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Victor Wepener - One of the best experts on this subject based on the ideXlab platform.
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prioritizing agricultural pesticides used in south africa based on their environmental mobility and Potential human health effects
Environment International, 2014Co-Authors: James M Dabrowski, Justinus Madimetja Shadung, Victor WepenerAbstract:South Africa is the largest user of pesticides in sub-Saharan Africa and many studies have highlighted the occurrence of pesticides in water resources. Poor management of water treatment facilities in combination with a relatively high dependency on untreated water from boreholes and rivers creates the Potential for Exposure of human communities to pesticides and their associated health effects. Pesticide use, physicochemical and toxicity data was therefore used to prioritize pesticides in terms of their Potential risk to human health. After eliminating pesticides used in very low quantities, four indices were used to prioritize active ingredients applied in excess of 1000 kg per annum; the quantity index (QI) which ranked pesticides in terms of the quantity of their use; the toxicity Potential index (TP) which ranked pesticides according to scores derived for their Potential to cause five health effects (endocrine disruption, carcinogenicity, teratogenicity, mutagenicity and neurotoxicity); hazard Potential index (HP) which multiplied the TP by an Exposure Potential score determined by the GUS index for each pesticide (to provide an indication of environmental hazard); and weighted hazard Potential (WHP), which multiplied the HP for a pesticide by the ratio of its use to the total use of all pesticides in the country. The top 25 pesticides occurring in each of these indices were identified as priority pesticides, resulting in a combined total of 69 priority pesticides. A principal component analysis identified the indices that were most important in determining why a specific pesticide was included in the final priority list. As crop specific application pesticide use data was available it was possible to identify crops to which priority pesticides were applied to. Furthermore it was possible to prioritize crops in terms of the specific pesticide applied to the crop (by expressing the WHP as a ratio of the total amount of pesticide applied to the crop to the total use of all pesticides applied in the country). This allows for an improved spatial assessment of the use of priority pesticides. The methodology applied here provides a first level of basic, important information that can be used to develop monitoring programmes, identify priority areas for management interventions and to investigate optimal mitigation strategies.
Yanjian Wan - One of the best experts on this subject based on the ideXlab platform.
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azole and strobilurin fungicides in source treated and tap water from wuhan central china assessment of human Exposure Potential
Science of The Total Environment, 2021Co-Authors: Juan Liu, Wei Xia, Yanjian WanAbstract:Abstract Fungicides are widely used in agriculture worldwide. However, data on the occurrence of fungicides in drinking water are scarce. This study aimed to determine the occurrence of 12 selected fungicides in drinking water, the removal efficiency of conventional water treatment processes for fungicides, and the risk of fungicide Exposure. In this study, source water (February and July), treated water (February and July), and tap water samples (February, April, July, and October) were collected from Wuhan, central China, in 2019. Seven of the twelve selected fungicides were 100% detected in the three types of water samples; tricyclazole was found with the highest concentrations in the source water phase (median: 15.2 ng/L; range: 4.21–67.9 ng/L). The concentrations of the 12 selected fungicides remaining in the treated water samples (median proportion of the remaining content: 77.5%) revealed that most of the target analytes may not be removed efficiently by conventional water treatment processes, though they could be removed efficiently by advanced treatment. Higher concentrations of the fungicides were observed in samples collected in July (median: 38.7 ng/L; range: 12.5–85.8 ng/L), followed by those in October (median: 21.8 ng/L; range: 10.2–58.8 ng/L), February (median: 9.82 ng/L; range: 5.63–93.3 ng/L), and April (median: 7.13 ng/L; range: 6.23–91.1 ng/L). The health risk assessment implied that estimated daily intake of these fungicides through tap water ingestion might pose a low risk to consumers, though risk associated with infant Exposure to the fungicides requires further attention. This study provides baseline data on the occurrence, removal efficiencies, and seasonal variations of the selected fungicides in tap water from central China.
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azole and strobilurin fungicides in source treated and tap water from wuhan central china assessment of human Exposure Potential
Science of The Total Environment, 2021Co-Authors: Juan Liu, Wei Xia, Yanjian WanAbstract:Abstract Fungicides are widely used in agriculture worldwide. However, data on the occurrence of fungicides in drinking water is scarce. This study aimed to determine the occurrence of 12 selected fungicides in drinking water, the removal efficiency of conventional water treatment processes for fungicides, and the risk of fungicide Exposure. In this study, source water (February and July), treated water (February and July), and tap water samples (February, April, July, and October) were collected from Wuhan, central China, in 2019. Seven of 12 selected fungicides were 100% detected in the three types of water samples; tricyclazole was found with the highest concentrations in the source water phase (median: 15.2 ng/L: range: 4.21–67.9 ng/L). The concentrations of the 12 selected fungicides remaining in the treated water samples (median proportion of the remaining content: 77.5%) revealed that the target analytes may not be removed efficiently by conventional water treatment processes, though they could be removed efficiently by advanced treatment. Higher concentrations of fungicides were observed in samples collected in July (median: 38.7 ng/L; range: 12.5–85.8 ng/L), followed by those in October (median: 21.8 ng/L; range: 10.2–58.8 ng/L), February (median: 9.82 ng/L; range: 5.63–93.3 ng/L), and April (median: 7.13 ng/L; range: 6.23–91.1 ng/L). The health risk assessment implied that estimated daily intake of these fungicides through tap water ingestion might pose a low risk to consumers, though risk associated with infant Exposure to fungicides requires further attention. This study provides baseline data on the occurrence, removal efficiencies, and seasonal variations of the selected fungicides in tap water from central China.
Juan Liu - One of the best experts on this subject based on the ideXlab platform.
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azole and strobilurin fungicides in source treated and tap water from wuhan central china assessment of human Exposure Potential
Science of The Total Environment, 2021Co-Authors: Juan Liu, Wei Xia, Yanjian WanAbstract:Abstract Fungicides are widely used in agriculture worldwide. However, data on the occurrence of fungicides in drinking water are scarce. This study aimed to determine the occurrence of 12 selected fungicides in drinking water, the removal efficiency of conventional water treatment processes for fungicides, and the risk of fungicide Exposure. In this study, source water (February and July), treated water (February and July), and tap water samples (February, April, July, and October) were collected from Wuhan, central China, in 2019. Seven of the twelve selected fungicides were 100% detected in the three types of water samples; tricyclazole was found with the highest concentrations in the source water phase (median: 15.2 ng/L; range: 4.21–67.9 ng/L). The concentrations of the 12 selected fungicides remaining in the treated water samples (median proportion of the remaining content: 77.5%) revealed that most of the target analytes may not be removed efficiently by conventional water treatment processes, though they could be removed efficiently by advanced treatment. Higher concentrations of the fungicides were observed in samples collected in July (median: 38.7 ng/L; range: 12.5–85.8 ng/L), followed by those in October (median: 21.8 ng/L; range: 10.2–58.8 ng/L), February (median: 9.82 ng/L; range: 5.63–93.3 ng/L), and April (median: 7.13 ng/L; range: 6.23–91.1 ng/L). The health risk assessment implied that estimated daily intake of these fungicides through tap water ingestion might pose a low risk to consumers, though risk associated with infant Exposure to the fungicides requires further attention. This study provides baseline data on the occurrence, removal efficiencies, and seasonal variations of the selected fungicides in tap water from central China.
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azole and strobilurin fungicides in source treated and tap water from wuhan central china assessment of human Exposure Potential
Science of The Total Environment, 2021Co-Authors: Juan Liu, Wei Xia, Yanjian WanAbstract:Abstract Fungicides are widely used in agriculture worldwide. However, data on the occurrence of fungicides in drinking water is scarce. This study aimed to determine the occurrence of 12 selected fungicides in drinking water, the removal efficiency of conventional water treatment processes for fungicides, and the risk of fungicide Exposure. In this study, source water (February and July), treated water (February and July), and tap water samples (February, April, July, and October) were collected from Wuhan, central China, in 2019. Seven of 12 selected fungicides were 100% detected in the three types of water samples; tricyclazole was found with the highest concentrations in the source water phase (median: 15.2 ng/L: range: 4.21–67.9 ng/L). The concentrations of the 12 selected fungicides remaining in the treated water samples (median proportion of the remaining content: 77.5%) revealed that the target analytes may not be removed efficiently by conventional water treatment processes, though they could be removed efficiently by advanced treatment. Higher concentrations of fungicides were observed in samples collected in July (median: 38.7 ng/L; range: 12.5–85.8 ng/L), followed by those in October (median: 21.8 ng/L; range: 10.2–58.8 ng/L), February (median: 9.82 ng/L; range: 5.63–93.3 ng/L), and April (median: 7.13 ng/L; range: 6.23–91.1 ng/L). The health risk assessment implied that estimated daily intake of these fungicides through tap water ingestion might pose a low risk to consumers, though risk associated with infant Exposure to fungicides requires further attention. This study provides baseline data on the occurrence, removal efficiencies, and seasonal variations of the selected fungicides in tap water from central China.
Gregory M�ller - One of the best experts on this subject based on the ideXlab platform.
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Legacy lead arsenate soil contamination at childcare centers in the Yakima Valley, Central Washington, USA
Chemosphere, 2017Co-Authors: Jenna Durkee, Casey Bartrem, Gregory M�llerAbstract:Background From the early 1900s to the 1950s, Yakima Valley orchards were commonly treated with lead arsenate (LA) insecticides. Lead (Pb) and arsenic (As) soil contamination has been identified on former orchard lands throughout Central Washington and pose a threat to human health and the environment. Objectives The levels of Pb and As in soil and interior dust at participating childcare centers in the Upper Yakima Valley (Yakima County), Washington were sampled to explore Exposure Potential for young children. Methods Childcare center soils were collected from two soil depths, homogenized, and analyzed in bulk by a field-portable X-ray fluorescence spectrometer (XRF). Interior dust wipes samples were collected from at least two locations in each facility. All soil samples >250 mg/kg Pb and/or >20 As mg/kg were sieved to 250 μm, tested by XRF a second time, and analyzed via acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) analysis. Results Bulk and sieved XRF results, as well as ICP-MS to XRF results were strongly correlated. Maximum Pb and As XRF results indicated that 4 (21%) and 8 (42%) of the 19 childcare centers surveyed exceeded the regulatory standard for Pb and As, respectively. Historic land use was significantly associated with elevated Pb and As levels. Interior dust loadings were below United States Environmental Protection Agency (EPA) guidelines. Conclusions Childcare centers are areas of intensive use for children and when coupled with Potential residential Exposure in their homes, the total daily Exposure is a Potential hazard to children.
Elaine Cohen A Hubal - One of the best experts on this subject based on the ideXlab platform.
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comparison of modeling approaches to prioritize chemicals based on estimates of Exposure and Exposure Potential
Science of The Total Environment, 2013Co-Authors: Jade Mitchell, Jon A Arnot, Olivier Jolliet, John F. Wambaugh, Peter P Egeghy, Panos G Georgopoulos, Sastry S Isukapalli, Surajit Dasgupta, Muhilan Pandian, Elaine Cohen A HubalAbstract:Abstract While only limited data are available to characterize the Potential toxicity of over 8 million commercially available chemical substances, there is even less information available on the Exposure and use-scenarios that are required to link Potential toxicity to human and ecological health outcomes. Recent improvements and advances such as high throughput data gathering, high performance computational capabilities, and predictive chemical inherency methodology make this an opportune time to develop an Exposure-based prioritization approach that can systematically utilize and link the asymmetrical bodies of knowledge for hazard and Exposure. In response to the US EPA's need to develop novel approaches and tools for rapidly prioritizing chemicals, a “Challenge” was issued to several Exposure model developers to aid the understanding of current systems in a broader sense and to assist the US EPA's effort to develop an approach comparable to other international efforts. A common set of chemicals were prioritized under each current approach. The results are presented herein along with a comparative analysis of the rankings of the chemicals based on metrics of Exposure Potential or actual Exposure estimates. The analysis illustrates the similarities and differences across the domains of information incorporated in each modeling approach. The overall findings indicate a need to reconcile Exposures from diffuse, indirect sources (far-field) with Exposures from directly, applied chemicals in consumer products or resulting from the presence of a chemical in a microenvironment like a home or vehicle. Additionally, the Exposure scenario, including the mode of entry into the environment (i.e. through air, water or sediment) appears to be an important determinant of the level of agreement between modeling approaches.
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informing selection of nanomaterial concentrations for toxcast in vitro testing based on occupational Exposure Potential
Environmental Health Perspectives, 2011Co-Authors: Sumit Gangwal, James S Brown, Amy Wang, Keith A Houck, David J Dix, Robert J Kavlock, Elaine Cohen A HubalAbstract:Background: Little justification is generally provided for selection of in vitro assay testing concentrations for engineered nanomaterials (ENMs). Selection of concentration levels for hazard evalu...
