THE EFFECT OF STORAGE, HANDLING AND TRANSPORT TRAUMAS ON FILTER-MOUNTED DUSTS

The loss of material from dust-loaded filters was examined using five load ranges of four types of dust. Twelve replicate samples for each l oad range and dust type, a total of 240 samples, were collected on gla ss-fibre filters in the laboratory. Three of each group of 12 loaded f ilters were subjected to one of four levels of trauma: gentle shaking; dropping from table height; posting; or no trauma (control). The perc entage weight loss was calculated for each sample. Weight loss from th e control and shaken filters was low with a mean loss of 10.4% (SD = 1 5.4) and 5.2% (SD = 11.8), respectively. Weight loss from the dropped and posted filters was much higher (mean losses of 68.2 and 54.4% with SDs of 18.8 and 27.9). The pattern of weight loss with increasing loa d varied with type of dust, being most marked for wood dust. The amoun t of loss following dropping or posting was also related to initial lo ad. Three-way analysis of variance suggested strong interactions among dust type, load and trauma, with main effects for initial load and tr auma being significantly related to percentage weight loss. Copyright (C) 1996 British Occupational Hygiene Society.