Nitrogen dioxide is genotoxic in urban concentrations. (May 2013)

• Record Type: Journal Article
• Authors: Koehler, Christian; Thielen, Sebastian; Ginzkey, Christian; Hackenberg, Stephan; Scherzed, Agmal; Burghartz, Marc; Paulus, Michael; Hagen, Rudolf; Kleinsasser, Norbert Helmut
• Is Part Of: Inhalation toxicology. Volume 25:Number 6(2013)
• Page Start: 341
• Page End: 347
• Publication Date: 2013-05
• Subjects: Pulmonary toxicology -- Animal models -- Periodicals; Pulmonary toxicology -- Periodicals; Air -- Pollution -- Health aspects -- Periodicals; 616.200471
• DOI: 10.3109/08958378.2013.788104
• Languages: English
• ISSNs: 0895-8378

Abstract

<abstract> <title>Abstract</title> <p>In the discussion on toxic and genotoxic thresholds of air pollutants such as nitrogen dioxide (NO<sub>2</sub>), realistically low urban concentration ranges are of major interest. For NO<sub>2</sub>, the WHO defines the annual limit value as corresponding to 0.02 ppm. In the present study, the toxicity and genotoxicity of NO<sub>2</sub> is set at a concentration under this limit value and examined in human nasal epithelium at different exposure durations <italic>in vitro</italic>. Nasal epithelial mucosa samples of 10 donors were harvested during nasal air passage surgery and cultured as an air–liquid interface. Exposure to 0.01 ppm NO<sub>2</sub> or synthetic air as a control was performed for 0.5, 1, 2 and 3 h. Analysis included the caspase-3 ELISA, the single cell microgel electrophoresis (comet) assay and the micronucleus assay. The caspase-3 activity was not influenced by NO<sub>2</sub> exposure, DNA strand fragmentation correlated with exposure durations to NO<sub>2</sub> at 0.01 ppm NO<sub>2</sub>, and no cytotoxic effects such as apoptosis, necrosis or disturbances of cell proliferation were present. However, micronucleus induction as a sign of genotoxicity at an exposure duration of 3 h could be shown. Shorter exposures did not induce micronucleus formation. In summary, genotoxicity of NO<sub>2</sub> could be demonstrated at a common urban concentration <italic>in vitro</italic>, but a threshold of NO<sub>2</sub> genotoxicity could not be defined based on the present experiments.</p> </abstract>