Effects of Air Pollution on Materials and Cultural Heritage: ICP Materials Celebrates 25 Years of Research
Figure 6
Annual average HNO3 concentration at ICP Materials test sites for the three one-year campaigns 2002-2003, 2005-2006, and 2008-2009. The grey squares have been excluded when calculating the linear regression lines (2005-2006 versus 2002-2003), (2008-2009 versus 2005-2006), (2008-2009 versus 2002-2003).