Around 55% of the world’s population lives in cities, up from just 47% in 2000. This number is expected to rise to 68% by the year 2050 and continue to trend in the upward direction for the foreseeable future. While there are many advantages to living in condensed urban areas, they have the potential to cause serious long-term harm to the environment without the proper sustainable infrastructure in place. Unfortunately, such infrastructure is something of a novelty, and while the technology continues to develop, many cities around the world are beginning to experience the adverse effects of pollution first hand.
As of the end of 2019, Ghaziabad, India was the most dangerously polluted city in the world based on the Air Quality Index (AQI). AQI is a metric that determines the toxicity of a city’s air. As a city’s AQI increases, it becomes increasingly inhospitable for human breathability. The AQI takes five factors into consideration: ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide.
Ghaziabad, India has an AQI of 110.2. It’s air is considered “unhealthy” or even “hazardous” for most of the year. Six of the world’s top ten most polluted cities, according to the AQI, are located in India, where poor air quality leads to the premature deaths of up to 2 million residents each year. Part of the issue stems from India’s density and the concentrated volume of vehicle emissions and biomass burnoff from cooking and agriculture. Additionally, zoning is relatively arbitrary in many Indian cities and expansive industrial complexes have the tendency to infringe upon residential districts.
The list of the ten cities with the most severe air pollution according to the AQI:
While air pollution is most hazardous to the average person, one could argue that it doesn’t necessarily exemplify the world’s “dirtiest” city. In the defense of many of the top cities on the previous list, AQI isn’t based purely on human intervention. Topography, climate, and natural disasters (forest fires) all have a considerable effect on a region’s air quality.
If we choose, instead, to evaluate “dirtiness” by the sheer volume of solid waste a city produces, then New York City is the dirtiest city in the world and it’s not even remotely close. Annually, the New York City Metropolitan area produces some 33.2 million metric tons of waste. With close to 19 million residents, that’s about 1.75 metric tons of waste per capita, over 3,800 pounds. The majority of New York’s waste is generated by businesses and industries who have begun to ship their garbage upstate or even several states over as the landfills reach capacity. While private households are not the bulk of the issue, they are not entirely absolved from the blame. The United States has consistently ranked above the 90th percentile for the amount of municipal waste generated per capita. As of 2019, the average American citizen produced 4.4 lbs of waste each day.
The cities in second and third place, Mexico City and Tokyo respectively, produce barely a third as much solid waste as New York City despite having higher populations.
The top ten most wasteful cities in the world, measured in millions of metric tons: