Songbirds incidentally ingest soil contaminated with lead and several species in the Southeast Missouri Lead Mining District have a negative relationship between soil lead concentration and reproduction. We used an individual-based model (IBM) to simulate nesting processes throughout the breeding season to estimate annual productivity for 5 songbirds in relation to soil-lead concentration. We modeled daily nest survival and number fledged in relation to soil lead and incorporated these relationships into the IBM using a Bayesian approach that fully captured parameter uncertainty and process variation. The proportion of the posterior distribution for the effect of soil lead on daily nest survival was mostly negative for Pipilo erythrophthalmus (Eastern Towhee), Passerina cyanea (Indigo Bunting), Cardinalis cardinalis (Northern Cardinal), Sialia sialis (Eastern Bluebird; f = 0.972, 0.990, 0.741, 0.581, respectively), and slightly positive for Spizella pusilla (Field Sparrow; f = 0.680). The proportion of the posterior distribution for the effect of soil lead on the number fledged from successful nests was mostly negative for S. pusilla, P. erythrophthalmus, and C. cardinalis (f = 0.867, 0.585, 0.508, respectively) and positive for P. cyanea and S. sialis (f = 0.773, 0.744). Simulated annual productivity decreased by 0.04-1.47 young/female/year among species across the range of soil lead concentrations, with the greatest declines for P. erythrophthalmus and P. cyanea. The probability of fledging one or more young changed from 51% to 15% for P. erythrophthalmus, 57% to 23% for P. cyanea, 60% to 48% for C. cardinalis, 94% to 84% for S. sialis, and 57% to 64% for S. pusilla as soil-lead concentration around a nest increased from 20 to 4,000 ppm. Most nest failures were the result of predation; therefore, we suggest lead may have affected birds' behavior at the nest, or affected nest site quality, which resulted in higher nest predation. center dot Songbirds incidentally consume soil contaminated with lead while foraging near mining operations. Previous research in the Southeast Missouri Lead Mining District found a negative relationship between soil lead concentration and some songbird reproductive parameters, such as nest survival and number of young fledged.center dot We used data from this earlier study in an individual-based model to predict annual productivity by a female in a breeding season at increasing soil lead levels.center dot Annual productivity decreased by 0.04-1.47 offspring/female/year and the probability of fledging one or more young changed from 51% to 15% for Pipilo erythrophthalmus (Eastern Towhee), 57% to 23% for Passerina cyanea (Indigo Bunting), 60% to 48% for Cardinalis cardinalis (Northern Cardinal), 94% to 84% for Sialia sialis (Eastern Bluebird), and 57% to 64% for Spizella pusilla (Field Sparrow) as soil-lead concentrations increased.center dot Most nest failures were due to predation; therefore, we suggest possible explanations for the reduction in productivity are that lead affected birds' behavior and activity at the nest, or affected nest site quality, and resulted in higher nest predation. Las aves canoras ingieren incidentalmente suelo contaminado con plomo y varias especies en el Distrito Minero de Plomo del sureste de Missouri tienen una relaci & oacute;n negativa entre la concentraci & oacute;n de plomo en el suelo y la reproducci & oacute;n. Utilizamos un modelo basado en individuos (MBI) para simular los procesos de anidaci & oacute;n a lo largo de la temporada reproductiva para estimar la productividad anual de cinco aves canoras en relaci & oacute;n con la concentraci & oacute;n de plomo en el suelo. Modelamos la supervivencia diaria del nido y el n & uacute;mero de volantones en relaci & oacute;n con el plomo en el suelo e incorporamos estas relaciones en el MBI usando un enfoque bayesiano que captur & oacute; completamente la incertidumbre de los par & aacute;metros y la variaci & oacute;n del proceso. La proporci & oacute;n de la distribuci & oacute;n posterior para el efecto del plomo en el suelo sobre la supervivencia diaria del nido fue mayormente negativa para Pipilo erythrophthalmus, Passerina cyanea, Cardinalis cardinalis y Sialia sialis (f = 0.972, 0.990, 0.741, 0.581, respectivamente) y ligeramente positiva para Spizella pusilla (f = 0.680). La proporci & oacute;n de la distribuci & oacute;n posterior para el efecto del plomo en el suelo sobre el n & uacute;mero de volantones de nidos exitosos fue mayormente negativa para S. pusilla, P. erythrophthalmus y C. cardinalis (f = 0.867, 0.585, 0.508, respectivamente) y positiva para P. cyanea y S. sialis (f = 0.773, 0.744). La productividad anual simulada disminuy & oacute; en 0.04-1.47 j & oacute;venes/hembra/a & ntilde;o entre las especies a lo largo del rango de concentraciones de plomo en el suelo, con las mayores disminuciones para P. erythrophthalmus y P. cyanea. La probabilidad de emplumar uno o m & aacute;s j & oacute;venes cambi & oacute; del 51% al 15% para P. erythrophthalmus, del 57% al 23% para P. cyanea, del 60% al 48% para C. cardinalis, del 94% al 84% para S. sialis, y del 57% al 64% para S. pusilla a medida que la concentraci & oacute;n de plomo en el suelo alrededor de un nido aument & oacute; de 20 a 4000 ppm. La mayor & iacute;a de los fracasos de los nidos fueron resultado de la depredaci & oacute;n; por lo tanto, sugerimos que el plomo puede haber afectado el comportamiento de las aves en el nido, o afectado la calidad del sitio del nido, lo que result & oacute; en una mayor depredaci & oacute;n de los nidos.

First posted August 11, 2023 For additional information, contact: Director, Columbia Environmental Research CenterU.S. Geological Survey4200 New Haven RoadColumbia, MO 65201Contact Pubs Warehouse Lead mining in the Southeast Missouri Lead Mining District began in the 1700s and continued for nearly 300 years; the waste piles associated with smelting, mining, and milling of lead ores have released metal residues that have contaminated soil and water in the region. Previous studies in the district have indicated potential harm to wildlife, including birds, because of elevated lead concentrations associated with mining. Exposure to soil-borne lead was correlated with elevated lead concentrations in tissues, inhibition of δ-aminolevulinic acid dehydratase (δALAD), and renal lesions in birds foraging on ground-dwelling invertebrates at contaminated sites (compared to reference sites) in the Southeast Missouri Lead Mining District.This study assessed reproductive outcomes for songbirds exposed to soil-borne lead in the district, examined the relation between lead concentrations in soils and in tissues of ground-feeding birds and prey species, and compared the results to literature-based toxicity thresholds for lead that are associated with negative effects in birds. Three lead-contaminated sites and three reference sites (with background concentrations of lead and no known mining inputs) were compared in two ways: individually to all other sites or by site type. Additional effects of lead exposure were evaluated by examining concentrations of biomarkers (oxidative stress, lipid peroxidation, and deoxyribonucleic acid damage) in liver tissues, δALAD inhibition, and renal and hepatic microscopic lesions in birds from lead-contaminated and reference sites.Lead concentrations in soil were site-dependent and were also generally heterogeneous within the lead-contaminated sites. Between 17 and 74 percent of all soil samples at contaminated sites had lead concentrations that exceeded a threshold (1,000 milligrams per kilogram [mg/kg] lead in soil) previously associated with adverse physiological effects in birds in the Southeast Missouri Lead Mining District. Lead concentrations in mixed invertebrates from lead-contaminated sites (282 to 2,230 mg/kg dry weight [dw]) indicated that consuming soil-dwelling prey species is a potential exposure pathway for adult birds and their broods. At lead-contaminated sites, lead concentrations in 40.5 percent of blood samples (adults and their broods) were within a subclinical effects range (0.9 to 2.3 mg/kg dw), and 18.7 percent of samples had lead concentrations that exceeded clinical effects criteria (greater than 2.3 mg/kg dw). In contrast, only 2.6 percent of blood samples from reference sites were within the subclinical effects range for lead; all other blood samples from the reference sites had lead concentrations representative of background concentrations (less than 0.9 mg/kg dw). Subclinical and clinical threshold exceedances for lead concentrations in livers and kidneys were similarly more prevalent at the contaminated sites compared to the reference sites.Lead concentrations in blood were positively correlated with lead concentrations in soil, livers, and kidneys. Lead concentrations in blood were negatively correlated with δALAD activity; greater than 50 percent of the birds collected at lead-contaminated sites exhibited injury via greater than 50 percent inhibition of δALAD in blood compared to birds at reference sites. Birds with elevated lead concentrations in tissues also exhibited enhanced oxidative stress. Microscopic lesions in the livers and kidneys of birds had similar rates of occurrence at the contaminated and reference sites, and lesion prevalence could not be directly linked to lead exposure. Reproductive success was monitored at 585 nests, and 3 out of 5 species had reduced nest success associated with elevated lead concentrations in soil; habitat measures did not help explain nest success. Reduced nest success may have resulted from greater nest predation resulting from neurological and behavioral effects of lead exposure. Ultimately, these lines of evidence indicate that bird health and reproduction have been negatively affected by exposure to lead-contaminated soils in the Southeast Missouri Lead Mining District.

The Big River in southeast Missouri drains the largest historical lead mining area in the United States. Ongoing releases of metal contaminated sediments into this river are well documented and are suspected of suppressing freshwater mussel populations. We characterized the spatial extent of metal contaminated sediments and evaluated its relationship with mussel populations in the Big River. Mussels and sediments were collected at 34 sites with potential metal effects and 3 reference sites. Analysis of sediment samples showed that lead (Pb) and zinc (Zn) concentrations were 1.5 to 65 times greater than background concentrations in the reach extending 168 km downstream from Pb mining releases. Mussel abundance decreased acutely downstream from these releases where sediment Pb concentrations were highest and increased gradually as Pb sediment concentrations attenuated downstream. We compared current species richness with historical survey data from three reference rivers with similar physical habitat characteristics and human effects, but without Pb-contaminated sediment. Big River species richness was on average about one-half that expected based on reference stream populations and was 70-75 % lower in reaches with high median Pb concentrations. Sediment Zn and cadmium, and particularly Pb, had significant negative correlations with species richness and abundance. The association of sediment Pb concentrations with mussel community metrics in otherwise high-quality habitat indicates that Pb toxicity is likely responsible for depressed mussel populations observed within the Big River. We used concentration-response regressions of mussel density verses sediment Pb to determine that the Big River mussel community is adversely affected when sediment Pb concentrations are above 166 ppm, the concentration associated with 50 % decreases in mussel density. Based on this assessment of metals concentrations sediment and mussel fauna, our findings indicate that sediment in approximately 140 km of the Big River with suitable habitat has a toxic effect to mussels.

Today's conservation challenges are complex. Solving these challenges often requires scientific collaborations that extend beyond the scope, expertise, and capacity of any single agency, organization, or institution. Conservation efforts can benefit from interdisciplinary collaboration, scientific and technological innovations, and the leveraging of capacity and resources among partners. Here we explore a series of case studies demonstrating how collaborative scientific partnerships are furthering the mission of the US Fish and Wildlife Service (USFWS), including: (1) contaminants of emerging concern in the Great Lakes Basin, (2) Poweshiek skipperling conservation, (3) using technology to improve population survey methods for bats and monarch butterfly, and (4) Big River restoration in the Southeast Missouri lead mining district. These case studies illustrate how strategic and effective scientific collaboration is a multi-stage process that requires investment of time and resources by all participants. Early coordination and communication is crucial to aligning planned work with scientific and decision-making needs. Collaborations between USFWS and external scientists can be mutually beneficial by supporting the agency mission while also providing an avenue for innovative research to be directly applied in conservation decisions and management actions.

Hazards of soil-borne lead (Pb) to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, the authors measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from 5 Pb-contaminated Superfund sites had relative bioavailabilities from 33% to 63%, with a mean of approximately 50%. Treatment of 2 of the soils with phosphorus (P) significantly reduced the bioavailability of Pb. Bioaccessibility of Pb in the test soils was then measured in 6 in vitro tests and regressed on bioavailability: the relative bioavailability leaching procedure at pH 1.5, the same test conducted at pH 2.5, the Ohio State University in vitro gastrointestinal method, the urban soil bioaccessible lead test, the modified physiologically based extraction test, and the waterfowl physiologically based extraction test. All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the relative bioavailability leaching procedure at pH 2.5 and Ohio State University in vitro gastrointestinal tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter (24%), or present as Pb sulfate (18%). Additional Pb was associated with P (chloropyromorphite, hydroxypyromorphite, and tertiary Pb phosphate) and with Pb carbonates, leadhillite (a lead sulfate carbonate hydroxide), and Pb sulfide. The formation of chloropyromorphite reduced the bioavailability of Pb, and the amendment of Pb-contaminated soils with P may be a thermodynamically favored means to sequester Pb. Environ Toxicol Chem 2016;35:2311-2319. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater ( p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal ( Cardinalis cardinalis ) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin ( Turdus migratorius ) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

This study relates tissue concentrations and toxic effects of Pb in Japanese quail (Coturnix japonica) to the dietary exposure of soil-borne Pb associated with mining and smelting. From 0% to 12% contaminated soil, by weight, was added to 5 experimental diets (0.12 to 382mg Pb/kg, dry wt) and fed to the quail for 6 weeks. Benchmark doses associated with a 50% reduction in delta-aminolevulinic acid dehydratase activity were 0.62mg Pb/kg in the blood, dry wt, and 27mg Pb/kg in the diet. Benchmark doses associated with a 20% increase in the concentration of erythrocyte protoporphyrin were 2.7mg Pb/kg in the blood and 152mg Pb/kg in the diet. The quail showed no other signs of toxicity (histopathological lesions, alterations in plasma-testosterone concentration, and body and organ weights). The relation of the blood Pb concentration to the soil Pb concentration was linear, with a slope of 0.013mg Pb/kg of blood (dry wt) divided by mg Pb/kg of diet. We suggest that this slope is potentially useful in ecological risk assessments on birds in the same way that the intake slope factor is an important parameter in risk assessments of children exposed to Pb. The slope may also be used in a tissue-residue approach as an additional line of evidence in ecological risk assessment, supplementary to an estimate of hazard based on dietary toxicity reference values. Integr Environ Assess Manag 2014;10:22-29. (c) 2013 SETAC

In situ soil treatment using phosphoric acid (H3PO4) may be an effective remedial technology for immobilizing soil Pb and reducing Pb risk to human health and ecosystem. The treatment efficacy of three H3PO4 application methods was assessed in a smelter-contaminated urban soil located in the Jasper County Superfund Site, Missouri. Soil, with an average of 3529 mg Pb kg−1 and in the 2- by 4-m plot size, was treated with H3PO4 at a rate of 10 g P kg−1 in four replicates by each of three methods: rototilling; surface application; pressure injection. Three soil cores, 2.5-cm diameter and 30-cm long, were taken from each plot before and 90 days after treatment and analyzed for soluble P, bioaccessible Pb and solid-Pb speciation. Applications of H3PO4 induced the heterogeneity of soluble P in soil, with the highest concentrations in the surface. Three application methods mixed the H3PO4 more effectively in the horizontals than the verticals of treated soil zone. The H3PO4 applications significantly reduced Pb bioaccessibility in the soil, which was influenced by the concentrations of soil soluble P and solid-Pb species. The risk reductions of soil Pb were achieved by formation of pyromorphites or pyromorphite-like minerals. The rototilling appears to be the most effective treatment method in context of the homogeneity of soluble P and the reduction of Pb bioaccessibility in treated soil.