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Historical transport of ore concentrate over a 50-mile haul road from the Red Dog zinc/lead mine in northwest Alaska to a seaport has been associated with elevated lead levels on moss growing near the road and with concerns about the safety of subsistence foods. As part of a comprehensive evaluation of potential impacts to human health and the environment from metals released during overland transport of ore concentrate, a human health risk assessment was conducted. Exposure to site-related metals through subsistence food consumption, water ingestion, and incidental soil ingestion was evaluated for three scenarios: child subsistence use, adult subsistence use, and adult combined occupational and subsistence use. The risk assessment used local subsistence food consumption data and subsistence harvest area information, along with metal concentrations from soil, water, caribou, fish, ptarmigan, berries, and sourdock collected on or near the road and port. The results, along with other lines of evidence, indicate that risks associated with subsistence food consumption and harvest activities are well within acceptable limits for each scenario and that subsistence foods remain safe to eat. Additionally, human health risks are not elevated even when data from restricted areas of the road and port are included. [ABSTRACT FROM AUTHOR]

Abstract: Risks of allergic contact dermatitis (ACD) from consumer products intended for extended (nonpiercing) dermal contact are regulated by E.U. Directive EN 1811 that limits released Ni to a weekly equivalent dermal load of ≤0.5 μg/cm2. Similar approaches for thousands of known organic sensitizers are hampered by inability to quantify respective ACD‐elicitation risk levels. To help address this gap, normalized values of cumulative risk for eliciting a positive (“≥+”) clinical patch test response reported in 12 studies for a total of n = 625 Ni‐sensitized patients were modeled in relation to observed ACD‐eliciting Ni loads, yielding an approximate lognormal (LN) distribution with a geometric mean and standard deviation of GMNi = 15 μg/cm2 and GSDNi = 8.0, respectively. Such data for five sensitizers (including formaldehyde and 2‐hydroxyethyl methacrylate) were also ∼LN distributed, but with a common GSD value equal to GSDNi and with heterogeneous sensitizer‐specific GM values each defining a respective ACD‐eliciting potency GMNi/GM relative to Ni. Such potencies were also estimated for nine (meth)acrylates by applying this general LN ACD‐elicitation risk model to respective sets of fewer data. ACD‐elicitation risk patterns observed for Cr(VI) (n = 417) and Cr(III) (n = 78) were fit to mixed‐LN models in which ∼30% and ∼40% of the most sensitive responders, respectively, were estimated to exhibit a LN response also governed by GSDNi. The observed common LN‐response shape parameter GSDNi may reflect a common underlying ACD mechanism and suggests a common interim approach to quantitative ACD‐elicitation risk assessment based on available clinical data. [ABSTRACT FROM AUTHOR]

As part of the remediation process at a former creosote-handling facility in Washington, target groundwater concentrations were developed as goals for the planned cleanup efforts. Considering state regulatory requirements and site-specific conditions, these concentrations were established to protect surface water in the lake adjacent to the site. These risk-based values were calculated assuming that chemicals will (1) be transported in groundwater, (2) discharge into the lake, and (3) be taken up by aquatic organisms that may be consumed by humans. Among the primary chemicals driving remediation decisions at this site are carcinogenic polycyclic aromatic hydrocarbon (cPAH) compounds, which have limited environmental mobility and are metabolized by many types of potentially edible aquatic organisms. This work included assessing the validity for cPAH compounds of the required default regulatory assumptions and deriving alternative risk-based concentrations. These analyses focused on factors that would modify the generic assumption regarding bioconcentration of cPAH compounds in aquatic biota and influence bioavailability of cPAH compounds to humans consuming the biota. Modifications based on these factors and the use of toxicity equivalency factors resulted in alternative risk-based concentrations for individual cPAH compounds that ranged from approximately 7 to 700 times greater than the default value of 0.03 μg/L. [ABSTRACT FROM AUTHOR]

Risks of allergic contact dermatitis (ACD) from consumer products intended for extended (nonpiercing) dermal contact are regulated by E.U. Directive EN 1811 that limits released Ni to a weekly equivalent dermal load of ≤0.5 μg/cm 2 . Similar approaches for thousands of known organic sensitizers are hampered by inability to quantify respective ACD-elicitation risk levels. To help address this gap, normalized values of cumulative risk for eliciting a positive ("≥+") clinical patch test response reported in 12 studies for a total of n = 625 Ni-sensitized patients were modeled in relation to observed ACD-eliciting Ni loads, yielding an approximate lognormal (LN) distribution with a geometric mean and standard deviation of GM Ni = 15 μg/cm 2 and GSD Ni = 8.0, respectively. Such data for five sensitizers (including formaldehyde and 2-hydroxyethyl methacrylate) were also ∼LN distributed, but with a common GSD value equal to GSD Ni and with heterogeneous sensitizer-specific GM values each defining a respective ACD-eliciting potency GM Ni /GM relative to Ni. Such potencies were also estimated for nine (meth)acrylates by applying this general LN ACD-elicitation risk model to respective sets of fewer data. ACD-elicitation risk patterns observed for Cr(VI) (n = 417) and Cr(III) (n = 78) were fit to mixed-LN models in which ∼30% and ∼40% of the most sensitive responders, respectively, were estimated to exhibit a LN response also governed by GSD Ni . The observed common LN-response shape parameter GSD Ni may reflect a common underlying ACD mechanism and suggests a common interim approach to quantitative ACD-elicitation risk assessment based on available clinical data., (© 2017 Society for Risk Analysis.)