This study evaluated the levels and potential health risks of particulate and gaseous pollutants associated with emissions from the Port Talbot steelworks in South Wales, United Kingdom. Air pollutants were monitored at four locations: Fire Station (FS), Prince Street (PS), Dyffryn School (DS), and Little Warren (LW) over a four-week period (April-May 2012) using both offline (Partisol) and online instruments, including the Filter Dynamics Measurement System (FDMS). Concentrations of PM10, PM2.(5), NOx, SO2, CO, O-3, and black carbon (BC) were analyzed to characterize pollutant dynamics and source contributions. The mean PM10 concentrations ranged from 21.4 to 49.7 & micro;g m(-)& sup3;, and PM2.(5) from 13.2 to 27.6 & micro;g m(-)& sup3;, occasionally exceeding the World Health Organization 24-h guideline of 50 & micro;g m(-)& sup3;. FDMS PM2.(5)/PM10 ratios indicated dominance of fine particles, whereas Partisol ratios showed higher coarse-particle contributions, likely due to semi-volatile losses in the Partisol sampler. Average gaseous pollutant concentrations were 20.2 +/- 8.6 & micro;g m(-)& sup3; (NOx), 68.6 +/- 13.1 & micro;g m(-)& sup3; (O-3), 4.6 +/- 5.6 & micro;g m(-)& sup3; (SO2), and 0.3 +/- 0.2 mg m(-)& sup3; (CO). Polar plots and diagnostic ratios (SO2/NOx approximate to 0.5 during episodes) identified the steelworks as the dominant emission source under south-westerly winds. The non-carcinogenic health risk assessment (HQ, HI < 1.0) indicated no significant short-term health hazard, while the Air Quality Index (AQI) ranged from "Good" to "Moderate." These findings characterize air quality and associated health risks during the April-May 2012 monitoring campaign and establish a historical baseline against which subsequent emission-control measures, industrial transition, and air-quality improvements in Port Talbot can be evaluated.
Understanding the persistence of gasoline residues on porous substrates is fundamental to arson investigations, which may provide critical evidence of malicious intent through the identification of ignitable liquid residues (ILRs). In forensic practice, delays between fire suppression and evidence collection frequently result in the recovery of weathered debris, where volatile organic compounds (VOCs) have been significantly depleted by environmental factors. In tropical regions such as Malaysia, high ambient temperatures and relative humidity are hypothesised to accelerate this evaporation process, potentially hindering residue recovery. This study evaluates the retention and chemical profiling of gasoline residues on natural (100% cotton) and synthetic (100% polyester) substrates subjected to outdoor tropical weathering. Following controlled ignition and suppression, samples were exposed to environmental conditions for durations ranging from 30 min to 960 min (16 h). Residues were extracted via passive headspace adsorption and analysed using gas chromatography-mass spectrometry (GC-MS) in strict accordance with American Standards for Testing and Materials (ASTM) E1618-19 standards. Nine diagnostic target compounds, including critical alkylbenzenes and indane, were consistently identified using the National Institute of Standards and Technology (NIST) library with a minimum match quality of 85%. The findings demonstrated that both natural and synthetic substrates successfully retained identifiable gasoline residues throughout the 960-minute exposure period, despite the aggressive tropical environment. This confirms a viable window for short-term ILR recovery in warm, humid climates and underscores the significance of substrate-environment interactions in environmental forensic investigations.
The eastern Biga Peninsula (northwestern T & uuml;rkiye) hosts numerous polymetallic mineral deposits associated with complex magmatic and hydrothermal systems, which may contribute to elevated natural radioactivity in ore-bearing rocks and their surrounding lithologies. This study aimed to determine the activity concentrations of naturally occurring radionuclides (226Ra, 2 & sup3;2Th, 40K), and the artificial radionuclide (1 & sup3;7Cs) in base metal deposits and associated host rocks, and to evaluate their potential radiological impacts on the environment and human health. Thirty-nine representative rock samples were collected from mineralized zones and adjacent wall rocks. Gamma-ray spectrometric measurements were performed using a high-purity germanium (HPGe) detector. Standard radiological hazard indices, including absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure rate (ER), annual effective dose equivalent (AEDE), excess lifetime cancer risk (ELCR), external hazard index (Hex), internal hazard index (Hin), and gamma radiation level (GRL), were calculated to assess potential radiological risks. The mean activity concentrations of 226Ra, 2 & sup3;2Th, 40K, and 137Cs were 35.11, 44.73, 697.53, and 0.62 Bq kg-1, respectively. Among the naturally occurring radionuclides, 40K exhibited the highest activity concentration, reflecting the abundance of potassium-bearing minerals within the investigated lithologies. The calculated mean values of Raeq, Hex, and Hin were below the internationally recommended safety limits, indicating generally acceptable radiological conditions across most of the study area. However, several localized sampling sites, particularly sample EY22DR-05 and, to a lesser extent, YO13-01, exceeded the recommended thresholds for Raeq, Hex, and Hin, demonstrating the presence of spatially heterogeneous radiological anomalies associated with localized geological conditions rather than region-wide radiological contamination. Similarly, the mean absorbed gamma dose rate was slightly higher than the global average reported by UNSCEAR, whereas the elevated ELCR values observed at a limited number of sampling locations further emphasize the importance of site-specific environmental assessment. Overall, the results indicate that radiological conditions in the eastern Biga Peninsula are generally within acceptable levels for the majority of the investigated area; nevertheless, localized radiological hotspots require particular attention in future environmental monitoring and land-use planning. In addition to descriptive statistical evaluation, Pearson correlation analysis was performed to quantify the relationships between radionuclide concentrations and radiological hazard indices, providing further insight into the principal contributors controlling environmental radiation levels in the investigated mineralized system.
Understanding background concentrations of chemicals in the environment can be important for delineating the extent of impacts from known or suspected sources and for assessing cleanup responsibilities. Recent statewide surveys carried out in Vermont (VT), New Hampshire (NH), Maine (ME), and Massachusetts (MA) measured per- and polyfluoroalkyl substances (PFAS) in soils to better understand the presence of anthropogenic background concentrations. We combined data from these statewide surveys and used multivariate statistical analysis techniques to compare PFAS fingerprints in surface soils (top 0-6 inches) across the four states. Total PFAS concentrations in the combined dataset ranged from 153 to 34,034 ng/kg, with a mean of 3,945 ng/kg. The results show that PFAS fingerprints in the New England region were generally similar, suggesting influence from widespread, diffuse sources of PFAS. Principal component analysis (PCA) showed that perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorobutanoic acid (PFBA) were the main contributors to the variability in the combined dataset. Hierarchical cluster analysis (HCA) confirmed the findings from PCA and identified three distinct clusters: one predominated by PFOS, another by PFOS and PFOA, and a third by PFOS, PFOA, and PFBA. The spatial variations observed in the clusters suggest that in some areas, background PFAS concentrations may reflect a combination of diffuse global and regional PFAS signatures and may additionally suggest differential PFAS transport in shallow soils due to age-related weathering. Incorporation of Total Oxidizable Precursor (TOP) assay data into PCA for the NH samples showed a notable increase in PFBA following oxidation, indicating that a portion of the background PFAS loading may be due to transformation of shorter-chain precursors. Overall, the results indicate that the source of background PFAS in New England soils is consistent with long-range atmospheric transport.
The efficacy of polycyclic aromatic compound (PAC) diagnostic and weathering ratios was tested on a weathered petroleum-contaminated site located in the boreal region of northern Ontario, Canada. The site, a former petroleum distribution terminal (1920-1998) with documented spills and adjacent industrial activity (e.g., cement manufacturing), exhibited mixed petrogenic and pyrogenic PAC sources. Contaminated soil from the site was analyzed for unbranched, alkylated (Cn), nitrogen-, sulfur-, and oxygen-containing PACs using GC-MS-SIM, while hydrocarbon fraction concentrations based on effective carbon number were previously determined by GC-FID. Results underscore the limitations of several conventional diagnostic ratios in resolving mixed-source contamination, as overlapping chemical fingerprints from multiple inputs (diesel, fuel residues, and combustion byproducts) and site-specific weathering processes obscured clear source attribution. Weathering ratios may be used to observe changes in PAC composition over time and predict toxicity. Four weathering ratios suggested in earlier studies were validated: i. fluorene/(C1-anthracene/phenanthrenes), ii. C3-naphthalenes/(C2-anthracene/phenanthrenes), iii. dibenzothiophene/(C4-anthracene/phenanthrenes), and iv. benzo[e]pyrene/benzo[a]pyrene. Three newly proposed weathering ratios indicated weathering: i. acenaphthenone/acenaphthene (<1), ii. anthraquinone/anthracene (<1), and iii. benzanthrone/anthracene (>1). Novel weathering ratios may be established during photolysis, biodegradation, and other site weathering mechanisms for application to legacy polluted sites where the timing of contamination is unknown.
