"Any location with is neither to be classified as “traffic” or “industrial”. Located such that its pollution levels are representative of the average exposure of the general population (or vegetation and natural ecosystems) within the type of area under assessment. The pollution level should not be dominated by a single source type (e.g. traffic), unless that source type is typical within the area under assessment. The station should usually be representative of a wider area of at least several square kilometres."(xsd:string)