How to identify nonattainment areas for projects outside of the US/Canada?

Hi Guillaume, You can refer to the local monitoring station data from the site of that region. For a recent project in India, I had referred to the below website which was also confirmed by USGBC. http://tspcb.cgg.gov.in/Pages/Envdata.aspx  

Hi Guillaume,  Agree with Devendra, you can refer to the local monitoring station data. Based on LEED BD+C v4 Guide page 611, the nonattainment area for ozone is where ozone exceeds the most recent three-year average, annual fourth-highest daily maximum eight-hour average ozone concentration of 0.107 ppm. Based on ASHRAE 62.1-2010 page 51, the nonattainment area for PM2.5 is where the three-year average of the weighted annual mean PM2.5 concentrations from single or multiple community-oriented monitors exceed 15.0 μg/m3 or the three-year average of the 98th percentile of 24-hour concentrations at each population-oriented monitor within an area exceed 35 μg/m3. Actually, these numbers are for locations within the US. You can use your local code if the local code is more stringent than ASHRAE 62.1–2010. Until now, we have not found yet any map or list of nonattainment areas outside the US/Canada.