The study reveals high-risk exposure across metro

More than 40% of Cape Town residents face high or very high air pollution levels, a new study led by the University of Cape Town shows.

The study’s findings, which appear in GeoHealth, present the first high-resolution risk map for the metro, showing where pollution overlaps with social vulnerability.

High-risk areas identified

Researchers found that about 1.9 million people live in high- or very-high-risk zones. That equals 40.3% of Cape Town’s population, says Dr Meryl Jagarnath who led the study at the University of Cape Town.

Most affected areas include informal settlements and historically disadvantaged communities, Jagarnath adds: “These residents face poor housing, limited healthcare access and nearby pollution sources.”

Gaps in traditional monitoring

The study highlights limitations of current air quality tracking methods. According to Jagarnath, traditional systems focus on pollution levels only, often ignoring social and economic conditions. These conditions shape how people experience pollution exposure and health risks.

Jagarnath said Cape Town’s inequality patterns worsen environmental risk. Spatial segregation, she explained, drives unequal exposure to pollution and limits how communities respond to health threats.

How the study measured pollution

The study, which received funding from the National Research Foundation, involved collaboration with Dr Lerato Shikwambana from the South African National Space Agency. Researchers used satellite data from the European Space Agency. They measured nitrogen dioxide, sulphur dioxide, ozone and particulate matter. The team combined this with data on housing, infrastructure and demographics. This helped identify pollution “hotspots” across the city.

Policy implications

The study calls for targeted action in high-risk areas. These include cutting emissions, improving housing and expanding healthcare access. Urban green spaces also form part of recommended interventions.

Jagarnath said the risk maps can support public health planning. Air pollution links to respiratory and cardiovascular diseases. Better data can help health systems respond earlier and more effectively.

Broader significance

The study offers a model for other African cities. It shows how satellite data can support urban health research. Jagarnath said the approach strengthens environmental justice efforts. “Spatial data reveals how pollution and inequality overlap,” she said.

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