Pulmonary Clearance and Lesions in Rats after a Single Inhalation of Ultrafine Metallic Nickel at Dose Levels Comparable to the Threshold Limit Value.

Abstract

This study aimed to (1) determine the deposition and clearance rates of utrafine metallic nickel (Uf-Ni) in rats after a 5 hours single inhalation exposure, and (2) to histopathologically examine the pulmonary lesions induced at dose levels comparable to the Occupational Exposure Limit recommended in Japan (OEL). The exposure concentrations of Uf-Ni for the 3 groups were 0.15 (Low), 1.14 (Medium), and 2.54 (High) mg/m3. Five rats/group were sacrificed at Oh and 1, 3, 7, 14, and 21 days post exposure. The amount of Ni in the lung accumulated dose-dependently. The halftimes for Ni in the lung were estimated as 32 days on average, and were similar to each other regardless of the initial dosage. The histopathologically observed pulmonary lesions induced by a single inhalation of Uf-Ni were, (1) a significant increase in lung weight in the High and Medium groups with time, (2) accumulation of foamy alveolar macrophages (AM), (3) degenerated AM indicating alveolar lipoproteinosis which was aggravated for up to 4 weeks in the High group and (4) acute calcification of the degenerated AM was remarkable. The present results suggest that even a single inhalation of Uf Ni induces potency of lung lesions at dose levels comparable to the OEL (1 mg/m3 as Ni), or the TWA of ACGIH (1.5 mg/m3 for elemental/metal).

Pulmonary Toxicity Induced by Intratracheal Instillation of Coarse and Fine Particles of Cerium Dioxide in Male Rats

“…The present result of the Ce-F-induced pulmonary alveolar proteinosis is comparable with the previously reported findings regarading other particulate matters that intratracheal instillation of crystalline quartz of respirable sizes in rats induces prominent pulmonary alveolar proteinosis together with foamy and degenerative AMs 30) , and that pulmonary alveolar proteinosis is also induced in rats by intratracheal instillation of nickel fumes and nickel oxide powder 21) and by inhalation exposure to ultrafine metallic nickel 31) .…”

Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health

“…Some laboratory studies have shown strong responses from short exposures to high particle concentrations. 462 Figure 22 shows the time-resolved PM 10 and PM 2.5 measured at an active military base located near an urban area. 440 These transients are suspected to result from nearby sources.…”

Targeted removal of bioavailable metal as a detoxification strategy for carbon nanotubes

“…Fine metal-containing particles pose known inhalation health risks [13][14][15], based on studies concerned with occupational health and safety in the metals industry [16,17] or the health effects of atmospheric fine and ultrafine particulates [18][19][20]. Based on these studies, and on the limited available literature on nanotube toxicity [21][22][23][24][25][26][27][28], there is a real concern that CNT-metals will trigger similar mechanisms of toxicity and carcinogenicity.…”