Mussels are suggested as bioindicators of marine microplastic pollution. However, they are selective in regards to accumulation of microplastics. To make studies more targeted and comparable, ultimately helping to determine the suitability of the mussel as a bioindicator species for microplastic exposure, we review the published literature that has directly or indirectly demonstrated particle selection in mussels. The reported difference between microplastic levels in mussel tissues and environmental matrices provides evidence for their selective uptake characteristics. Both the organ-specific fate characteristics of microplastics, and the different movement patterns of microplastics in the same organ, show that selective translocation processes take place. The selective elimination is reflected in multiple aspects which include (1) the different characteristics of microplastics in excretion and mussel body; (2) the different retention time of various microplastics in mussels; and (3) the tissue-specific change in the numbers of microplastics during the depuration process. This selectivity is affected by the characteristics of the microplastics, the environmental, or laboratory exposure concentrations, feeding status, and other factors. There are still many research gaps and contradictory viewpoints in this field due to this complexity. The current methodology needs improvement and a breakthrough in standardization.

Transformation products (TPs) of micropollutants contaminating our water resources have become an emerging issue due to the potential threats they pose to environmental and human health. This study investigated the transformation chemistry, toxicity, physicochemical properties and environmental behavior resulting from photocatalytic transformation of organic UV filters as model micropollutants. 3-Benzylidene camphor (3-BC), 4-hydroxybenzophenone (4-HB) and octocrylene (OC) were effectively degraded by UV-A/TiO₂ treatment, with TPs identified and characterized with high resolution mass spectrometry. Nitrated-TPs were observed to be formed in the presence of nitrite and nitrate for 3-BC and 4-HB, suggesting that the transformation process could be altered by components in the water matrix. Vibrio fischeri bioluminescence inhibition assay revealed an increase in toxicity of TPs derived from photocatalytic treatment, with quantitative structure-activity relationship model (ECOSAR) predicted an enhanced toxicity of individual TPs' after transformation. Assessment of physicochemical properties and environmental behavior suggested that TPs as compared to parent organic UV filters, may represent even greater hazards due to their increased water solubility, persistence and mobility – in addition to retaining the parent organic UV filter's toxicity. The results provide important information relevant to the potential risks for the selected organic UV filters, and their corresponding transformation products.

Converting biomass waste into biochar by slow pyrolysis with subsequent soil amendment is a prospective approach with multiple environmental benefits including soil contamination remediation, soil amelioration and carbon sequestration. This study selected cow manure as precursor to produce biochar under 300 °C, 400 °C, 500 °C and 600 °C, and a remarkable promotion of carbon (C) retention in biochar by incorporation of exogenous Ca was achieved at all investigated pyrolysis temperatures. The C retention was elevated from 49.2 to 68.3% of pristine biochars to 66.1–79.7% of Ca-composite biochars. It was interesting that extent of this improvement increased gradually with rising of pyrolysis temperature, i.e., doping Ca in biomass promoted pyrolytic C retention in biochar by 16.6%, 23.4%, 29.1% and 31.1% for 300 °C, 400 °C, 500 °C and 600 °C, respectively. Thermogravimetric-mass spectrometer (TG-MS) and X-ray photoelectron spectroscopy (XPS) showed that Ca catalyzed thermal-chemical reactions and simultaneously suppressed the release of small organic molecular substances (C₂–C₇) via physical blocking (CaO, CaCO₃, and CaClOH) and chemical bonding (CO and OC–O). The catalyzation mainly occurred at 200–400 °C, while the suppression was more prominent at higher temperatures. Raman spectra and 2D FTIR analysis on biochar microstructure showed that presence of Ca had negative influence on carbon aromatization and thus weakened biochar's stability, while increasing pyrolysis temperature enhanced the stability of carbon structure. Finally, with integrating “C retention” during pyrolysis and “C stability” in biochar, the maximum C sequestration (56.3%) was achieved at 600 °C with the participation of Ca. The study highlights the importance of both Ca and pyrolysis temperature in enhancing biochar's capacity of sequestrating C.

To help understand the pathophysiologic mechanisms linking air pollutants and cardiovascular disease (CVD), we employed a repeated measures design to investigate the associations of four short-term air pollution exposures – particulate matter less than 2.5 μm in diameter (PM₂.₅), nitrogen dioxide (NO₂), ozone (O₃) and sulfur dioxide (SO₂), with two blood markers involved in vascular effects of oxidative stress, soluble lectin-like oxidized LDL receptor-1 (sLOX-1) and nitrite, using data from the Multi-Ethnic Study of Atherosclerosis (MESA). Seven hundred and forty participants with plasma sLOX-1 and nitrite measurements at three exams between 2002 and 2007 were included. Daily PM₂.₅, NO₂, O₃ and SO₂ zero to seven days prior to blood draw were estimated from central monitors in six MESA regions, pre-adjusted using site-specific splines of meteorology and temporal trends, and an indicator for day of the week. Unconstrained distributed lag generalized estimating equations were used to estimate net effects over eight days with adjustment for sociodemographic and behavioral factors. The results showed that higher short-term concentrations of PM₂.₅, but not other pollutants, were associated with increased sLOX-1 analyzed both as a continuous outcome (percent change per interquartile increase: 16.36%, 95%CI: 0.1–35.26%) and dichotomized at the median (odds ratio per interquartile increase: 1.21, 95%CI: 1.01–1.44). The findings were not meaningfully changed after adjustment for additional covariates or in several sensitivity analyses. Pollutant concentrations were not associated with nitrite levels. This study extends earlier experimental findings of increased sLOX-1 levels following PM inhalation to a much larger population and at ambient concentrations. In light of its known mechanistic role in promoting vascular disease, sLOX-1 may be a suitable translational biomarker linking air pollutant exposures and cardiovascular outcomes.

Development of non-noble metal cluster catalysts, aiming at concurrently high activity and stability, for emission control systems has been challenging because of sintering and overcoating of clusters on the support. In this work, we reported the role of well-dispersed copper nanoclusters supported on TiO₂ in CO oxidation under industrially relevant operating conditions. The catalyst containing 0.15 wt% Cu on TiO₂ (0.15 CT) exhibited a high dispersion (59.1%), a large specific surface area (381 m²/gCᵤ), a small particle size (1.77 nm), and abundant active sites (75.8% Cu₂O). The CO oxidation activity measured by the turnover frequency (TOF) was found to be enhanced from 0.60 × 10⁻³ to 3.22 × 10⁻³ molCO·molCᵤ⁻¹·s⁻¹ as the copper loading decreased from 5 to 0.15 wt%. A CO conversion of approximately 60% was still observed in the supported cluster catalyst with a Cu loading of 5 wt% at 240 °C. No deactivation was observed for catalysts with low copper loading (0.15 and 0.30 CT) after 8 h of time-on-stream, which compares favorably with less stable Au cluster-based catalysts reported in the literature. In contrast, catalysts with high copper loading (0.75 and 5 CT) showed deactivation over time, which was ascribed to the increase in copper particle size due to metal cluster agglomeration. This study elucidated the size-activity threshold of TiO₂-supported Cu cluster catalysts. It also demonstrated the potential of the supported Cu cluster catalyst at a typical temperature range of diesel engines at light-load. The supported Cu cluster catalyst could be a promising alternative to noble metal cluster catalysts for emission control systems.

Bisphenol A (BPA), an endocrine-disrupting chemical that is largely produced and used in the plastics industry, causes environmental pollution and is absorbed by humans through consumption of food and liquids in polycarbonate containers. BPA exerts developmental and genetic toxicities to embryos and offsprings, but the embryotoxicity mechanism of this chemical is unclear. This study aimed to explore the toxic effect of BPA on embryonic development and elucidate its toxicity mechanism. Embryos of Xenopus laevis as a model were treated with different concentrations (0.1, 1, 10, and 20 μM) of BPA at the two-cell stage to investigate the developmental toxicity of BPA. Embryonic development and behaviors were monitored 24 h–96 h of BPA exposure. BPA concentrations greater than 1 μM exerted significant teratogenic effects on the Xenopus embryos, which showed short tail axis, miscoiled guts, and bent notochord as the main malformations. The 20 μM BPA-treated embryos were seriously damaged in all aspects and exhibited deformity, impaired behavioral ability, and tissue damage. The DNA integrity and apoptosis of the Xenopus embryos were also investigated. Exposure to BPA concentrations higher than 0.1 μM significantly induced DNA damage (p < 0.05). The 10 and 20 μM BPA-treated embryos exhibited higher levels of cleaved caspase-3 protein than the control. The ratios of bax/bcl-2 mRNA were significantly higher in the 10 μM and 20 μM-treated embryos than the ratio in the control group. Overall, data indicated that BPA can delay the early development, induce DNA damage and apoptosis, and eventually cause multiple malformations in Xenopus embryos.

The ongoing loss of global biodiversity is endangering ecosystem functioning and human food security. While environmental pollutants are well known to reduce fertility, the potential effects of common neonicotinoid insecticides on insect fertility remain poorly understood. Here, we show that field-realistic neonicotinoid exposure can drastically impact male insect fertility. In the laboratory, male and female solitary bees Osmia cornuta were exposed to four concentrations of the neonicotinoid thiamethoxam to measure survival, food consumption, and sperm traits. Despite males being exposed to higher dosages of thiamethoxam, females revealed an overall increased hazard rate for survival; suggesting sex-specific differences in toxicological sensitivity. All tested sublethal concentrations (i.e., 1.5, 4.5 and 10 ng g⁻¹) reduced sperm quantity by 57% and viability by 42% on average, with the lowest tested concentration leading to a reduction in total living sperm by 90%. As the tested sublethal concentrations match estimates of global neonicotinoid pollution, this reveals a plausible mechanism for population declines, thereby reflecting a realistic concern. An immediate reduction in environmental pollutants is required to decelerate the ongoing loss of biodiversity.

Phosphorus-inactivating agents (PIAs) as geoengineering tools in lakes have been investigated extensively, but PIA resuspension in the photic layer occurs frequently in shallow lakes and little is known about the influence of algae on PIA performance. Our results proved that algae increased the dissolved oxygen, pH and dissolved organic carbon concentration substantially. In the absence of sediment, lanthanum modified zeolite (LMZ) as a representative PIA and algae could deplete dissolved inorganic phosphorus (DIP) from water but the former was faster than the latter. When LMZ and algae coexisted, the amount of phosphorus that was captured by LMZ was 3.1 times greater than that taken up by algae. An increase in pH or dissolved organic carbon increased the zero-equilibrium phosphorus concentration (EPC₀) of the sediment but LMZ addition could lower the EPC₀ and reduce the risk of phosphorus release during the algal blooming season. In the presence of sediment, LMZ reduced the DIP concentration more rapidly and yielded a lower final DIP concentration compared with algae. In conclusion, the influence of algae on the performance of LMZ by (i) taking up DIP to reduce the availability of DIP and convert DIP into a releasable phosphorus form and (ii) increasing the pH and dissolved organic carbon concentration to hinder the adsorption ability of DIP were recognized. The LMZ performed well, even in the presence of algae.

Cadmium (Cd) and lead (Pb) are ubiquitously present in surface soils, due to anthropogenic activities, causing threat to ecological and human health because of their carcinogenic nature. They accumulate in large quantities in the environment and affect negatively soil microbiota, plants, animals, and humans. For the cleanup of Cd/Pb polluted soils, different plant species have been studied. Many plants have shown the potential to hyperaccumulate Cd/Pb in their above-ground tissues. These plants decrease soil pH by root exudation or by releasing H⁺ ions, and this, in turn, increases the bioavailability of Cd/Pb for plant uptake. Different environmental processes related to soil organic matter, microorganisms, pH, genetic modifications, and various soil-borne chelating agents affect the potential of phytoremediation technology. Review papers trying to identify a single factor influencing the phytoremediation of heavy metals are available in the literature. However, an integrated approach dealing with different factors involved in the remediation of both metals is scarcely discussed. The main focus of this review is to discuss the phytoextraction technique for Cd/Pb removal from contaminated sites along with detoxification mechanisms. Further, the challenges in the Cd/Pb phytoextraction and different options available to cope with these challenges are also discussed. The update on the relevant findings on the use of microorganisms and amendments in enhancing the Cd/Pb phytoextraction is also provided. Finally, the areas to be explored in future research for the removal of Cd/Pb by integrated strategies have been discussed.

Antifouling paint particles (APPs) and associated metals have been identified in sediments around boatyards and marinas globally, but the effects of APPs on benthic organisms are largely unknown. Sub-lethal endpoints were measured following laboratory exposures of the harbour ragworm (Hediste diversicolor) and the common cockle (Cerastoderma edule) to environmentally relevant concentrations of biocidal (‘modern’ and ‘historic’) and biocide-free (‘silicone’) APPs added to clean estuarine sediment. Further, the 5-day median lethal concentrations (LC₅₀) and effects concentrations (EC₅₀) for modern biocidal APPs were calculated. For ragworms, significant decreases in weight (15.7%; p < 0.01) and feeding rate (10.2%; p < 0.05) were observed in the modern biocidal treatment; burrowing behaviour was also reduced by 29% in this treatment, but was not significant. For cockles, the modern biocidal treatment led to 100% mortality of all replicates before endpoints were measured. In cockles, there was elevated levels of metallothionein-like protein (MTLP) in response to both modern and historic biocidal treatments. Ragworms had a higher tolerance to modern APPs (5-day LC₅₀:19.9 APP g L⁻¹; EC₅₀: 14.6 g L⁻¹) compared to cockles (5-day LC₅₀: 2.3 g L⁻¹ and EC₅₀: 1.4 g L⁻¹). The results of this study indicate that modern biocidal APPs, containing high Cu concentrations, have the potential to adversely affect the health of benthic organisms at environmentally relevant concentrations. The findings highlight the need for stricter regulations on the disposal of APP waste originating from boatyards, marinas and abandoned boats.