Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetically manufactured chemicals recognized to be toxic, bioaccumulative, and persistent. Previous studies on PFAS exposure and serum lipid levels have mainly focused on individual PFASs; however, the influence of multiple-PFAS exposure on the serum lipid profile remains unclear. This study was performed to evaluate the combined effects of multiple PFASs on serum lipid levels. Based on the National Health and Nutrition Examination Survey (NHANES) data (2011–2014), we first established a linear regression model to estimate the association between single-PFAS exposure and the serum lipid profile. Then, a weighted quantile sum (WQS) regression model and a Bayesian kernel machine regression (BKMR) model were used to evaluate the effects of multiple-PFAS exposure on the serum lipid profile. A mediating effect model was used to assess how albumin mediates these effects. We found that PFASs were significantly associated with the levels of serum lipids, including high-density lipoprotein (HDL), low-density lipoprotein (LDL) and total cholesterol (TC). The WQS index was significantly correlated with the levels of HDL (β: 2.03, 95% CI: 0.74–3.32, P-value = 0.002), LDL (β: 4.16, 95% CI: 1.07–7.24, P-value = 0.008) and TC (β: 6.54, 95% CI: 3.00–10.1, P-value < 0.001). In the BKMR analysis, our results demonstrated that the effect of PFASs on serum lipids increased significantly when the concentrations of the PFASs were at their 60th percentiles or above compared to those at their 50th percentile. Mediation analysis showed that albumin mediated the effects of selected PFASs on the levels of serum lipids except for triglycerides (TG). PFAS exposure was correlated with the levels of serum lipids, and this correlation was mediated by albumin. Our results suggest that a comprehensive evaluation of multi-PFAS exposure could better characterize real-life exposure compared with single-PFAS exposure.

Cell wall acts as a major metal sink in plant roots, while a few studies focused on root cell wall binding in plants for the phytostabilization of multi-metal contaminated soils. A pot experiment was performed to characterize root cell wall properties of the mining ecotype (ME) and non-mining ecotype (NME) of Athyrium wardii (Hook.) in response to Cd and Pb. The cell wall was found to be the major sink for Cd (41.3–54.3%) and Pb (71.4–73.8%) accumulation in roots of the ME when exposed to Cd and/or Pb. The ME showed more Cd and Pb accumulation in root cell walls when exposed to Cd and Pb simultaneously, compared with those exposed to single Cd or Pb as well as the NME, suggesting some modifications for cell walls. The uronic acid contents of pectin and hemicellulose 1 (HC1) in root cell walls of the ME increased significantly when exposed to Cd and Pb simultaneously, suggesting enhanced cell wall binding capacity, thus resulting in more Cd and Pb bound to pectin and HC1. In particular, pectin was found to be the predominant binding site for Cd and Pb. Greater pectin methylesterase activity along with a lower degree of methylesterification were observed in the cell walls of the ME when exposed to Cd and Pb simultaneously. Furthermore, the ME present more O–H, N–H, C–OH, C–O–C, C–C and/or Ar–H in root cell walls when exposed to Cd and Pb simultaneously. These changes of root cell wall properties of the ME lead to enhanced cell wall binding ability in response to the co-contamination of Cd and Pb, thus could be considered a key process for enhanced Cd and Pb accumulation in roots of the ME when exposed to Cd and Pb simultaneously.

Microplastics in commercially important seafood species is an emerging area of food safety concern. While there have been reports of plastic particles in the gastrointestinal tract of several species, presence of microplastics in edible fish tissues has not yet been reported from India. This study examined the presence of microplastics in the edible (muscle and skin) and inedible (gill and viscera) tissues of nine commercially important pelagic fish species from Kerala, India. A total of 163 particles consisting mainly of fragments (58%) were isolated. Out of 270 fishes analysed (n = 30 per species), 41.1% of the fishes had microplastics in their inedible tissues while only 7% of fishes had microplastics in their edible tissues. The quantity of microplastics in inedible tissue was significantly larger in filter feeders than, that in visual predators (p < 0.05). The average abundance of microplastics in edible tissues was 0.07 ± 0.26 items/fish (i.e., 0.005 ± 0.02 items/g) and was 0.53 ± 0.77 items/fish (i.e., 0.054 ± 0.098 items/g) in inedible tissues. The results suggest the possibility of human intake of microplastics by the consumption of pelagic fishes from this region, albeit in small quantities.

Nightjars are considered human-tolerant species due to the population densities reached in strongly managed landscapes. However, no studies have been done evaluating metal-related effects on physiology, condition or fitness in any nightjar species. The main aim of this study was to evaluate how metal exposure affects physiology and condition in red-necked nightjar (Caprimulgus ruficollis) populations inhabiting three different environments in southeastern Spain: agricultural-urban area (n = 15 individuals), mining area (n = 17) and control area (n = 16).Increased plasma mineral levels (magnesium and calcium) and alkaline phosphatase (ALP) activity were observed in breeding females, and ALP was significantly higher in young birds due to bone growth and development. In the mining-impacted environment, nightjars showed decreased retinol (17.3 and 23.6 μM in the mining area and control area), uric acid (28.8 and 48.6 mg/dl in the mining area and control area) and albumin (16.2 and 19.6 g/l in the mining area and control area), probably impaired by a combination of toxic metal exposure and low prey quantity/quality in that area. Moreover, they showed increased plasma tocopherol levels (53.4 and 38.6 μM in the mining area and control area) which may be a response to cope with metal-induced oxidative stress and lipid peroxidation. Blood concentrations of toxic metals (As, Pb, Cd and Hg) were negatively associated with calcium, phosphorus, magnesium, ALP, total proteins and body condition index. This could lead to metal-related disorders in mineral metabolism and ALP activity that may potentially increase the risk of skeletal pathologies and consequent risk of fractures in the long term, compromising the survival of individuals. Further studies need to be carried out to evaluate potential metal-related effects on the antioxidant status and bone mineralization of nightjars inhabiting mining environments.

Surface waters are becoming increasingly contaminated by pharmaceutically active compounds (PhACs), which is a potential risk factor for drinking water quality owing to incomplete riverbank filtration. This study examined the efficiency of riverbank filtration with regard to 111 PhACs in a highly urbanized section of the river Danube. One hundred seven samples from the Danube were compared to 90 water samples from relevant drinking water abstraction wells (DWAW) during five sampling periods. The presence of 52 PhACs was detected in the Danube, the quantification of 19 agents in this section of the river was without any precedent, and 10 PhACs were present in >80% of the samples. The most frequent PhACs showed higher concentrations in winter than in summer. In the DWAWs, 32 PhACs were quantified. For the majority of PhACs, the bank filtration efficiency was >95%, and not influenced by concentrations measured in the river. For carbamazepine lidocaine, tramadol, and lamotrigine, low (<50%) filtration efficiency was observed; however, no correlations were observed between the concentrations detected in the Danube and in the wells. These frequently occurring PhACs in surface waters have a relatively even distribution, and their sporadic appearance in wells is a function of both space and time, which may be caused by the constantly changing environment and micro-biological parameters, the dynamic operating schedule of abstraction wells, and the resulting sudden changes in flow rates. Due to the changes in the efficiency of riverbank filtration in space and time, predicting the occurrence and concentrations of these four PhACs poses a further challenge to ensuring a safe drinking water supply.

The choice of sediment quality assessment methodologies can strongly influence assessment outcomes and management decisions for contaminated sites. While in situ (field) methods may potentially provide greater realism, high costs and/or complex logistics often prevent their use and assessment must rely on laboratory-based methods. In this study, we utilised static-renewal and flow-through ecotoxicology tests in parallel on sediments with a wide range of properties and varying types and concentrations of contaminants. The prediction of chronic effects to amphipod reproduction was explored using multiple linear regression (MLR). The study confirmed the considerable over-estimation of the risk of toxicity of contaminated sediments in field locations when assessments rely on the results of laboratory-based static and static-renewal tests. Improved prediction of toxicity risks was achieved using a combination of contaminant exposure measures from sediment and overlying water. Existing sediment and water quality guideline values (GVs) were effective for predicting risks posed by sediments containing mixtures of common metal and organic contaminants. For 17 sediments with paired data sets from static-renewal and flow-through tests, the best prediction of toxicity to reproduction was achieved using a 2-parameter MLR that included hazard quotients for sediment contaminants and toxic units for dissolved metals (r² = 0.892). The inclusion of particle size, organic carbon and acid-volatile sulfide did not improve toxicity predictions, despite these parameters being recognised as modifying contaminant bioavailability. The use of dilute-acid-extractable metal concentrations in place total recoverable metal concentrations did not improve the predictions. The study also confirmed that sediments existing within the estuarine and marine bays of Sydney Harbour pose significant risks of adverse effects to benthic organisms.

Rapid economic growth, urban sprawl, and unplanned industrialization has increased socioeconomic statuses but also decreased air quality in South Asian developing countries. Therefore, severe increase in air pollution has been a threat of local population, regarding health statuses, livability and quality of life. It is necessary to estimate fine-scale spatiotemporal distribution of ambient PM₂.₅ in a national context so that the environmental planners and government officials can use it for environmental protocol development and policy-making. In this study, a spatiotemporal land use regression (LUR) model is developed to refine global air quality data to the national-scale ambient PM₂.₅ exposure in a high-density country in South Asia – Pakistan. Combining with transport network, patterns of land use, local meteorological conditions, geographic characteristics, landscape characteristics, and satellite-derived data, our resultant model explains 54.5% of the variation in ambient PM₂.₅ concentration level. Furthermore, tree coverage and road transport are identified to be two influential factors of the national-scale spatial variation of PM₂.₅ in Pakistan, which implied that urbanization might be the major cause of air pollution across the country. In conclusion, our resultant LUR model as well as the spatial map of ambient PM₂.₅ concentration level can be used as a supporting tool for national health risk management and environmental planning, and could also contribute to the air quality management and pollution reduction actions of Pakistan.

This study evaluates the effects of biological factors of fish and seasonality on Polycyclic Aromatic Hydrocarbon (PAH) accumulation in red mullet (Mullus barbatus) tissue. Specimens were collected monthly with a bottom trawl net in an offshore fishing ground in the Northern and Central Adriatic Sea (Geographical Sub Area 17) throughout 2016.The edible fillets of 380 individuals were analyzed for the concentrations of individual PAH, total PAH, and low, medium and high molecular weight (MW) PAHs. PAH bioaccumulation was related to their physicochemical characteristics (MW, and logarithm of the octanol-water partition coefficient, log Kₒw), some biological parameters of fish (body size, age, sex, reproductive stage and total lipid content), and catch season.The PAH bioaccumulation pattern and the effects of the different factors varied according to PAH MW. The heavier (medium and high MW) PAHs showed higher levels in winter-autumn and in pre-spawners compared with spawners and post-spawners. Our findings suggest that an important detoxification mechanism, albeit limited to the heavier PAHs, acts in the spawning and post-spawning stage. Low MW PAHs appeared to be unaffected by reproductive stage, lipid content and seasonality. Reproductive stage and seasonality seem to play an important role in the accumulation of heavier PAH, whereas total lipid content and age seem to exert a limited influence, and body size no effect at all.

Soil contamination by toxic heavy metals such as copper is a serious problem. In this study, the extracellular polymeric substance (EPS) extracted from Rahnella sp. LRP3 was found with the potential of immobilizing Cu-polluted in soil. The EPS could bond to Cu (II) through functional groups (polysaccharides, amide, proteins, and carboxyl groups), which further developed into the porous sphere with a diameter of 20 μm. Besides, EPS could induce the formation of Cu₅(PO₄)₂(OH)₄ crystal by the biomineralization process. Finally, the EPS in the culture solution reduced 89.4 mg/kg of DTPA-Cu content by 78.99% in soil for 10 d under the condition of 25 °C via biomineralization. The results demonstrated that EPS produced by Rahnella sp. LRP3 will be a promising factor in the remediation of Cu contaminated soil.

Edible cod liver products including cod liver oil and canned cod liver, sampled over the last five decades from the North Atlantic region, including the Baltic Sea were analysed for a set of persistent and toxicologically significant polychlorinated naphthalene (PCN) congeners with some of the highest relative potencies (dioxin-like toxicity) among PCNs. The targeted congeners showed a near-universality of occurrence in all samples apart from the most recent sample of cod liver oil which was assumed to be highly purified, as cod livers from the same period and location showed appreciable amounts of PCNs. The majority of dominant congeners in legacy technical PCN mixtures were absent or occurred in low concentrations, raising the possibility that congeners arising from combustion related sources may be acquiring a greater significance following the decline and elimination of PCN production. The apparent appreciation in the relative amounts of PCN#70 in the last three to four decades may provide support for this view. The PCN contribution to dioxin-like toxic equivalence (TEQ) that was estimated for these samples (range 1.2–15.9 pg TEQ g⁻¹) was significant in comparison to the EU regulated value of 1.75 pg TEQ g⁻¹ for dioxins in fish oils. Most of the TEQ was associated with PCNs 66/67, 64/68, 69 and 73. Although metabolic processes are likely to influence this distribution, the profile is a little different to that observed in the tissues of higher order animals where PCNs #66/67 and #73 may contribute approximately 90% to the summed TEQ.