Hiking the trail down to the Dudh Kosi from Thyangboche can be an awful. dusty experience. We walked it in early November 2004 and it was dreadful - far too many people and animals. On this occasion it was quite bearable but the dust still went flying especially when the animals were being pushed on quickly like these. We were wearing surgical masks carried for occasions like this and the hike down the Kali Gandaki in Annapurna.