AKU study finds air pollution in Karachi causing surge in respiratory disorders

Air pollution in Karachi has been creating serious respiratory health risks, particularly for men, elderly people and individuals with pre-existing lung diseases, according to a recent study conducted by the Aga Khan University (AKU).

The study, which was published in Atmospheric Pollution Research, analysed data from Karachi’s leading hospitals, including the National Institute of Cardiovascular Diseases (NICVD), Jinnah Postgraduate Medical Centre (JPMC) and Aga Khan University Hospital (AKUH).

The data highlighted a surge in respiratory-related visits correlating closely with rising pollution levels, underlining the pressing need for immediate intervention.

The AKU study focused specifically on fine particulate matter (PM2.5), a microscopic pollutant capable of penetrating deep into the lungs and bloodstream, causing systemic damage.

Researchers also detected high concentrations of sulfate, ammonium, nitrate, and black carbon across the city’s two busiest areas — Korangi and Tibet Centre on M.A. Jinnah Road. These pollutants originating from industrial emissions, vehicular exhaust and waste burning contribute heavily to Karachi’s deteriorating air quality.

Karachi’s average PM2.5 levels are among the highest globally, exceeding the World Health Organisation’s (WHO) safety thresholds by a significant margin. According to the 2023 World Air Quality Report, Pakistan ranks as the third most polluted country, with Karachi among its worst-hit cities. With dense traffic, bustling industries, and minimal green spaces, Karachi’s air pollution now poses serious health risks to its 15 million residents.

“PM2.5 particles pose the highest risk to human respiratory systems and are emitted in large quantities from human activities,” explained Prof Zafar Fatmi, head of the Environmental and Occupational Health wing at the AKU’s Department of Community Health Sciences.

“These particles have been shown to contribute to chronic bronchitis, respiratory infections and exacerbate pre-existing lung conditions. It’s time we treat air pollution as a crisis and adopt urgent measures to lower PM2.5 in our environment,” he urged.

Globally, studies indicate that air pollution is now responsible for more deaths than road accidents, tobacco use and even certain infectious diseases. Pollutants like PM2.5 are not only linked to respiratory issues but are increasingly implicated in cardiovascular diseases, stroke, cancer and impaired cognitive functions, affecting both children and adults.

According to the study, data from the NICVD, JPMC, and AKUH show an alarming rise in patients suffering from cardiovascular diseases linked to poor air quality. It cites a recent report by the American Heart Association that found that PM2.5 can significantly increase the risk of heart attacks and strokes due to its impact on blood vessels. The particles promote inflammation and oxidative stress, which can trigger blood clots and hypertension, and ultimately lead to cardiovascular episodes.

Experts said air pollution’s impact on lung health is profound, and Karachi’s high pollution levels mean that many residents are experiencing chronic respiratory issues, including asthma, bronchitis and pneumonia.

Fine particulate matter, due to its microscopic size, lodges deep in the lungs, making it difficult for the body to expel. This leads to persistent inflammation, chronic obstructive pulmonary disease (COPD), and increased vulnerability to infections.

Research from the World Health Organisation notes that long-term exposure to PM2.5 can reduce lung function, especially in children, and increases the risk of developing respiratory cancers.

Emerging research points to air pollution as a contributor to neurodegenerative diseases, including Alzheimer’s and Parkinson’s. Studies from institutions like the Harvard University have shown that PM2.5 can cross the blood-brain barrier, leading to neuroinflammation and potentially accelerating cognitive decline.

Air pollution has also been shown to impact blood health. Pollutants, particularly PM2.5 and black carbon, can interfere with oxygen transport in the blood, leading to conditions like anemia and hypoxia.

Health experts are sounding alarms emphasising the urgent need for Karachi to address its air quality crisis. “We see a pattern where hospital visits for respiratory, cardiovascular and even neurological problems spike in line with poor air quality days,” said Prof Fatmi. “Without immediate intervention, these health issues will become even more prevalent.”

To combat these challenges, public health officials are calling for strict emission regulations for industries and vehicles, development of green spaces to offset carbon emissions, and better public awareness campaigns about the dangers of pollution. According to a WHO report, each 10 g/m³ increase in PM2.5 levels corresponds with a 4% increased risk of death from all causes. In Karachi, where PM2.5 levels often exceed safe limits by several times, these interventions are increasingly

essential.