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. 2000 Feb;57(2):86–93. doi: 10.1136/oem.57.2.86

Associations between ambient ozone, hydrocarbons, and childhood wheezy episodes: a prospective observational study in south east London

R Buchdahl 1, C D Willems 1, M Vander 1, A Babiker 1
PMCID: PMC1739904  PMID: 10711275

Abstract

OBJECTIVES—To explore the hypothesis that hydrocarbon species and other air pollutants which accumulate at low and high concentrations of ozone are more directly associated with childhood wheezy episodes than ozone.
METHODS—Prospective observational study over 1 year set in the Lewisham district of south east London. The daily attendance rate of children with acute wheeze at the accident and emergency department of Lewisham Hospital was related to local measurements of ozone, hydrocarbon species, nitrogen dioxide (NO2), sulphur dioxide (SO2) and small particulate matter with diameter <10µm (PM10).
RESULTS—An inverse relation was found between the air pollutants and ozone. After seasonal and meteorological adjustment a non-linear U shaped trend was found between incidence of wheeze and ozone. The trend was significant in children <2 years of age but not in older children. In the younger age group, after adjustment for season, temperature, wind speed, and respiratory infection, the incidence relative to that at the mean daily ozone concentration of 32.7 µg/m3, was estimated to increase by 65% (95% confidence interval (95% CI) 22% to 122%) at an ozone concentration of 5 µg/m3 (1.5 SDs below the mean) and by 63% (95%CI −6% to 184%) at 80 µg/m3 (2.5 SDs above the mean). For several hydrocarbons there were significant positive linear relations found, again in children <2 years of age but not older children. For benzene, the incidence increased by 8% (95% CI 2 to 13%) per SD (SD 2.8 µg/m3) increase in benzene concentration. A same day association between incidence and ozone was found to be the most significant but for other pollutants a lag of 2 days gave the most significant associations. No significant association was found for the non-hydrocarbon pollutants including SO2, NO2, and PM10.
CONCLUSIONS—A U shaped relation was found between ozone and the incidence of wheezy episodes in young children. Certain hydrocarbon pollutants accumulate in the atmosphere when ozone concentrations are low, and are associated with childhood wheezy episodes. However, the U shaped association of ozone on incidence cannot be explained by these other pollutants. The finding supports an earlier finding that incidences of wheeze are at a minimum when ozone concentrations are 30-40 µg/m3.


Keywords: air pollution; ozone; hydrocarbons; childhood wheezing

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Selected References

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  1. Anderson H. R., Ponce de Leon A., Bland J. M., Bower J. S., Emberlin J., Strachan D. P. Air pollution, pollens, and daily admissions for asthma in London 1987-92. Thorax. 1998 Oct;53(10):842–848. doi: 10.1136/thx.53.10.842. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bates D. V., Baker-Anderson M., Sizto R. Asthma attack periodicity: a study of hospital emergency visits in Vancouver. Environ Res. 1990 Feb;51(1):51–70. doi: 10.1016/s0013-9351(05)80182-3. [DOI] [PubMed] [Google Scholar]
  3. Buchdahl R., Parker A., Stebbings T., Babiker A. Association between air pollution and acute childhood wheezy episodes: prospective observational study. BMJ. 1996 Mar 16;312(7032):661–665. doi: 10.1136/bmj.312.7032.661. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cody R. P., Weisel C. P., Birnbaum G., Lioy P. J. The effect of ozone associated with summertime photochemical smog on the frequency of asthma visits to hospital emergency departments. Environ Res. 1992 Aug;58(2):184–194. doi: 10.1016/s0013-9351(05)80214-2. [DOI] [PubMed] [Google Scholar]
  5. Durrleman S., Simon R. Flexible regression models with cubic splines. Stat Med. 1989 May;8(5):551–561. doi: 10.1002/sim.4780080504. [DOI] [PubMed] [Google Scholar]
  6. Hajat S., Haines A., Goubet S. A., Atkinson R. W., Anderson H. R. Association of air pollution with daily GP consultations for asthma and other lower respiratory conditions in London. Thorax. 1999 Jul;54(7):597–605. doi: 10.1136/thx.54.7.597. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Martinez F. D., Wright A. L., Taussig L. M., Holberg C. J., Halonen M., Morgan W. J. Asthma and wheezing in the first six years of life. The Group Health Medical Associates. N Engl J Med. 1995 Jan 19;332(3):133–138. doi: 10.1056/NEJM199501193320301. [DOI] [PubMed] [Google Scholar]
  8. McIntosh K., Ellis E. F., Hoffman L. S., Lybass T. G., Eller J. J., Fulginiti V. A. The association of viral and bacterial respiratory infections with exacerbations of wheezing in young asthmatic children. J Pediatr. 1973 Apr;82(4):578–590. doi: 10.1016/S0022-3476(73)80582-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Spektor D. M., Thurston G. D., Mao J., He D., Hayes C., Lippmann M. Effects of single- and multiday ozone exposures on respiratory function in active normal children. Environ Res. 1991 Aug;55(2):107–122. doi: 10.1016/s0013-9351(05)80167-7. [DOI] [PubMed] [Google Scholar]
  10. Stedman J. R., Anderson H. R., Atkinson R. W., Maynard R. L. Emergency hospital admissions for respiratory disorders attributable to summer time ozone episodes in Great Britain. Thorax. 1997 Nov;52(11):958–963. doi: 10.1136/thx.52.11.958. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Stein R. T., Holberg C. J., Morgan W. J., Wright A. L., Lombardi E., Taussig L., Martinez F. D. Peak flow variability, methacholine responsiveness and atopy as markers for detecting different wheezing phenotypes in childhood. Thorax. 1997 Nov;52(11):946–952. doi: 10.1136/thx.52.11.946. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Strachan D. P., Cook D. G. Health effects of passive smoking. 6. Parental smoking and childhood asthma: longitudinal and case-control studies. Thorax. 1998 Mar;53(3):204–212. doi: 10.1136/thx.53.3.204. [DOI] [PMC free article] [PubMed] [Google Scholar]

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