A yearly survey of rain water depositions in Southern Sardinia (Italy)

The dissolved content of bulk samples of rain water, collected in a forest in Southern Sardinia, were analyzed during an annual survey. When the rain events are grouped according to the meteorological conditions the following results are obtained: a) the average of pH is 4.7 when northwestern perturbances occur, while southern or variable winds result in a neutralization of the rain; b) the marine contribution is higher than 80% in northwestern events and lower than 40% in southern events; c) the Saharan dust neutralizes the rain water by means of its large calcite content and supplies additional SO 4 as gypsum; d) the pollution level measured as anthropic SO 4 plus nitrogen species is not closely correlated to the associated meteorological disturbance, indicating a contamination over long distances in the Western Mediterranean Sea.