Effects of nitrogen dioxide on respiratory tract clearance in the ferret
- Univ. of California, Irvine, CA (United States)
During growth and development, young children are periodically exposed to relatively high concentrations of various air contaminants, including tobacco smoke and environmental pollutants generated by fossil fuel use. The effects of these exposures on respiratory function and lung development are difficult to determine because of interindividual variation and lack of accurate dosimetry. To provide information on the effects of chronic exposure to a common indoor and outdoor pollutant during lung development, a study was performed to assess the effects of exposure to two concentrations of nitrogen dioxide (NO[sub 2]; 0.5 or 10 ppm) on tracer particle clearance from the airways of ferrets exposed during postnatal respiratory tract development. Separate groups of ferrets were exposed nose-only to the test atmospheres or clean air 4 h/d, 5 d/wk, for either 8 or 15 wk. Those animals exposed for 8 wk were subsequently housed in a filtered air environment until the particle clearance measurements commenced at 3 wk prior to the end of the 15-wk exposure protocol. Radiolabeled ([sup 51]Cr) tracer particles were deposited in the respiratory tract of all animals by inhalation, and the clearance rates from the head and thoracic regions were separately monitored for 18 d. No significant effects of the NO[sub 2] exposure on head airways clearance were seen. In contrast, the rates of particle clearance from the thorax of both the 8- and 15-wk groups exposed to 10 ppm NO[sub 2] were significantly reduced, and did not differ from each other. Thoracic clearance was also reduced in animals exposed to 0.5 ppm, but the rate was not significantly different from that of the clean air exposed controls. These results show that NO[sub 2] at moderate concentrations caused highly significant changes in the deep lung of the juvenile ferret, and suggest that impairment of the clearance function may be only slowly recovered after chronic exposure. 35 refs., 1 fig., 1 tab.
- OSTI ID:
- 7033529
- Journal Information:
- Journal of Toxicology and Environmental Health; (United States), Vol. 41:1; ISSN 0098-4108
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
CHILDREN
CHRONIC EXPOSURE
NITROGEN DIOXIDE
DOSE-RESPONSE RELATIONSHIPS
RESPIRATORY SYSTEM
BIOLOGICAL RECOVERY
RESPONSE FUNCTIONS
RODENTS
LUNGS
MORPHOLOGICAL CHANGES
AIR POLLUTION
AGE GROUPS
ANIMALS
BODY
CHALCOGENIDES
FUNCTIONS
MAMMALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANS
OXIDES
OXYGEN COMPOUNDS
POLLUTION
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology
551000 - Physiological Systems