In-pram babies are more susceptible to air pollution effects, yet studies assessing their exposure are limited. We measured size-resolved particle mass (PMC; 0.25–32 μm) and number (PNC; 0.2–1 μm) concentrations on a 2.7 km route. The instruments were placed inside a baby pram. The route passed through 4 traffic intersections (TIs) and a bus stand. A total of ∼87 km road length was covered through 64 trips, made during school drop-in (morning) and pick-up (afternoon) hours. The objectives were to assess PMC and PNC exposure to in-pram babies at different route segments, understand their physicochemical characteristics and exposure differences between in-pram babies and adults carrying them. Over 5-fold variability (14.1–78.2 μg m⁻³) was observed in PMCs. Small-sized particles, including ultrafine particles, were always higher by 66% (PM1), 29% (PM2.5) and 31% (PNC) during the morning than afternoon. Coarse particles (PM2.5-10) showed an opposite trend with 70% higher concentration during afternoon than morning. TIs emerged as pollution hotspots for all the particle types. For example, PM2.5, PM2.5-10 and PNCs during the morning (afternoon) at TIs were 7 (10)%, 19 (10)% and 68 (62)% higher, respectively, compared with the rest of the route. Bus stand was also a section of enhanced exposure to PNC and PM2.5, although not so much for PM2.5-10. EDX analyses revealed Cl, Na and Fe as dominant elements. Road salt might be a source of NaCl due to de-icing during the measurements while Fe contributed by non-exhaust emissions from brake abrasion. The respiratory deposition rates imitated the trend of PMC, with higher doses of coarse and fine particles during the afternoon and morning runs, respectively. Special protection measures during conveyance of in-pram babies, especially at pollution hotspots such as traffic intersections and bus stands, could help to limit their exposure.

As an emerging contaminant, 1-H-benzotriazole (1H-BTR) has been detected in the engineered and natural aquatic environments, which usually coexists with heavy metals and causes combined pollution. In the present study, wild-type and transgenic zebrafish Danio rerio were used to explore the acute toxicity as well as the single and joint hepatotoxicity of cadmium (Cd) and 1H-BTR. Although the acute toxicity of 1H-BTR to zebrafish was low, increased expression of liver-specific fatty acid binding protein was observed in transgenic zebrafish when the embryos were exposed to 5.0 μM of 1H-BTR for 30 days. Besides, co-exposure to 1H-BTR not only reduced the acute toxic effects induced by Cd, but also alleviated the Cd-induced liver atrophy in transgenic fish. Correspondingly, effects of combined exposure to 1H-BTR on the Cd-induced expressions of several signal pathway-related genes and superoxide dismutase and glutathione-s-transferase proteins were studied. Based on the determination of Cd bioaccumulation in fish and the complexing stability constant (β) of Cd-BTR complex in solution, the detoxification mechanism of co-existing 1H-BTR on Cd to the zebrafish was discussed.

Organochlorine pesticides (OCPs) can persistently accumulate in body and threaten human health. Bile acids and intestinal microbial metabolism have emerged as important signaling molecules in the host. However, knowledge on which intestinal microbiota and bile acids are modified by OCPs remains unclear. In this study, adult male C57BL/6 mice were exposed to p, p’-dichlorodiphenyldichloroethylene (p, p’-DDE) and β-hexachlorocyclohexane (β-HCH) for 8 weeks. The relative abundance and composition of various bacterial species were analyzed by 16S rRNA gene sequencing. Bile acid composition was analyzed by metabolomic analysis using UPLC-MS. The expression of genes involved in hepatic and enteric bile acids metabolism was measured by real-time PCR. Expression of genes in bile acids synthesis and transportation were measured in HepG2 cells incubated with p, p’-DDE and β-HCH. Our findings showed OCPs changed relative abundance and composition of intestinal microbiota, especially in enhanced Lactobacillus with bile salt hydrolase (BSH) activity. OCPs affected bile acid composition, enhanced hydrophobicity, decreased expression of genes on bile acid reabsorption in the terminal ileum and compensatory increased expression of genes on synthesis of bile acids in the liver. We demonstrated that chronic exposure of OCPs could impair intestinal microbiota; as a result, hepatic and enteric bile acid profiles and metabolism were influenced. The findings in this study draw our attention to the hazards of chronic OCPs exposure in modulating bile acid metabolism that might cause metabolic disorders and their potential to cause related diseases in human.

Previous studies worldwide have suggested the potential role of bioaerosols as ice-nuclei and cloud-condensation nuclei. Furthermore, their participation in regulating the global carbon cycle urges systematic studies from different environmental conditions throughout the globe. Towards this through one-year study, conducted from June 2015–May 2016, we report on atmospheric abundance and variability of viable bioaerosols, organic carbon (OC) and particles number and deduced mass concentrations from Indo-Gangetic Plain (IGP; at Kanpur). Among viable bioaerosols, the highest concentrations of Gram-positive bacteria (GPB), Gram-negative bacteria (GNB) and Fungi were recorded during December–January (Avg.: 189 CFU/m³), November (244 CFU/m³) and September months (188 CFU/m³), respectively. Annual average concentration of GPB, GNB and Fungi were 105 ± 58, 144 ± 82 and 116 ± 51 CFU/m³. Particle number concentration (PNC) associated with fine-fraction aerosols (FFA) predominates throughout the year. However, mineral dust (coarser particle) remains a perennial constituent of atmospheric aerosols over the IGP. Temporal variability records and significant positive linear relationship (p < 0.05) of GPB and GNB with OC and biomass burning derived potassium (K⁺BB) indicates their association with massive emissions from paddy-residue burning (PRB) and bio-fuel burning. Influence of meteorological parameters on viable bioaerosols abundance has been rigorously investigated herein. Accordingly, ambient temperature seems to be more affecting the bacteria (anti-correlation), whereas wet-precipitation (1–4 mm) relates to higher abundance of Fungi. High abundance of GNB during large-scale biomass burning emissions has implications to endotoxin exposure on human health. Field-based data-set of bioaerosols, OC, PNC and deduced mass concentrations reported herein could serve to better constraint their role in human health and climate relevance.

Quantum dots (QDs) have attracted broad attention due to their special optical properties and promising prospect in medical and biological applications. However, the process of QDs on cell membrane is worth further investigations because such process may lead to harmful effects on organisms and also important for QD application. In this study, adhesion of amino- and carboxyl-coated CdTe QDs (A-QDs and C-QDs) on cell membrane and the subsequent internalization are studied using a series of endocytosis-free model membranes, including giant and small unilamellar vesicles, supported lipid bilayers and giant plasma membrane vesicles (GPMVs). The adhered QD amounts on model membranes are quantified by a quartz crystal microbalance. The CdTe QD adhesion on model membranes is governed by electrostatic forces. Positively charged A-QDs adhere on GPMV surface and passively penetrate the plasma membrane via endocytosis-free mechanism, but negatively charged C-QDs cannot. Rat basophilic leukemia (RBL-2H3) cells are exposed to CdTe QDs to monitor the QD internalization process. Both A- and C-QDs are internalized by RBL-2H3 cells mainly via endocytosis. CdTe QDs do not accumulate on the plasma membrane of living cells due to the fast endocytosis and the weakened electrostatic attraction in biological medium, resulting in low chance of passive penetration. The suspended cells after trypsin digestion take more QDs than the adherent cells. A-QDs cause lower cell viability than C-QDs, probably because the approach of positively charged QDs to cells is favored and the smaller aggregates of A-QDs.

Intensive exploitation and transport of oil and derivatives are increasing the risk of coastal contamination by either dramatic disasters or diffuse sources. Tools for monitoring diffuse contamination, such as diesel oil that leaks from marine vessels are much needed. We experimentally tested the efficiency of antioxidant biomarkers as indicators of chronic exposure to diesel oil in a mudflat from the subtropical Bay of Paranaguá, in southern Brazil. We examined the effects of three successive diesel oil spills, with two weeks of recovery time between exposures, on the edible clam Anomalocardia flexuosa. Previous studies have highlighted its potential as a bioindicator species for diesel oil contamination in subtropical and tropical ecosystems. Endpoints measured in gill and digestive gland homogenates included the activity of antioxidant enzymes SOD, GPx, GST and levels of lipid peroxides. PAHs concentration in sediments and soft tissue were also quantified. GST and SOD were the most responsive biomarkers to the exposure. There were significant but non–cumulative departures from control levels in organisms from treated samples, which were, in all cases, more common 48 h after each experimental spill. Biomarker responses were more evident in the digestive gland than in gills. This work validated the short–term responsiveness of biomarkers as measures of repeated pulsed in situ exposure to low concentrations of diesel oil. For their routine implementation into monitoring programs for tropical estuaries our general recommendations are 1) to include several reference sites, 2) to analyze biomarker data using a logarithmic–scale and 3) to interpret deviations from “normal” activity as multiplicative interval differences.

Iron (Fe)-based solids can reduce arsenic (As) mobility and bioavailability in soils, which has been well recognized. However, to our knowledge, there are few studies on As uptake at different growth stages of rice under Fe compound amendments. In addition, the formation of Fe plaques at different growth stages of rice has also been rarely reported. Therefore, the present study was undertaken to investigate As mobility and bioavailability in paddy soil under Fe compound amendments throughout the whole growth stage of rice plants. Amendments of poorly crystalline Fe oxides (PC-Fe), FeCl2+NaNO3 and FeCl2 reduced grain As by 54% ± 3.0%, 52% ± 3.0% and 46% ± 17%, respectively, compared with that of the non-amended control. The filling stage was suggested to be the key stage to take measures to reduce As uptake. At this stage, all soil amendments significantly reduced As accumulation in rice plants. At the maturation stage, PC-Fe amendment significantly reduced mobile pools and increased immobile pools of soil As. Besides, PC-Fe treatment promoted the transformation of Fe fractions from dissolved Fe to adsorbed, poorly crystalline and free Fe oxides. Moreover, significant positive correlations between soil Fe fractions and As fractions were found. Accordingly, we hypothesized that Fe compound amendments might affect the concentration distribution of Fe fractions first and then affect As fractionation in soil and its bioavailability to rice plants indirectly. The formation of Fe plaques varied with growth stages and different treatments. Significantly negative correlations between mobile pools of As and Fe or As in Fe plaques indicated that Fe plaques could immobilize mobile As in soils and thus affect As bioavailability. Overall, the effect of the soil amendments on reduction of As uptake varied with growth stages and different treatments, and further research on the key stage for reducing As uptake is still required.

Increase in industrial growth, urban and agricultural pollution, with consequent impacts on aquatic ecosystems are a major focus of research worldwide. Still, not many studies assess the impacts of contamination through in situ studies, using native species, also considering the influence of seasonality on their responses. This study aimed to evaluate the water quality of the basin of the Upper Iguaçu River, the main source of water supply to Curitiba, a major capital of Southern Brazil, and its Metropolitan area. Several biomarkers were evaluated after in situ exposure of the native catfish Rhamdia quelen inside cages for 7 days. Ten study sites were chosen along the basin, based on a diffuse gradient of contamination, corresponding to regions upstream, downstream, and within “great Curitiba”. In each site, fish were exposed in Summer and Winter. The complex mixture of contaminants of this hydrographic basin generated mortality, and ion-, osmoregulatory and respiratory disturbances in the catfish as, for example, reduction of plasma osmolality and ionic concentrations, increased hematocrit levels and gill water content, altered branchial and renal activities of the enzyme carbonic anhydrase, as well as raised levels of plasma cortisol and glucose. Biomarkers were mostly altered in fish exposed in Great Curitiba and immediately downstream. There was a notable influence of season on the responses of the jundiá. A multivariate redundancy analysis revealed that the best environmental variables explained 30% of the variation in biomarkers after controlling for spatial autocorrelation. Thus, this approach and the chosen parameters can be satisfactorily used to evaluate contamination environments with complex mixtures of contaminants, in other urban basins as well.

The Qinling subspecies of giant panda (Ailuropoda melanoleuca qinlingensis), is highly endangered; fewer than 350 individuals still inhabit Qinling Mountains. Previous research revealed captive pandas were exposed to bromine, so we hypothesized that captive pandas were exposed to and affected by polybrominated diphenyl ethers (PBDEs). To test this hypothesis, we tested blood and feces of captive and wild pandas, their drinking water, food (bamboo leaves) from SWARC (Shaanxi Wild Animal Research Center)and FNNR (Foping National Nature Reserve) and supplemental feedstuff given to captive panda at SWARC. We found 13 congeners of PBDEs in fecal samples, of which BDE47, BDE66, BDE71, BDE99, and BDE154 were the dominant, total PBDE concentration in feces of captive pandas was 255% higher than in wild pandas. We found nine PBDEs congeners in blood samples: BDE153 and BDE183 were the predominant congers. PBDEs in blood from captive pandas were significantly higher than in wild pandas. The total concentration of PBDEs were 5473 and 4835 (pg.g) in Fargesia qinlingensis, were 2192 and 1414 (pg.g) in Bashannia fargesii (2192, 1414 pg g), 0.066, 0.038 (pg/ml) in drinking water, and 28.8 (pg.g) in supplemental feedstuff for captive and wild pandas, which indicate that the PBDEs came from its bamboo feed, especially from Bashannia fargesii. Our results demonstrate that BDE99 and BDE47 could be threatening the pandas’ health especially for captive panda and there are potential health risks from PBDEs for pandas. In the short term, this risk may be ameliorated by strict control of food quality. In the long term, however, reducing air, water and soil contamination so as to improve environmental quality can best reduce these risks to meet the international standard such as Stockholm Convention.