Comparison of emerging contaminants in receiving waters downstream of a conventional wastewater treatment plant and a forest-water reuse system.

Forest-water reuse (FWR) systems treat municipal, industrial, and agricultural wastewaters via land application to forest soils. Previous studies have shown that both large-scale conventional wastewater treatment plants (WWTPs) and FWR systems do not completely remove many contaminants of emerging concern (CECs) before release of treated wastewater. To better characterize CECs and potential for increased implementation of FWR systems, FWR systems need to be directly compared to conventional WWTPs.

Suspect screening and non-targeted analysis of drinking water using point-of-use filters.

Monitored contaminants in drinking water represent a small portion of the total compounds present, many of which may be relevant to human health. To understand the totality of human exposure to compounds in drinking water, broader monitoring methods are imperative. In an effort to more fully characterize the drinking water exposome, point-of-use water filtration devices (Brita filters) were employed to collect time-integrated drinking water samples in a pilot study of nine North Carolina homes.

Evaluation of the immunomodulatory effects of 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate in C57BL/6 mice.

2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate was designed to replace perfluorooctanoic acid (PFOA), which has been mostly phased out of U.S. production due to environmental persistence, detectable human and wildlife serum concentrations, and reports of systemic toxicity.

Novel Polyfluorinated Compounds Identified Using High Resolution Mass Spectrometry Downstream of Manufacturing Facilities near Decatur, Alabama.

Concern over persistence, bioaccumulation, and toxicity has led to international regulation and phase-outs of certain perfluorinated compounds and little is known about their replacement products. High resolution mass spectrometry was used to investigate the occurrence and identity of replacement fluorinated compounds in surface water and sediment of the Tennessee River near Decatur, Alabama. Analysis of legacy Per- and polyfluoroalkyl substances (PFASs) revealed a marked increase in concentrations downstream of manufacturing facilities, with the most abundant compounds being perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate (PFBS), and perfluorooctanoic acid (PFOA) as high as 220 ng L, 160 ng L, and 120 ng L, respectively.

Identification of Biomarkers of Exposure to FTOHs and PAPs in Humans Using a Targeted and Nontargeted Analysis Approach.

Although historic perfluorinated compounds are currently under scrutiny and growing regulatory control in the world, little is known about human exposure to other polyfluorinated compounds presently in use. Fluorotelomer alcohols (FTOHs) and polyfluoroalkyl phosphate esters (PAPs) are known to degrade to terminal perfluorinated acids and toxic reactive intermediates through metabolic pathways. Therefore, it is important to characterize their human exposure by the identification of unique biomarkers.

Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater.

Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which makes the greatest contribution to fipronil in surface water has yet to be determined. A sampling effort designed to prioritize known fipronil inputs (golf courses, residential areas, biosolids application sites and wastewater facilities) was conducted in North Carolina to learn more about the origins of fipronil in surface water.

Linking high resolution mass spectrometry data with exposure and toxicity forecasts to advance high-throughput environmental monitoring.

There is a growing need in the field of exposure science for monitoring methods that rapidly screen environmental media for suspect contaminants. Measurement and analysis platforms, based on high resolution mass spectrometry (HRMS), now exist to meet this need. Here we describe results of a study that links HRMS data with exposure predictions from the U.

Identification of Novel Perfluoroalkyl Ether Carboxylic Acids (PFECAs) and Sulfonic Acids (PFESAs) in Natural Waters Using Accurate Mass Time-of-Flight Mass Spectrometry (TOFMS).

Recent scientific scrutiny and concerns over exposure, toxicity, and risk have led to international regulatory efforts resulting in the reduction or elimination of certain perfluorinated compounds from various products and waste streams. Some manufacturers have started producing shorter chain per- and polyfluorinated compounds to try to reduce the potential for bioaccumulation in humans and wildlife. Some of these new compounds contain central ether oxygens or other minor modifications of traditional perfluorinated structures.

Identification of fipronil metabolites by time-of-flight mass spectrometry for application in a human exposure study.

Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks for human exposure associated with fipronil, urine and serum from dosed Long Evans adult rats (5 and 10mg/kg bw) were analyzed to identify metabolites as potential biomarkers for use in human biomonitoring studies. Urine from treated rats was found to contain seven unique metabolites, two of which had not been previously reported-M4 and M7 which were putatively identified as a nitroso compound and an imine, respectively.

Assessment of serum biomarkers in rats after exposure to pesticides of different chemical classes.

There is increasing emphasis on the use of biomarkers of adverse outcomes in safety assessment and translational research. We evaluated serum biomarkers and targeted metabolite profiles after exposure to pesticides (permethrin, deltamethrin, imidacloprid, carbaryl, triadimefon, fipronil) with different neurotoxic actions. Adult male Long-Evans rats were evaluated after single exposure to vehicle or one of two doses of each pesticide at the time of peak effect.

Palladium-catalyzed Heck-type reactions of alkyl iodides.

A palladium-catalyzed Heck-type reaction of unactivated alkyl iodides is described. This process displays broad substrate scope with respect to both alkene and alkyl iodide components and provides efficient access to a variety of cyclic products. The reaction is proposed to proceed via a hybrid organometallic-radical mechanism, facilitating the Heck-type process with alkyl halide coupling partners.