Latin America, just like any other continent in our world is facing Air Pollution. The recent 2014 report by the World Health Organization on Ambient (outdoor) Air Pollution gives some annual mean figures for several cities in Latin America. Without surprise, the worst scenarios are in Asia, but yet, some cities in Latin America have high indexes too (see table on the left).

The ranking from the WHO should however by considered carefully, especially considering the measurement methods used the report can be argued - for instance, for Lima, the Peruvian EPA is arguing that the data from the WHO is not correct because the samples were not taken in the right places (read this article from P. Estupinya for full feedback from several countries). This is actually for this reason that we only publish real-time information on the World Air Quality project since we do believe than more than ranking, it is the current conditions that are important for the world citizen.

Looking back at the reason for Air Pollution in Latin America, there are several explanations, one of them beeing the impressive amount of dust traveling from the Sahara desert towards the Amazon, as reported by the NASA. The other reasons are very much specific specific for each country. For instance, for Santiago de Chile, it is both the topography formed by the Andes in the East preventing the pollution from dispersing latteraly, and the constant stream of air from the Hadley cell circulation which prevents the pollution from escaping upwards (creating an inverstion layer).

Our colleagues from the Clean Air Institute as well as the National Resources Defence Council (NRDC) have both produced excellent summaries on the Air Quality in Latin America. The one from CAI is called ' Air Quality in Latin America: An Overview' (por español) and the one from NRDC Dumping Dirty Diesels in Latin America. The article from Pere Estupinya from the MIT is also giving a lot of pointers for each countries.

All of the above reports confirm our findings on the Air Quality monitoring availability in Latin Amercia, i.e. that data is available at least for those 12 countries: Mexico, Brazil, Colombia, Chile, El Salvador, Guatemala, Argentina, Peru, Bolivia, Puerto Rico, French Guiyana as well as Ecuador.

Here are some more details from our investigation:

• Uruguay: Air Quality readings for Montevideo are available from the ICaire system, but unfortunately not in real-time. They are however made available once a week.
• Dominican Republic: Air Quality should be available for Santo Domingo, but from the Enviromental Information System (Sistema de Informacion Ambiental) does not provide any information.
• Panama: The article from la estrella de Panama indicates that several monitoring stations are setup in Panama. However, there is no clear infomration about the measured data from the Ministerio de Ambiente or the SINIA system.
• Venezuela: No information is available from the , but this study on Caracas' Particule Matter concentration highlights that an existing monitoring network is (or was?) available.
• Paraguay: No online data available from the Secretaría del Ambiente (SEAM), but a project involving the Centro Mario Molina, the UNEP, the CONADERNA should hopefully give the way to a proper standard and monitoring solution.
• Trinidad & Tongbao: No information, but this slide from the Environmental Management Authority shows that T&T is moving toward monitoring solution. (Note: T&T AQI is now available on our map, since 2018)
• French Guiana: As an overseas Department and Region of France, Air Quality monitoring is mandatory as part of the European regulations. However, only PM₁₀ data is available (from ora-guyane).

Back to the main topic of this article, i.e. the Air Quality Scales used in Latin America, there is no surprise in mentionning that every single country is have a different scale, with different conventions for the colors, concentration breakpoints and nomenclature. However, except from Brazil which is using an AQI scale slighlty more compact, i.e with breakpoints defined at 40,80,120, 200 and 300 instead of 50,100,200,300 and 500, the scales are more or less the same in settings levels towards good - unhealthy - and hazardous breakpoints. And this is actually what matters the most, since it is those three breakpoints our citizen will use to decide on their outdoor activity.

Historically, the US EPA standard has been used on the World Air Quality Index project for reporting the real-time Air Quality all over the world. But based on this analysis, sometimes it does not make sense. For instance for the city of Monterrey in Nuovo Leon, Mexico, we are now directly reporting the AQI usign the IMECA standard, considering the the IMECA PM₁₀ is actually more strict than the US EPA PM₁₀ standard. You can check it yourself from the graphs below.

Fortunately, this article is just a snapshot in the Air Quality monitoring and scales in May 2015. Things change and evolve, and some countries for which data is not available will start to monitor their environement. Same, the scale will be updated, at least to follow the gradual guidelines from the WHO. But the most important is that each country keeps its own identity: What makes our world beautiful is its diversity, and we are starting to believe that having only one unique scale might not be the right solution. But, that's something will write more about soon.

Air Quality Scales comparison (for PM2.5 and PM10) - to be used for real-time readings (e.g. based on 24 hours exposure):

The nomenclature and colors used for the different countries is highlighted in the following table:

The reference to the standards used in this report can be found from the following table: