Luongo, G., Perrotta A. e Scarpati C. 2001. 'L'impatto dei prodotti di eruzioni esplosive sull' ambiente: l'eruzione del 79 d.C. a Pompei'. In: La casa di Giulio Polibio. Studi Interdisciplinari. Ministero per i Beni e le Attività Culturali. Edizione: Centro Studi Arte Figurative, Università di Tokyo, pp. 215-238.
Of course, this doesn't mean that they're not still working on it ... I wonder where Der Spiegel got its information from?
Luongo, Perrotta and Scarpati were involved in the production of a Japanese CDRom: 'La casa di Julius Polybius' by Masanori Aoyagi, 2001. They have published a whole bunch of articles on the impact on the eruption on structures, and I will list those in a comment to this post.
In 2003, the BBC made a documentary entitled 'Pompeii. The Last Day', which tells the story of the final hours of the inhabitants of the House of Julius Polybius, and also of other characters (such as Stephanus, of the Fullery of Stephanus). The work of Luongo, Perrotta and Scarpati is not explicitly credited, but I can't believe that it didn't influence the documentary ...(Four other parts of this documentary can also be seen on UTube.)