WHO: Air quality in world’s cities deteriorates
8 May 2014
Air quality in most cities worldwide that monitor outdoor air pollution fails to meet the safe exposure guidelines established by the UN’s World Health Organization (WHO), according to the most recent WHO data.
Only 12% of the people living in cities reporting on air quality reside in areas where exposures to ambient pollutants are below WHO air quality guideline levels. About half of the urban population being monitored is exposed to air pollution that is at least 2.5 times higher than the levels WHO recommends.
WHO’s urban air quality database covers 1600 cities across 91 countries—500 more cities than the previous, 2011 database, revealing that more cities worldwide are monitoring outdoor air quality.
In most cities where there is enough data to compare the situation today with previous years, air pollution is getting worse, said the WHO. Many factors contribute to this increase, including reliance on fossil fuels such as coal fired power plants, dependence on private transport motor vehicles, inefficient use of energy in buildings, and the use of biomass for cooking and heating.
While air quality is generally deteriorating, some cities are making improvements—noted the WHO—demonstrating that air quality can be improved by implementing policy measures. Cities such as Copenhagen and Bogotà, for example, have improved air quality by promoting ‘active transport’ and prioritizing dedicated networks of urban public transport, walking and cycling.”
High concentrations of fine particulate pollution is particularly associated with high numbers of deaths from heart disease and stroke, as well as respiratory illnesses and cancers. WHO considers the measurement of fine particulate matter (PM2.5) to be the best indicator of the level of health risks from air pollution. In cities that measure and report only PM10 exposures, PM2.5 concentrations were derived from the PM10 measurements.
The latest available data have prompted WHO to call for greater awareness of health risks caused by air pollution, implementation of effective air pollution mitigation policies, and close monitoring of the situation in cities worldwide. In March 2014, WHO issued new estimates, reporting that in 2012 around 7 million people died as a result of air pollution exposure—a finding that more than doubled previous estimates and confirmed that air pollution has become the world’s largest single environmental health risk.
Source: WHO