Background: Today’s rapid industrialization and urbanization have significantly increased human exposure to environmental pollutants. Lead is a neurotoxicant with known serious health related problems, especially in children. This heavy metal is widely spread in our surrounding environment. Breast milk is the recommended form of enteral nutrition for all infants, including preterm infants. Human breast milk contaminated with lead poses potential risk of exposing recipient infant to this neurotoxic heavy metal. The primary aims of this study were to: a) evaluate the breast milk lead levels in breastfeeding mothers in three major regions of the West Bank, and b) to investigate the effects of sociodemographic variables on the breast milk lead levels.
Methods: This study was conducted in a cross-sectional design. Breast milk samples were collected from 89 breastfeeding mothers from Nablus, Ramallah and Jerusalem regions in polyethylene tubes previously incubated in 10% nitric acid. The ethics and protocol of this study were approved by the institutional review board of An-Najah National University. Samples collection protocol was also approved by the Ministry of Health. Breast milk lead levels were quantified using a previously validated graphite furnace atomic absorption spectrophotometric method. Breastfeeding mothers were interviewed and their sociodemographic variables were collected using a standard questionnaire.
Findings: The median breast milk lead level was 4.0 µg/L, ranging from 2.0 to 12.0 µg/L. Breast milk lead levels in 19.1% of the samples analyzed were higher than the World Health Organization’s (WHO) safety limits for occupationally unexposed population. Breast milk lead levels were significantly higher in breast milk obtained from mothers who resided in refugee camps and cities than those obtained from mothers who resided in villages (p < 0.01). Breast milk lead levels were also significantly higher in breast milk samples obtained from mothers with lower monthly household income (p < 0.05), lived close to paints shop (p < 0.05), lived in a house with peeling or chipping paint (p < 0.05), worked in agriculture (p < 0.05), spent more than 3 years working in agriculture (p < 0.01), and used eye kohl (p < 0.01). Multiple linear regression analysis showed that using eye kohl was a significant (p = 0.039) predictor of higher breast milk lead levels above the WHO’s safety limits.
Interpretation: In this study, breast milk lead levels were higher than the WHO’s safety limits for occupationally unexposed populations. In the Middle East, the major sources of lead are smelters, battery factories, radiator repair shops, unleaded fuel, eye kohl, leaded paints, flour from traditional stone mills, and the occasional burning of wastes. In this study, using eye kohl was a significant predictor of higher breast milk lead levels than any other sociodemographic variable. Previous studies showed that some eye kohl manufactured in countries with loose industrial regulations contain significant amounts of lead. Health authorities need to implement measures to eliminate or reduce exposure to lead.