High Environmental Risk Research Articles

Assessment of environmental risk related to the polycyclic aromatic hydrocarbons (PAH) in the sediments along the eastern Adriatic coast

Polycyclic aromatic hydrocarbons (PAH) were investigated in the sediments at 24 locations in the coastal area of Adriatic Sea. Total PAH concentrations ranged from 14,98 to 26145,62 µg kg-1, with the highest levels determined in the sediments of Šibenik Bay and the lowest in the sediment near Island of Pag. Unsubstituted PAH were prevailing PAH group in the sediments from the Šibenik Bay and in the Coastal area, while methyl-substituted PAH were dominant group in the sediments of the Kaštela Bay. In order to estimate the possible toxicological significance of PAH concentrations, Sediment Quality Assessment was done according to three different sets of sediment quality guidelines. A high environmental risk was calculated for each station in Šibenik Bay; for the station in vicinity of the Industrial port of Split and for the two stations in Coastal zone. Low environmental risk was determined in less urbanised areas such as Island of Pag. Sediment extracts were further analysed for acute toxicity by measurements of decrease in bioluminescence upon exposure to sediment extracts. Obtained results show disagreement between sediment toxicity predicted upon PAH levels in sediment and experimentally obtained sediment toxicity. Sediment extracts in which low PAH levels were measured showed high acute toxicity indicating that concentrations of PAH alone are a poor indicator of sediment toxicity. Correlation analysis between concentrations of specific PAH compounds and toxicity revealed the strongest association between acute sediment toxicity and sulphur-containing PAH suggesting the S-PAH should be considered in sediment toxicity assessment.

Association of screening status, polygenic risk score and environmental risk factors with colorectal cancer incidence and mortality risks.

Whether screening can attenuate the influence of genetic risk and environmental risk factors for colorectal cancer (CRC) mortality risk remains unknown. Our study is to investigate the association of the screening history, genetic risk and environmental risk factors with CRC incidence and mortality risks using UK Biobank data. Screening history was associated with lower CRC incidence (hazard ratio [HR]: 0.63, 95% confidence interval [CI]: 0.58-0.69) and mortality risk (HR: 0.56, 95% CI: 0.49-0.63). Compared to the HRs of participants with a low genetic risk, low environmental risk and no screening history, the HRs of participants with a high genetic risk, high environmental risk and no screening history were 3.42 (95% CI: 2.76-4.24) for CRC incidence and 3.36 (95% CI: 2.48-4.56) for CRC mortality. In contrast, the HRs of participants with a high genetic risk and no screening history, but a low environmental risk, were 1.92 (95% CI: 1.55-2.36) for CRC incidence and 1.88 (95% CI: 1.39-2.53) for CRC mortality. Furthermore, the HRs of participants with a high genetic risk and a low environmental risk, but a screening history were 1.62 (95% CI: 1.15-2.28) for CRC incidence and 1.77 (95% CI: 1.08-2.89) for CRC mortality. Participants benefited more substantially from screenings for CRC mortality than for CRC incidence risk. A higher environmental risk was associated with higher risk of CRC incidence and mortality within each category of genetic risk. These findings emphasize the importance of CRC screening and identifying environmental factors to reduce CRC incidence and mortality risks.

Management of Macrolide Antibiotics (Erythromycin, Clarithromycin and Azithromycin) in the Environment: A Case Study of Environmental Pollution in Lithuania

Of all the antibiotics used today for human treatment in the world, macrolide antibiotics—erythromycin, clarithromycin and azithromycin—stand out the most for misuse, and they were included as high-risk substances in the monitoring Watch List of Regulation 2018/840/EU. The aim of the present research was to investigate the level of target human pharmaceuticals’ prevalence in the environment by the substance flow analysis (SFA) approach and to determine the potential risks of the antibiotics for the environment. The target for the environmental investigations was Lithuania. For SFA, 2021 consumption input data were used, and such key processes as the consumption rate, disposal and distribution of pharmaceuticals in the environment were analyzed. The analysis revealed that the largest part of pharmaceutical contaminants (80.1%) enters wastewater treatment plants. The risk quotient approach was based on the determination of predicted environmental concentrations (PECs), measured environmental concentrations (MECs) and their ratio to the predicted no-effect environmental concentrations (PNECs). The analysis revealed that clarithromycin causes a high potential risk for the aquatic environment in effluents from the wastewater treatment plants (WWTP); PEC/PNEC > 7. For azithromycin and erythromycin, the estimated PEC values were between 0.1 and 1. Clarithromycin concentration in the effluents of two target WWTPs showed a significant risk quotient (MEC/PNEC) of higher than 7. Recommendations on how to reduce the release of pharmaceutical residues into the environment have been proposed in the framework of the environmental management system.

Typical Sulfonamide Antibiotics Removal by Biochar-Amended River Coarse Sand during Groundwater Recharge.

The high porosity of medium-coarse sand (MCS) layers in groundwater recharge areas presents a high environmental risk. Sulfamethoxazole (SMX) and trimethoprim (TMP) are two common sulfonamide antibiotics in surface water that have a high propensity to migrate into groundwater. In this study, four biochars were prepared and biochar-amended soil aquifer treatment (SAT) columns were constructed to remove SMX and TMP. Batch experiments demonstrated that the sorption isotherms conformed to the Freundlich model. The maximum adsorptions of biochars prepared at 700 °C were 54.73 and 67.62 mg/g for SMX and 59.3 and 73.38 mg/g for TMP. Electrostatic interaction may be one of the primary mechanisms of adsorption. The column experiments showed that the SMX and TMP removal rate of the biochar-amended SAT was as high as 96%, while that of the MCS SAT was less than 5%. The addition of biochar greatly improved the retention capacity of the pollutants in the MCS layer in the groundwater recharge area and effectively reduced environmental risk.

Characterizing surface water concentrations of hundreds of organic chemicals in United States for environmental risk prioritization.

Thousands of chemicals are observed in freshwater, typically at trace levels. Measurements are collected for different purposes, so sample characteristics vary. Due to inconsistent data availability for exposure and hazard, it is complex to prioritize which chemicals may pose risks. We evaluated the influence of data curation and statistical practices aggregating surface water measurements of organic chemicals into exposure distributions intended for prioritizing based on nation-scale potential risk. The Water Quality Portal includes millions of observations describing over 1700 chemicals in 93% of hydrologic subbasins across the United States. After filtering to maintain quality and applicability while including all possible samples, we compared concentrations across sample types. We evaluated statistical methods to estimate per-chemical distributions for chosen samples. Overlaps between resulting exposure ranges and distributions representing no-effect concentrations for multiple freshwater species were used to rank estimated chemical risks for further assessment. When we apply explicit data quality and statistical assumptions, we find that there are 186 organic chemicals for which we can make screening-level estimates of surface water chemical concentration. Of the original 1700 observed chemicals, this number decreased primarily due to a predominance of censored values (that is, observations indicating concentrations too low to be measured). We further identify 423 chemicals where all measurements were censored but, through consideration of detection limits, risk might still be prioritized based on the detection limits themselves. In the final set of 1.5 million samples, the median environmental concentration of one chemical (acetic acid) exceeded the 5th percentile of no-effect concentrations for the most delicate freshwater species (the highest priority risk condition identified here), and a further 29 chemicals were identified for possible further evaluation based on a small margin between occurrence and toxicity values. This method shows the broad range of chemical concentrations seen for organic chemicals across the country and identifies methods of determining their central tendency, allowing for researchers to characterize higher-than-normal or lower-than-normal surface water conditions as well as providing an overall indication of the presence of organic chemicals in the United States. The highest chemical concentrations did not always indicate the highest-risk conditions. Even when accounting for the high level of uncertainty in these data due to differences in data collection and reporting across the set, some chemicals may still be categorized as higher environmental risk than others using this method, providing value to chemical safety decision makers and researchers by suggesting avenues for more focused investigation.

ESG risks and corporate survival.

This research is the first attempt to examine the impact of corporate sustainability risks factors on its financial stability. By using S&P500 stocks data from 2019 to 2021 and calculating Altman's Z-score, we examined the influence of ESG (Environmental, Social, and Corporate Governance) risks score on the company survival chances. We documented diminishing total ESG scores of S&P500 stocks in recent years pointing out that companies pay attention to sustainability issues and invest resources to reduce them. We documented that Altman's Z-score is negatively influenced by E and S and not by G. These findings are very important since they prove for the first time that high environmental and social risks may reduce corporates' financial stability and rise their default risks incurring default costs. Moreover, high sensitivity of Altman's Z-score changes to S changes was found especially for relatively smaller firms. The result of this study emphasizes the importance of sustainability risk and especially social risk to a firm's survival chances and therefore mitigating those risks can dramatically improve corporates' financial stability.

3D-printed polymeric lattice-enhanced sustainable municipal solid waste incineration fly ash alkali-activated cementitious composites

The disposal of municipal solid waste incineration fly ash (MSWIFA) has become a prominent issue due to high environmental risks. In this study, as a potential aluminosilicate precursor, MSWIFA was further alkali-activated as a sustainable construction material in the form of an alkali-activated MSWIFA-based material (AAFM), with a low leaching level of heavy metals. Various 3D-printed polymeric lattices were designed and inserted into the AAFM to promote its inherent brittleness. A special coating was also considered to enhance the alkali resistance of the PEGT lattices. Through a flexural tension test with a 3D digital image correlation (3D-DIC) technique, the failure patterns and strain distributions of the 3D-printed polymeric lattice-enhanced MSWIFA-based composites were tracked. These polymeric lattice-containing composites indicated the promotion of mechanical performance, i.e., higher flexural strengths and good ductility. The 3D polymeric lattice-enhanced MSWIFA-based composites showed application prospects as sustainable construction materials, gaining both environmental benefits and good mechanical performance.

Offshore CO2 Capture and Utilization Using Floating Wind/PV Systems: Site Assessment and Efficiency Analysis in the Mediterranean

A methanol island, powered by solar or wind energy, indirectly captures atmospheric CO2 through the ocean and combines it with hydrogen gas to produce a synthetic fuel. The island components include a carbon dioxide extractor, a desalinator, an electrolyzer, and a carbon dioxide-hydrogen reactor to complete this process. In this study, the optimal locations to place such a device in the Mediterranean Sea were determined, based on three main constraints: power availability, environmental risk, and methanol production capability. The island was numerically simulated with a purpose built python package pyseafuel. Data from 20 years of ocean and atmospheric simulation data were used to “force” the simulated methanol island. The optimal locations were found to strongly depend on the power availability constraint, with most optimal locations providing the most solar and/or wind power, due to the limited effect the ocean surface variability had on the power requirements of methanol island. Within this context, optimal locations were found to be the Alboran, Cretan, and Levantine Sea due to the availability of insolation for the Alboran and Levantine Sea and availability of wind power for the Cretan Sea. These locations were also not co-located with areas with larger maximum significant wave heights, thereby avoiding areas with higher environmental risk. When we simulate the production at these locations, a 10 L s−1 seawater inflow rate produced 494.21, 495.84, and 484.70 mL m−2 of methanol over the course of a year, respectively. Island communities in these regions could benefit from the energy resource diversification and independence these systems could provide. However, the environmental impact of such systems is poorly understood and requires further investigation.

“Hot spots” of geoecological risk and problems of territorial planning

Introduction. The tasks of territorial planning are closely related to the problems of locating new high-risk facilities without increasing the environmental load. Thus, the task of locating high environmental risk facilities for recycling and deep processing of wastes appears to an essential economic and scientific problem that requires an immediate solution. The long-term consequences of such decisions should be forecasted and analysed.Aim. To identify “hot spots” according to their risk degree in order to exclude the most dangerous areas from further planning and use.Materials and methods. The stated problem is solved on the basis of environmental risk management, which includes the following concepts: 1) hazard identification; 2) vulnerability assessment; 3) risk analysis; 4) acceptable risk concept; 5) risk assessment; 6) risk mapping; 7) risk reduction measures, including a) legislative; b) organisational and administrative; c) economic, including insurance; d) engineering; e) modelling; f) monitoring; g) informational. Data and maps of hazardous natural and technogenic processes and potential damage to the territories of the Moscow Oblast were used.Results. When carrying out territorial planning and location of additional hazard facilities, representing an increased ecological load, such as incineration plants and landfills for recycling and deep processing of wastes, high ecological risk regions should be excluded from the potential location list. In the Moscow Oblast, these are primarily Lyuberetsky and Ramensky districts (east-southeast of Moscow). Lyubertsky district can be considered as a “hot spot” of the first class in terms of ecological risk due to the high natural hazard and potential damage. The findings obtained when determining “hot spots” based on geological, geodynamic, tectonic and socio-economic parameters, were confirmed by the areas of geochemical pollution and environmental stress zones.Conclusion. The developed method of identifying the risk “hot spots” represents a basis for solving the problems of territorial planning for the purpose of excluding the most ecologically stressed sites and selecting suitable sites for locating hazard facilities, in particular, recycling and waste processing plants.

Effect of operating parameters on monomer production from depolymerization of waste polyethylene terephthalate in supercritical ethanol

Waste plastic presents a high risk for environment and ecosystem, and it is essential to recycle the discarded plastic. In this study, supercritical ethanol depolymerization (SCED) is used to recover monomer from waste polyethylene terephthalate (PET). The effect of reaction temperature (230–350 °C), reaction time (2–60 min), and liquid/solid (ethanol/waste PET) mass ratio (L/S ratio = 8:1, 10:1 and 12:1) on depolymerization of waste PET in supercritical ethanol (SCE) were investigated by experiments. The solid residue after depolymerization process was characterized by FTIR, TG-DSC, and SEM. It was found that the main components of liquid product include diethyl terephthalate (DET), and ethylene glycol (EG), etc. The optimum depolymerization efficiency (100%), DET yield (98%), and EG yield (89.8%) could be obtained from SCED of transparent waste PET at 310 °C, 60 min, and L/S ratio= 10:1. Such optimal condition was also applied for depolymerization of various waste PET. When recycled ethanol from preceding depolymerization was reused in subsequent depolymerization, the yield of DET and EG decreased by 6.0–7.5% and 3.5–4.0%, respectively. The potential reaction pathway of waste PET in SCE was also proposed. Generally, SCED is potential technology for monomer recovery from waste PET.

Ultrafast and selective adsorption of pharmaceuticals from wastewater by precisely designed metal organic framework with missing linker defects

Pharmaceuticals and personal care products (PPCPs) are widely used and frequently detected in the environment. A series of novel, precisely designed metal-organic framework (MOF) materials with long-range ordered defective structure was proposed by tuning the node connectivity and missing linkers/clusters. The adsorption abilities of anti-inflammatory drugs were significantly improved (79.87 mg/g, 561.37 mg/g·min for ibuprofen (IBU)) over the defective UiO-66 (node connectivity = 7.8), which were 2.5 and 59.8 times higher than that over the defect-free one (32.16 mg/g, 9.39 mg/g • min). The adsorption rate constant of IBU was accelerated 1.12 × 104 times greater than that of the activated carbon. For the first time, the performance was evaluated under the environmentally relevant concentration (200 μg/L to 0.025 μg/L) with removal percentages ∼ 90% within 1 min. Theoretical calculations were conducted to study the mechanism. Furthermore, 15 micropollutants with various functional groups (sulfonamides, quinolones, macrolides, etc.) with high environmental risks proved our concept that electrostatic interaction could be the primary mechanism. Real wastewater in Beijing was sampled and evaluated the performance of removing the pharmaceuticals (concentration: 199.21 ± 3.65 ng/L ∼ 0.10 ± 0.01 ng/L), a complete removal can be achieved in only 3 min with concentrations below instrumental detection limits. This finding provides a promising strategy for designing materials for rapidly removing pharmaceuticals in water.

Association of Non-Steroidal Anti-Inflammatory Drugs, Genetic Risk, and Environmental Risk Factors with Incidence of Colorectal Cancer.

Simple SummaryIt remains unknown whether regular use of non-steroidal anti-inflammatory drugs (NSAIDs) could attenuate the impact of genetic risk and environmental risk factors on colorectal cancer (CRC). In the current study, we evaluated the association of NSAID use, genetic risk, and environmental risk factors with CRC incidence using data from a UK Biobank cohort. We found that regular use of NSAIDs was associated with a lower risk of CRC. Although there were no statistical interactions observed between NSAID use, environmental risk and genetic risk, regular NSAID use was still associated with lower CRC incidence among subjects with either high environmental risk or high genetic risk. Furthermore, low environmental risk was associated with lower CRC incidence among subjects with high genetic risk. These findings emphasized the importance of the chemopreventive effect of regular use of NSAIDs and controlling modifiable environmental risk factors to reduce CRC incidence, even among individuals with a moderate or high genetic risk of CRC.Regular use of non-steroidal anti-inflammatory drugs (NSAIDs) was associated with the lower risk of colorectal cancer (CRC). However, whether regular use of NSAIDs could attenuate the effect of genetic risk and environmental risk factors on CRC is unknown. We aimed to evaluate the association of NSAID use, genetic risk, and environmental risk factors with CRC. Using data from a UK Biobank, a Cox proportional hazards model was performed to estimate the risk of CRC according to NSAID use, polygenic risk score, and environmental risk factors. Regular use of NSAIDs was associated with a 36.0% lower risk of CRC. No statistically significant interaction was observed between NSAID use and the genetic risk score (p = 0.190), and between NSAID use and the environmental risk score (p = 0.740). However, regular NSAID use was still associated with lower CRC incidence among subjects with either high environmental risk or high genetic risk. Furthermore, the genetic and environmental risk of CRC were additives. These findings appear to support the chemopreventive effect of regular NSAID use. Furthermore, controlling of modifiable environmental risk factors can reduce the CRC risk, especially among individuals with a moderate or high genetic risk of CRC.

Occurrences, distribution and risk assessment of polar pesticides in Niger River valley and its tributary the Mekrou River (Niger Republic).

The increase in food needs due to high population growth in Niger has led to the intensification of urban agriculture and the increased use of pesticides. The objective of this study is primarily to assess the polar pesticide contamination (mainly herbicides) of the Niger River and its tributary, the Mekrou River, in Niger, using both grab sampling and POCIS (Polar Organic Chemical Integrative Samplers), and then to evaluate the risk to the aquatic environment. Two water sampling campaigns were carried out during the wet and dry seasons. The polar pesticides were analyzed by liquid chromatography coupled with tandem mass spectrometry, which allowed the identification of compounds with concentrations in the grab samples above the WHO guide values and the EU directive: diuron with 2221ng/L (EU quality guideline: 200ng/L), atrazine with 742ng/L (EU quality guideline: 600ng/L) and acetochlor with 238ng/L (EU quality guideline: 100ng/L). The risk assessment study indicated that diuron and atrazine present a high risk for the aquatic environment during the wet season. The main source of water contamination is the intensive use of pesticides in urban agriculture near the city of Niamey, and the intensive cotton farming in the Benin. Moreover, the surveys (30 producers interviewed) showed that 70% of the pesticides used are not approved by the Interstate Committee for Drought Control in the Sahel (CILSS) and some are prohibited in Niger. The inventory of pesticides sold in the zone showed that active ingredients used by producers are 48% insecticides, 45% herbicides, and 7% fungicides.

Wide-scope target and suspect screening of emerging contaminants in sewage sludge from Nigerian WWTPs by UPLC-qToF-MS

There is currently a paucity of scientific data in Africa on the analysis and occurrence of emerging contaminants in sewage sludge. In this work, the occurrence of European Union (EU) Water Framework Directive priority substances and wide-range emerging contaminants were investigated and discussed comprehensively in the sewage sludge samples from three different wastewater treatment plants (WWTPs) in Lagos, Nigeria. The identification strategy was implemented by target and suspect screening in liquid chromatography-high resolution mass spectrometry. 250 compounds were identified in the sewage sludge samples from the investigated WWTPs. From 250 detected compounds, 182 compounds were quantified, and 78 compounds significantly show high environmental risk score (calculated from provisional no-effect concentrations values (PNEC) as well as their environmental quality data (EQs)). Most of contaminants detected at high amount belong to pharmaceuticals and are from hospital WWTP. While the highest concentration (72.4 mg kg−1) was measured for salicylic acid (a non-steroidal anti-inflammatory drug), antibiotics showed high concentrations up to 24.4 and 28.4 mg kg−1 for ciprofloxacin and ofloxacin, respectively. Three simple factors including frequency of exceedance, frequency of occurrence and extent of exceedance were used to aid prioritization of these substances in future monitoring campaigns. This work presents the first comprehensive and wide-scope screening of a large number of emerging contaminants in sewage sludge from Nigerian WWTPs.

Crude oil associated heavy metals (HMs) contamination in agricultural land: Understanding risk factors and changes in soil biological properties

Ecological and human risks of crude oil associated heavy metals (HMs) in the contaminated agricultural lands were evaluated employing different indices. The indices that were employed includes enrichment factor (EF), contamination factor (Cf),pollution load index (PLI), geo-accumulation index (Igeo), ecological risk index (ERI), contamination degree (Cd), Nemerow's pollution index (PN), exposure factor (ExF), hazard quotient (HQ) and hazard index (HI). Besides, the adverse effects of crude oil associated HMs on the soil biological properties were also analyzed. The results of Cf and EF were found consistent with each other showing the HMs in the decreasing order of contamination as Mn > Zn > Cr > Ni > Cu. The Igeo and ERI fall in the grade (Igeo>5) and (ERI ≥40) respectively. The results of PLI, Cd, PN and ExF values clearly indicate a high environmental risk of crude oil-associated HMs. The results of the human health risks assessment revealed the maximum level of HMs enters the body via ingestion. There were significant(p < 0.05) decreases (5.7–15.5 folds) in the activities of cellulase (0.194 ± 0.02–0.998 ± 0.1), phosphatase (0.173 ± 0.3–0.612 ± 1.5), catalase (0.328 ± 0.3–2.036 ± 1.5), urease (0.44 ± 0.3–1.80 ± 1.2), dehydrogenase (0.321 ± 0.2–0.776 ± 0.7),polyphenol oxidase (0.21 ± 0.5–0.89 ± 2.5)and peroxidase (0.13 ± 0.4–0.53 ± 1.03)in crude oil-contaminated soil. The Pearson's correlation confirmed the significant negative impact of HMs on the soil's biological properties.

Natural Enemies and Biological Control of Stink Bugs (Hemiptera: Heteroptera) in North America.

Simple SummaryStink bugs are important pests of many crops in the US, including row crops, vegetables, and tree fruits and nuts. Most stink bug management relies on broad-spectrum, disruptive insecticides with high human and environmental risks associated with them. These issues and increasing pesticide resistance in stink bugs are forcing pest managers to explore safer and more sustainable options. Here, we review the natural enemies of stink bugs in the US, noting that the egg and the late nymphal and adult stages of stink bugs are the most commonly attacked by parasitoids, whereas eggs and young nymphs are the stages most commonly attacked by predators. The effectiveness of stink bugs’ natural enemies varies widely with stink bug species and habitats, influencing the biological control of stink bugs across crops. Historically, biological control of stink bugs has focused on the introduction of exotic natural enemies against exotic stink bugs. Conservation and augmentation methods of biological control have received less attention in the US, although there may be good opportunities to utilize these approaches. We identify some considerations for the current and future use of biological control for stink bugs, including the potential for area-wide management approaches.Stink bugs comprise a significant and costly pest complex for numerous crops in the US, including row crops, vegetables, and tree fruits and nuts. Most management relies on the use of broad-spectrum and disruptive insecticides with high human and environmental risks associated with them. Growing concerns about pesticide resistance in stink bugs are forcing pest managers to explore safer and more sustainable options. Here, we review the diverse suite of natural enemies of stink bugs in the US, noting that the egg and the late nymphal and adult stages of stink bugs are the most commonly attacked by parasitoids, whereas eggs and young nymphs are the stages most commonly attacked by predators. The effectiveness of stink bugs’ natural enemies varies widely with stink bug species and habitats, influencing the biological control of stink bugs across crops. Historically, biological control of stink bugs has focused on introduction of exotic natural enemies against exotic stink bugs. Conservation and augmentation methods of biological control have received less attention in the US, although there may be good opportunities to utilize these approaches. We identify some considerations for the current and future use of biological control for stink bugs, including the potential for area-wide management approaches.

Effects of air pollution on accounting conservatism

We examine the impact of air pollution on a firm's accounting policy conservatism. We hypothesize that, in response to risks associated with increased air pollution, firms apply more conservative accounting practices and utilize more conservative estimates in their reporting. Using a sample of Chinese firms, accounting conservatism measures, and a satellite-based air pollution metric, we confirm the validity of our hypothesis. Additional analysis suggests that the impact of air pollution on accounting policy conservatism is more salient for firms in high-pollution industries, firms under severe financial constraint, firms with higher environmental risk, and firms that receive high media coverage. Further, we document that air pollution does not significantly affect a firm's return on assets, year-on-year sales growth, or Tobin's Q measure. Hence, it is management's risk perception, not objective performance concern, that is driving accounting conservatism. Finally, specifically investigating accounting conservatism, we discover that, for firms with higher pollution levels, selling general and administrative expenses, liabilities provision, accrued expenses, and asset impairment loss are significantly higher.

Human-Health and Environmental Risks of Heavy Metal Contamination in Soil and Groundwater at a Riverside Site, China

The contaminated site is considered a high-risk pollution source due to the accumulation of industrial waste and wastewater, which affects the soil and groundwater environment. In this study, through soil and groundwater investigation, we outlined the characteristics of heavy metal contamination in the soil and groundwater of the contaminated site, assessed the health risk of the contaminated site to humans, and established a numerical model to predict the ecological and environmental risks of the site. The results of the study showed that the maximum contamination concentration of pollutants (lead, arsenic, cadmium) in the soil all exceeded the Chinese environmental standard (GB36600-2018, Grade II), that the maximum contamination concentration (cadmium, Cd) of the groundwater exceeded the Chinese environmental standard (GB14848–2017, Grade IV), and that the heavy metal pollution was mainly concentrated in the production area of the site and the waste-residue stockpiles. The total carcinogenic risk and non-carcinogenic hazard quotient of the site’s soil heavy metal contaminants exceed the human acceptable limit, and there is a human health risk. However, the groundwater in the area where the site is located is prohibited from exploitation, and there is no volatility of the contaminants and no exposure pathway to the groundwater, so there is no risk to human health. The simulation prediction results show that, with the passage of time, the site groundwater pollutants as a whole migrate from south to north, affecting the northern surface water bodies after about 12 years, and there is a high ecological and environmental risk. The above findings provide a scientific basis for the study of the soil and groundwater at the riverside contaminated site.

Seasonal variation of distribution and removal of high-risk tetracycline resistance genes in constructed wetland.

Livestock wastewater is an important reservoir of antibiotic resistance genes (ARGs), with high environmental risks. We investigated the seasonal variations of distribution and removal of swine wastewater originated high-risk tetracycline resistance genes (TRGs) in horizontal subsurface flow constructed wetlands. The effects of exogenous addition of tetracycline (TC) and copper ion (Cu2+) on the abundance of TRGs in effluent with single and combined pollution of antibiotic and heavy metal were studied. The results showed that all the three high-risk TRGs (tetM, tetO and tetW) were detected in swine wastewater. Wetlands could effectively reduce the ARGs, with the absolute abundance of TRGs in effluent being decreased by 1.1-2.4 and 1.7-2.9 orders of magnitude in summer and winter compared with the influent, respectively. The abundance of TRGs in wetland soils showed the characte-ristics that the outflow side was lower than the inflow side, the non-rhizosphere area was lower than the rhizosphere area, and lower in winter than in summer. In summer and winter, single and combined pollution of TC and Cu2+ in swine wastewater would increase the abundance of TRGs in effluent compared with that in the control. The constructed wetland is suitable for controlling the environmental diffusion of ARGs in livestock wastewater.

Functionally Graded Materials Pile Structure for Seismic Noise Cancellation

This study explores surface-wave propagation through periodic arrangements of multilayered piles in a single-layer soil medium from the viewpoint of bandgaps. The influence of the geometrical parameters of the model on the bandgaps is discussed. The periodic theory of solid-state physics is imposed to derive the dispersion equation. The finite-element method is implemented to calculate the dispersion relation and attenuation zones for surface waves in a periodic pile and soil system. The results show that the bandgaps are sensitive to the size and arrangement of the piles. The practicability of ground vibration-isolation by periodic pile barriers are verified in the time domain. The location and width of bandgaps are further authenticated through finite unit cell–based frequency response analyses. It is found that the frequency range of the Rayleigh wave reduction agrees well with the theoretical attenuation zone. This work provides new insights into the design of periodic piles as wave barriers. This approach has scope for protecting infrastructures, such as nuclear power plants, which pose high environmental risks. It is found that the dispersion analysis gives essential information for Rayleigh wave isolation using piles, including the frequency range and the form of decline.