###### Abstract
Unlike some heavy metals (cadmium, for instance), which have high water solubility and mobility in soil due to weak sorption to organic matter [17; 18], Pb has a high affinity for particle surfaces [9]. As a result, it strongly binds to organic and colloidal materials, limiting its solubility [9]. For this reason, only a small amount of the total Pb present in soil is available for plant uptake [9]. Exposure to Pb, which has no known biological function in animals or plants [9], occurs via inhalation, dermal contact, and ingestion, typically through food crops grown in contaminated soils [3; 19; 20; 21]. Plants sometimes accumulate heavy metals in concentrations that are detrimental to humans before phytotoxic effects are visible [22]. Even low-level exposure to Pb is associated with many adverse effects in humans, especially in children, who are particularly at risk due to increased direct contact with soils and associated hand-to-mouth play [3; 23]. These include neurological disorders, such as depression and schizophrenia, the effects of which are particularly concerning in children because they can impair learning and memory, affect behavior and mood, and alter neuromotor and neurosensory functions [23]. Lead is also known to impair plant growth, root elongation, seed germination, seedling development, transpiration, chlorophyll production, lamellar organization in the chloroplast, and cell division [9]. In a study on the effects of two different Pb concentrations (0.1 and 0.5 mM) on radish (_Raphanus sativus_, L.), [PERSON] et al. (2008) observed a 30-50% reduction in dry weight compared with the control, along with decreased chlorophyll concentrations [24]. However, the impact of Pb on plants varies by species and depends on several factors, including Pb concentration, duration of exposure, and stage of plant development [9]. For most species, the majority of absorbed lead (approximately 95% or more) is accumulated in the roots [9]. Some plants, specifically expanded hypocotyl root vegetables, are more likely to accumulate Pb in their core [3]. These include popular root vegetables among gardeners, like _Daucus carota_, L. (carrot), _Brassica rapa_, L. (turnip), _Beta vulgaris_, L. (beets), and radish [3]. Evidence also suggests that heavy metals have serious adverse effects on soil health through changes in microbiota populations and community structures, and can inhibit important microbial metabolic processes like respiration, denitrification, and enzymatic activity [25]. Moreover, heavy metals can negatively impact soil physicochemical properties, including soil organic C sequestration and degradation [7; 26]. Lead contaminated soils are often associated with low soil organic matter (OM); low soil fertility, including nitrogen (N) and phosphorous (P) availability; and micronutrient imbalances [27]. Gardeners apply a variety of substances (hereinafter \"amendments\") to their gardens to improve vegetable production, stabilize pH, and to condition the soil. These amendments effect the physicochemical properties of the soil in different ways, which can, in turn, influence Pb availability in soil, along with plant uptake [28; 29]. Soil pH, for example,is one of the most important factors determining heavy metal availability in soil [30; 31]. In general, for cationic metal species like Pb+2, a higher pH results in decreased availability, while anions (e.g., arsenic (As\({}^{-3}\))) become more available [19]. Organic matter (OM) content is also a significant factor influencing the availability of heavy metals and can reduce the mobility of many heavy metals through sorption to surfaces, along with precipitation and complexation reactions [7].