Salinity influences glutathione S-transferase activity and lipid peroxidation responses in the Crassostrea gigas oyster exposed to diesel oil

Biochemical responses in bivalve mollusks are commonly employed in environmental studies as biomarkers of aquatic contamination. The present study evaluated the possible influence of salinity (35, 25, 15 and 9 ppt) in the biomarker responses of Crassostrea gigas oysters exposed to diesel at different nominal concentrations (0.01, 0.1 and 1 mL.L^− 1) using a semi-static exposure system. Salinity alone did not resulted in major changes in the gill's catalase activity (CAT), glutathione S-transferase activity (GST) and lipid peroxidation levels (measured as malondialdehyde, MDA), but influenced diesel related responses. At 25 ppt salinity, but not at the other salinity levels, oysters exposed to diesel showed a strikingly positive concentration-dependent GST response. At 25 ppt and 1 mL.L^− 1 diesel, the GST activity in the gills remained elevated, even after one week of depuration in clean water. The increased MDA levels in the oysters exposed to diesel comparing to control groups at 9, 15 and 35 ppt salinities suggest the occurrence of lipid peroxidation in those salinities, but not at 25 ppt salinity. The MDA quickly returned to basal levels after 24 h of depuration. CAT activity was unaltered by the treatments employed. High toxicity for 1 mL.L^− 1 diesel was observed only at 35 ppt salinity, but not in the other salinities. Results from this study strongly suggest that salinity influences the diesel related biomarker responses and toxicity in C. gigas, and that some of those responses remain altered even after depuration.     

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on early life stages of the pike (Esox lucius L.)

Freshly fertilized pike eggs were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at concentrations of 0.1, 1.0 and 10 ppt (ng/liter) for 96 hours. At all concentrations examined egg development was retarded by 23%, and the growth of fry was also significantly retarded for a long period after exposure. A dose-related mortality was observed. Highest mortality rates occurred during resorption of the yolk and reached almost 100 percent at a concentration of 10 ppt. Death was preceded by development of severe generalized edemas.Histopathologically edemas and hemorrhages were observed, together with alterations of bloodvessel walls. In the liver, two stages of pathological changes were distinguished. The first was characterized by a dilation of sinusoids and a slight swelling of hepatocyte nuclei; in the second stage the nuclei were enlarged up to twice the normal diameter. Hepatocytes were degenerated and varied in size and shape and liver architecture was a almost completely lost.     

Impact of sonication at 20 kHz on Microcystis aeruginosa, Anabaena circinalis and Chlorella sp

Blooms of toxic cyanobacteria such as Microcystis aeruginosa periodically occur within wastewater treatment lagoons in the warmer months, and may consequently cause contamination of downstream water and outages of the supply of recycled wastewater. Lab-scale sonication (20 kHz) was conducted on suspensions of M. aeruginosa isolated from a wastewater treatment lagoon, and two other algal strains, Anabaena circinalis and Chlorella sp., to investigate cell reduction, growth inhibition, release of microcystin and sonication efficiency in controlling the growth of the M. aeruginosa. For M. aeruginosa, for all sonication intensities and exposure times trialled, sonication led to an immediate reduction in the population, the highest reduction rate occurring within the initial 5 min. Sonication for 5 min at 0.32 W/mL, or for a longer exposure time (>10 min) at a lower power intensity (0.043 W/mL), led to an immediate increase in microcystin level in the treated suspensions. However, prolonged exposure (>10 min) to sonication at higher power intensities reduced the microcystin concentration significantly. Under the same sonication conditions, the order of decreasing growth inhibition of the three algal species was: A. circinalis > M. aeruginosa > Chlorella sp., demonstrating sonication has the potential to selectively remove/deactivate harmful cyanobacteria from the algal communities in wastewater treatment lagoons.     

Effect of chromium on the level of IL-12 and IFN-gamma in occupationally exposed workers

Chromium may affect humoral and cellular immunity, acting on T lymphocytes as well as on granulocytes and monocytes cells. Cytokines play an important role in the immune balance. In this study, the level of IL-12 and IFN-γ were evaluated in the sera and PHA/LPS stimulated culture supernatant of human PBMCs of healthy volunteers and occupationally exposed chromium workers. All the workers were highly exposed to chromium having mean of 104.65 ± 77.21 µg/dL (range 23.7-316.8 µg/dL). A suspension of exposed and unexposed human PBMC (0.5 × 10⁶ cells/ml) prepared and cultured in RPMI-1640 supplemented with 10% FCS for 18 h in the presence or absence of LPS (10 ng/ml) which used for stimulation of IL-12 and IFN-γ. The level of IL-12 and IFN-γ were evaluated in the sera samples as well as LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers. In these chromium exposed workers the level of IL-12 was 433.66 ± 197.49 pg/ml and 983.45 ± 330.99 pg/ml in LPS stimulated culture supernatant of normal individuals and highly chromium exposed workers, which was significant (P < 0.05). Although the level of IL-12 was (78.61 ± 61.03 pg/ml to 146.52 ± 46.37 pg/ml) elevated in unstimulated culture supernatant of h-PBMCs of chromium exposed individuals as compared to control, but it was not significant. This observation also suggests that a significant increase in IFN-γ production in LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers as compared to control. However, IFN-γ level have a significant positive correlation between blood chromium level (r = 0.833, t = 6.3872, P 0.05) and exposure time (in years) (r = 0.8916, t = 8.3540, P 0.05) of the occupationally exposed workers.     

Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand

Coral sand is one kind of the important building materials in coral reef engineering practice. The use of cement as a stabilizing agent can significantly improve the mechanical properties of coral sands and is widely applied in the subbase engineering construction in coral reef islands. Cement-stabilized coral sand structures may contain high contents of fine coral particles and salinity because of the high crushability of coral sands and the existence of seawater surrounding them. In this study, the effects of coral sand powders and seawater salinity on the dynamic mechanical properties of cemented coral sand (CCS) were investigated through the split Hopkinson pressure bar (SHPB) tests and Scanning Electron Microscope (SEM) analysis. It was found that the strength (i.e., the peak stress) of CCS specimens increased firstly and then decreased with the increase of powder content. The specimens reached the maximum peak stress when 3% powder content was included. The initial improvement of CCS strength was attributed to the pore-filling effect of coral powders, namely, the micro pores of the CCS specimens could be more effectively filled with higher percentages of coral powders being used in the experiments. However, excessive coral powders resulted in the reduction of specimen strength because these powders could easily be cemented into agglomerates by absorbing water from the specimens. These agglomerates could reduce the cementation strength between the coarse coral particles and the cement. Meanwhile, the peak stress of CCS specimens was found to be negatively correlated with the average strain rate and the ultimate strain. The degree of specimen fracture was found to be correlated with the amount of specific energy absorption during the tests. Furthermore, the “sulfate attack” caused by the inclusion of salinity of water had different influences on the CCS specimens with different coral powder contents. The ettringite and gypsum produced in “sulfate attack” could fill the pores and lead to cracking of the specimens, significantly affecting the specimen strength.     

Influence of temperature and salinity on Ostreopsis cf. ovata growth and evaluation of toxin content through HR LC-MS and biological assays

In the Mediterranean Sea, blooms of Ostreopsis cf. ovata and Ostreopsis siamensis have become increasingly frequent in the last decade and O. cf. ovata was found to produce palytoxin-like compounds (putative palytoxin, ovatoxin-a, -b, -c, -d and -e), a class of highly potent toxins. The environmental conditions seem to play a key role in influencing the abundance of Ostreopsis spp. High cell densities are generally recorded in concomitance with relatively high temperature and salinity and low hydrodynamics conditions. In this study the effects of temperature and salinity on the growth and toxicity of an Adriatic O. cf. ovata isolate were investigated. The highest growth rates of the Adriatic strain were recorded for cultures grown at 20 °C and at salinity values of 36 and 40, in accordance with natural bloom surveys. Toxicity was affected by growth conditions, with the highest toxin content on a per cell basis being measured at 25 °C and salinity 32.However, the highest total toxin content on a per litre basis was recorded at 20 °C and salinity 36, since under such conditions the growth yield was the highest.O. cf. ovata had lethal effects on Artemia nauplii and juvenile sea basses, and produced haemolysis of sheep erythrocytes. A comparison between haemolysis neutralization assay and HR LC-MS results showed a good correlation between haemolytic effect and total toxin content measured through HR LC-MS. Considering the increasing need for rapid and sensitive methods to detect palytoxin in natural samples, the haemolytic assay appears a useful method for preliminary quantification of the whole of palytoxin-like compounds in algal extracts.     

Effect of pre- and post-UV disinfection conditions on photoreactivation of fecal coliforms in wastewater effluents

Photoreactivation of microorganisms following UV disinfection can represent a disadvantage to using UV technology for wastewater treatment since recovery may, in some cases, reach several logs. Thus, decreasing photoreactivation can lead to considerable savings in capital and operating costs. Objectives of this study were to determine pre- and post-UV irradiation conditions which could decrease fecal coliform (FC) photoreactivation in wastewater effluents. Results indicated that delaying exposure to photoreactivating light for 3 h suppressed photoreactivation after relatively low UV doses of 10 and 20 mJ/cm². Moreover, at least 440 lux (0.065 mW/cm²) of visible light was needed to initiate photoreactivation. Additionally, photoreactivation decreased significantly when samples were exposed to visible light simultaneously or prior to UV irradiation. This was more significantly observed for winter samples, where photoreactivation decreased by nearly 50%. Finally, summer FC populations were more sensitive to inactivation and less able to photoreactivate than winter populations. The effect of visible light on photoreactivation levels may be explained by several photo-mechanisms of FC photolyase, such as photodecomposition of the MTHF co-factor and reduction of FAD.     

Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 ± 4 cm and weight of 86 ± 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl₂.H₂O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl₂.H₂O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.     

Bioaugmentation for improved recovery of anaerobic digesters after toxicant exposure

Bioaugmentation was investigated as a method to decrease the recovery period of anaerobic digesters exposed to a transient toxic event. Two sets of laboratory-scale digesters (SRT = 10 days, OLR = 2 g COD/L-day), started with inoculum from a digester stabilizing synthetic municipal wastewater solids (MW) and synthetic industrial wastewater (WW), respectively, were transiently exposed to the model toxicant, oxygen. Bioaugmented digesters received 1.2 g VSS/L-day of an H₂-utilizing culture for which the archaeal community was analyzed. Soon after oxygen exposure, the bioaugmented digesters produced 25-60% more methane than non-bioaugmented controls (p < 0.05). One set of digesters produced lingering high propionate concentrations, and bioaugmentation resulted in significantly shorter recovery periods. The second set of digesters did not display lingering propionate, and bioaugmented digesters recovered at the same time as non-bioaugmented controls. The difference in the effect of bioaugmentation on recovery may be due to differences between microbial communities of the digester inocula originally employed. In conclusion, bioaugmentation with an H₂-utilizing culture is a potential tool to decrease the recovery period, decrease propionate concentration, and increase biogas production of some anaerobic digesters after a toxic event. Digesters already containing rapidly adaptable microbial communities may not benefit from bioaugmentation, whereas other digesters with poorly adaptable microbial communities may benefit greatly.     

Assessing the effects of sodium hypochlorite exposure on the characteristics of PVDF based membranes

Sodium hypochlorite is commonly used as a cleaning agent to remove adsorbed foulants from PVDF based micro/ultra filtration membranes in water and wastewater treatment applications. Although effective for fouling control, extended sodium hypochlorite exposure can affect the physical/chemical characteristics and hinder the treatment performance of these membranes. To assess these effects, PVDF based membranes were exposed to sodium hypochlorite at different concentrations for varying periods of time, and the physical/chemical characteristics of the virgin and sodium hypochlorite exposed membranes were compared. The membranes were characterized based on chemical composition (FTIR and NMR), mechanical strength (yield strength), surface hydrophilicity (contact angle), pore size and porosity (scanning electron microscopy and challenge test), and membrane resistance (clean water permeation test). The results indicated that exposure dose and concentration of the sodium hypochlorite used have significant influence on the membrane characteristics. The impact of sodium hypochlorite exposure on the parameters investigated could be most accurately and consistently correlated to an exposure dose relationship of the form Cⁿt (where, C = concentration and t = exposure time) rather than the Ct relationship commonly used to define the extent of exposure to cleaning agents. For all the parameters investigated, the power coefficient n was less than 1 indicating that time had a greater impact on the changes than did the concentration of the sodium hypochlorite. The results suggest that the use of sodium hypochlorite for chemical cleaning, at concentrations that are higher than those typically used for chemical cleaning would have less of an effect on the characteristics of the membrane materials. Changes in the characteristics were attributed to the oxidation of the hydrophilic additives (HA) present in blended PVDF membranes.     

Dermal uptake of nicotine from air and clothing: Experimental verification

This study aims to elucidate in greater detail the dermal uptake of nicotine from air or from nicotine‐exposed clothes, which was demonstrated recently in a preliminary study. Six non‐smoking participants were exposed to gaseous nicotine (between 236 and 304 μg/m³) over 5 hours while breathing clean air through a hood. Four of the participants wore only shorts and 2 wore a set of clean clothes. One week later, 2 of the bare‐skinned participants were again exposed in the chamber, but they showered immediately after exposure instead of the following morning. The 2 participants who wore clean clothes on week 1 were now exposed wearing a set of clothes that had been exposed to nicotine. All urine was collected for 84 hours after exposure and analyzed for nicotine and its metabolites, cotinine and 3OH‐cotinine. All participants except those wearing fresh clothes excreted substantial amounts of biomarkers, comparable to levels expected from inhalation intake. Uptake for 1 participant wearing exposed clothes exceeded estimated intake via inhalation by >50%. Biomarker excretion continued during the entire urine collection period, indicating that nicotine accumulates in the skin and is released over several days. Absorbed nicotine was significantly lower after showering in 1 subject but not the other. Differences in the normalized uptakes and in the excretion patterns were observed among the participants. The observed cotinine half‐lives suggest that non‐smokers exposed to airborne nicotine may receive a substantial fraction through the dermal pathway. Washing skin and clothes exposed to nicotine may meaningfully decrease exposure.     

Effects of exposure to oil sands process-affected water from experimental reclamation ponds on Chironomus dilutus

Effective detoxification of oil sands process-affected water (OSPW) is one issue associated with bitumen extraction in the Alberta oil sands. It has been suggested that reclamation ponds can be used to passively treat OSPW, potentially allowing for its safe return to the environment. In this study, OSPW was sampled in two batches (A and B) from the Syncrude Canada Ltd. West In-Pit (WIP) settling pond and from three experimental reclamation ponds - Big Pit, FE5, and TPW. Acute (10 d) and chronic (until adult emergence) exposures of Chironomus dilutus larvae to OSPW were conducted and survival, growth, development, and behavior were assessed. Masses of larvae exposed to WIP-OSPW were 64-77% less than the freshwater control (p < 0.001). Similarly, chronic exposure to WIP-OSPW resulted in significantly (p < 0.05) less pupation than in the freshwater control, with 31% (A) and 71% (B) less pupation of larvae exposed to WIP-OSPW. Rates of emergence were significantly less for larvae exposed to WIP-OSPW, with only 13% (A) and 8% (B) of larvae emerging as adults when exposed to WIP-OSPW, compared to 81% in the freshwater control (p < 0.0001). Pupation and emergence rates were significantly less in TPW than freshwater control (p < 0.05), but there were no differences observed in Big Pit or FE5. Lesser toxicity was observed in reclaimed OSPW compared to fresh OSPW and this coincided with lesser concentrations of NAs. The results presented are consistent with the hypothesis that an organic fraction is the cause of the toxicity of OSPW toward C. dilutus and that OSPW aged in reclamation ponds retains toxicity and therefore, more aggressive, targeted treatment of OSPW is required to accelerate decreases.     

Environmental perceptions,mental performance,and physiological responses of people with respiratory allergies exposed to reduced Indoor Air Quality

To investigate the need of allergic population for indoor environment quality, exposure effects of poor air quality on subjects with respiratory allergies were compared with those on healthy people, including perceptual responses, health symptoms, mental performance, and physiological responses. The experimental intervention was with and without ventilation at thermally neutral rooms, creating two exposure conditions indicated by CO₂ concentration ranges of 502 to 3297 ppm (2438 ± 1527 ppm) and 517 to 5687 ppm (3615 ± 1527 ppm). 63 subjects (32 allergic subjects and 31 non-allergic subjects) were exposed to both conditions for 3 hours. The main results suggested that, compared with healthy people, people with respiratory allergy seem to be more sensitive or less acceptable to reduced air quality polluted by occupants during instantaneous exposure. Besides, the allergic group performed worse in cognitive tests than non-allergic group. After 3 hours of continuous exposure, people with respiratory allergy reported stronger intensity of respiratory irritations and seemed to suffer more inflammation indicated by a higher level of interleukin 1L-1β.     

CFD study of exhaled droplet transmission between occupants under different ventilation strategies in a typical office room

This paper investigated the transmission of respiratory droplets between two seated occupants equipped with one type of personalized ventilation (PV) device using round movable panel (RMP) in an office room. The office was ventilated by three different total volume (TV) ventilation strategies, i.e. mixing ventilation (MV), displacement ventilation (DV), and under-floor air distribution (UFAD) system respectively as background ventilation methods. Concentrations of particles with aerodynamic diameters of 0.8 μm, 5 μm, and 16 μm as well as tracer gas were numerically studied in the Eulerian frame. Two indexes, i.e. intake fraction (IF) and concentration uniformity index R_C were introduced to evaluate the performance of ventilation systems. It was found that without PV, DV performed best concern protecting the exposed manikin from the pollutants exhaled by the polluting manikin. In MV when the exposed manikin opened RMP the inhaled air quality could always be improved. In DV and UFAD application of RMP might sometimes, depending on the personalized airflow rate, increase the exposure of the others to the exhaled droplets of tracer gas, 0.8 μm particles, and 5 μm particles from the infected occupants. Application of PV could reduce R_C for all the three TV systems of 0.8 μm and 5 μm particles. PV enhanced mixing degree of particles under DV and UFAD based conditions much stronger than under MV based ones. PV could increase the average concentration in the occupied zone of the exposed manikin as well as provide clean personalized airflow. Whether inhaled air quality could be improved depended on the balance of pros and cons of PV.     

Modeling the effects of sodium chloride on degradation of chloramphenicol in aquaculture pond sediment

Sodium chloride was added to aquaculture pond sediment to determine effects of different salinities on degradation of chloramphenicol (CM). In this experiment, freshwater (0 ppt salinity) eel pond sediment slurries (10% w/v) were amended with sodium chloride to obtain salinities of 12, 24 and 36 ppt. There were no significant differences in sorption rate either between aerobic and anaerobic conditions or among various salinities. Degradation of CM fitted well to the decaying exponential curve. The degradation rates under anaerobic conditions were significantly greater than those under aerobic conditions. As salinity increased, the degradation rates decreased under both aerobic and anaerobic conditions. The differences in degradation rates either between aerobic and anaerobic conditions or among various salinities were attributed to the effects of microbial activities under different environments.     

Measurements of dermal uptake of nicotine directly from air and clothing

In this preliminary study, we have investigated whether dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smoke (ETS), generated by mechanically “smoking” cigarettes, for three hours in a chamber while breathing clean air from head‐enveloping hoods. The average nicotine concentration (420 μg/m³) was comparable to the highest levels reported for smoking sections of pubs. Urine samples were collected immediately before exposure and 60 hour post‐exposure for bare‐skinned participants. For the clothed participant, post‐exposure urine samples were collected for 24 hour. This participant then entered the chamber for another three‐hour exposure wearing a hood and clothes, including a shirt that had been exposed for five days to elevated nicotine levels. The urine samples were analyzed for nicotine and two metabolites—cotinine and 3OH‐cotinine. Peak urinary cotinine and 3OH‐cotinine concentrations for the bare‐skinned participants were comparable to levels measured among non‐smokers in hospitality environments before smoking bans. The amount of dermally absorbed nicotine for each bare‐skinned participant was conservatively estimated at 570 μg, but may have been larger. For the participant wearing clean clothes, uptake was ~20 μg, and while wearing a shirt previously exposed to nicotine, uptake was ~80 μg. This study demonstrates meaningful dermal uptake of nicotine directly from air or from nicotine‐exposed clothes. The findings are especially relevant for children in homes with smoking or vaping.     

Estimate of treatment plant effluent impact on chloride concentrations and oyster environment within the murderkill river estuary

The Murderkill River is a partially tidal body of water with summer-time 50-percentile freshwater flows ranging from 17.9 to 27.6ft³s⁻¹ (0.5 to 0.77m³s⁻¹) at a point coincident with the effluent discharge from the Kent County Regional Wastewater Treatment Plant (start-up late 1972). Chloride concentrations were determined over six summers to characterize river conditions prior to start-up of the 10-million gal day⁻¹ (37.850 m³ day⁻¹) (design) plant. Use of a one-dimensional steadystate model for a conservative substance shows that chloride values would be reduced by up to 20% at low water slack (LWS) periods for wastewater flows of 10 million gal day⁻¹ (37,850 m³ day⁻¹). The LWS chloride concentrations in the area of oyster production would be reduced to 3–6 ppt (5.9–10.8 ppt salinity) for wastewater loadings greater than 10 million gal day⁻¹ (37,850 m³ day⁻¹) . It is suggested that chloride additions in the treatment plant effluent be implemented to maintain minimum summertime low-water-slack levels of 5.6 ppt chloride (10 ppt salinity), consistent with a proper environment for oyster development.     

Organ specific antioxidant responses in golden grey mullet (Liza aurata) following a short-term exposure to phenanthrene

Phenanthrene (Phe) is among the most abundant and ubiquitous polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment as a result of human activities. Even so, the knowledge about its impact on fish health is still limited. In this study, the teleost Liza aurata was exposed to 0.1, 0.3, 0.9 and 2.7 µM Phe concentrations during 16 h. Enzymatic antioxidants such as selenium dependent glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and catalase (CAT), as well as a non-enzymatic antioxidant (glutathione — GSH) were quantified in three target organs — gill, kidney and liver. The lipid peroxidation (LPO) was also assessed as a marker of oxidative damage. GPx activity was decreased in gill (0.1 and 0.9 µM), whereas in the liver it was increased (0.3-2.7 µM). GST activity was decreased in kidney (0.3-2.7 µM) and CAT activity was increased in gill after 0.9 µM exposure. GSH content was significantly increased in gill by the lowest concentration and in liver by all Phe concentrations. Despite the antioxidant defense responses, LPO increased in gill (0.3-2.7 µM), kidney (0.1 µM) and liver (0.1 and 2.7 µM). These results revealed organ specific antioxidant defenses depending on the Phe concentration. Liver demonstrated a higher adaptive competence expressed as antioxidant defenses activation, namely GSH and GPX. The lower vulnerability of the kidney to oxidative damage (compared to gill and liver) seems to be related to its higher antioxidant basal levels. Globally, current data highlight the Phe potential to induce oxidative stress and, consequently, to affect the well-being of fish.     

Chronic exposure to biomass fuel smoke and markers of endothelial inflammation

Indoor smoke exposure may affect cardiovascular disease (CVD) risk via lung‐mediated inflammation, oxidative stress, and endothelial inflammation. We sought to explore the association between indoor smoke exposure from burning biomass fuels and a selected group of markers for endothelial inflammation. We compared serum concentrations of amyloid A protein, E‐selectin, soluble intercellular adhesion molecule 1 (ICAM‐1) and VCAM‐1, von Willebrand factor (vWF), and high‐sensitivity C‐reactive protein (hs‐CRP) in 228 biomass‐exposed vs. 228 non‐exposed participants living in Puno, Peru. Average age was 56 years (s.d. = 13), average BMI was 26.5 kg/m² (s.d. = 4.4), 48% were male, 59.4% completed high school, and 2% reported a physician diagnosis of CVD. In unadjusted analysis, serum levels of soluble ICAM‐1 (330 vs. 302 ng/ml; P < 0.001), soluble VCAM‐1 (403 vs. 362 ng/ml; P < 0.001), and E‐selectin (54.2 vs. 52.7 ng/ml; P = 0.05) were increased in biomass‐exposed vs. non‐exposed participants, respectively, whereas serum levels of vWF (1148 vs. 1311 mU/ml; P < 0.001) and hs‐CRP (2.56 vs. 3.12 mg/l; P < 0.001) were decreased, respectively. In adjusted analyses, chronic exposure to biomass fuels remained positively associated with serum levels of soluble ICAM‐1 (P = 0.03) and VCAM‐1 (P = 0.05) and E‐selectin (P = 0.05), and remained negatively associated with serum levels of vWF (P = 0.02) and hs‐CRP (P < 0.001). Daily exposure to biomass fuel smoke was associated with important differences in specific biomarkers of endothelial inflammation and may help explain accelerated atherosclerosis among those who are chronically exposed.     

Cadmium accumulation by muskmelon under salt stress in contaminated organic soil

Human-induced salinization and trace element contamination are widespread and increasing rapidly, but their interactions and environmental consequences are poorly understood. Phytoaccumulation, as the crucial entry pathway for biotoxic Cd into the human foodstuffs, correlates positively with rhizosphere salinity. Hypothesising that organic matter decreases the bioavailable Cd²⁺ pool and therefore restricts its phytoextraction, we assessed the effects of four salinity levels (0, 20, 40 and 60 mM NaCl) and three Cd levels (0.3, 5.5 and 10.4 mg kg^− 1) in peat soil on mineral accumulation/distribution as well as vegetative growth and fruit yield parameters of muskmelon (Cucumis melo L.) in a greenhouse. Salt stress reduced shoot biomass and fruit production, accompanied by increased Na and Cl and decreased K concentration in above-ground tissues. A 25- and 50-day exposure to salinity increased Cd accumulation in leaves up to 87% and 46%, respectively. Accumulation of Cd in the fruits was up to 43 times lower than in leaves and remained unaltered by salinity. Soil contamination by Cd enhanced its accumulation in muskmelon tissues by an order of magnitude compared with non-contaminated control. In the drainage solution, concentrations of Na and Cl slightly exceeded those in the irrigation solution, whereas Cd concentration in drainage solution was lower by 2-3 orders of magnitude than the total amount added. Chemical speciation and distribution modelling (NICA-Donnan) using Visual MINTEQ showed predominance of dissolved organic ligands in Cd chemisorption and complexation in all treatments; however, an increase in salt addition caused a decrease in organic Cd complexes from 99 to 71%, with free Cd²⁺ increasing up to 6% and Cd-chlorocomplexes up to 23%. This work highlights the importance of soil organic reactive surfaces in reducing trace element bioavailability and phytoaccumulation. Chloride salinity increased Cd accumulation in leaves but not in fruit peel and pulp.