The World Health Organization (WHO) released a new report on air pollution around the world. Delhi, India topped the list as the city with the worst problems with air quality.
The Ambient Air Pollution database for 2014 contains information on air quality in 1600 cities, spread over 91 nations. Special attention was paid to particulate matter, measuring less than 2.5 microns in diameter, called PM2.5 pollution.
Levels in Delhi were measured at 163 micrograms - the worst air conditions in the world. Particles four times larger, PM10's, have a concentration of 121 micrograms in India's capital. Both of these concentrations are far greater than what is usually considered safe.
"Too many urban [centers] today are so enveloped in dirty air that their skylines are invisible. Not surprisingly, this air is dangerous to breathe. So a growing number of cities and communities worldwide are striving to better meet the needs of their residents - in particular children and the elderly," Flavia Bustreo, WHO Assistant Director-General for Family, Children and Women's Health, said.
The World Health Organization lately released reports naming air pollution - both indoor and outdoor - as leading causes of death worldwide. In 2012, they estimated pollutants in the air were responsible for the deaths of 3.7 million people under 60 years old.
Air pollution comes in many forms, and from a multitude of sources. Yet, small particles are of particular interest to researchers, because these can travel deep into lungs, causing severe problems.
The report reminds ordinary people that their communities can take local action to combat air pollution.
"Measures include ensuring that houses are energy efficient, that urban development is compact and well served by public transport routes, that street design is appealing and safe for pedestrians and cyclists, and waste is well managed," the report stated.
The study encountered challenges gathering data, as air pollution is not monitored in many areas, especially lower-income cities. Data was taken from cities for the time period from 2008 to 2013, with most of the records being taken between 2011 and 2012.
India is home to 13 of the 20 most-polluted cities in the world, based on the report. Particulate matter can cause respiratory problems, in addition to heart disease, stroke and an increased risk of cancer.
Air pollution is now believed to be the fifth-leading cause of death on the Indian subcontinent. Comparing data from the 2014 study to previous years reveals the problem of air pollution is becoming worse.
