TRACE INORGANIC ELEMENTS IN RAINFALL IN THE MONTREAL ISLAND

Using inductively coupled plasma-mass spectrometry (ICP-MS), 24 inorganic elements were analysed for about 65 station-events during the summer of 1989, at Montreal Island (Canada). Enrichment factors indicate that numerous elements are enriched as compared to the Earth's crust, since only six elements (titanium, iron, rubidium, yttrium, zirconium, and cerium) can be considered natural. A comparison with results from a rural area indicates that most elements are affected by urbanization. For the majority of the elements, scavenging below the cloud (wash-out) seems to be a significant atmosphere cleansing mechanism, although one element, lead, appears to be rather governed by long-range transportation and rain-out (in-cloud scavenging). Correlation between elements indicates that some elements have similar behaviour, which can be partly explained by sorption phenomena or chemical bonding in the same compound.