Arsenic in Drinking Water and Diabetes.

Arsenic is ubiquitous in soil and water environments and is consistently at the top of the Agency for Toxic Substances Disease Registry (ATSDR) substance priority list. It has been shown to induce toxicity even at low levels of exposure. One of the major routes of exposure to arsenic is through drinking water. This review presents current information related to the distribution of arsenic in the environment, the resultant impacts on human health, especially related to diabetes, which is one of the most prevalent chronic diseases, regulation of arsenic in drinking water, and approaches for treatment of arsenic in drinking water for both public utilities and private wells. Taken together, this information points out the existing challenges to understanding both the complex health impacts of arsenic and to implementing the treatment strategies needed to effectively reduce arsenic exposure at different scales.

Evaluating the Portable X-ray Fluorescence Reliability for Metal(loid)s Detection and Soil Contamination Status.

Environmental Justice (EJ) communities may experience barriers that can prevent soil monitoring efforts and knowledge transfer. To address this gap, this study compared two analytical methods: portable X-ray Fluorescence Spectroscopy (pXRF, less time and costs) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS, "gold standard"). Surface soil samples were collected from yards and gardens in three counties in Arizona, USA (N=124) and public areas in Troy, New York, USA (N=33). Statistical calculations, i.e., two-sample t-tests, Bland-Altman plots, and a two-way ANOVA indicated no significant difference for As, Ba, Ca, Cu, Mn, Pb, and Zn concentrations except for Ba in the two-sample t-test. Iron, Ni, Cr, and K were statistically different for Arizona soils and V, Ni, Fe and Al concentrations were statistically different for New York soils. To assess the degree of contamination, a pollution load index (PLI), enrichment factors (EF), and geo-accumulation index (Igeo) were calculated for both methods using U.S. Geological Survey soils data. The PLI were >1, indicating pollution across the two states. Between pXRF and ICP-MS, the Igeo and EF in Arizona had similar degree of soil contamination for most elements except Zn in garden and Pb in yard, respectively. In New York, the Igeo of As, Cu, and Zn differed by an order of magnitude between the two methods. The results of this study demonstrate that pXRF is a reliable method for the inexpensive and rapid analysis of As, Ba, Ca, Cu, Mn, Pb, and Zn. Thus, EJ communities may use pXRF to screen large numbers of soil samples for several environmentally relevant contaminants to protect environmental public health.

Analyzing Patterns of Community Interest at a Legacy Mining Waste Site to Assess and Inform Environmental Health Literacy Efforts.

Understanding a community's concerns and informational needs is crucial to conducting and improving environmental health research and literacy initiatives. We hypothesized that analysis of community inquiries over time at a legacy mining site would be an effective method for assessing environmental health literacy efforts and determining whether community concerns were thoroughly addressed. Through a qualitative analysis, we determined community concerns at the time of being listed as a Superfund site. We analyzed how community concerns changed from this starting point over the subsequent years, and whether: 1) communication materials produced by the USEPA and other media were aligned with community concerns; and 2) these changes demonstrated a progression of the community's understanding resulting from community involvement and engaged research efforts. We observed that when the Superfund site was first listed, community members were most concerned with USEPA management, remediation, site-specific issues, health effects, and environmental monitoring efforts related to air/dust and water. Over the next five years, community inquiries shifted significantly to include exposure assessment and reduction methods and issues unrelated to the site, particularly the local public water supply and home water treatment systems. Such documentation of community inquiries over time at contaminated sites is a novel method to assess environmental health literacy efforts and determine whether community concerns were thoroughly addressed.

Building a co-created citizen science program with gardeners neighboring a superfund site: The Gardenroots case study.

A research project that is only expert-driven may ignore the role of local knowledge in research, give low priority to the development of a comprehensive communication strategy to engage the community, and may not deliver the results of the study to the community in an effective way. OBJECTIVE: To demonstrate how a research program can respond to a community research need, establish a community-academic partnership, and build a co-created citizen science program. METHODS: A place-based, community-driven project was designed where academics and community members maintained a reciprocal dialogue, and together, we: 1) defined the question for study, 2) gathered information, 3) developed hypotheses, 3) designed data collection methodologies, 4) collected environmental samples (soil, irrigation water, and vegetables), 5) interpreted data, 6) disseminated results and translated results into action, and 7) discussed results and asked new questions. RESULTS: The co-created environmental research project produced new data and addressed an additional exposure route (consumption of vegetables grown in soils with elevated arsenic levels). Public participation in scientific research improved environmental health assessment, information transfer, and risk communication efforts. Furthermore, incorporating the community in the scientific process produced both individual learning outcomes and community-level outcomes. CONCLUSIONS: This approach illustrates the benefits of a community-academic co-created citizen-science program in addressing the complex problems that arise in communities neighboring a contaminated site. Such a project can increase the community's involvement in risk communication and decision-making, which ultimately has the potential to help mitigate exposure and thereby reduce associated risk.

Environmental Research Translation: enhancing interactions with communities at contaminated sites.

The characterization and remediation of contaminated sites are complex endeavors fraught with numerous challenges. One particular challenge that is receiving increased attention is the development and encouragement of full participation by communities and community members affected by a given site in all facets of decision-making. Many disciplines have been grappling with the challenges associated with environmental and risk communication, public participation in environmental data generation, and decision-making and increasing community capacity. The concepts and methods developed by these disciplines are reviewed, with a focus on their relevance to the specific dynamics associated with environmental contamination sites. The contributions of these disciplines are then synthesized and integrated to help develop Environmental Research Translation (ERT), a proposed framework for environmental scientists to promote interaction and communication among involved parties at contaminated sites. This holistic approach is rooted in public participation approaches to science, which includes: a transdisciplinary team, effective collaboration, information transfer, public participation in environmental projects, and a cultural model of risk communication. Although there are challenges associated with the implementation of ERT, it is anticipated that application of this proposed translational science method could promote more robust community participation at contaminated sites.

A greenhouse and field-based study to determine the accumulation of arsenic in common homegrown vegetables grown in mining-affected soils.

The uptake of arsenic by plants from contaminated soils presents a health hazard that may affect home gardeners neighboring contaminated environments. A controlled greenhouse study was conducted in parallel with a co-created citizen science program (home garden experiment) to characterize the uptake of arsenic by common homegrown vegetables near the Iron King Mine and Humboldt Smelter Superfund site in southern Arizona. The greenhouse and home garden arsenic soil concentrations varied considerably, ranging from 2.35 to 533 mg kg(-1). In the greenhouse experiment four vegetables were grown in three different soil treatments and in the home garden experiment a total of 63 home garden produce samples were obtained from 19 properties neighboring the site. All vegetables accumulated arsenic in both the greenhouse and home garden experiments, ranging from 0.01 to 23.0 mg kg(-1) dry weight. Bioconcentration factors were determined and show that arsenic uptake decreased in the order: Asteraceae>Brassicaceae>Amaranthaceae>Cucurbitaceae>Liliaceae>Solanaceae>Fabaceae. Certain members of the Asteraceae and Brassicaceae plant families have been previously identified as hyperaccumulator plants, and it can be inferred that members of these families have genetic and physiological capacity to accumulate, translocate, and resist high amounts of metals. Additionally, a significant linear correlation was observed between the amount of arsenic that accumulated in the edible portion of the plant and the arsenic soil concentration for the Asteraceae, Brassicaceae, Amaranthaceae, and Fabaceae families. The results suggest that home gardeners neighboring mining operations or mine tailings with elevated arsenic levels should be made aware that arsenic can accumulate considerably in certain vegetables, and in particular, it is recommended that gardeners limit consumption of vegetables from the Asteraceae and Brassicaceae plant families.

Economical and environmental implications of solid waste compost applications to agricultural fields in Punjab, Pakistan.

Application of municipal solid waste compost (MSWC) to agricultural soils is becoming an increasingly important global practice to enhance and sustain soil organic matter (SOM) and fertility levels. Potential risks associated with heavy metals and phosphorus accumulations in surface soils may be minimized with integrated nutrient management strategies that utilize MSWC together with mineral fertilizers. To explore the economic feasibility of MSWC applications, nutrient management plans were developed for rice-wheat and cotton-wheat cropping systems within the Punjab region of Pakistan. Three-year field trials were conducted to measure yields and to determine the economic benefits using three management strategies and two nutrient doses. Management strategies included the application of mineral fertilizers as the sole nutrient source and application of mineral fertilizers in combination with MSWC with and without pesticide/herbicide treatments. Fertilizer doses were either based on standard N, P and K recommendations or on measured site-specific soil plant available phosphorus (PAP) levels. It was found that combining MSWC and mineral fertilizer applications based on site-specific PAP levels with the use of pesticides and herbicides is an economically and environmentally viable management strategy. Results show that incorporation of MSWC improved soil physical properties such as bulk density and penetration resistance. The PAP levels in the surface layer increased by the end of the trials relative to the initial status. No potential risks of heavy metal (Zn, Cd, Cr, Pb and Ni) accumulation were observed. Treatments comprised of MSWC and mineral fertilizer adjusted to site-specific PAP levels and with common pest management showed highest cumulative yields. A basic economic analysis revealed a significantly higher cumulative net profit and value-to-cost ratio (VCR) for all site-specific doses.

Transport of molybdenum in a biosolid-amended alkaline soil.

The transport of molybdenum (Mo) in a biosolid-amended, alkaline, agricultural soil was examined in the research reported herein. Batch-equilibrium and miscible-displacement experiments were conducted to examine the transport of Mo in soil with and without 10% by weight biosolid amendment. The results of geochemical modeling, conducted using PHREEQC, indicated that no mineral dissolution or precipitation reactions were expected for the system under the prevailing conditions. Sorption equilibrium coefficients (Kd) obtained from moment analysis of the Mo breakthrough curves were similar to those calculated from the results of the batch-equilibrium experiments. Mo sorption was greater for the biosolid-amended soil (Kd of 1.3 versus 0.35). Sorption of Mo was shown to be linear, rate limited, and reversible for both unamended and amended soil. The results suggest that Mo associated with biosolid-amended soils is relatively bioavailable and mobile.

Use of cyclodextrin and calcium chloride for enhanced removal of mercury from soil.

The use of solutions containing carboxymethyl-beta-cyclodextrin (CMCD) or CaCl2 for enhancing the removal of Hg from a sandy soil was investigated using batch and column experiments. The retention of Hg appeared to be controlled by specific adsorption reactions, which greatly constrained Hg removal when using water (KNO3 solution) to flush columns packed with contaminated soil. The results showed that the two reagents did enhance the removal of Hg from the soil. For example, 81% and 60% of Hg was recovered after 50 pore volumes of flushing with 50 mM CaCl2 and 2 mM CMCD, respectively, compared to 24% recovery for a 10 mM KNO3 solution. However, significant tailing and delayed recovery of Hg during the elution process occurred in the presence of all reagents, indicating that the removal of Hg from the soil was rate limited.

Characterization of lead removal from contaminated soils by nontoxic soil-washing agents.

Few effective strategies exist for remediating and restoring metal-contaminated soils. We have evaluated the potential of two environmentally compatible, nondestructive, biological soil-washing agents for remediating aged, lead-contaminated soils. Two contaminated soils were washed with 10 mM rhamnolipid biosurfactant and 5.3% carboxymethyl-beta-cyclodextrin (CMCD). The metal removal efficiency of these agents was compared with 10 mM diethylenetriamine pentaacetic acid (DTPA) and 10 mM KNO3. Lead removal rates by both soil-washing agents exceeded the removal by KNO3, but were an order of magnitude less than removal by the synthetic chelator, DTPA. Analysis of soil extractions revealed that the Pb in the first soil (3780 mg kg(-1)) was primarily associated with the soluble, exchangeable, oxide, and residual fractions while the Pb in the second soil (23 900 mg kg(-1)) was found in the soluble, exchangeable, carbonate, and residual fractions. After 10 consecutive washes, rhamnolipid had removed 14.2 and 15.3% of the Pb from the first and second soils, respectively, and CMCD had removed 5 and 13.4% from the same two soils. The Pb removal rate by both agents either increased or was consistent throughout the 10 extractions, indicating a potential for continued removal with extended washing. Significant levels of Cu and Zn in both soils did not prevent Pb removal by either agent. Interestingly, the effectiveness of each agent varied as a function of Pb speciation in the soil. Rhamnolipid was more effective than CMCD in removing Pb bound to amorphous iron oxides, while both agents demonstrated similar potential for removing soluble, exchangeable, and carbonate-bound Pb. Neither agent demonstrated potential for the complete remediation of metal-contaminated soils.

Sulfur and carbon cycling in a flue gas desulfurization sludge disposal site.

Products of a power plant flue gas desulfurization scrubber are discharged into a pond as sludge consisting of calcite (initial delta13C 3.2-3.8 per thousand), gypsum (initial delta34S 7.6-8.6 per thousand), and aqueous solution. Reducing conditions exist below a boundary that appears to move vertically as a function of changes in pond water level. Under reducing conditions, bacteria partially reduce aqueous sulfate to low-delta34S sulfide, consuming organic carbon and generating low-delta13C bicarbonate. Under oxidizing conditions, sulfide is converted to sulfate, leading to calcite dissolution, gypsum precipitation, and isotopic re-equilibration of remaining calcite with dissolved bicarbonate near the pond surface. The gypsum has delta34S near 6 per thousand, and calcite has delta13C as low as -1.7 per thousand; the changes from initial values correspond to predictions based on isotopic balance and reaction stoichiometry. The pond largely contains the products of bacterial reduction. After the pond is abandoned, these products may adversely affect attempts to revegetate the site. Future bacterial reduction may be best controlled by dewatering and limiting the supply of organic matter in percolating surface water.