Relation between children's height and outdoor air pollution from coal-burning sources in the British 1946 birth cohort.
OBJECTIVE
Air pollution is associated with a number of health outcomes in childhood. In this study, we investigated whether air pollution is related to children's height.


METHODS
The 1946 British birth cohort study recruited 5,362 children born in 1 week in March 1946. Height was measured when the children were aged 2, 4, 6, 7, 11 and 15 years. Data on socio-economic conditions and other characteristics were obtained in interviews. Areas of children's residence were categorised into four groups of air pollution on the basis of published coal-consumption data.


RESULTS
After controlling for socio-economic factors, we found that air pollution was associated with children's height at several ages. The association, adjusted for socio-economic factors, was strongest at the age of 7 years, when children in the most polluted areas were 1.2 (95% confidence interval 0.5-1.8) cm shorter than those in the least polluted areas. After the age of 7 years the effect of air pollution diminished and disappeared by the age of 15 years. Further adjustment for birth weight and respiratory illness in childhood did not change this pattern.


CONCLUSIONS
Children's height was inversely associated with air pollution, but the magnitude of the effect depended on age. However, the biological mechanisms linking children's growth with air pollution are not evident, and it remains to be confirmed whether the relationship is genuine and causal.
Bobak
Martin
M
International Centre for Health and Society, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, WC1E 6BT, UK. m.bobak@ucl.ac.uk
Richards
Marcus
M
Wadsworth
Michael
M
D000293:Adolescent; D000393:Air Pollutants / Q000145:classification / Q000633:toxicity*; D001827:Body Height / Q000187:drug effects / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D003031:Coal / Q000706:statistics & numerical data*; D003296:Cooking; D004781:Environmental Exposure / Q000009:adverse effects*; D006128:Growth / Q000502:physiology; D006361:Heating; D006801:Humans; D007407:Interviews as Topic; D016014:Linear Models; D008137:Longitudinal Studies; D012959:Socioeconomic Factors; D006113:United Kingdom
D000393:Air Pollutants; D003031:Coal