QUANTIFYING LEAD EXPOSURE THROUGH DUST, VEGETABLES AND FRUITS IN KABWE, ZAMBIA

Lead pollution is one of the major global environmental problems that affects both highly industrialized and less industrialized countries. While urban gardening has become increasingly popular, in places contaminated with lead, these gardens can be a potential risk for lead exposure through contaminated produce. This study aimed to evaluate the potential health risk due to the consumption of vegetables and fruits grown in residential gardens contaminated with lead and compare that to the exposure risk from contaminated dust and dermal contact. The study also establishes the relationship between lead concentrations in soils and the crops grown in them. Soil, dust, fruits and vegetable samples were collected over two seasons from Kabwe, Zambia and tested for lead using Atomic Absorption Spectrometry and X-ray Fluorescence. The most common vegetables sampled were Brassica napus, Brassica rapa and sweet potatoes (leaves). Lead concentrations in all sampled fruits were below detection limit, while all leafy vegetables had significant amounts of lead. The vegetables did not show any statistical difference (from each other) in the amount of lead taken up (p = 0.22). All the vegetables were above the tolerable consumption limit per week (0.025 mg/kg body weight). Plant lead uptake was directly related to soil concentrations. Average dermal contact exposure was 0.006 and 0.044 mg/kg.day in children and adults respectively. Average lead in indoor dust was above 40 μg/ft2 which is a cause for concern. Vegetables, dust and dermal contact are significant exposure pathways in this area. These results imply that, in environments contaminated with lead, dust and diets that rely on home grown leafy vegetables will substantially contribute to a person’s lead burden and impact individual and community health. Thus, there exists a great need for testing lead levels in gardens and homes to develop site-specific strategies to ensure safety