Combined temperature and salinity effects on the passive sampling of PAHs with an assessment of impacts to petroleum toxicity.

In equilibrium-based passive sampling applications, the accuracy of estimating freely dissolved concentration () of hydrophobic organic compounds (HOCs) relies on the passive sampler-water partition coefficient () values applied. The vast majority of are generated under standard conditions: 20 °C in deionized or freshwater. Few empirically derived values are available for non-standard conditions.

Application of low-density polyethylene (LDPE) passive samplers for monitoring PAHs in groundwater.

Equilibrium passive sampling continues to find increasing use for performing in situ assessments and monitoring of hydrophobic organic compounds (HOCs). Although this method has been successfully used in several field studies including open surface waters and sediments, comparatively, their use in groundwater has been very limited. In this study, low-density polyethylene (LDPE) passive samplers were deployed for 80 days in three groundwater wells contaminated with polycyclic aromatic hydrocarbons (PAHs).

Assessing petroleum contamination in parts of the Niger Delta based on a sub-catchment delineated field assessment.

The Niger Delta in Nigeria is a complex and heavily contaminated area with over 150,000 interconnected contaminated sites. This intricate issue is compounded by the region's strong hydrological processes and high-energy environment, necessitating a science-based approach for effective contamination assessment and management. This study introduces the concept of sub-catchment contamination assessment and management, providing an overarching perspective rather than addressing each site individually.

The distribution of sediment microplastics assemblages is driven by location and hydrodynamics, not sediment characteristics, in the Gulf of Maine, USA.

Microplastics (MP) are found in marine sediments across the globe, but we are just beginning to understand their spatial distribution and assemblages. In this study, we quantified MP in Gulf of Maine, USA sediments. MP were extracted from 20 sediment samples, followed by polymer identification using Raman spectroscopy.

Sediment Toxicity Tests: A Critical Review of Their use in Environmental Regulations.

Sediments are an integral component of aquatic systems, linking multiple water uses, functions, and services. Contamination of sediments by chemicals is a worldwide problem, with many jurisdictions trying to prevent future pollution (prospective) and manage existing contamination (retrospective). The present review assesses the implementation of sediment toxicity testing in environmental regulations globally.

Where the rubber meets the road: Emerging environmental impacts of tire wear particles and their chemical cocktails.

About 3 billion new tires are produced each year and about 800 million tires become waste annually. Global dependence upon tires produced from natural rubber and petroleum-based compounds represents a persistent and complex environmental problem with only partial and often-times, ineffective solutions. Tire emissions may be in the form of whole tires, tire particles, and chemical compounds, each of which is transported through various atmospheric, terrestrial, and aquatic routes in the natural and built environments.

Quantitative thermodynamic exposure assessment of PCBs available to sandworms () in activated carbon remediated sediment during ongoing sediment deposition.

Marine mesoscale studies with sandworms () were conducted to isolate important processes governing the exposure and bioaccumulation of polychlorinated biphenyls (PCBs) at contaminated sediment sites. equilibrium sampling with silicone-coated jars, and passive sampling with low-density polyethylene (LDPE) were used to determine the performance of an activated carbon (AC) amendment remedy applied to the bed sediment. A quantitative thermodynamic exposure assessment ('QTEA') was performed, showing that PCB concentrations in polymers at equilibrium with the surficial sediment were suited to measure and assess the remedy effectiveness with regard to PCB bioaccumulation in worms.

A Review of Mechanistic Models for Predicting Adverse Effects in Sediment Toxicity Testing.

Since recognizing the importance of bioavailability for understanding the toxicity of chemicals in sediments, mechanistic modeling has advanced over the last 40 years by building better tools for estimating exposure and making predictions of probable adverse effects. Our review provides an up-to-date survey of the status of mechanistic modeling in contaminated sediment toxicity assessments. Relative to exposure, advances have been most substantial for non-ionic organic contaminants (NOCs) and divalent cationic metals, with several equilibrium partitioning-based (Eq-P) models having been developed.

Using eRNA/eDNA metabarcoding to detect community-level impacts of nanoplastic exposure to benthic estuarine ecosystems.

Plastic particles are ubiquitous in marine systems and fragment into smaller pieces, such as nanoplastics (NPs). The effects of NPs on marine organisms are of growing concern but are not well understood. Marine sediments act as a sink for many contaminants, like microplastics, and are rich habitats for benthic micro- and meiofauna which are ecologically-important components of marine food webs; however, little is known about the sensitivities of specific organisms to NPs or the effects on community diversity and composition.

Passive Sampling-Based versus Conventional-Based Metrics for Evaluating Remediation Efficacy at Contaminated Sediment Sites: A Review.

Passive sampling devices (PSDs) are increasingly used at contaminated sites to improve the characterization of contaminant transport and assessment of ecological and human health risk at sediment sites and to evaluate the effectiveness of remedial actions. The use of PSDs after full-scale remediation remains limited, however, in favor of evaluation based on conventional metrics, such as bulk sediment concentrations or bioaccumulation. This review has three overall aims: (1) identify sites where PSDs have been used to support cleanup efforts, (2) assess how PSD-derived remedial end points compare to conventional metrics, and (3) perform broad semiquantitative and selective quantitative concurrence analyses to evaluate the magnitude of agreement between metrics.

Occurrence and Bioaccumulation Patterns of Per- and Polyfluoroalkyl Substances (PFAS) in the Marine Environment.

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic compounds used in commercial applications, household products, and industrial processes. The concern around the environmental persistence, bioaccumulation and toxicity of this vast contaminant class continues to rise. We conducted a review of the scientific literature to compare patterns of PFAS bioaccumulation in marine organisms and identify compounds of potential concern.

Assessment of filter subsampling and extrapolation for quantifying microplastics in environmental samples using Raman spectroscopy.

A common method for characterizing microplastics (MPs) involves capturing the plastic particles on a filter after extraction and isolation from the sediment particles. Microplastics captured on the filter are then scanned with Raman spectroscopy for polymer identification and quantification. However, scanning the whole filter manually using Raman analysis is a labor-intensive and time-consuming process.

Comparison of two procedures for microplastics analysis in sediments based on an interlaboratory exercise.

Microplastics (MP) are distributed throughout ecosystems and settle into sediments where they may threaten benthic communities; however, methods for quantifying MP in sediments have not been standardized. This study compares two methods for analyzing MP in sediments, including extraction and identification, and provides recommendations for improvement. Two laboratories processed sediment samples using two methods, referred to as "core" and "augmentation", and identified particles with visual microscopy and spectroscopy.

Comparing Equilibrium Concentrations of Polychlorinated Biphenyls Based on Passive Sampling and Bioaccumulation in Water Column Deployments.

Biomonitoring at contaminated sites undergoing cleanup, including Superfund sites, often uses bioaccumulation of anthropogenic contaminants by field-deployed organisms as a metric of remedial effectiveness. Bioaccumulation studies are unable to assess the equilibrium status of the organisms relative to the contaminants to which they are exposed. Establishing equilibrium provides a reproducible benchmark on which scientific and management decisions can be based (e.

Environmental RNA as a Tool for Marine Community Biodiversity Assessments.

Microscopic organisms are often overlooked in traditional diversity assessments due to the difficulty of identifying them based on morphology. Metabarcoding is a method for rapidly identifying organisms where Environmental DNA (eDNA) is used as a template. However, legacy DNA is problematically detected from organisms no longer in the environment during sampling.

Assessing the Environmental Effects Related to Quantum Dot Structure, Function, Synthesis and Exposure.

Quantum dots (QDs) are engineered semiconductor nanocrystals with unique fluorescent, quantum confinement, and quantum yield properties, making them valuable in a range of commercial and consumer imaging, display, and lighting technologies. Production and usage of QDs are increasing, which increases the probability of these nanoparticles entering the environment at various phases of their life cycle. This review discusses the major types and applications of QDs, their potential environmental exposures, fates, and adverse effects on organisms.

Nano-enabled pesticides for sustainable agriculture and global food security.

Achieving sustainable agricultural productivity and global food security are two of the biggest challenges of the new millennium. Addressing these challenges requires innovative technologies that can uplift global food production, while minimizing collateral environmental damage and preserving the resilience of agroecosystems against a rapidly changing climate. Nanomaterials with the ability to encapsulate and deliver pesticidal active ingredients (AIs) in a responsive (for example, controlled, targeted and synchronized) manner offer new opportunities to increase pesticidal efficacy and efficiency when compared with conventional pesticides.

Human and ecological health effects of nanoplastics: may not be a tiny problem.

Nanoplastics (NPs) are present in food, soil, water, air and personal care products, resulting in concern regarding exposure and potential adverse effects. NPs principally arise from the degradation of larger-sized plastic particles. The uptake and effects of NPs in humans is not yet known.

Quantification of microplastics in sediments from Narragansett Bay, Rhode Island USA using a novel isolation and extraction method.

Microplastics are small plastic particles found ubiquitously in marine environments. In this study, a hybridized method was developed for the extraction of microplastics (45-1000 μm) from sediments using sodium bromide solution for density separation. Method development was tested using spiked microplastics as internal standards.

Effect of Activated Carbon in Thin Sand Caps Challenged with Ongoing PCB Inputs from Sediment Deposition: PCB Uptake in Clams (Mercenaria mercenaria) and Passive Samplers.

Ongoing inputs, in the form of sediment deposition along with associated dissolved contaminants, have challenged the assessment of cap performance at contaminated sediment sites. To address this issue, thin 2-3 cm layer sand caps amended with activated carbon (AC) were investigated for the remediation of polychlorinated biphenyl (PCB) contaminated marine sediments using 90-day mesocosms. All treatments were challenged with (1) ongoing clean or marker-PCB-spiked sediment inputs and (2) bioturbation.

Evaluating sedimentary PAH bioavailability based on equilibrium partitioning and passive sampling at the Dover Gas Light Superfund Site (Dover, Delaware, USA).

From 1859 to 1948, the Dover Gas Light plant produced combustible gas for industrial, commercial, and residential applications using pine resin, coking coal, oil, and wood, and finally, a coal-gas process. Waste coal tar was discharged into the St. Jones River in Dover, Delaware (USA), via a ditch and culvert and, following plant closure in the 1940s, through groundwater flow from structures buried on the site.