Bioavailable soil Pb minimized by in situ transformation to plumbojarosite.

Exposure to lead (Pb) during early life has persistent adverse health effects. During childhood, ingestion of bioavailable Pb in contaminated soils can be a major route of Pb absorption. Remediation to alter physiochemical properties of soil-borne Pb can reduce Pb bioavailability. Our laboratory-based approach for soil Pb remediation uses addition of iron (Fe) sulfate and application of heat to promote formation of plumbojarosite (PLJ), a sparingly soluble Pb-Fe hydroxysulfate mineral. We treated two soils with anthropogenic Pb contamination and samples of clean topsoil spiked with various Pb compounds (i.e., carbonate, chloride, phosphate [P], or sulfate) to convert native Pb species to PLJ and used a mouse assay to assess relative bioavailability (RBA) of Pb in untreated (U) and remediated soils. Bone and blood Pb levels were significantly lower (P < 0.001, Student's t test) in mice that consumed diets amended with remediated soils than with U soils. Estimated RBA for Pb in both remediated natural soils and Pb-mineral spiked soils were reduced by >90% relative to Pb RBA for U soils, which is substantially more effective than other soil amendments, including P. X-ray absorption spectroscopy showed that >90% of all Pb species in remediated soils were converted to PLJ, and ingested PLJ was not chemically transformed during gastrointestinal tract transit. Post treatment neutralization of soil pH did not affect PLJ stability, indicating the feasibility in field conditions. These results suggest that formation of PLJ in contaminated soils can reduce the RBA of Pb and minimize this medium's role as a source of Pb exposure for young children.

Emotional arousal and reflective functioning among parents participating in attachment-based family therapy for LGBTQ+ young adults and their nonaccepting parents.

OBJECTIVE: Parents' rejection of their LGBTQ + young adults can have a negative impact on their young adult's psychological welfare, and on the young adult-parent relationship. Parents' ability to reflect on their child's pain and unmet needs is thought to evoke empathy and compassion, and reduce rejection. Empirical and clinical evidence suggest that parents' level of reflective functioning (RF) is impacted by their level of emotional arousal (EA). This study examined the association between parents' EA and RF within the context of attachment-based family therapy for nonaccepting parents and their LGBTQ+ young adults. METHODS: 43 therapy sessions drawn from six different cases were coded for parental RF and EA, based on 30-second segments. This generated a total of 343 observations for analyses. RESULTS: Hierarchal linear modeling revealed that parents' level of RF was a function of their concomitant EA, with moderate levels of arousal predicting the highest RF levels. CONCLUSION: Moderate EA may facilitate optimal parental reflective functioning. With nonaccepting parents, who typically present for treatment with high levels of maladaptive fear and shame, therapists would do well to assess their level of arousal and, when indicated, employ downregulating interventions before inviting them to reflect on their young adult's experience and needs.

Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract.

Inhalation is a portal-of-entry for aerosols via the respiratory tract where particulate burden accumulates depending on sites of particle deposition, normal clearance mechanisms, and particle solubility. The time available for dissolution of particles is determined by the balance between the rate of particle clearance from a region and their solubility in respiratory solvents. Dissolution is a function of particle surface area divided by particle volume or mass (i.e., dissolution is inversely proportional to the physical diameter of particles). As a conservative approach, investigators commonly assume the complete and instantaneous dissolution of metals from particles depositing in the alveolar region of the respiratory tract. We derived first-order dissolution rate constants to facilitate biokinetic modeling of particle clearance, dissolution, and absorption into the blood. We then modeled pulmonary burden and total dissolution of particles over time as a function of particle size, density, and solubility. We show that assuming poorly soluble particle forms will enter the blood as quickly as highly soluble forms causes an overestimation of concentrations of the compound of interest in blood and other extrapulmonary tissues while also underestimating its pulmonary burden. We conclude that, in addition to modeling dose rates for particle deposition into the lung, physiologically based pharmacokinetic modeling of pulmonary and extrapulmonary tissues concentrations of moderately and poorly soluble materials can be improved by including estimates of lung burden and particle dissolution over time.

Dietary lead modulates the mouse intestinal microbiome: Subacute exposure to lead acetate and lead contaminated soil.

The effect of dietary lead on the intestinal microbiome has not been fully elucidated. To determine if there was an association between microflora modulation, predicted functional genes, and Pb exposure, mice were provided diets amended with increasing concentrations of a single lead compound, lead acetate, or a well characterized complex reference soil containing lead, i.e. 6.25-25 mg/kg Pb acetate (PbOAc) or 7.5-30 mg/kg Pb in reference soil SRM 2710a having 0.552 % Pb among other heavy metals such as Cd. Feces and ceca were collected following 9 days of treatment and the microbiome analyzed by 16 S rRNA gene sequencing. Treatment effects on the microbiome were observed in both feces and ceca of mice. Changes in the cecal microbiomes of mice fed Pb as Pb acetate or as a constituent in SRM 2710a were statistically different except for a few exceptions regardless of dietary source. This was accompanied by increased average abundance of functional genes associated with metal resistance, including those related to siderophore synthesis and arsenic and/or mercury detoxification. Akkermansia, a common gut bacterium, was the highest ranked species in control microbiomes whereas Lactobacillus ranked highest in treated mice. Firmicutes/Bacteroidetes ratios in the ceca of SRM 2710a treated mice increased more than with PbOAc, suggestive of changes in gut microbiome metabolism that promotes obesity. Predicted functional gene average abundance related to carbohydrate, lipid, and/or fatty acid biosynthesis and degradation were greater in the cecal microbiome of SRM 2710a treated mice. Bacilli/Clostridia increased in the ceca of PbOAc treated mice and may be indicative of increased risk of host sepsis. Family Deferribacteraceae also was modulated by PbOAc or SRM 2710a possibly impacting inflammatory response. Understanding the relationship between microbiome composition, predicted functional genes, and Pb concentration, especially in soil, may provide new insights into the utility of various remediation methodologies that minimize dysbiosis and modulate health effects, thus assisting in the selection of an optimal treatment for contaminated sites.

Interconnected soil iron and arsenic speciation effects on arsenic bioaccessibility and bioavailability: a scoping review.

Extensive research has examined arsenic (As) bioavailability in contaminated soils and is routinely assessed using in vitro bioaccessibility (IVBA) assays. Analysis of differences in bioaccessibility measurements across IVBA assays and phases is expected to provide valuable insights into geochemical mechanisms controlling soil As bioaccessibility and bioavailability. Soil iron (Fe) content and As speciation are expected to significantly influence IVBA gastric and intestinal phases due to fluctuations in precipitation-dissolution chemistry and sorption reactivity as pH and assay chemical complexity changes. The aim of this review was to examine these relationships by 1) conducting a meta-analysis (n = 47 soils) determining the influence of total Fe on As bioaccessibility measurements and 5 IVBA assays and 2) investigating the effect of As speciation on gastric/intestinal phase IVBA and in vitro-in vivo correlations. Our findings indicate that soil Fe content and As speciation heterogeneity are important in elucidating variability of bioaccessibility measurements across IVBA assays and gastrointestinal phases. Greater focus on coupled As speciation and Fe precipitation chemistry may (1) improve our understanding of soil geochemical factors and assay constituents that influence As in vitro-in vivo correlations and (2) resolve variability in the precision of oral relative bioavailability (RBA) estimated using IVBA assays for soils possessing heterogenous As speciation and Fe composition.

Evaluating the mouse model for estimation of arsenic bioavailability: Comparison of estimates of absolute bioavailability of inorganic arsenic in mouse, humans, and other species.

Accurate assessment of adverse health effects attributable to ingestion of inorganic arsenic (As) present in contaminated soils requires determination of the internal dose of metal provided by ingested soil. This calculation requires estimation of the oral bioavailability of soil-borne (As). Animal models to assess the bioavailability of soil (As) are frequently used as surrogates for determination of this variable in humans. A mouse assay has been widely applied to estimate the bioavailability of As in soils at sites impacted by mining, smelting, and pesticides. In the mouse assay, the relative bioavailability (RBA) of soil (As) is determined as the ratio of the fraction of the ingested arsenic dose excreted in urine after consumption of diets containing a test soil or the soluble reference compound, sodium arsenate. The aim of the current study was to compare (As) bioavailability measured in the mouse assay with reported estimates in humans. Here, a pharmacokinetic model based on excretion of arsenic in urine and feces was used to estimate the absolute bioavailability (ABA) of As in mice that received an oral dose of sodium arsenate. Based upon this analysis, in mice that consumed diet amended with sodium arsenate, the ABA was 85%. This estimate of arsenic ABA for the mouse is comparable to estimates in humans who consumed (As) in drinking water and diet, and to estimates of ABA in monkeys and swine exposed to sodium arsenate. The concordance of estimates for ABA in mice and humans provides further support for use of the mouse model in human health risk assessment. Sodium arsenate ABA also provides a basis for estimating soil arsenic ABA from RBA estimates obtained in the mouse model.

Attachment-based family therapy for sexual and gender minority young adults and their nonaccepting parents.

This pilot open trial examined the efficacy of attachment-based family therapy (ABFT) for Israeli sexual and gender minority (SGM) young adults and their persistently nonaccepting parents. Thirty families received up to 26 weeks of treatment, with parental rejection, parental acceptance, and young adults' attachment avoidance and attachment anxiety assessed at baseline, 8, 16, 24, and 36 weeks (three months post-treatment). Analyses using multilevel growth models revealed that both young adults and their mothers independently reported increases in mothers' acceptance of their young adult's same-sex orientation or noncisgender identity. In addition, young adults reported decreases in both parents' levels of rejection. Also, mothers, but not fathers, reported decreases in their own level of rejection. Finally, young adults reported a decrease in attachment avoidance in their relationships with both mothers and fathers, but not a decrease in attachment anxiety. Importantly, these treatment gains were maintained three months after the end of treatment. Together, these results suggest that ABFT-SGM, a manualized, affirmative, experiential, family-based treatment, may be effective in reducing long-standing parental rejection, promoting parental acceptance, and improving the quality of LGBTQ+ young adults' relationships with their parents. These findings are encouraging in light of the urgent need for efficacious interventions to reduce family generated minority stress and promote safer, more supportive environments for sexual and gender minority people.

Corrective attachment episodes in attachment-based family therapy: the power of enactment.

Corrective attachment episodes, therapeutic enactments designed to increase openness and trust between young adults and their parents, are the purported primary change mechanism in attachment-based family therapy. This study examined whether sequences of therapist interventions, young adults' productive emotional processing, and parental behaviors thought to reflect corrective attachment episodes were characteristic of good versus poor outcome cases. Thirty conjoint attachment sessions were analyzed using the THEME algorithm. Results revealed that only in good outcome cases were there four-step sequences hypothesized to facilitate attachment. One sequence began with the therapist focusing on the young adult's primary adaptive emotions, followed by the young adult's productive emotional processing of their vulnerable emotions, followed by the therapist empathizing with and validating the parent, followed by parents' expressions of warmth toward their young adult. The second sequence began with the therapist focusing on the young adult's unmet attachment needs, followed by the young adult productively processing their vulnerable emotions, followed by the parent expressing a willingness to fulfill their young adult's attachment needs, followed by parents' expressions of warmth toward their young adult. Findings provide an empirically-based clinical map for conducting therapeutic enactments in family therapy and have implications for treatment development, therapist training and supervision.

[HOW HAVE WE DEVELOPED? THE HISTORY OF DEVELOPMENTAL AND REHABILITATION SERVICES FOR CHILDREN IN ISRAEL].

INTRODUCTION: Public health and welfare organizations, as well as governmental agencies in Israel, charged with the provision of services for children with special needs and their families, have reached a timely watershed. This large network finds its roots at the dawn of the last century in the history of the notable efforts made by idealistic individuals who immigrated to the country and in the many Jewish philanthropic community organizations, charged with helping others less fortunate. Beginning with services for the handicapped, who were either victims of polio or suffering from cerebral palsy, the gamut of providers blossomed to encompass many others in need, which today number in the hundreds of thousands each year, suffering from a wide range of impairments, and with a multitude of needs. We found it incumbent upon us to undertake a prodigious review of those pioneering individuals and organizations, contributing to the current wealth of services available to the public.

Plumbojarosite Remediation of Soil Affects Lead Speciation and Elemental Interactions in Soil and in Mice Tissues.

Lead (Pb) contamination of soils is of global concern due to the devastating impacts of Pb exposure in children. Because early-life exposure to Pb has long-lasting health effects, reducing exposure in children is a critical public health goal that has intensified research on the conversion of soil Pb to low bioavailability phases. Recently, plumbojarosite (PLJ) conversion of highly available soil Pb was found to decrease Pb relative bioavailability (RBA <10%). However, there is sparse information concerning interactions between Pb and other elements when contaminated soil, pre- and post-remediation, is ingested and moves through the gastrointestinal tract (GIT). Addressing this may inform drivers of effective chemical remediation strategies. Here, we utilize bulk and micro-focused Pb X-ray absorption spectroscopy to probe elemental interactions and Pb speciation in mouse diet, cecum, and feces samples following ingestion of contaminated soils pre- and post-PLJ treatment. RBA of treated soils was less than 1% with PLJ phases transiting the GIT with little absorption. In contrast, Pb associated with organics was predominantly found in the cecum. These results are consistent with transit of insoluble PLJ to feces following ingestion. The expanded understanding of Pb interactions during GIT transit complements our knowledge of elemental interactions with Pb that occur at higher levels of biological organization.

High Lead Bioavailability of Indoor Dust Contaminated with Paint Lead Species.

House dust and soils can be major sources of lead (Pb) exposure for children. The American Healthy Homes Survey (AHHS) was developed to estimate Pb exposure from house dust and soil, in addition to other potential household contaminants and allergens. We have combined X-ray absorption spectroscopic (XAS) fingerprinting and in vivo mouse relative bioavailability (RBA) measurements for a subset of house dust and residential soils collected in the AHHS, with the primary objective of gaining a better understanding of determinants of house dust Pb bioavailability. Lead speciation was well related to variations in RBA results and revealed that highly bioavailable Pb (hydroxy)carbonate (indicative of Pb-based paint) was the major Pb species present in house dusts. Measured Pb RBA was up to 100% and is likely driven by paint Pb. To our knowledge, this is the first report of in vivo Pb RBA for U.S. house dust contaminated in situ with paint Pb and corroborates results from a previous study that demonstrated high RBA of paint Pb added to soil. We also report a relatively low RBA (23%) in a residential soil where the major Pb species was found to be plumbojarosite, consistent with a previous report that plumbojarosite lowers Pb RBA in soils.

A Physiological-Based Pharmacokinetic Model For The Broad Spectrum Antimicrobial Zinc Pyrithione: II. Dermal Absorption And Dosimetry In The Rat.

The broad spectrum antimicrobial/antifungal zinc pyrithione (ZnPT) is used in products ranging from antifouling paint to antidandruff shampoo. The hazard profile of ZnPT was established based upon comprehensive toxicological testing, and products containing this biocide have been safely used for years. The purpose of this study was to create a dermal physiologically based pharmacokinetic (PBPK) model for ZnPT in the rat for improving dose-response analysis of ZnPT-induced toxicity where reversible hindlimb weakness was the endpoint used as the basis for ZnPT risk assessments. Previously, we developed a PBPK model which simulated the kinetics of pyrithione (PT) and its major metabolites 2-(methylsulfonyl)pyridine and S-glucuronide conjugates in blood and tissues of rats following oral ZnPT administration. The dermal model was optimized utilizing in vitro dermal penetration investigations conducted with rat skin and with historical data from a dermal repeat dose study using rats. The model replicated the observed temporal patterns and elimination kinetics of [14C]PT equivalents in blood and urine during and following repeated dermal dosing and replicated the observed dose-dependencies of absorption, blood [14C]PT equivalents and plasma PT concentrations. The model provided internal dosimetry predictions for a benchmark dose analysis of hindlimb weakness in rats that combined dermal, gavage and dietary studies into a single internal dose-response model with area-under-the-curve (AUC) for plasma PT, the toxic moiety in the rat, as the internal dose metric. This PBPK model has predictive validity for calculating internal doses of PT and/or [14C]PT equivalents from different routes of exposure in the rat.

Emotional processing in attachment-based family therapy for suicidal adolescents.

Objective: This study examined proposed sequential pathways through which suicidal adolescents are thought to shift from secondary global distress and rejecting anger to primary adaptive hurt, grief and assertive anger in the context of attachment-based family therapy (ABFT). Method: Participants were 39 suicidal adolescents who had received 16 weeks of ABFT as part of a randomized clinical trial, and who had been assigned to one of three outcome groups (i.e., good responders, slow responders and non-responders). Adolescents' in-session emotions were observationally coded using the Classification of Affective-Meaning States. Results: Across outcome groups, adolescents evidenced shifts from global distress to maladaptive shame, from maladaptive rejecting anger to adaptive assertive anger, and from adaptive assertive anger to adaptive grief/hurt. Adolescents who did not respond to treatment evidenced higher rates of maladaptive global distress. Conclusions: Findings are discussed in the context of ABFT and sequential emotional processing theories.

Therapist Interventions Associated with Productive Emotional Processing in the Context of Attachment-Based Family Therapy for Depressed and Suicidal Adolescents.

Productive emotional processing is considered a key change mechanism in attachment-based family therapy (ABFT). This study examined the impact of attachment-based family therapy therapist interventions aimed to promote productive emotional processing of primary adaptive emotions in a sample of 30 depressed and suicidal adolescents who had participated in a larger randomized clinical trial. Results of sequential analyses revealed that relational reframes and therapists' focus on primary adaptive emotions were associated with the subsequent initiation of adolescents' productive emotional processing of primary adaptive emotions. In contrast, interpretations, reassurances, and therapists' focus on adolescents' rejecting anger toward their parents were all followed by the discontinuation of adolescents' emotional processing that had already begun. Finally, therapists' general encouragement of affect and focus on adolescents' unmet attachment/identity needs were associated with both the initiation of adolescents' productive emotional processing, and with the discontinuation of such processing once it had already begun. Theoretical and clinical implications are discussed.

El procesamiento emocional productivo (Greenberg, Auszra y Hermann, 2007) se considera un mecanismo de cambio clave en la terapia familiar centrada en apego (ABFT en inglés; Diamond, Diamond, & Levy, 2014). Este estudio examinó el impacto de intervenciones terapéuticas ABFT dirigidas a promover el procesamiento emocional productiva de emociones adaptativas primarias en una muestra de 30 estudiantes deprimidos y suicidas que participaron en un ensayo clínico aleatorio de mayor escala. Los resultados de los análisis secuenciales revelaron que los reencuadres relacionales y el enfoque de los terapistas en las emociones adaptativas primarias se asociaron al inicio subsiguiente del procesamiento emocional productivo de emociones adaptativas primarias por parte de los adolescentes. En cambio, las interpretaciones, afirmaciones y el enfoque de los terapistas en el enojo rechazador de los adolescentes hacia sus padres fueron seguidas por la suspensión del procesamiento emocional que había ya comenzado. Por último, la motivación general por parte de los terapistas del afecto y enfoque en las necesidades insatisfechas de apego/identidad de los adolescentes se asociaron tanto al inicio del procesamiento emocional productivo de los adolescentes como a la suspensión de dicho procesamiento cuando había ya comenzado. Se discuten las implicaciones teóricas y clínicas.

Dietary Lead and Phosphate Interactions Affect Oral Bioavailability of Soil Lead in the Mouse.

Effects of dietary P level on the oral bioavailability of Pb present in soil were examined in a mouse model. Adult female C57BL/6 mice had free access to AIN-93G purified rodent diet amended with Pb as a soluble salt, Pb acetate, or in a soil matrix (NIST SRM 2710a). In these studies, the basal diet contained P at a nutritionally sufficient level (0.3% w/w) and the modified diets contained P at a lower (0.15%) or a higher (1.2%) level. For either dietary Pb source (Pb acetate or NIST SRM 2710a), low dietary P level markedly increased accumulation of Pb in bone, blood, and kidney. Tissue Pb levels in mice fed a high P in diet were not different from mice fed the basal P diet. Dietary P and Pb interacted to affect body weight change and feed efficiency in mice. The relative contribution of different Pb species in diet and feces was also affected by dietary P level. Differences in Pb species between diet and feces indicated that transformation of Pb species can occur during gastrointestinal tract transit. These interactions between Pb and P that alter Pb speciation may be important determinants of the bioavailability of Pb ingested in soil.

Urinary cadmium clearance, its relationship to glomerular filtration rate and implications for cadmium epidemiology.

Decreasing renal glomerular filtration rate (GFR) in association with increasing blood cadmium levels was reported in epidemiological studies of general populations. Dependence of cadmium clearance on GFR has implications for interpreting causation in these studies. Associations between cadmium clearance and creatinine clearance, a metric of GFR, were evaluated in a sample of the U.S. population. Blood to urine cadmium clearance and serum creatinine clearance were estimated in approximately 6000 individuals included in the National Health and Nutrition Examination Survey (NHANES 2009-2016). Linear regression models explained approximately 45% of variance in cadmium clearance in adults, with 74% of the explained variance attributed to creatinine clearance and 25% explained by age. In adolescents (12-<20 years), linear regression models explained 55% of variance in cadmium clearance with >99% of the explained variance attributed to creatinine clearance. The models predicted that halving creatinine clearance would result in a 40% decrease in cadmium clearance and a 20% rise in blood cadmium. Dependence of cadmium clearance on GFR has implications for assigning causation to studies in which increasing blood cadmium levels have been associated with increasing risk of low GFR. Statistical associations between blood cadmium and low GFR, such as elevated odds ratios in upper percentile strata of populations, may be partially a consequence of lower cadmium clearance in association with low GFR that is reverse causation.

Estimates of urinary blood lead clearance and its relationship to glomerular filtration rate based on a large population survey.

Blood lead (Pb) clearance (CbPb) and serum creatinine clearance (CsCr), a metric of glomerular filtration rate (GFR), were estimated in approximately 7,600 subjects from the NHANES (2009-2016). Median CbPb in adults was 0.04 L/day (5th-95th percentile range: 0.01-0.12). Linear regression models explained approximately 68% of variance in CbPb in adults, with >98% of explained variance attributed to CsCr. These results provide an improved quantitative understanding of the possible effects of reverse causality in the interpretation of studies of associations between blood Pb and decrements in GFR.

Exploring the process of change in emotion-focused therapy for social anxiety.

Objective: This study examined purported change mechanisms in emotion-focused therapy for social anxiety disorder. Methods: The sample included nine clients who had participated in a multiple-baseline case study trial examining the efficacy of emotion-focused therapy for social anxiety disorder (SAD). Multilevel analyses were conducted to examine the trajectories of emotions over the course of treatment, and whether primary adaptive emotions in a given session predicted levels of SAD symptoms, self-criticism, and self-reassurance over the course of the following week. Results: Findings showed a significant decrease in shame, and a marginally significant increase in assertive anger, over the course of treatment. Adaptive sadness/grief in a given session predicted less fear of negative evaluation over the course of the following week. Shame in a given session predicted higher levels of inadequate-self over the course of the following week. Finally, shame, and to a lesser degree assertive anger, in a given session predicted reassurance of self over the course of the following week. Neither assertive anger nor adaptive sadness/grief in a given session predicted levels of self-criticism over the course of the following week. Conclusions: These findings lend partial preliminary support for the therapeutic role of evoking and processing adaptive sadness/grief and assertive anger in the treatment of SAD.

In vivo and in vitro methods for evaluating soil arsenic bioavailability: relevant to human health risk assessment.

Arsenic (As) is the most frequently occurring contaminant on the priority list of hazardous substances, which lists substances of greatest public health concern to people living at or near U.S. National Priorities List site. Accurate assessment of human health risks from exposure to As-contaminated soils depends on estimating its bioavailability, defined as the fraction of ingested As absorbed across the gastrointestinal barrier and available for systemic distribution and metabolism. Arsenic bioavailability varies among soils and is influenced by site-specific soil physical and chemical characteristics and internal biological factors. This review describes the state-of-the science that supports our understanding of oral bioavailability of soil As, the methods that are currently being explored for estimating soil As relative bioavailability (RBA), and future research areas that could improve our prediction of the oral RBA of soil As in humans. The following topics are addressed: (1) As soil geochemistry; (2) As toxicology; (3) in vivo models for estimating As RBA; (4) in vitro bioaccessibility methods; and (5) conclusions and research needs.

Long-Term in Situ Reduction in Soil Lead Bioavailability Measured in a Mouse Model.

Effects of different treatments on the bioavailability of lead (Pb) in soil from a smelter emission contaminated site in Joplin, Missouri, were evaluated in a mouse model. Similar estimates of relative bioavailability for Pb in untreated or treated soil were obtained in mice and in the well-established juvenile swine model. In the mouse model, treatments that used phosphate (phosphoric acid or triple superphosphate) combined with iron oxide or biosolids compost significantly reduced soil Pb bioavailability. Notably, effects of these remediation procedures were persistent, given that up to 16 years had elapsed between soil treatment and sample collection. Remediation of soils was associated with changes in Pb species present in soil. Differences in Pb species in ingested soil and in feces from treated mice indicated that changes in Pb speciation occurred during transit through the gastrointestinal tract. Use of the mouse model facilitates evaluation of remediation procedures and allows monitoring of the performance of procedures under laboratory and field conditions.