing illnesses in susceptible children. These discoveries have informed major public health initiatives.
An international influence
Sir Stephen became the first Chair of the UK’s Committee on the Medical Effects of Air Pollutants and led DEFRA’s Expert Panel on Air Quality Standards.
He helped develop the UK Daily Air Quality Index that alerts the public to pollution risks, directly influenced the UK Government's Clean Air Strategy and the World Health Organization’s (WHO) air quality guidelines.
He also oversaw the RCP’s landmark 2016 report Every Breath We Take: The Lifelong Impact of Air Pollution that linked air pollution to around 40,000 premature UK deaths annually. It has become one of the most cited publications in the RCP’s history.
In 2013, Sir Stephen served as an expert witness in the case of nine-year-old Ella Adoo-Kissi-Debrah, whose death from asthma became the first in the world to have air pollution cited on a death certificate.
His detailed testimony linked Ella's illegal pollution exposure to profound airway damage, a finding that helped position air pollution as a public health priority. The case became a catalyst for stronger clean air legislation and interventions including the London Ultra Low Emission Zone (ULEZ).
Following the ruling, the Greater London Authority and the UK Government admitted liability for Ella’s death. Her mother, Rosamund, is now both a UK and a WHO Clean Air Ambassador.
Building on this case, Sir Stephen co-authored two reports:
- The Inside Story: Health effects of indoor air quality on children and young people - the first comprehensive report on the health impacts of indoor air pollution on children and young people
- A Breath of Fresh Air: responding to the health challenges of modern air pollution – that sets out 19 recommendations for national and local governments and health practitioners
Shining a light on indoor air quality
As a UKRI Clean Air Champion, Sir Stephen has overseen a £42.5million UKRI Clean Air research programme to advance air quality science and inform future policy by linking over 32 projects, networks and consortia. He is now leading a Coordination Node to augment the communication and outreach activities for seven hubs of the £42million UKRI/NIHR Net Zero Health Benefits research programme.
This work is shining a light on how poor the indoor air quality is in UK homes that is characterised by damp, mould, allergens, and pollution. This is causing and worsening asthma and other diseases, with the greatest burden falling on disadvantaged communities.
My research is continuing to influence policy, legal frameworks, and clinical practice to deliver lasting health benefits for vulnerable populations, especially the disadvantaged and children, and ensuring cleaner air for future generations.
Sir Stephen Holgate, Professor of Immunopharmacology
