Non-Targeted PFAS Suspect Screening and Quantification of Drinking Water Samples Collected through Community Engaged Research in North Carolina's Cape Fear River Basin.

A community engaged research (CER) approach was used to provide an exposure assessment of poly- and perfluorinated (PFAS) compounds in North Carolina residential drinking water. Working in concert with community partners, who acted as liaisons to local residents, samples were collected by North Carolina residents from three different locations along the Cape Fear River basin: upper, middle, and lower areas of the river. Residents collected either drinking water samples from their homes or recreational water samples from near their residence that were then submitted by the community partners for PFAS analysis.

Use of the RISK21 roadmap and matrix: human health risk assessment of the use of a pyrethroid in bed netting.

The HESI-coordinated RISK21 roadmap and matrix are tools that provide a transparent method to compare exposure and toxicity information and assess whether additional refinement is required to obtain the necessary precision level for a decision regarding safety. A case study of the use of a pyrethroid, "pseudomethrin," in bed netting to control malaria is presented to demonstrate the application of the roadmap and matrix. The evaluation began with a problem formulation step.

Approaches for assessing risks to sensitive populations: lessons learned from evaluating risks in the pediatric population.

Assessing the risk profiles of potentially sensitive populations requires a "tool chest" of methodological approaches to adequately characterize and evaluate these populations. At present, there is an extensive body of literature on methodologies that apply to the evaluation of the pediatric population. The Health and Environmental Sciences Institute Subcommittee on Risk Assessment of Sensitive Populations evaluated key references in the area of pediatric risk to identify a spectrum of methodological approaches.

Evidence for a separate mechanism of toxicity for the Type I and the Type II pyrethroid insecticides.

Neurotoxicity and mechanistic data were collected for six alpha-cyano pyrethroids (beta-cyfluthrin, cypermethrin, deltamethrin, esfenvalerate, fenpropathrin and lambda-cyhalothrin) and up to six non-cyano containing pyrethroids (bifenthrin, S-bioallethrin [or allethrin], permethrin, pyrethrins, resmethrin [or its cis-isomer, cismethrin] and tefluthrin under standard conditions. Factor analysis and multivariate dissimilarity analysis were employed to evaluate four independent data sets comprised of (1) fifty-six behavioral and physiological parameters from an acute neurotoxicity functional observatory battery (FOB), (2) eight electrophysiological parameters from voltage clamp experiments conducted on the Na(v)1.8 sodium channel expressed in Xenopus oocytes, (3) indices of efficacy, potency and binding calculated for calcium ion influx across neuronal membranes, membrane depolarization and glutamate released from rat brain synaptosomes and (4) changes in chloride channel open state probability using a patch voltage clamp technique for membranes isolated from mouse neuroblastoma cells.

Comparative functional observational battery study of twelve commercial pyrethroid insecticides in male rats following acute oral exposure.

Twelve commercial pyrethroid insecticides (technical-grade active ingredients) were evaluated individually for acute neurobehavioral manifestations of toxicity under conditions suited to assist with determining whether they act by a common mechanism of toxicity. The pyrethroids that were tested reflect a diversity of structures, including six with an alpha-cyano phenoxybenzyl moiety (beta-cyfluthrin, lambda-cyhalothrin, cypermethrin, deltamethrin, esfenvalerate and fenpropathrin) and six without this moiety (bifenthrin, S-bioallethrin, permethrin, pyrethrins, resmethrin and tefluthrin). These chemicals also present a variety of behavioral effects, including ones that are historically classified as causing a T (tremor), CS (choreoathetosis with salivation) or intermediate syndrome of intoxication, and others that have not previously been classified.

Mechanisms of pyrethroid neurotoxicity: implications for cumulative risk assessment.

The Food Quality Protection Act (FQPA) of 1996 requires the United States Environmental Protection Agency to consider the cumulative effects of exposure to pesticides having a 'common mechanism of toxicity.' This paper reviews the information available on the acute neurotoxicity and mechanisms of toxic action of pyrethroid insecticides in mammals from the perspective of the 'common mechanism' statute of the FQPA. The principal effects of pyrethroids as a class are various signs of excitatory neurotoxicity.