Impact of PM filter extraction solvent on oxidative potential and chemical analysis.

Fine particulate matter (PM) is hypothesized to induce oxidative stress, and has been linked to acute and chronic adverse health effects. To better understand the risks and underlying mechanisms following exposure, PM is collected onto filters but prior to toxicological analysis, particles must be removed from filters. There is no standard method for filter extraction, which creates the possibility that the methods of extraction selected can alter the chemical composition and ultimately the biological implications.

Environmental significance of PAH photoproduct formation: TiO nanoparticle influence, altered bioavailability, and potential photochemical mechanisms.

Interactions between polycyclic aromatic hydrocarbons (PAHs) and titanium dioxide (TiO) nanoparticles (NPs) can produce unforeseen photoproducts in the aqueous phase. Both PAHs and TiO-NPs are well-studied and highly persistent environmental pollutants, but the consequences of PAH-TiO-NP interactions are rarely explored. We investigated PAH photoproduct formation over time for benzo[a]pyrene (BaP), fluoranthene (FLT), and pyrene (PYR) in the presence of ultraviolet A (UVA) using a combination of analytical and computational methods including, identification of PAH photoproducts, assessment of expression profiles for gene indicators of PAH metabolism, and computational evaluation of the reaction mechanisms through which certain photoproducts might be formed.

Indoor and Personal PM Samples Differ in Chemical Composition and Alter Zebrafish Behavior Based on Primary Fuel Source.

Fine particulate matter (PM) exposure has been linked to diverse human health impacts. Little is known about the potential heterogeneous impacts of PM generated from different indoor fuel sources and how exposure differs between personal and indoor environments. Therefore, we used PM collected by one stationary sampler in a kitchen and personal samplers (female and male participants), in homes ( = 24) in Kheri, India, that used either biomass or liquified petroleum gas (LPG) as primary fuel sources.

A comparison of fine particulate matter (PM) in vivo exposure studies incorporating chemical analysis.

The complex, variable mixtures present in fine particulate matter (PM) have been well established, and associations between chemical constituents and human health are expanding. In the past decade, there has been an increase in PM toxicology studies that include chemical analysis of samples. This investigation is a crucial component for identifying the causal constituents for observed adverse health effects following exposure to PM.

Assessing the oxidative potential of PAHs in ambient PM using the DTT consumption assay.

The oxidative potential (OP) of atmospheric fine particulate matter (PM) has been linked to organic content, which includes polycyclic aromatic hydrocarbons (PAHs). The OP of 135 individual PAHs (including six subclasses) was measured using the dithiolthreitol (DTT) consumption assay. The DTT assay results were used to compute the concentration of each PAH needed to consume 50% of the DTT concentration in the assay (DTT), and the reduction potential of the PAHs (ΔG).

Time-Related Alteration of Aqueous-Phase Anthracene and Phenanthrene Photoproducts in the Presence of TiO Nanoparticles.

Polycyclic aromatic hydrocarbons (PAHs) and titanium dioxide (TiO) nanoparticles (NPs) are photoactive environmental pollutants that can contaminate aquatic environments. Aqueous-phase interactions between PAHs and TiO-NPs are of interest due to their emerging environmental relevance, particularly with the deliberate application of TiO-NPs to remediate pollution events (e.g.

Advances and limitations in the determination and assessment of gunshot residue in the environment.

Gunshot residue (GSR) stemming from the discharge of firearms has been essential to advancements in the field of forensic science however the human and environmental health impacts from GSR are far less researched. GSR represents a multifaceted concern: it contains a complex mixture of inorganic and organic components and produces airborne particles with variable sizes, depositions, and fates. Herein we evaluate studies in the literature examining GSR collection, deposition, composition, environmental contamination, and potential remediation techniques within the last two decades (2000 - 2020).

Workflow for Comparison of Chemical and Biological Metrics of Filter Collected PM.

There is limited understanding of adverse health effect associations with chemical constituents of fine particulate matter (PM) as well as the underlying mechanisms. We outlined a workflow to assess metrics, beyond concentration, using household and personal PM filter samples collected in India as a proof of concept for future large-scale studies. Oxidative potential, chemical composition (polycyclic aromatic hydrocarbons and elements), and bioactivity (developmental exposures in zebrafish) were determined.

Neurodevelopmental toxicity assessments of alkyl phenanthrene and Dechlorane Plus co-exposure in zebrafish.

Alkyl phenanthrene (A-Phen) and Dechlorane Plus (DP) are ubiquitous environmental pollutants that widely co-exist in the environment. It has been established that both A-Phen and DP elicit neurotoxicity, but the potential interactive toxicity of these contaminants is not well-known. To determine whether a mixture of A-Phen and DP would exhibit interactive effects on neurodevelopment, we co-exposed 3-methylphenanthrene (3-MP), a representative of A-Phen, with DP.

Assessment of Spatial Variability across Multiple Pollutants in Auckland, New Zealand.

Spatial saturation studies using source-specific chemical tracers are commonly used to examine intra-urban variation in exposures and source impacts, for epidemiology and policy purposes. Most such studies, however, has been performed in North America and Europe, with substantial regional combustion-source contributions. In contrast, Auckland, New Zealand, a large western city, is relatively isolated in the south Pacific, with minimal impact from long-range combustion sources.

Formation of PAH Derivatives and Increased Developmental Toxicity during Steam Enhanced Extraction Remediation of Creosote Contaminated Superfund Soil.

Steam enhanced extraction (SEE) is an in situ thermal remediation technique used to remove and recover polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. However, limited studies have been conducted on the formation of PAH derivatives during and after SEE of PAH contaminated soils. Creosote contaminated soil samples collected from the Wyckoff-Eagle Harbor Superfund site were remediated with laboratory scale SEE.

Separating spatial patterns in pollution attributable to woodsmoke and other sources, during daytime and nighttime hours, in Christchurch, New Zealand.

During winter nights, woodsmoke may be a predominant source of air pollution, even in cities with many sources. Since two major earthquakes resulted in major structural damage in 2010 and 2011, reliance on woodburning for home heating has increased substantially in Christchurch, New Zealand (NZ), along with intensive construction/demolition activities. Further, because NZ is a relatively isolated western country, it offers the unique opportunity to disentangle multiple source impacts in the absence of long-range transport pollution.

PM Filter Extraction Methods: Implications for Chemical and Toxicological Analyses.

Toxicology research into the global public health burden of fine particulate matter (PM) exposures frequently requires extraction of PM from filters. A standardized method for these extractions does not exist, leading to inaccurate interlaboratory comparisons. It is largely unknown how different filter extraction methods might impact the composition and bioactivity of the resulting samples.

Fine-Scale Source Apportionment Including Diesel-Related Elemental and Organic Constituents of PM across Downtown Pittsburgh.

Health effects of fine particulate matter (PM) may vary by composition, and the characterization of constituents may help to identify key PM sources, such as diesel, distributed across an urban area. The composition of diesel particulate matter (DPM) is complicated, and elemental and organic carbon are often used as surrogates. Examining multiple elemental and organic constituents across urban sites, however, may better capture variation in diesel-related impacts, and help to more clearly separate diesel from other sources.

Spatial Patterns in Rush-Hour vs. Work-Week Diesel-Related Pollution across a Downtown Core.

Despite advances in monitoring and modelling of intra-urban variation in multiple pollutants, few studies have attempted to separate spatial patterns by time of day, or incorporated organic tracers into spatial monitoring studies. Due to varying emissions sources from diesel and gasoline vehicular traffic, as well as within-day temporal variation in source mix and intensity (e.g.

Development of a high-throughput in vivo screening platform for particulate matter exposures.

Particulate matter (PM) exposure is a public health burden with poorly understood health effect mechanisms and lacking an efficient model to compare the vast diversity of PM exposures. Zebrafish (Danio rerio) are amenable to high-throughput screening (HTS), but few studies have investigated PM toxicity in zebrafish, despite the multitude of advantages. To develop standardized exposure procedures, the urban PM standard reference material (SRM) 1649b was used to systematically determine sample preparation methods, design experimental controls, determine concentration ranges and evaluation procedures.

Developmental and behavioral alterations in zebrafish embryonically exposed to valproic acid (VPA): An aquatic model for autism.

Autism spectrum disorder (ASD) has complex neurodevelopmental impairments and origins that are linked to both genetic and environmental factors. Hence, there is an urgency to establish animal models with ASD-like characteristics to understand the underlying mechanisms of ASD. Prenatal exposure to valproic acid (VPA) produced ASD-like symptoms in humans, rats, and recently zebrafish.

Association of IL-6 with PM Components: Importance of Characterizing Filter-Based PM Following Extraction.

Filter-based toxicology studies are conducted to establish the biological plausibility of the well-established health impacts associated with fine particulate matter (PM) exposure. Ambient PM collected on filters is extracted into solution for toxicology applications, but frequently, characterization is nonexistent or only performed on filter-based PM, without consideration of compositional differences that occur during the extraction processes. To date, the impact of making associations to measured components in ambient instead of extracted PM has not been investigated.

Spatial variation in diesel-related elemental and organic PM components during workweek hours across a downtown core.

Capturing intra-urban variation in diesel-related pollution exposures remains a challenge, given its complex chemical mix, and relatively few well-characterized ambient-air tracers for the multiple diesel sources in densely-populated urban areas. To capture fine-scale spatial resolution (50×50m grid cells) in diesel-related pollution, we used geographic information systems (GIS) to systematically allocate 36 sampling sites across downtown Pittsburgh, PA, USA (2.8km), cross-stratifying to disentangle source impacts (i.

Characterization of ambient and extracted PM2.5 collected on filters for toxicology applications.

Research on the health effects of fine particulate matter (PM2.5) frequently disregards the differences in particle composition between that measured on an ambient filter versus that measured in the corresponding extraction solution used for toxicological testing. This study presents a novel method for characterizing the differences, in metallic and organic species, between the ambient samples and the corresponding extracted solutions through characterization of extracted PM2.

Spatial variation in inversion-focused vs 24-h integrated samples of PM2.5 and black carbon across Pittsburgh, PA.

A growing literature explores intra-urban variation in pollution concentrations. Few studies, however, have examined spatial variation during "peak" hours of the day (e.g.

Saturation sampling for spatial variation in multiple air pollutants across an inversion-prone metropolitan area of complex terrain.

Background: Characterizing intra-urban variation in air quality is important for epidemiological investigation of health outcomes and disparities. To date, however, few studies have been designed to capture spatial variation during select hours of the day, or to examine the roles of meteorology and complex terrain in shaping intra-urban exposure gradients.

Methods: We designed a spatial saturation monitoring study to target local air pollution sources, and to understand the role of topography and temperature inversions on fine-scale pollution variation by systematically allocating sampling locations across gradients in key local emissions sources (vehicle traffic, industrial facilities) and topography (elevation) in the Pittsburgh area.