New model for health effects of air pollutants: evidence for synergistic effects of mixtures of ozone and sulfuric acid aerosols on rat lungs
Chronic respiratory disease-free rats were exposed to relatively low levels of ozone (0.4 to 0.5 ppM) and H/sub 2/SO/sub 4/ aerosols (11 to 3,000 ..mu..g/m/sup 3/) and to mixtures of these pollutants. We independently evaluated exposure effects on conducting airway metabolism as rate of secretion of mucus glycoproteins by tracheal explants and on lung homogenates (predominantly lung parenchyma) by various chemical assays. True synergism was observed in that the response to the mixture of gases exceeded the sum of effects observed with the same concentration of either gas alone. Wet to dry weight ratios; DNA, protein, and RNA content; and the activities of various lysosomal hydrolases in the lung homogenate all increased upon exposure to O/sub 3/-H/sub 2/SO/sub 4/ mixtures concomitant with observed increases in the rate of secretion of mucus glycoproteins by tracheal explants from the same rats. Preliminary experiments suggest that all of these effects are reversible when rats are allowed to recover after exposure. We conclude that the lack of toxicity noted upon exposure of experimental animals to individual pollutant gases at near-ambient levels should be interpreted with caution, since there is now epidemiological, physiological, and biochemical evidence that mixtures of pollutant gases may show synergistic effects.
- Research Organization:
- Univ. of California, Davis
- OSTI ID:
- 6921214
- Journal Information:
- J. Lab. Clin. Med.; (United States), Vol. 91:2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of 0. 5 ppm ozone on glycoprotein secretion, ion and water fluxes in sheep trachea
Synergistic effects on rat lungs of mixtures of oxidant air pollutants (ozone or nitrogen dioxide) and respirable aerosols
Related Subjects
AIR POLLUTION
BIOLOGICAL EFFECTS
OZONE
SYNERGISM
SULFURIC ACID
AEROSOLS
BIOLOGICAL MODELS
BIOLOGICAL RECOVERY
DNA
GLUCOPROTEINS
HOMOGENATES
LUNGS
RATS
RNA
ANIMALS
BODY
CARBOHYDRATES
COLLOIDS
DISPERSIONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
POLLUTION
PROTEINS
RECOVERY
RESPIRATORY SYSTEM
RODENTS
SACCHARIDES
SOLS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)