Dichlorodiphenyltrichloroethane (DDT) is an organochlorine insecticide whose introduction led to the control of malaria in many endemic regions in the world. For instance, malaria was eliminated through the use of DDT in Europe and the US. However, DDT has a slow breakdown, thus it persists in the environment for long.
It has been classified under persistent organic pollutants. Its use is outlawed in almost all countries due to its toxicity (Kacew & Lee, 2013). The article titled, “In utero exposure to dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) and neurodevelopment among young Mexican American children” by Eskenazi et al. (2006) reports about a study that was conducted in California to explore how prenatal exposure to DDT and its metabolite (DDE) is related to neurodevelopment.
This article sought to gather evidence to substantiate the claim that DDT is a neurodevelopmental toxicant in animals. This study used a cohort. The participants were recruited from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) between October 1999 and October 2000. A total of 601 women aged between 18 and 20 years were enrolled.
The women were subjected to interviews during pregnancy and shortly after giving birth. They were also assessed when the infants were 6, 12, and 24 months old. The developmental features of the infants were assessed and exposure to DDT/DDE measured.
Results indicated that almost all DDT/DDE levels rose beyond the LOD. Most women had a lower total PCB level and higher DAP, HCB, and beta-HCCH levels. The outcome of DDT/DDE measurement indicated that a 10-fold increase in DDT/DDE serum levels caused a significant decrease in Psychomotor Developmental Index scores at 6 and 12 months. A significant decrease in the Mental Developmental Index score was noted for both DDT and DDE at 12 and 24 months.
Based on these findings, the study came to a conclusion that exposure to DDT and DDE during the prenatal period can to lead to delays in the development of infants. However, the findings of this study were not conclusive and should not be generalized. The study further determined that breastfeeding was associated with low chances of poor psychomotor and mental development, even among women who were exposed to high DDT levels. The authors, therefore, recommended breastfeeding.
The findings of this study have been supported by recent studies. Ribas-Fito (2006) found out that exposure to substantial levels of DDT was associated with decreased cognitive skills at the age of four years. Another study by Sagiv et al. (2008) demonstrated the relationship between in utero exposure to DDT/DDE and developmental neurotoxity.
The authors found out that even very low levels of exposure to this toxicant in the serum in the umbilical cord during delivery led to decreased attention in the early stages of life. Most recently, Kacew and Lee (2013) also demonstrated the relationship between exposure to DDT and neurodevelopment in infancy.
It is, therefore, evident that DDT is toxic and it affects the neurodevelopment of infants. Although DDT is an effective insecticide that has been successfully used to curb mosquitoes, it is important that whoever chooses to use it should consider the benefits of controlling mosquitoes and malaria compared to the toxicity brought about by the use of this insecticide. It is for this reason that most countries absolutely prohibit its use.
Personally, although my mother was exposed to DDT as an insecticide, none of my siblings have developed neurodevelopment problems. Perhaps this is because the exposure was low. Moreover, breastfeeding may have prevented the effects of DDT. The findings of this study, as well as the other studies on the same subject find application in cases where DDT is still in use, whether lawfully or unlawfully.
References
Eskenazi, B., Marks, A. R., Bradman, A., Fenster, L., Johnson, C., Dana, B., & Jewell N. P. (2006). In utero exposure to dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) and neurodevelopment among young Mexican American children. Journal of American Pediatrics, 118(1), 233 -241. doi: 10.1542/peds.2005-311
Kacew, S., & Lee, B. M. (2013). Lu’s basic toxicology: Fundamentals, target organs, and risk assessment (6th ed.). New York, NY: Informa Healthcare
Ribas-Fitó, N., Torrent, M., & Carrizo, D. (2006). In utero exposure to background concentrations of DDT and cognitive functioning among preschoolers. American Journal of Epidemiology, 164(10), 955–62. doi:10.1093/aje/kwj299.
Sagiv, S. K., Nugent, J. K., & Brazelton, T. B. et al. ( 2008). Prenatal organochlorine exposure and measures of behavior in infancy using the Neonatal Behavioral Assessment Scale (NBAS). Environmental Health Perspective, 116(5), 666–73. doi:10.1289/ehp.10553.