Effects of rock wool on the lungs evaluated by magnetometry and biopersistence test

Table 1 Geometric mean of number of fibers retained in the lung (geometric standard deviation)

Observation period	All fibers	L ≤ 5	5 < L ≤ 20	20 < L	WHO fibers
	10E5 fibers/g dry lung weight
1D group	93.3 (1.2)	45.6 (1.2)	41.4 (1.2)	6.2 (1.3)	47.6 (1.2)
3D group	85.6 (1.2)	41.5 (1.2)	38.8 (1.3)	4.1 (1.7)	43.0 (1.4)
14D group	65.5 (1.1)^a	32.2 (1.2)^a	29.8 (1.2)	2.7 (1.7)^a	32.7 (1.3)
28D group	55.6 (1.2)^{a, b}	26.4 (1.3)^{a, b}	26.9 (1.1)^{a, b}	2.0 (1.3)^a	29.0 (1.1)^{a, b}

^a: Comparison with the 1D group (p < 0.05)
^b: Comparison with the 3D group (p < 0.05)
L = Fiber length (μm)
WHO fibers: Fibers having a length of longer than 5 μm and width of shorter than 3 μm.

ISSN: 1745-6673