In a report (pdf) released Tuesday (Sept. 27), the World Health Organization (WHO) found that 92% of the earth's population breathes air with unhealthy levels of pollutants.
WHO collected air quality data from 3,000 locations across the globe and looked for concentrations of fine particulate matter, including sulfates, nitrates, mineral dust, and black carbon, which are less than 2.5 micrometers in diameter—about 1/1000 of a millimeter, or the width of a credit card. Both indoors and outdoors, these particles work their way into the lungs when we breathe, and can cause cardiovascular disease like lung cancer, stroke, and chronic obstructive pulmonary disease.
