Objective: To examine whether indoor coal combustion for heating, which releases pollutants into the air, affects early childhood growth.
Design: A prospective longitudinal study, with growth measurements extracted from medical records of the children's well-child care visits at age 36 months. Data were compiled from self-administered questionnaires and medical records, both completed at 2 time points: delivery and follow-up.
Setting: Teplice and Prachatice districts in the Czech Republic.
Participants: A total of 1133 children followed from birth to age 36 months.
Main exposure: Maternally reported use of coal for heating.
Main outcome measure: The z score for height for age and sex at age 36 months.
Results: Adjusted for covariates, indoor coal use was significantly associated with a lower z score for height for age and sex at age 36 months (z score = -0.37; 95% confidence interval, -0.60 to -0.14). This finding translates into a reduction in height of about 1.34 cm (95% confidence interval, 0.51 to 2.16) for boys and 1.30 cm (95% confidence interval, 0.50 to 2.10) for girls raised in homes that used coal. The association between coal use and height was modified by postnatal cigarette smoke exposure.
Conclusions: Pollution from indoor coal use may impair early childhood skeletal growth to age 36 months. Because a significant proportion of the world population still uses coal indoors, the finding has public health consequences.