2. Exchange process

Depending on the nature of the exchanges and the mode of transport of the aerosols, the extent of their impact can be very different. At the local level, particularly close to sources, their impact on health and visibility will be all the less pronounced as they may mix. On the other hand, these mixing processes mean that aerosols can exert an influence far beyond their source. Taking air transport as an example, it is well known that it can be severely disrupted by the injection of ash into the atmosphere, as was the case following the eruption of the Icelandic volcano in 2010