Chinese traditional smoked pork was contaminated with polycyclic aromatic hydrocarbons (PAHs) and chlorinated and brominated PAHs (ClPAHs and BrPAHs; XPAHs) during the smoking process. Therefore, our study investigated the concentrations, enrichment characteristics, and health risks associated with PAHs, as well as ClPAHs and BrPAHs in Chinese traditional smoked pork. The total concentrations of PAHs, ClPAHs and BrPAHs in traditional smoked pork ranged from 90.0 to 79200 ng/g fat weight (fw), 23.6 to 2340 pg/g fw and 0.550 to 200 pg/g fw, respectively, which were significantly higher than their levels found in raw pork. Additionally, the concentrations of PAHs and XPAHs in the surface of smoked pork were higher than those in the inner parts. High-ring PAHs exhibited a greater enrichment compared to low-ring PAHs, and BrPAHs exhibited greater enrichment ability than ClPAHs in smoked pork. Furthermore, the ability of individual congeners to migrate from the surface to the inner parts of the smoked pork were varied. When the smoking fuels were similar, a longer smoking time resulted in higher concentrations of PAHs and XPAHs in smoked pork, while casing effectively reduced their concentrations. The correlation between XPAH and parent PAH concentrations indicated that chlorination of PAHs was one of the primary formation mechanisms of some monochlorinated PAHs. Over half of the smoked pork samples posed a potential carcinogenic risk, particularly the surface samples. It is recommended to remove the surface parts when consuming smoked pork and to improve traditional smoking methods to mitigate the health risks.
Thermal power plants serve as significant CO2 sources, and accurate monitoring of their emissions is crucial for improving the precision of global carbon emission estimates. In this study, a measurement method based on measuring point source plumes was employed in ground-based remote sensing experiments at the thermal power plant. By simulating CO2 plumes, we analyzed the impact of surrounding urban structures, the geometric relationship between measurement points and plumes, and the influence on measurement points selection. We also assessed the capability and uncertainties in quantifying CO2 emissions. For the Hefei power plant, CO2 emission estimates were on average 7.98 10.01 kg/s higher with surface buildings compared to scenarios without buildings (approximately 4.09% error). By selectively filtering discrete data, the emission estimation errors were significantly reduced by 7.31 7.13 kg/s compared to pre-filtered data. Regarding the relationship between observation paths and plume geometry, simulation studies indicated that the ability to estimate CO2 emissions varied for near and middle segment observations. The lowest emission rate error was found in the mid-segment near 1.5-2.0 km, reaching 7.13 5.39 kg/s. CO2 distribution at the mid-segment position becomes more uniform relative to the near segment, making it more suitable for meeting emission estimation requirements. Optimizing measurement schemes by considering environmental factors and precisely selecting measurement points significantly enhances emission estimation accuracy, providing crucial technical support for top-down estimates of anthropogenic CO2 emissions.
Variability in biogenic volatile organic compound (BVOC) emissions across species and seasons poses challenges for accurate regional emission estimates and effective ozone (O3) control policies. To address this issue, we conducted in-situ measurements of emission factors for six dominant tree species in Beijing across four seasons. Subsequently, we developed monthly dynamic standard emission factors (SER-MDs) to model monthly BVOC emissions and their impacts on O3 formation at citywide and district levels. Our observations revealed pronounced seasonal differences in the BVOC composition and emission rates, as well as their responsiveness to monthly average temperature. By introducing the SER-MDs, we estimated BVOC emissions from the dominant tree species in Beijing to be 38.2 Gg yr−1, with monoterpenes and isoprene contributing 49% and 11%, respectively. This calculation reduced the overestimation associated with constant standard emission factors by 31%–38% at district level. The estimates also revealed regional differences in plant compositions rather than simple feedback from regional temperature and photosynthetically active radiation periods. Under these conditions, the maximum monthly BVOC-induced O3 concentration occurred in August and ranged from 4 to 17 μg m−3 across districts, with isoprene being the dominant contributor. Quercus mongolica and Populus tomentosa played significant roles in the formation of BVOC-induced O3 due to their strong isoprene emitting potential in July–August. These results indicate the necessity of introducing species-specific rhythms of BVOC emissions from dominant species in the development of urban BVOC emission inventories. This approach could inform the development of air pollution management policies that are consistent with the local vegetation composition and O3 pollution characteristics. For Beijing and other similar northern cities, reducing the use of tree species emitting substantial amounts of isoprene during periods of regional peak ambient O3 concentrations could constitute an effective nature-based solution for improving urban air quality in the future.
Polycyclic aromatic hydrocarbons (PAHs) are a class of contaminants that cannot be banned. Exposure to PAHs has been reported to alter spermatogenesis in mammals, but little is known about prenatal exposure to a mixture of PAHs on the reproductive toxicity of adult offspring. In this study, we investigated the associations between prenatal exposure to environmentally relevant levels of PAHs in mice and testicular dysfunction, including impaired spermatogenesis and steroid hormone dysfunction in male offspring on postnatal day 180. The percentage of testicular apoptotic cells was significantly increased, which was further verified by the up-regulated BAX protein. The expression of Ar and the Leydig cell marker Cyp11a1 was down-regulated, suggesting an impairment in the synthesis of steroid hormones. DNA hypermethylation of the Tnp1 and Sohlh2 promoters suppresses transcriptional expression, consequently altering the sperm production process. This study shows that prenatal exposure to PAHs may induce long-term reproductive toxicity.
Triclosan, a widely used antimicrobial agent, is frequently detected in aquatic environments, prompting concerns about its toxic effects on aquatic species. Understanding its occurrence and ecological risks is crucial for mitigating triclosan contamination, formulating water quality criteria, and protecting aquatic organisms. This study systematically analyzed triclosan occurrence and ecological risks in surface water across China using the Risk Quotient methodology. A total of 139 and 134 data points were collected for triclosan concentrations and toxicities of aquatic organisms, respectively. Triclosan concentrations in surface water across China ranged from 0.06 to 612 ng/L. Higher triclosan levels were observed in Eastern China compared to Central and Western China, with the average concentration being 4.21- and 7.25-fold higher, respectively. Specifically, the Southeast Rivers Basin (132.98 ng/L) and Pearl River Basin (86.64 ng/L) exhibited maximum triclosan levels, 2.57–19.58 times higher than the other river basins. Further analysis revealed elevated triclosan concentrations in small rivers and surface water within residential areas, with values of 246.1 ng/L in Zhejiang, 86.64 ng/L in Guangdong, 67.58 ng/L in Jiangsu, and 127.99 ng/L in Beijing. Additionally, species sensitivity distribution curves indicated that algae was the most sensitive species to triclosan exposure, followed by invertebrates, while fish exhibited the highest tolerance. The Predicted No-Effect Concentration for the algae, invertebrates, fish, and combined aquatic species were determined to be 0.09, 2.95, 4.44, and 1.51 μg/L, respectively. The occurrence of triclosan in surface water across China did not pose widespread ecological risks. However, targeted monitoring and mitigation efforts are needed, especially in highly developed regions. This study provides crucial insights into the status of triclosan contaminations and risks in China and contributes valuable knowledge to global efforts aimed at safeguarding aquatic ecosystems.
Air pollution from transport hubs is a recognised health concern for local urban inhabitants. Within the domain of transport hubs, significant attention has been given to larger airport and port settings, however concerns have been raised about emissions from urban railway hubs, especially those with diesel trains. This paper presents an approach that adopts low-cost monitoring (LCM) for fixed site monitoring (FSM) to quantify and disaggregate PM2.5 and NO2 contributions from railway station and road traffic on air quality in the vicinity of railway station in Dublin, Ireland. The NO2 sensor showed larger discrepancies than the PM2.5 sensor when compared to the reference monitor. Machine learning models (XGBoost and Random Forest (RF) regression) were applied to calibrate the LCM devices, with the XGBoost model (NO2, R2 = 0.8 and RSME = 9.1 μg/m3 & PM2.5, R2 = 0.92 and RSME = 2.2 μg/m3) deemed more appropriate than the RF model. Local wind conditions, pressure, PM2.5 concentrations, and road traffic significantly impacted NO2 model results, while raw PM2.5 sensor readings greatly influenced the PM2.5 model output. This highlights that the NO2 sensor requires more input data for accurate calibration, unlike the PM2.5 sensor. The monitoring results from the one-month monitoring campaign from 25 May 2023 to 25 June 2023 presented elevated NO2 and PM2.5 concentrations measured at the railway station, which translated to exceedances of the annual WHO limits (PM2.5 = 5 μg/m3, NO2 = 10 μg/m3) by 1.6-1.8 and 3.2-5.2 times respectively at the study site. A subsequent data filtering technique based on wind orientation, revealed that the railway station was the main PM2.5 source and road traffic was the main NO2 source when winds come from the railway station. This study highlights the value of LCM devices alongside robust machine learning techniques to capture air quality in urban settings.
There is mounting evidence implicating the potential neurotoxic effects of PM2.5 during brain development, as it has been observed to traverse both the placental barrier and the fetal blood-brain barrier. However, the current utilization of 2D cell culture and animal models falls short in providing an accurate representation of human brain development. Consequently, the precise mechanisms underlying PM2.5-induced developmental neurotoxicity in humans remain obscure. To address this research gap, we constructed three-dimensional (3D) cortical organoids that faithfully recapitulate the initial stages of human cerebral cortex development. Our goal is to investigate the mechanisms of PM2.5-induced neurotoxicity using 3D brain organoids that express cortical layer proteins. Our findings demonstrate that exposure to PM2.5 concentrations of 5 μg/mL and 50 μg/mL induces neuronal apoptosis and disrupts normal neural differentiation, thereby suggesting a detrimental impact on neurodevelopment. Furthermore, transcriptomic analysis revealed PM2.5 exposure induced aberrations in mitochondrial complex I functionality, which is reminiscent of Parkinson's syndrome, potentially mediated by misguided axon guidance and compromised synaptic maintenance. This study is a pioneering assessment of the neurotoxicity of PM2.5 pollution on human brain tissues based on 3D cortical organoids, and the results are of great significance in guiding the formulation of the next air pollution prevention and control policies in China to achieve the sustainable improvement of air quality and to formulate pollution abatement strategies that can maximize the benefits to public health.
Plastic pollution is a notable environmental issue, being plastic widespread and characterized by long lifetime. Serious environmental problems are caused by the improper management of plastic end-of-life. In fact, plastic litter is currently detected in any environment. Biodegradable Polymers (BPs) are promising materials if correctly applied and managed at their end of life, to minimize environmental problems. However, poor data on the fate and toxicity of BPs on marine organisms still limit their applicability. In this work we tested the effects of five biodegradable polymers (polybutylene succinate, PBS; polybutylene succinate-co-butylene adipate, PBSA; polycaprolactone, PCL; poly (3-hydroxybutyrates, PHB; polylactic acid, PLA) widely used for several purposes. Adult individuals of the isopod Idotea balthica basteri were fed on these polymers for twenty-seven days by adding biodegradable microplastic polymers (BMPs) to formulated feeds at two concentrations, viz. 0.84 and 8.4 g/kg feed. The plastic fragments affected the mortality rates of the isopods, as well as the expression levels of eighteen genes (tested by Real Time qPCR) involved in stress response and detoxification processes. Our findings confirmed that I. balthica basteri is a convenient model organism to study the response to environmental pollution and emerging contaminants in the aquatic environment, and highlighted the need for the correct use of BMPs.
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants and inherent components of coal and coal gangue. The similarities and differences in PAH characteristics between these two source materials are largely unknown. In this study, raw coal, cleaned coal, slime, middlings, and gangue from the Wangjialing Coal Preparation Plant in China were analyzed to determine the concentration and distribution of extractable PAHs. The total concentrations of 41PAHs (∑41PAH), US EPA 16 priority parent PAHs (∑16PAH), and their alkylated derivatives (∑aPAH) ranged from 18.3 to 89.6, 8.70 to 34.5, and 8.40 to 48.0 mg/kg, respectively, and were ranked as raw coal > cleaned coal > slime > middlings > gangue. The PAH characteristics of raw coal and its preparation products were consistent, with predominant 2-3-ring PAHs and similar PAH isomer ratio distributions. The distribution of conventional PAH isomer ratios for different ranks of coal and coal gangue from different origins was compiled from the literature. The resulting distribution was consistent and overlapped with both petrogenic and pyrogenic sources defined by the ratios. Therefore, coal and coal gangue should be considered one category and classified as a mixed source (mixture of petrogenic and pyrogenic sources). To accurately identify environmental PAH sources, investigations of aPAHs in the environment and PAH characteristics in coal and coal gangue should be expanded.
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