One quarter of the global population is breathing unsafe air. Last year, the World Health Organization estimated that air pollution was responsible for 7 million premature deaths in 2012. That’s one out of every eight total deaths in the world. Although invisible to the human eye, (fine particulate matter) PM2.5 contributes to acute lower respiratory infections and other diseases such as cancer. It can penetrate human lung and blood tissue, leading to higher incidences of cardiovascular and lung disease.
Where is it worst? The world’s most polluted cities and countries have been revealed, but all countries experience some level of unhealthy air. Unlike other urban environmental issues that closely track economic development, such as access to clean drinking water and sanitation, air quality affects countries both rich and poor. Poor air quality is responsible for up to 1 in 12 deaths in some parts of London and shortens the average Briton’s life span by six months. Last year Paris had to impose major restrictions on motor vehicles when air pollution hit dangerously high levels. Salt Lake City in the United States regularly experiences severe smog in the winter time, leading to public health concerns among residents there.
Within the United States the Midwest and East Coast are among the areas with the highest levels of pollution, with the map confirming air quality is worst in heavily populated urban environments.
Areas of high population density generally attract some of the worst air quality, with big cities in China and India attracting high levels of pollution. China is revealed to have the most power plants that release the highest levels of carbon into the air, producing some of the worst pollution found in its northeastern regions. China has the highest number of dirty power plants, with a total of 610, followed by the US with 371 and India with 187.
“If we consider countries with the highest density of dirty power plants, small countries like Malta and Singapore are among the top 10, along with Germany and Poland,” wrote the researchers. “But what is also striking is that some countries, like Bangladesh and others in Southeast Asia, lack “dirty” power plants but are still exposed to high levels of air pollution.”
New Delhi, the capital of India, for instance, is the city with the worst air pollution. Many other cities in South Asia, including in Pakistan, Iran, and Bangladesh, all suffer pollution levels more than 10 times higher than the safe threshold. This data further corroborates reports that suggested India, and in particular New Delhi, has severe air pollution that is often overlooked in lieu of China’s air pollution problem. While India’s air comes out worst among cities, China’s air quality at a national scale is the worst globally.
Though Africa is relatively less densely populated, it still has high levels of particles in the air due to Saharan mineral dust.
Large swaths of Russia and Canada were revealed to have some of the cleanest air.
Click here to study the global interactive map.