Air pollution is the introduction of chemicals, particulates, biological materials, or other harmful materials into the earth’s atmosphere, posibly causing disease, death to human, damage to other living organisms such as food crops,or the natual or built enviroment. Stratospheric ozone depletion due to air pollution has long been recognized as a threath to human health as well asto the earth’s ecosystems. Indoor air pollution and urban air quality are listed as two of the world’s worst toxic pollution problems in the 2008 Blacksmith Institute World’s worst polluted places report. SPAIN Over three-quarters of Spain’s population lives in urban environments and a significant proportion is intermittently exposed to high concentrations of pollutants. As a result, there is growing public interest in and demand for information about air quality. In Spain, the principal pollutants are particulate matter (concentration increases naturally with African dust outbreaks), tropospheric ozone caused by precursor emissions and affects peripheral areas far away from the source of emission) and nitrogen dioxide. Environmental noise is also a major air pollutant in Spain and the principal cause in urban environments is traffic. CO2 of European Countries (2010)

Urban Population of European Countries (2010)BARCELONA The Energy, Climate Change and Air Quality Plan of Barcelona 2011-2020 (PECQ) is a local administration instrument aimed at the following during that time frame: • Improving energy efficiency and reducing energy consumption in the city, • Cutting the increase of greenhouse gas emissions (GHGs), • Improving urban air quality, in particular with regard to NOx gases and PM10 particles, • Improving the quality of energy supply. AIR POLLUTION INVENTORY SOURCES: 

https://w110.bcn.cat/MediAmbient/Continguts/Vectors_Ambientals/Energia_i_qualitat_ambiental/Documents/Traduccions/PECQ_english_def01.pdf

http://data.worldbank.org/indicator/EN.ATM.CO2E.KT