Elsevier

Toxicology

Volume 50, Issue 2, July 1988, Pages 131-144
Toxicology

Comparison of daily and seasonal exposures of young monkeys to ozone

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Abstract

Oxidant air pollution tends to occur in both seasonal and daily cycles of polluted and clean air. To compare the effects of these 2 cycles, we exposed 2 groups of 7-month-old male monkeys to 0.25 ppm (0.49 mg/m3) of ozone (UV photometric standard) 8 h/day either daily or, in the seasonal model, days of alternate months during a total exposure period of 18 months. This is a longer ozone exposure period than any previously reported. A control group breathed only filtered air. Young monkeys were studied as their lungs are similar to those of man and their lungs, like those of man, grow over a period of several years. Monkeys from the seasonal exposure model, but not those exposed daily, had significantly increased total lung collagen content, chest wall compliance, and inspiratory capacity. All monkeys exposed to ozone had respiratory bronchiolitis with significant increases in related morphometric parameters. The only significant difference between seasonal and daily groups was in the volume fraction of macrophages. Even though the seasonally exposed monkeys were exposed to the same concentration of ozone for only half as many days, they had larger biochemical and physiological alterations and equivalent morphometric changes as those exposed daily. Lung growth was not completely normal in either exposed group. Long-term effects of oxidant air pollutants which have a seasonal occurence may be more dependent upon the sequence of polluted and clean air than on the total number of days of pollution. Estimations of the risks of human exposure to seasonal air pollutants from effects observed in animals exposed daily may underestimate long-term pulmonary damage.

References (41)

  • Environmental Protection Agency

    Air quality criterion for ozone and other photochemical documents. Chapter 9. Toxicological effects of ozone and other photochemical oxidants

    EPA-600/8-84-020aF

    (1986)
  • G. Freeman et al.

    Delayed maturation of rat lung in an environment containing nitrogen dioxide

    Am. Rev. Respir. Dis.

    (1974)
  • J.A. Raub et al.

    Effects of low-level ozone exposure on pulmonary function in adult and neonatal rats

    Adv. Mod. Environ. Toxicol.

    (1983)
  • B.E. Barry et al.

    Alveolar epithelial injury caused by inhalation of 0.25 ppm of ozone

    Adv. Mod. Environ. Toxicol.

    (1983)
  • D. Barlett et al.

    Effect of chronic ozone exposure on lung elasticity in young rats

    J. Appl. Physiol.

    (1974)
  • W.S. Tyler

    Comparative subgross anatomy of lungs. Pleural, interlobular septums, and distal airways

    Am. Rev. Respir. Dis.

    (1983)
  • N.K. Tyler et al.

    Morphology of the distal conducting airways in rhesus monkey lungs

    Anat. Rec.

    (1985)
  • F.E. Speizer et al.

    Respiratory disease rates and pulmonary function in children associated with NO2 exposure

    Am. Rev. Respir. Dis.

    (1980)
  • R.G. Hinners et al.

    Animal inhalation exposure chambers

    Arch. Environ. Health

    (1968)
  • California Air Resources Board

    Change in California's oxidant calibration procedure

    Calif. Air Qual. Data

    (1975)
  • Cited by (0)

    Supported in part by NIH grants ES-00628 and RR-00169 and in part by EPRI RP1112-2.

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