Useful information on the potential radon risk in existing buildings can be obtained by combining data from sources such as potential risk maps, the ‘Sistema de Información sobre Ocupación del Suelo de España’ (SIOSE) [information system on land occupancy in Spain], cadastral data on built property and population surveys. The present study proposes a method for identifying urban land, premises and individuals potentially subject to radon risk. The procedure draws from geographic information systems (GIS) pooled at the municipal scale and data on buildings possibly affected. The method quantifies the magnitude of the problem in the form of indicators on the buildings, number of premises and gross floor area that may be affected in each risk category. The findings are classified by type of use: residential, educational or office. That information may guide health/prevention policies by targeting areas to be measured based on risk category, or protection policies geared to the construction industry by estimating the number of buildings in need of treatment or remediation. Application of the methodology to Greater Madrid showed that 47% of the municipalities have houses located in high radon risk areas. Using cadastral data to zoom in on those at highest risk yielded information on the floor area of the vulnerable (basement, ground and first storey) premises, which could then be compared to the total. In small towns, the area affected differed only scantly from the total, given the substantial proportion of low-rise buildings in such municipalities.

Anthropogenic activities, such as mining and agriculture, have resulted in many freshwater systems having elevated concentrations of copper. Despite the prevalence of this contamination, and the vital ecological function of prokaryotes, just three studies have investigated prokaryote community responses to copper concentration in freshwater sediments. To address this, the current study investigated these communities in outdoor mesocosms spiked with varying copper concentrations. We profiled the prokaryotic communities at the taxonomic level, using next-generation high-throughput sequencing techniques, as well as their function, using baiting with leaf analogues, and Biolog Ecoplates for community-level physiological profiling. Sediments containing just 46 mg kg⁻¹ of copper, had distinctly different microbial communities compared with controls, as determined by both DNA and RNA 16S ribosomal RNA gene (rRNA) profiling. In addition to this, sediment communities displayed a greatly reduced utilisation of carbon substrates under elevated copper, while the communities recruited onto leaf analogues were also disparate from those of control ponds. Given the vital role of prokaryotes in ecosystem processes, including carbon cycling, these changes are potentially of great ecological relevance, and are seen to occur well below the ‘low risk’ sediment quality guideline values (SQGV) used by regulatory bodies internationally.

There is currently great interest in replacing fossil-oil with renewable fuels in energy production. Fast pyrolysis bio-oil (FPBO) made of lignocellulosic biomass is one such alternative to replace fossil oil, such as heavy fuel oil (HFO), in energy boilers. However, it is not known how this fuel change will alter the quantity and quality of emissions affecting human health. In this work, particulate emissions from a real-scale commercially operated FPBO boiler plant are characterized, including extensive physico-chemical and toxicological analyses. These are then compared to emission characteristics of heavy fuel-oil and wood fired boilers. Finally, the effects of the fuel choice on the emissions, their potential health effects and the requirements for flue gas cleaning in small-to medium-sized boiler units are discussed.The total suspended particulate matter and fine particulate matter (PM₁) concentrations in FPBO boiler flue gases before filtration were higher than in HFO boilers and lower or on a level similar to wood-fired grate boilers. FPBO particles consisted mainly of ash species and contained less polycyclic aromatic hydrocarbons (PAH) and heavy metals than had previously been measured from HFO combustion. This feature was clearly reflected in the toxicological properties of FPBO particle emissions, which showed less acute toxicity effects on the cell line than HFO combustion particles. The electrostatic precipitator used in the boiler plant efficiently removed flue gas particles of all sizes. Only minor differences in the toxicological properties of particles upstream and downstream of the electrostatic precipitator were observed, when the same particulate mass from both situations was given to the cells.

Tight junctions (TJs) in the epithelium play a critical role in the formation of a paracellular epithelial barrier against the extracellular environment. Diesel exhaust particles (DEPs) disrupt the epithelial barrier. The aim of this study was to investigate how DEPs disrupt the epithelial barrier and whether Toll-like receptor 4 (TLR4) is involved in DEP-induced epithelial barrier dysfunction in primary human nasal epithelial (PHNE) cells.PHNE cells were cultured at an air–liquid interface (ALI) to create a fully differentiated in vivo-like model of the epithelium and then exposed to DEPs (particulate matter <4 μm) or lipopolysaccharide (LPS) alone (mono-exposure) and DEPs plus LPS (co-exposure) at the apical side of the PHNE. TJ formation and integrity were monitored by measuring transepithelial electric resistance (TEER) and fluorescently labeled dextran permeability. The expression of TJ proteins was assessed by confocal microscopy and a biochemical assay.PHNE cell viability was reduced in a time- and dose-dependent manner following DEP exposure. TEER was significantly decreased at ALI day 20 but not at day 12 following DEP exposure. The dextran permeability of the PHNE was significantly increased at both ALI day 12 and day 20 following DEP exposure. The increased dextran permeability recovered to that of the control following co-exposure to DEPs plus LPS. In the presence of DEPs, the membrane expression of myosin light chain kinase (MLCK) was dramatically increased, and the expression of occludin, ZO1, claudin-1, and E-cadherin was significantly decreased. Co-exposure to DEPs plus LPS significantly reduced membrane MLCK, claudin-1, and E-cadherin but increased occludin and ZO1 expression at ALI day 12.The activation of TLR4 by LPS inhibits MLCK trafficking to the plasma membrane, and this increased during DEP exposure, resulting in increased occludin expression at the plasma membrane that partially recovered TJ barrier dysfunction following DEP exposure.

Microplastics (MPs) are now one of the major environmental problems due to the large amount released in aquatic and terrestrial ecosystems, as well as their diffuse sources and potential impacts on organisms and human health. Still the molecular and cellular targets of microplastics’ toxicity have not yet been identified and their mechanism of actions in aquatic organisms are largely unknown. In order to partially fill this gap, we used a mass spectrometry based functional proteomics to evaluate the modulation of protein profiling in zebra mussel (Dreissena polymorpha), one of the most useful freshwater biological model. Mussels were exposed for 6 days in static conditions to two different microplastic mixtures, composed by two types of virgin polystyrene microbeads (size = 1 and 10 μm) each one. The mixture at the lowest concentration contained 5 × 105 MP/L of 1 μm and 5 × 105 MP/L of 10 μm, while the higher one was arranged with 2 × 106 MP/L of 1 μm and 2 × 106 MP/L of 10 μm.Proteomics’ analyses of gills showed the complete lack of proteins’ modulation after the exposure to the low-concentrated mixture, while even 78 proteins were differentially modulated after the exposure to the high-concentrated one, suggesting the presence of an effect-threshold. The modulated proteins belong to 5 different classes mainly involved in the structure and function of ribosomes, energy metabolism, cellular trafficking, RNA-binding and cytoskeleton, all related to the response against the oxidative stress.

The influence of trophic status on the distribution of hydrophobic organic contaminants (HOCs) in different subtropical shallow waters at large spatial scales remains largely unknown. In this study, samples of surface sediments, water, total suspended particles, phytoplankton, and zooplankton were simultaneously collected from 83 sampling sites in 20 subtropical oligotrophic to hyper-eutrophic shallow lakes in China to investigate the influence of trophic status on the spatial distribution and sinking fluxes of 16 polycyclic aromatic hydrocarbons (PAHs). The total concentration of the 16 PAHs (ΣPAH₁₆) in the water columns of these lakes varied from 0.22 to 5.81 μg L⁻¹, and increased with the trophic state index (TSI) and phytoplankton biomass. Phytoplankton were the dominant reservoir for the PAHs in the water column. However, the fraction of ΣPAH₁₆ in phytoplankton decreased with the TSI. The average sinking flux of ΣPAH₁₆ of the individual lakes varied from 2257.1 to 261674.1 mg m⁻² d⁻¹, and increased with the TSI of the lakes. The concentration of ΣPAH₁₆ in the surface sediments ranged from 385.77 to 3784.37 ng gdw⁻¹, and increased with the TSI and the ratio of phycocyanin/sediment organic carbon. It suggested that cyanobacterial biomass affected by trophic status dominated the occurrence of the PAHs in the surface sediments of these lakes. Biomass dilution and the biological pump affected the accumulation of the PAHs in phytoplankton, and zooplankton, and had more influence on the PAHs with higher hydrophobicity. Both the bioconcentration factors and bioaccumulation factors of the PAHs decreased with the TSI. No biomagnification was observed for the PAHs from phytoplankton to zooplankton in these lakes in spring. Our study provided novel knowledge for the coupling between eutrophication and HOCs in 20 subtropical shallow lakes with different trophic status.

Aryl phosphorus-containing flame retardants (aryl-PFRs) have been frequently detected with increasingly used worldwide as one of alternatives for brominated flame retardants. However, information on their adverse effects on human health and ecosystem is insufficient, with limited study on their molecular mode of action in vitro. In this study, the cytotoxicity, DNA damage, mitochondrial impairment and the involved molecular mechanisms of certain frequently detectable aryl-PFRs, including 2-ethylhexyldiphenyl phosphate (EHDPP), methyl diphenyl phosphate (MDPP), bisphenol-A bis (diphenyl phosphate) (BDP), isodecyl diphenyl phosphate (IDPP), cresyl diphenyl phosphate (CDP) and the structurally similar and widely used organophosphorus pesticide chlorpyrifos (CPF), were evaluated in A549 cells using high-content screening (HCS) system. Aryl-PFRs showed different lethal concentration 50 (LC50) values ranging from 97.94 to 546.85 μM in A549 cells using CCK-8 assay. EHDPP, IDPP, CDP, MDPP and CPF demonstrated an ability to induce DNA damage, evidenced by increased DNA content and S phase-reducing cell cycle arrest effect using fluorophore dye cocktail assay. Additionally, the selected aryl-PFRs induced mitochondrial impairment by the increasing mitochondrial mass and decreasing mitochondrial membrane potential. Moreover, BDP, MDPP, and CDP, which contain short alkyl chains showed their potential oxidative stress with intracellular ROS and mitochondrial superoxide overproduction from an initially relatively low concentration. Additionally, based on the promotion of firefly luminescence in p53-transfected A549 cells, p53 activation was found to be involved in aryl-PFRs-induced DNA damage. Further real-time PCR results showed that all selected aryl-PFRs triggered p53/p21/gadd45β-, and p53/p21/mdm2-mediated cell cycle pathways, and the p53/bax mediated apoptosis pathway to induce DNA damage and cytotoxic effects. These results suggest that aryl-PFRs (e.g., BDP, MDPP, CDP) cause oxidative stress-mediated DNA damage and mitochondrial impairment, and p53-dependent pathway was involved in the aryl-PFRs-induced DNA damage and cell cycle arrest. In conclusion, this study improves the understanding of PFRs-induced adverse outcomes and the involved molecular mechanism.

The ubiquity of microplastics in the world's ocean has aroused great concern. However, the ecological effects of microplastics at environmentally realistic concentrations are unclear. Here we showed that exposure of marine medaka (Oryzias melastigma) to environmentally relevant concentrations of 10 μm polystyrene microplastics for 60 days not only led to microplastic accumulation in the gill, intestine, and liver, but also caused oxidative stress and histological changes. Moreover, 2, 20, and 200 μg/L microplastics delayed gonad maturation and decreased the fecundity of female fish. Alterations of the hypothalamus-pituitary-gonadal (HPG) axis were investigated to reveal the underlying mechanisms, and gene transcription analysis showed that microplastic exposure had significantly negative regulatory effects in female HPG axis. Transcription of genes involved in the steroidogenesis pathway in females were also downregulated. This disruption resulted in decreased concentrations of 17β-estradiol (E₂) and testosterone (T) in female plasma. Furthermore, parental exposure to 20 μg/L microplastics postponed the incubation time and decreased the hatching rate, heart rate, and body length of the offspring. Overall, the present study demonstrated for the first time that environmentally relevant concentrations of microplastics had adverse effects on the reproduction of marine medaka and might pose a potential threat to marine fish populations.

Decabromodiphenyl ethane (DBDPE) is an alternative to the commercial decabromodiphenyl ether (deca-BDE) mixture but has potentially similar persistence, bioaccumulation potential and toxicity. While it is widely used as a flame retardant in electrical and electronic equipment (EEE) in China, DBDPE could be distributed globally on a large scale with the international trade of EEE emanating from China. Here, we performed a dynamic substance flow analysis to estimate the time-dependent mass flows, stocks and emissions of DBDPE in China, and the global spread of DBDPE originating in China through the international trade of EEE and e-waste. Our analysis indicates that, between 2006 and 2016, ∼230 thousand tonnes (kt) of DBDPE were produced in China; production, use and disposal activities led to the release of 196 tonnes of DBDPE to the environment. By the end of 2016, ∼152 kt of the DBDPE produced resided in in-use products across China. During the period 2000–2016, ∼39 kt of DBDPE were exported from China in EEE products, most of which (>50%) ended up in North America. Based on projected trends of China's DBDPE production, use and EEE exports, we predict that, by 2026, ∼74 and ∼14 kt of DBDPE originating in China will reside in in-use and waste stocks, respectively, in regions other than mainland China, which will act as long-term emission sources of DBDPE worldwide. This study discusses the considerable impact of DBDPE originating in China and distributed globally through the international trade of EEE; this is projected to occur on a large scale in the near future, which necessitates countermeasures.

Crested ibis (Nipponia nippon), one of the rarest birds in the world, was almost extinct in the historically widespread areas partly due to the environmental pollution. Therefore, non-invasive indicators of feather, eggshell, and excrement were used to investigate the exposure of this endangered bird to eleven trace elements in this study. The results indicated that crested ibises under in situ and ex situ conservations were diversely exposed to trace elements, with higher exposure levels of As, Cd, and Mn in the wild, but higher exposure levels of Hg, Se, and Zn in the captive breeding center. In addition, concentrations of As, Co, Cr, and Ni were significantly greater in the sediments of three types of foraging habitats for wild crested ibis, but concentration of Se was greater in the soil of captive cages. Feather and eggshell of crested ibis exhibited a very consistent indication for most of the trace elements, and concentrations of almost all of the elements in the excrements were very consistent with the results in the environmental samples (sediments or soils). Concentrations of As, Hg, Mn, and Zn in feathers, and Mn and Zn in eggshells of wild and captive crested ibis were greater than those in other similar species. Moreover, As, Cd, Cu, and Mn concentrations in excrement of wild crested ibises were greater than that in captive individuals and other species, but Se and Zn concentrations in excrement of captive crested ibises were greater than that of the wild and other species. The present study provided evidence that both of the wild and captive crested ibis were exposed to trace elements, which may be harmful to their health.