WORLDWIDE, millions of people are losing their health and lives by breathing polluted air. Toxic emissions from industry, transport and power generation (from fossil fuels and agriculture) are contaminating the environment, particularly in the developing countries.

Air pollution is the world’s largest environmental health threat. A mixture of carbon monoxide, sulphur dioxide and nitrogen dioxide carrying tiny droplets are major contributors of outdoor air pollution. Invisible to the naked eye, these tiny particles, commonly known as particulate matter 2.5 (PM2.5) are 30 times thinner than human hair and highly toxic. Methane emissions from solid waste, agricultural processes, cattle and other ruminants like sheep, horses and goats add to the lethal mix that causes severe health issues.

Lung cancer, cardiovascular diseases, asthma, and other chronic respiratory problems are often caused by polluted air. A recent study by the Harvard T.H. Chan School of Public Health revealed that exposure to fine particulate air pollutants may also increase the risk of developing dementia.

The air so essential for our life is now ma­­king us sick. Being a transboundary issue, there is no escape from bad air quality.

Pakistan’s urban air pollution is the most severe in the world.

Globally, polluted air is responsible for 7m premature deaths, with 90 per cent of them occurring in low- and middle-income countries according to the WHO. The heavy burden of disease and job loss is severely impacting the economies of and societies in developing countries, impeding growth and destroying homes.

In addition to human-induced pollution, gases and ash from volcanic eruptions and smoke from wildfires also contribute to air pollution.

When smoke from wildfires in Canada engulfed parts of the US East Coast earlier this month, Manhattan’s iconic skylines nearly faded in a smoky haze, and the authorities advised citizens to stay indoors to avoid health risks. Soon after, London’s mayor imposed a two-day “high pollution alert” as winds blew “existing pollutants from the continent towards London”. These were short-lived aberrations in the otherwise clean air and blue skies of these two cities. Efforts by the city authorities to reduce pollution in most parts of the developed world are succeeding through policies and regulations on health and environmental standards, and are raising public awareness about the benefits of a clean environment.

In contrast, people living in cities across the Global South are forced to breath poisonous air on a daily basis for long periods. Nearly 90pc of the Asia-Pacific region’s 4.3bn people regularly inhale air considered unsafe by the WHO. Two-thirds of the 7m premature deaths attributed to air pollution occur in this region.

Economic losses attributed to air pollution are inflicting heavy costs on healthcare and development. In 2021, air pollution in South Asia was responsible for healthcare costs equivalent to 10.3pc of its GDP compared to 6.1pc of healthcare costs to global GDP, according to the World Bank.

Urban air pollution is the worst in South Asia, home to a quarter of the world’s population. Unsustainable urban sprawl, often at the expense of green cover, deprive the cities of natural air filters. The air in many cities in Pakistan, India and Bangladesh is counted among the world’s most polluted. Vulnerable and marginalised communities often face higher exposure and are affected disproportionately.

Pakistan’s urban air pollution is the most severe in the world. With the highest rate of urbanisation in the region, almost half of Pakistan’s population is expected to live in cities by 2025. If air pollution is not controlled, it will expose more than120m people to polluted air and impose heavy economic and social costs on the country.

Air pollution is not a stand-alone issue. It is intrinsically linked to climate change, biodiversity loss and other forms of pollution. One cannot be resolved without addressing the other.

Band-aid measures will only complicate the problem. A combination of cross-sectoral actions will be required to control air pollution especially in energy, transport and urban areas. Such targeted action must be supported by enabling policy frameworks and regulatory set-ups to monitor air quality in a systemic manner by involving the local authorities and civil society.

To support policymaking, UNEP has compiled actions that governments can take on air quality and identified implementation and policy gaps.

Pakistan has announced its first National Clean Air Policy which should be linked to time-bound targets of renewable energy, energy efficiency in industry, transport and infrastructure. For effective environmental action, it will also be desirable to design and implement provincial clean air strategies.

The writer is director of intergovernmental affairs, United Nations Environment Programme.

Published in Dawn, June 27th, 2023