7. Rainwater

7.1 Rainwater composition

The chemical composition of rainfall was monitored by Météo-France from 1977 to 2009 at three weather stations. The study , published in June 2011, showed that :

• the average pH rose steadily over the period, from around 4.6 to 5.2 (average for the three sites), indicating a drop in the acidity of the rainwater;

• sulfate deposits, averaging 3 kg/hectare/year (expressed as sulfur equivalent), fell by 65% over the period 1980-2008, which...