Indoor coal use and early childhood growth.

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.