Various studies have proposed that exposure to carcinogenic fumes, traditional fuels, and biofuels may negatively affect the growth and development of children. Especially within developing countries, childhood exposure to cigarettes, tobacco, fuels, and biofuels is widespread. Kyu et al. (2009) specifically investigated whether or not the exposure of children under five years old to cigarette smoke and biofuels is correlated with their height relative to their age. Using multilevel regression analyses, the researchers determined that exposure to maternal smoking negatively affected the height of the children in only three of the developing countries studied while biofuel exposure negatively affected height across all seven countries. Moreover, for children under five years old, biofuel exposure is connected with stunting and severe stunting in height. Thus, this study demonstrated that such exposures to cigarettes and biofuels might hinder childhood growth for young children in developing countries. —Christina Mainero
Kyu, H.H., Georgiades, K., and Boyle, M.H., 2009. Maternal smoking, biofuel smoke exposure and child height-for-age in seven developing countries. International Journal of Epidemiology, 38, 1342–1350.
In this study, Kyu et al. sought to examine the effects of maternal smoking and biofuel exposure on young children due to the rise of smoking and biofuel use in developing countries, the fact that maternal smoking may increase a child’s likelihood of exposure, the paucity of information regarding the effects of maternal smoking on children under five years old, and the increased use of biofuels in developing countries. For the seven developing countries studied, data were collected between 2005 and 2007. In setting up their sampling scheme, the researchers divided each country into clusters of roughly fifteen to twenty women. Within each cluster, they measured the heights of the children and also conducted interviews with their mothers. In some clusters, they questioned a subset of men regarding their daily activities and habits. In doing this, the researchers were able to assess the effects of maternal smoking, exposure to smoking by other members of the house, and biofuel exposure on the height of the children. Factors such as child age, child gender, breastfeeding initiation, mother’s age, mother’s educational history, estimated birth size of the child, household wealth and country acted as covariates.
Based on the data collected, Kyu et al. concluded that the children of women with fewer financial resources, less education, and more children tend to have increased smoking and biofuel exposure. Additionally, their regression models indicated that maternal smoking correlated negatively with height in Cambodia, Namibia, and Nepal; correlated positively with child height in Moldova; and showed no significant correlation either way in the remaining countries. Exposure to non-maternal smoking and biofuels, however, demonstrated a significant negative correlation with the height of young children. Moreover, biofuel exposure appears to be connected with stunting and severe stunting within all of the countries studied.
However, the researchers also noted several limitations of this study. Specifically, they mentioned the fact that there was no data regarding maternal smoking and biofuel exposure during pregnancy, which may be an important factor influencing the height of the children. Furthermore, actual biofuel exposures were measured indirectly rather than directly based on the type of biofuel used for cooking and daily activities. Additionally, the study lacked information regarding the duration of exposure. Studies such as these, though important for looking into potential correlations, do not conclusively establish causation. Yet, this study is significant because its conclusions suggested that there might be notable detrimental health effects associated with biofuel use as well as maternal smoking. Such heath effects must be considered in evaluating whether or not biofuels are plausible alternatives to traditional, petroleum-based fuels.