Measuring the Air We Breathe, Understanding the Science, and Confronting a Governance Crisis in Pakistan and Sindh
- In Pakistan, air pollution is not a future risk or an abstract environmental debate. It is a daily lived reality. Burning eyes, chronic coughs, breathlessness, and cardiovascular illness have become common experiences across cities
Mohammad Ehsan Leghari
Human beings take roughly twenty thousand breaths every day. With each breath, we draw oxygen into our lungs, but we also inhale whatever else is suspended in the air around us. In Pakistan and province of Sindh, this means that every day, millions of people are unknowingly breathing in a complex and invisible mixture of toxic gases and microscopic particles. Air pollution has therefore become one of the most serious yet least confronted public health crises of our time. The World Health Organization has aptly described it as a “silent killer,” capable of causing disease and premature death even at concentrations once thought to be safe (WHO, 2021).
Despite its deadly consequences, air quality has remained a marginal concern in Pakistan’s development and governance priorities. The air we breathe is no longer a simple mixture of oxygen and nitrogen. It has become a chemically active cocktail of particulate matter, nitrogen oxides, sulfur dioxide, carbon monoxide, ozone, and other pollutants that quietly penetrate our lungs, bloodstream, and vital organs. This invisible threat does not announce itself with sirens or headlines; it reveals itself slowly through rising hospital admissions, weakened lungs, heart disease, strokes, and shortened life expectancy (Pope and Dockery, 2006).
In Pakistan, air pollution is not a future risk or an abstract environmental debate. It is a daily lived reality. Burning eyes, chronic coughs, breathlessness, and cardiovascular illness have become common experiences across cities. From Karachi’s traffic-clogged roads to the rapidly expanding urban sprawl of Hyderabad, from the dusty winds of Sukkur to brick kilns and dust highways across Sindh, polluted air has become normalised. Pakistan’s major cities now rank among the most polluted in the world, particularly during winter months when atmospheric conditions trap pollutants close to the ground (World Bank, 2020). While Lahore often dominates national and international attention due to severe smog episodes, Sindh’s cities are deeply embedded in the same crisis. Karachi, despite its coastal geography, suffers persistently from vehicle emissions, industrial activity, port operations, diesel generators, and construction dust, with air quality frequently falling into unhealthy or hazardous ranges (Pak-EPA, 2010). Other major cities, once considered comparatively clean, are now experiencing rapid deterioration due to unplanned urban growth, rising vehicle numbers, conversion of agriculture land into housing schemes, agricultural burning, brick kilns on its outskirts, and rapidly shrinking green spaces.
From a scientific perspective, air pollution is not a single substance but a mixture of pollutants that broadly fall into two categories. Primary pollutants are emitted directly into the air from identifiable sources such as vehicle exhaust, industrial smokestacks, power plants, generators, and household combustion. These include particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide, and lead. Secondary pollutants, by contrast, are formed in the atmosphere itself through chemical reactions driven by sunlight and heat. Ground-level ozone, the main component of smog, is the most well-known example. It is not emitted directly by any source but is created when nitrogen oxides and volatile organic compounds react under sunlight (Seinfeld and Pandis, 2016).
Among all pollutants, fine particulate matter poses the gravest health risk. Particles smaller than ten micrometres (PM₁₀) and especially those smaller than 2.5 micrometres (PM₂.₅) are generated by vehicle exhaust, coal and biomass burning, industrial processes, brick kilns, and resuspended road dust. PM₂.₅ is particularly dangerous because it can bypass the body’s natural defences, penetrate deep into the lungs, and pass directly into the bloodstream. Once inside the circulatory system, these particles trigger systemic inflammation, damage blood vessels, and significantly increase the risk of heart attacks, strokes, lung cancer, and premature death (Brook et al., 2010). This is why air pollution is no longer understood as merely a respiratory issue; it is now recognised as a whole-body health crisis.
Children face severe public health impacts; as they breathe more air per unit of body weight than adults, and their lungs, brains, and immune systems are still developing. Scientific studies have linked prenatal and early childhood exposure to air pollution with low birth weight, premature birth, impaired lung growth, and increased lifetime vulnerability to asthma and respiratory disease (WHO, 2021). Long-term cohort studies have shown that children raised in highly polluted environments can enter adulthood with permanently reduced lung capacity, a deficit that may never be reversed (Pope and Dockery, 2006).
Air pollution also exposes deep social and spatial inequalities. Pollution does not affect all populations equally. Industrial zones, highways, ports, warehouses, and brick kilns are disproportionately located near low-income communities, where residents have fewer resources to mitigate exposure or access healthcare. Monitoring data around the world consistently shows “hotspots” where pollution levels are significantly higher than city averages, translating into higher disease burdens for already vulnerable populations. Clean air, therefore, is not only an environmental issue but a fundamental question of environmental justice (World Bank, 2020).
Sindh’s vulnerability to air pollution is shaped not only by emissions but by governance weaknesses, urban planning choices, and geography. Rapid urban expansion has taken place without adequate public transport, increasing reliance on motorcycles and private vehicles. The lack of green spaces, insufficient tree cover, and continuous construction worsen dust and heat retention. Sindh’s dry climate and dusty terrain amplify particulate pollution, while climate change alters wind patterns and temperature profiles, allowing pollutants to remain suspended in the air for longer periods (EEA, 2019). Institutional responsibility for air quality management remains fragmented, with weak coordination and limited enforcement capacity.
Effective air pollution control begins with a simple but powerful principle: what cannot be measured cannot be managed. Air quality monitoring provides the scientific foundation for policy, regulation, and public awareness. Using specialised instruments, scientists measure concentrations of key pollutants such as PM₂.₅, PM₁₀, ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide. These measurements are translated into the Air Quality Index (AQI), which converts complex chemical data into a single, health-based number that the public can easily understand (US EPA, 2018). The AQI is calculated by comparing observed pollutant concentrations with health-based breakpoints derived from epidemiological research, with the highest pollutant value determining the overall index. This reflects the reality that health risk is driven by the most dangerous pollutant present at any given time.
In Pakistan, the AQI has become widely referenced during smog episodes, yet its reliability remains limited by the scarcity of monitoring stations. A handful of stations cannot capture neighbourhood-level variations in exposure. The absence of data does not imply clean air; it indicates decision-making in the dark. Recent advances in low-cost air quality sensors offer an important opportunity to fill these gaps. These compact devices, when properly calibrated, can generate high-resolution pollution maps and reveal hidden hotspots. However, their data quality depends on careful calibration, environmental correction, and integration with reference-grade monitors (Vallero, 2020).
Air pollution forecasting represents the next stage in protecting public health. Traditional atmospheric dispersion models simulate pollutant movement using emissions, meteorology, and terrain. More recently, machine-learning and deep-learning models have been used to capture complex temporal and spatial relationships in pollution data. Hybrid systems that combine physical modelling with data-driven approaches offer the greatest potential for early warning systems, allowing governments and communities to act before pollution peaks rather than after damage is done (Seinfeld and Pandis, 2016).
Ultimately, air pollution in Pakistan is not the inevitable price of development. It is the outcome of weak governance, delayed action, and misplaced priorities. The same sources that poison our air also drive climate change, meaning that clean air policies can deliver immediate health benefits while supporting long-term climate goals. Every breath should sustain life, not undermine it. The science is clear, and the costs of inaction are written on our hospitals and children’s lungs. The question is no longer whether we understand the problem, but whether we are prepared to act before the damage becomes irreversible.
References
Bell, M.L., Dominici, F. and Samet, J.M. (2005). A meta-analysis of time-series studies of ozone and mortality. Environmental Health Perspectives, 113(6), 751–757.
Brook, R.D., Rajagopalan, S., Pope, C.A. et al. (2010). Particulate matter air pollution and cardiovascular disease. Circulation, 121(21), 2331–2378.
European Environment Agency (EEA) (2019). Air Quality in Europe – 2019 Report. Copenhagen.
Pakistan Environmental Protection Agency (Pak-EPA) (2010). National Environmental Quality Standards for Ambient Air. Government of Pakistan.
Pope, C.A. and Dockery, D.W. (2006). Health effects of fine particulate air pollution. Journal of the Air & Waste Management Association, 56(6), 709–742.
Seinfeld, J.H. and Pandis, S.N. (2016). Atmospheric Chemistry and Physics: From Air Pollution to Climate Change. 3rd ed., Wiley.
United States Environmental Protection Agency (US EPA) (2018). Technical Assistance Document for the Reporting of Daily Air Quality – the Air Quality Index.
Vallero, D.A. (2020). Fundamentals of Air Pollution. 4th ed., Elsevier.
World Bank (2020). Pakistan: Air Quality Management – A Strategic Framework. World Bank Group.
World Health Organization (WHO) (2006). Air Quality Guidelines: Global Update 2005. Geneva.
World Health Organization (WHO) (2021). WHO Global Air Quality Guidelines. Geneva.
Read: Beneath The Pakistan’s Soil
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Mohammad Ehsan Leghari is a water expert, former Member (Sindh), Indus River System Authority (IRSA), and former Managing Director, SIDA.
