Which City Has the Highest AQI?

Awareness of the dangers caused by air pollution has grown dramatically in recent years, with innovative new air quality research networks providing greater insight than ever before into the cleanliness of the air we breathe. Despite this, progress has not been rapid enough in many parts of the globe, with the World Health Organisation (WHO) estimating that over 90% of the global populace is exposed to unsafe levels of contamination.

Of course, some areas are worse affected than others, especially in the developing world. As such, this article will enumerate the cities with the worst air pollution according to the Air Quality Index (AQI) compiled by the US National Oceanic and Atmospheric Administration (NOAA). Given that certain countries account for a large swathe of the most contaminated metropoles, we have simplified things by including just one city from each country to give a better overview of where the situation is the most serious.

Hotan, China

With a population of over 1.35 billion people and an economy that, for all its efforts to transition to more renewable forms of energy generation, still relies heavily on coal, it’s perhaps no surprise to see a Chinese city on the top of the list. Hotan in the western province of Xinjiang is home to many coal mines and coal-burning facilities, while its status as an oasis town in the Tarim Basin means that the city is regularly battered by sand-filled winds. It’s for this reason that it has recorded the worst air quality levels of anywhere on the planet.

Ghaziabad, India

This industrial hub in the Delhi NCR is part of the state of Uttar Pradesh and, until recently, was the most polluted city in the world for many years running. Although it has been knocked off top spot by Hotan, it is followed by a dozen other Indian cities which round out the top 14, including Bhiwadi, Bulandshahr and Bisrakh Jalalpur. Although India has been on a continuous emissions monitoring system (CEMS) kick of late, it still relies heavily on coal and other damaging fuel sources for its power. Meanwhile, the topography of Ghaziabad in particular means that there is nowhere for the contaminants to disperse.

Onitsha, Nigeria

This bustling port city in the south of Nigeria experiences an incredible amount of particulate matter (PM) pollution, which is widely regarded as one of the most damaging contaminants there is. It is mostly generated by an outdated dependence on burning solid fuels for heating and powering homes and businesses, as well as the millions of exhaust fumes belonging to the vehicles of the city. Waste is also regularly incinerated without due care, further contributing to the problem. As a result, Onitsha recently recorded a mean annual concentration of 594μg/m³, which is over 30 times the level deemed safe by the WHO.

Lahore, Pakistan

The air quality issues plaguing Pakistani cities flew under the radar for decades, largely due to the fact that there was no adequate and overarching monitoring system in place. However, recent advances in urban air quality monitoring highlighted just how serious a problem air pollution is in the country, with Lahore named as the most contaminated city when data was first published in 2017 and it has remained so ever since. One of the wealthiest metropoles in the country, Lahore is home to a ballooning population and all the environmental complications that brings, though the public have recently petitioned the government to tackle the issue head on.

For those who would like to take a deeper dive into the topic of air pollution, the upcoming Air Quality and Emissions (AQE) Show in Telford in the UK will explore the subject in far greater detail. Interested parties are invited to register their interest and learn more by visiting the link above.