NiPERA

Durham, NC, United States
Durham, NC, United States

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PubMed | EcoTox and NiPERA
Type: | Journal: Environmental toxicology and chemistry | Year: 2016

Current ecological risk assessment and water quality regulation for nickel (Ni) use mechanistically-based, predictive tools such as Biotic Ligand Models (BLMs). However, despite many detailed studies, the precise mechanism(s) of Ni toxicity to aquatic organisms remains elusive. This uncertainty in the mechanism(s) of action for Ni has led to concern over the use of tools like the BLM in some regulatory settings. To begin addressing this knowledge gap, we used an Adverse Outcome Pathway (AOP) analysis, the first AOP for a metal, to identify multiple potential mechanisms of Ni toxicity and their interactions to freshwater aquatic organisms. The analysis considered potential mechanisms of action based on data from a wide range of organisms in aquatic and terrestrial environments on the premise that Molecular Initiating Events (MIEs) for an essential metal would potentially be conserved across taxa. Through this analysis we identified five potential MIEs by which Ni may exert toxicity on aquatic organisms: disruption of Ca


Oller A.R.,NiPERA | Oberdorster G.,University of Rochester | Seilkop S.K.,SKS Consulting Services
Inhalation Toxicology | Year: 2014

Nickel (Ni) in ambient air is predominantly present in the form of oxides and sulfates, with the distribution of Ni mass between the fine (particle aerodynamic diameter <2.5μm; PM2.5) and coarser (2.5-10μm) size-selected aerosol fractions of PM10 dependent on the aerosol's origin. When deriving a long-term health protective reference concentration for Ni in ambient air, the respiratory toxicity and carcinogenicity effects of the predominant Ni compounds in ambient air must be considered. Dosimetric adjustments to account for differences in aerosol particle size and respiratory tract deposition and/or clearance among rats, workers, and the general public were applied to experimentally- and epidemiologically-determined points of departure (PODs) such as no(low)-effect concentrations, for both cancer and non-cancer respiratory effects. This approach resulted in the derivation of threshold-based PM10 size-selected equivalent concentrations (modified PODs) of 0.5μg Ni/m based on workers' cancer effects and 9-11μg Ni/m based on rodent respiratory toxicity effects. Sources of uncertainty in exposure extrapolations are described. These are not reference concentrations; rather the derived PM10 size-selected modified PODs can be used as the starting point for the calculation of ambient air reference concentrations for Ni. The described approach is equally applicable to other particulates. © 2014 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted.


Oller A.R.,NiPERA | Oberdorster G.,University of Rochester
Journal of Aerosol Science | Year: 2016

Dosimetric models are essential tools to refine inhalation risk assessments based on local respiratory effects. Dosimetric adjustments to account for differences in aerosol particle size and respiratory tract deposition and/or clearance among rodents, workers, and the general public can be applied to experimentally- and epidemiologically-determined points of departure (PODs) to calculate size-selected (e.g., PM10, inhalable aerosol fraction, respirable aerosol fraction) equivalent concentrations (e.g., HEC or human equivalent concentration; REC or rodent equivalent concentration). A modified POD (e.g., HEC) can then feed into existing frameworks for the derivation of occupational or ambient air concentration limits or reference concentrations. HECs that are expressed in terms of aerosol particle sizes experienced by humans but are derived from animal studies allow proper comparison of exposure levels and associated health effects in animals and humans. This can inform differences in responsiveness between animals and humans, based on the same deposited or retained doses and can also allow the use of both data sources in an integrated weight of evidence approach for hazard and risk assessment purposes. Whenever possible, default values should be replaced by substance-specific and target population-specific parameters. Assumptions and sources of uncertainty need to be clearly reported. © 2016 Elsevier Ltd.


PubMed | University of Rochester and NiPERA
Type: | Journal: Journal of aerosol science | Year: 2016

Dosimetric models are essential tools to refine inhalation risk assessments based on local respiratory effects. Dosimetric adjustments to account for differences in aerosol particle size and respiratory tract deposition and/or clearance among rodents, workers, and the general public can be applied to experimentally- and epidemiologically-determined points of departure (PODs) to calculate size-selected (e.g., PM


Buekers J.,Flemish Institute for Technological Research | De Brouwere K.,Flemish Institute for Technological Research | Lefebvre W.,Flemish Institute for Technological Research | Willems H.,Flemish Institute for Technological Research | And 6 more authors.
Science of the Total Environment | Year: 2015

The paper describes the inhalation nickel (Ni) exposure of humans via the environment for the regional scale in the EU, together with a tiered approach for assessing additional local exposure from industrial emissions. The approach was designed, in the context of REACH, for the purpose of assessing and controlling emissions and air quality in the neighbourhood of Ni producers and downstream users. Two Derived No Effect Level (DNEL) values for chronic inhalation exposure to total Ni in PM10 (20 and 60ngNi/m3) were considered. The value of 20ngNi/m3 is the current EU air quality guidance value. The value of 60ngNi/m3 is derived here based on recently published Ni data (Oller et al., 2014). Both values are protective for respiratory toxicity and carcinogenicity but differ in the application of toxicokinetic adjustments and cancer threshold considerations. Estimates of air Ni concentrations at the European regional scale were derived from the database of the European Environment Agency. The 50th and 90th percentile regional exposures were below both DNEL values. To assess REACH compliance at the local scale, measured ambient air data are preferred but are often unavailable. A tiered approach for the use of modelled ambient air concentrations was developed, starting with the application of the default EUSES model and progressing to more sophisticated models. As an example, the tiered approach was applied to 33 EU Ni sulphate producers' and downstream users' sites. Applying the EUSES model demonstrates compliance with a DNEL of 60 ng Ni/m3 for the majority of sites, while the value of the refined modelling is demonstrated when a DNEL of 20 ng Ni/m3 is considered. The proposed approach, applicable to metals in general, can be used in the context of REACH, for refining the risk characterisation and guiding the selection of risk management measures. © 2015 Elsevier B.V.


PubMed | ARCHE Assessing Risks of Chemicals Consulting, Flemish Institute for Technological Research, University of Waterloo and NiPERA
Type: | Journal: The Science of the total environment | Year: 2015

The paper describes the inhalation nickel (Ni) exposure of humans via the environment for the regional scale in the EU, together with a tiered approach for assessing additional local exposure from industrial emissions. The approach was designed, in the context of REACH, for the purpose of assessing and controlling emissions and air quality in the neighbourhood of Ni producers and downstream users. Two Derived No Effect Level (DNEL) values for chronic inhalation exposure to total Ni in PM10 (20 and 60ngNi/m(3)) were considered. The value of 20ngNi/m(3) is the current EU air quality guidance value. The value of 60ngNi/m(3) is derived here based on recently published Ni data (Oller et al., 2014). Both values are protective for respiratory toxicity and carcinogenicity but differ in the application of toxicokinetic adjustments and cancer threshold considerations. Estimates of air Ni concentrations at the European regional scale were derived from the database of the European Environment Agency. The 50th and 90th percentile regional exposures were below both DNEL values. To assess REACH compliance at the local scale, measured ambient air data are preferred but are often unavailable. A tiered approach for the use of modelled ambient air concentrations was developed, starting with the application of the default EUSES model and progressing to more sophisticated models. As an example, the tiered approach was applied to 33 EU Ni sulphate producers and downstream users sites. Applying the EUSES model demonstrates compliance with a DNEL of 60ngNi/m(3) for the majority of sites, while the value of the refined modelling is demonstrated when a DNEL of 20ngNi/m(3) is considered. The proposed approach, applicable to metals in general, can be used in the context of REACH, for refining the risk characterisation and guiding the selection of risk management measures.


Peters A.,Wca environment Ltd | Simpson P.,Wca environment Ltd | Merrington G.,Wca environment Ltd | Schlekat C.,NiPERA | Rogevich-Garman E.,NiPERA
Environmental Science and Pollution Research | Year: 2014

A field-based evaluation of the biological effects of potential nickel (Ni) exposures was conducted using monitoring data for benthic macroinvertebrates and water chemistry parameters for streams in England and Wales. Observed benthic community metrics were compared to expected community metrics under reference conditions using RIVPACS III+ software. In order to evaluate relationships between Ni concentrations and benthic community metrics, bioavailable Ni concentrations were also calculated for each site. A limiting effect from Ni on the 90th percentile of the maximum achievable ecological quality was derived at "bioavailable Ni" exposures of 10.3 μg l-1. As snails have been identified as particularly sensitive to nickel exposure, snail abundance in the field in response to nickel exposure, relative to reference conditions, was also analysed. A "low effects" threshold for snail abundance based on an average of spring and autumn data was derived as 3.9 μg l-1 bioavailable Ni. There was no apparent effect of Ni exposure on the abundance of Ephemeroptera (mayflies), Plecoptera (stoneflies) or Tricoptera (caddisflies) when expressed relative to a reference condition within the range of "bioavailable Ni" exposures observed within the dataset. Nickel exposure concentrations co-vary with the concentrations of other stressors in the dataset, and high concentrations of Ni are also associated with elevated concentrations of other contaminants. © 2013 Springer-Verlag Berlin Heidelberg.


De Brouwere K.,Flemish Institute for Technological Research | Buekers J.,Flemish Institute for Technological Research | Cornelis C.,Flemish Institute for Technological Research | Schlekat C.E.,NiPERA | Oller A.R.,NiPERA
Science of the Total Environment | Year: 2012

This paper describes the indirect human exposure to Ni via the oral route for the regional scale in the EU, together with a method to assess additional local exposure from industrial emissions. The approach fills a gap in the generic REACH guidance which is inadequate for assessing indirect environmental exposure of metals. Estimates of regional scale Ni dietary intake were derived from Ni dietary studies performed in the EU. Typical and Reasonable Worst Case dietary Ni intakes for the general population in the EU were below the oral Derived No Effect Level (DNEL) of Ni sulfate for systemic effects. Estimates for the Ni dietary intake at the local scale take into account the influence of aerial Ni deposition and transfer from soil to crops grown near industrial plants emitting Ni. The additional dietary exposure via this local contribution was small. Despite the use of conservative parameters for these processes, this method may underestimate dietary exposure around older industrial sites because REACH guidance does not account for historical soil contamination. Nevertheless, the method developed here can also be used as a screening tool for community-based risk assessment, as it accounts for historical soil pollution. Nickel exposure via drinking water was derived from databases on Ni tap water quality. A small proportion of the EU population (< 5%) is likely to be exposed to tap water exceeding the EU standard (20 μg Ni/l). Taking into account the relative gastrointestinal absorption of Ni from water (30%) versus from solid matrices (5%), water intake constitutes, after dietary intake, the second most important pathway for oral Ni intake. Incidental ingestion of Ni from soil/dust at the regional scale, and also at the local scale, was low in comparison with dietary intake. © 2011 Elsevier B.V.


Peters A.,wca environment | Schlekat C.E.,NiPERA | Merrington G.,wca environment
Environmental Toxicology and Chemistry | Year: 2016

A bioavailability-based environmental quality standard (EQS) was established for nickel in freshwaters under the European Union's Water Framework Directive. Bioavailability correction based on pH, water hardness, and dissolved organic carbon is a demonstrable improvement on existing hardness-based quality standards, which may be underprotective in high-hardness waters. The present study compares several simplified bioavailability tools developed to implement the Ni EQS (biomet, M-BAT, and PNECPro) against the full bioavailability normalization procedure on which the EQS was based. Generally, all tools correctly distinguished sensitive waters from insensitive waters, although with varying degrees of accuracy compared with full normalization. Biomet and M-BAT predictions were consistent with, but less accurate than, full bioavailability normalization results, whereas PNECpro results were generally more conservative. The comparisons revealed important differences in tools in development, which results in differences in the predictions. Importantly, the models used for the development of PNECpro use a different ecotoxicity dataset, and a different bioavailability normalization approach using fewer biotic ligand models (BLMs) than that used for the derivation of the Ni EQS. The failure to include all of the available toxicity data, and all of the appropriate NiBLMs, has led to some significant differences between the predictions provided by PNECpro and those calculated using the process agreed to in Europe under the Water Framework Directive and other chemicals management programs (such as REACH). These considerable differences mean that PNECpro does not reflect the behavior, fate, and ecotoxicity of nickel, and raises concerns about its applicability for checking compliance against the Ni EQS. Environ Toxicol Chem 2016;35:2397–2404. © 2016 SETAC. © 2016 SETAC


A bioavailability-based environmental quality standard (EQS) was established for nickel in freshwaters under the European Unions Water Framework Directive. Bioavailability correction based on pH, water hardness, and dissolved organic carbon is a demonstrable improvement on existing hardness-based quality standards, which may be underprotective in high-hardness waters. The present study compares several simplified bioavailability tools developed to implement the Ni EQS (biomet, M-BAT, and PNECPro) against the full bioavailability normalization procedure on which the EQS was based. Generally, all tools correctly distinguished sensitive waters from insensitive waters, although with varying degrees of accuracy compared with full normalization. Biomet and M-BAT predictions were consistent with, but less accurate than, full bioavailability normalization results, whereas PNECpro results were generally more conservative. The comparisons revealed important differences in tools in development, which results in differences in the predictions. Importantly, the models used for the development of PNECpro use a different ecotoxicity dataset, and a different bioavailability normalization approach using fewer biotic ligand models (BLMs) than that used for the derivation of the Ni EQS. The failure to include all of the available toxicity data, and all of the appropriate NiBLMs, has led to some significant differences between the predictions provided by PNECpro and those calculated using the process agreed to in Europe under the Water Framework Directive and other chemicals management programs (such as REACH). These considerable differences mean that PNECpro does not reflect the behavior, fate, and ecotoxicity of nickel, and raises concerns about its applicability for checking compliance against the Ni EQS. Environ Toxicol Chem 2016;35:2397-2404. 2016 SETAC.

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