Organochlorine Levels in Human Milk and Risks to Exposed Breastfed Infants in Nandi County, Kenya

  • Nehemiah K. Birgen
  • Laetitia W. Kanja
  • Timothy Maitho
  • Sharon Koech
Keywords: Human Milk, Infants, Organochlorine Pesticides, Polychlorinated Biphenyls, Risk Assessment


Lipophilic persistent organochlorines (OCs) accumulate in the human adipose tissues and exposed lactating mothers can put breastfeeding infants at health risk. The study aimed to estimate the excretion levels of OCs in human milk and potential health risks to exposed breastfed infants. Between February and July 2019, 74 lactating mothers, across Nandi County, volunteered sociodemographic information and human milk samples. Milk lipids and OCs residues were extracted into an n-Hexane: Acetone (3:1) mixture using the Soxhlet technique. Twenty percent of the extract was gravimetrically analyzed to estimate milk lipid content and 80% with not more than 240 mg estimated lipids, was chromatographically purified by eluting through neutral Aluminium Oxide using 170 mL n-Hexane for GC-EI-MS/MS analysis. DDTs and PCBs residues occurred in 70.3% and 68.9% samples respectively while chlordane, endosulfan, and HCHs were each observed in less than 50% samples. The chemicals' average occurrence levels ranged from 0.04 to 7.30 ng/g lw. Statistically, there were no significant, p>0.05, differences in the average levels of OCs across the county, and between maternal parities and age groups. However, the average levels of OCs demonstrated significant, P<0.05, decreases over time in Kenya. The daily intake of chemicals by breastfed infants was computed for each of the sum OC groups. Three (4.05%) infants were exposed to residues of sum indicator PCBs above 20 ng/kg/day, the risk level given by the Agency for Toxic Substances and Disease Registry. The findings demonstrated that humans are moderately exposed to banned OCs in Nandi County and therefore underscore the need for effective control and monitoring of the safety of human food from environmental contaminants.


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How to Cite
Birgen, N. K., Kanja, L. W., Maitho, T., & Koech, S. (2023). Organochlorine Levels in Human Milk and Risks to Exposed Breastfed Infants in Nandi County, Kenya. European Journal of Science, Innovation and Technology, 3(6), 330-345. Retrieved from