The haze, in recent times, has reminded the public of the impact of air pollution on their lives, specifically their health.
While the focus has been on air pollution from the forest fires in Indonesia, there is less attention on what Malaysia can do locally to reduce air pollution, which is something within our control and not that of another government’s.
Leaving aside the forest fires within Malaysia, there is another factor that can be acted upon, i.e. traffic-related air pollution, which is a risk factor for lung disease and early death.
The health burden of air pollution was looked at by Britain’s Imperial College London, which found that it contributed to premature deaths in about 4,000 Londoners in 2019.
The causes included lung cancer, respiratory disease and cardiovascular (heart) disease.
The British Heart Foundation reported that living in London increased the risk of premature death by the equivalent of smoking 150 cigarettes a year.
In a landmark decision in December 2020, Coroner Phillip Barlow ruled that a nine-year-old girl in South London died in 2013 as a direct result of air pollution, stating that air pollution made a “material contribution to her death”.
Charging to lower emissions
The World Health Organization’s (WHO’s) global air quality guidelines (AQG) are evidence- based recommendations to protect public health from the adverse effects of air pollution.
There are AQG levels for particulate matter (PM2.5 and PM10), nitrogen dioxide, ozone, sulphur dioxide and carbon monoxide.
Road transport accounts for about 28% of carbon emissions in London.
These emissions are the atmospheric release of carbon compounds, primarily carbon dioxide and methane, which trap heat and drive global warming.
The plans for an ultra-low emission zone (Ulez) were laid by then-London Mayor Boris Johnson, who announced in 2015 that the zone would cover the same areas as the Congestion Charge Zone (CCZ) of central London by September 2020.
Since 2003, a fee has been levied on cars and vehicles driven in London’s CCZ between 7am and 6pm on weekdays, and between 12pm to 6pm on weekends.
Enforcement is primarily based on automatic number plate recognition, similar to Singapore’s Electronic Road Pricing System.
Sadiq Khan, who was Johnson’s successor, introduced an emissions surcharge termed “toxicity charge” for non-compliant vehicles in 2017.
The toxicity charge was replaced by the Ulez on April 8, 2019.
The Ulez was expanded on Oct 25, 2021, to include inner London, covering an area with 3.8 million people.
This was further expanded to all 32 London boroughs – an area of 1,500 square km – on Aug 29, 2023, with an additional five million people included.
The Ulez was targeted at getting the most polluting vehicles off the roads.
Vehicles that do not meet the Ulez emission standards have to pay GBP12.50 (RM67.60) daily to drive within London.
Currently, nine in 10 cars and eight in 10 vans driven in outer London on an average day meet the Ulez standards.
Studying clean air and lungs
There is a strong association between exposure to traffic-related air pollution and impaired lung development in children and adolescents.
The failure to reach maximal lung growth is a known risk factor for asthma, chronic obstructive pulmonary disease (COPD), cardiometabolic disease and premature death.
Clean air areas are policy interventions that can reduce traffic-related air pollution in urban areas.
The impact of clean air zones on poor lung growth is not known.
However, a novel study, published in October’s (2026) edition of The Lancet Public Health journal, provided a compelling case that clean air zones are helpful for lung growth or development in children.
The Children’s Health in London and Luton (CHILL) study was a prospective, two-arm, parallel cohort study.
Children aged six to nine years from primary schools in central London (the original area of the Ulez implementation) and Luton (a comparator site with no clean air zone) were recruited.
Children with symptoms of lung disease (excluding asthma), learning or physical disabilities were excluded.
Lung function was measured by spirometry during annual school visits at baseline (before Ulez implementation) and in the subsequent four years.
Annual residential exposures to nitrogen dioxide and particulate matter with diameters of less than 10μm (PM10) and less than 2.5μm (PM2.5) were estimated at each child’s home address.
The primary outcome was the annual rate of lung function growth, measured as post-bronchodilator FEV1 (forced expiratory volume in one second) over the five-year study period.
Growth trajectories were assessed against individualised residential exposure to nitrogen dioxide, PM10 and PM2.5.
Lung function growth between London and Luton were compared, and the association between air pollution exposures and lung growth were assessed.
Forty-four schools with 1,664 children in London, and 40 schools with 1,750 children in Luton agreed to participate.
Ninety-four percent of the children were included in the FEV1 analysis.
The children were similar across the two sites in terms of age, height and weight, with a higher proportion of girls in London (56%) than in Luton (49%).
The baseline-adjusted FEV1 was lower in London than Luton (a difference of 38ml).
At baseline, the children’s modelled annual exposures to nitrogen dioxide – the pollutant most reflective of exhaust emissions – were 18.95 μg/m³ higher in London than in Luton.
Over the five-year study period, children’s FEV1 growth increased by 10ml/year more in London than in Luton, with modelled residential exposures to nitrogen dioxide decreasing faster in London than in Luton.
After four years, mean FEV1 reached parity across both cities: 2,283ml in London and 2,282ml in Luton.
The proportion of children with clinically-impaired lung function fell from 184 (14%) of 1,280 children to 51 (9%) of 585 children in London, and from 126 (9%) of 1,339 children to 41 (7%) of 606 children in Luton.
The researchers stated that their findings showed that “quality improvements following implementation of a clean air zone are associated with accelerated lung growth trajectories, a key parameter of children’s development relating to risk of future morbidity and mortality.
“Children continue to be exposed to poor air quality in cities globally.
“Decision-makers globally should consider accelerating the introduction of clean air zones to improve children’s lung health”.
Lessons for Malaysia
According to the 2025 World Air Quality report, Malaysia’s annual average PM2.5 concentration fell from 18.3 μg/m³ in 2024 to 16 μg/m³ in 2025.
Kuala Lumpur recorded an 11% improvement, dropping from 17.7 μg/m³ to 15.7 μg/m³.
However, the numbers still exceed WHO’s annual AQG of 5 μg/m³.
This means that millions of Malaysians remain exposed to unhealthy levels of air pollution.
The Ulez in London is projected to:
- Reduce harmful roadside nitrogen dioxide, with levels 46% lower in central London and 21% lower in inner London than they would have been without the Ulez
- Prevent more than one million air pollution-related hospital admissions by 2050
- Help save Britain’s National Health Service (NHS) and social care system in London GBP5bil (RM27bil), due to the projected reduction in hospital admissions.
The number of cars continue to increase in Malaysia, with traffic jams – and by extension, traffic-related air pollution – the norm in the urban areas.
Whils the government’s emphasis has been on the economy, it is time to also factor in the impact of traffic-related air pollution on our children’s health, especially their lung development.
We do not need to reinvent the wheel.
All that is needed is humility and the political will to learn from the experiences of others.
Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email starhealth@thestar.com.my. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
