Figure 11From: Fine particulate matter in indoor cultural heritage: a literature reviewCollection of soiling measurements using reflectance. Experimental values of loss of reflectance. S = sheltered, I = indoors, U = unsheltered. Data adapted from [103] (Oporto), [4] (roadside, London), [105] (road tunnel, Hertfordshire), [106] (theatre museum, London), [104] (British Museum, London) and [107] (unsheltered roadside, London).Back to article page