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[en] The Kuril Islands region is considered promising for development of salmon aquaculture. There are 41 salmon fish hatcheries in the Sakhalin Island and the Kuril Islands, 34 of them are hatcheries of the chum. Therefore, concentrations of six elements (Zn, Cu, Cd, Pb, As, and Hg) were determined in chum salmon were caught in this region. The contents of toxic elements (Cd, Pb, As, and Hg) don't exceed their maximum permissible concentrations (MPC) according to the Russian sanitary standards, but concentration of Pb are closely to MPC. Increased concentrations of Pb in wild chum have the natural origin. The unusual conditions of the Western Pacific are formed under the influence such factors as volcanism and upwelling. - Highlights: • High content of Pb, found in chum from the Kuril Islands, is caused by natural sources. • The content of elements do not exceed maximum permissible concentrations in Russia. • Kuril region is considered as promising zone for development of salmon aquaculture. - Kuril region is suitable for aquaculture development of Pacific salmon.
[en] In this work, agricultural and background soil concentrations of p,p′-DDT, p,p′-DDE, HCB, α-, β- and γ-HCH from 1993 to 2012 were collected from 73 peer-reviewed publications, and analysed statistically. For the period 2003–2012 and for all chemicals, the mean concentration in agricultural soil is significantly higher than the concentration in background soil. In addition to the statistical analysis, concentrations of p,p′-DDT and α-HCH in soils were calculated with a global environmental fate and transport model. A decrease in the mean soil concentration from the first decade to the second was observed with the model, but this decrease is not visible in the measured concentrations, which could result from ongoing use of p,p′-DDT and α-HCH Furthermore, modelled background soil concentrations are generally lower than measurements. This implies that background soil may have received p,p′-DDT and α-HCH through additional routes not described by the model such as spray drift. - Highlights: • Collation of soil measurements of DDT, HCH and HCB globally from 1993 to 2012. • Time trends of p,p′-DDT and α-HCH modelled in background and agricultural soil. • Decrease in modelled soil concentration not observed in measurements. • Possible ongoing use of p,p′-DDT and α-HCH. - Global data on organochlorine pesticides in soils do not show decrease over the last 20 years.
[en] Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is considered a re-emerging environmental pollutant, and exposure to environmentally relevant concentrations has been shown to cause individual developmental toxicity in zebrafish and the water flea (Daphnia magna). However, multigenerational effects during exposure to TDCIPP and after subsequent recovery were unknown. In the present study, individuals of a model aquatic organism, the ciliated protozoan, T. thermophila were exposed to environmentally-relevant concentrations of TDCIPP (0, 300 or 3000 ng/L) for 60 days (e.g., theoretically 372 generations) followed by a 60-day period of recovery, during which T. thermophila were not exposed to TDCIPP. During exposure and after exposure, effects at the molecular, histological, individual and population levels were examined. Multigenerational exposure to 300 or 3000 ng TDCIPP/L for 60 days significantly decreased numbers of individuals, sizes of individuals, expressed as length and width of bodies, number of cilia, and depth and diameter of basal bodies of cilia, and up-regulated expressions of genes related to assembly and maintenance of cilia. Complete or partial recoveries of theoretical sizes of populations as well as sizes of individuals and expressions of genes were observed during the 60-day recovery period. Effects on number of cilia and depth and diameter of basal body of cilia were not reversible and could still be observed long after cease of TDCIPP exposure. Collectedly, and shown for the first time, multigenerational effects to T. thermophila were caused by exposure to environmentally relevant concentrations of TDCIPP. Also, there were multi-generational effects at the population level that were not caused by carry-over exposure to TDCIPP. The “permanent” alterations and their potential significance are discussed. - Highlights: • Multigenerational effects of TDCIPP were studies in Tetrahymena thermophila. • Multigenerational exposure to TDCIPP caused significant effects on population, individual and molecular levels. • Complete or partial recoveries of effects were observed during the 60-day recovery period. • Effects on number of cilia, ultrastructure of cilia and expression of several genes were not reversible. - This study provides evidence multi-generational exposure of T. thermophila to TDCIPP caused adverse effects and partial effects were not reversible.
[en] Many paddy fields have been contaminated by mercury (Hg) in mining areas of China. In this study, twenty-six rice cultivars and three Hg contaminated paddy fields in different geographic regions were selected for field trials and aimed to investigate the variations and similarities in total Hg (THg) and methylmercury (MeHg) accumulations in brown rice (seeds) across sites. Our results revealed widescale cultivar variation in THg (13–52 ng g−1 at Wanshan) and MeHg (3.5–23 ng g−1) accumulation and %MeHg (17.7–89%) in seeds. The ability to translocate is an important factor in the levels of THg and MeHg in seed. Cultivar tended to stability in THg accumulation across sites. Some cultivars accumulated lower concentrations of both THg and MeHg in seeds at fields seriously contaminated by Hg. Present results suggest that appropriate cultivar selection is a possible way to reduce THg and MeHg accumulation in seeds of rice grown in Hg-contaminated regions. -- Highlights: •Widescale cultivar variations in THg and MeHg accumulation in rice grain. •Some cultivars accumulated lower concentrations of both THg and MeHg in grains at fields seriously contaminated by Hg. •Rice cultivar possesses constancy in grain THg accumulation under different field conditions. -- Rice possesses widescale variations between cultivars and stability within a cultivar in grain THg and MeHg under different filed conditions
[en] We set up a free-air ozone (O3) exposure system for determining the photosynthetic responses of Siebold's beech (Fagus crenata) and oak (Quercus mongolica var. crispula) to O3 under field conditions. Ten-year-old saplings of beech and oak were exposed to an elevated O3 concentration (60 nmol mol−1) during daytime from 6 August to 11 November 2011. Ozone significantly reduced the net photosynthetic rate in leaves of both species in October, by 46% for beech and 15% for oak. In beech there were significant decreases in maximum rate of carboxylation, maximum rate of electron transport in photosynthesis, nitrogen content and photosynthetic nitrogen use efficiency, but not in oak. Stomatal limitation of photosynthesis was unaffected by O3. We therefore concluded photosynthesis in beech is more sensitive to O3 than that in oak, and the O3-induced reduction of photosynthetic activity in beech was due not to stomatal closure, but to biochemical limitation. -- Highlights: ► A free air ozone exposure system was set up in northern Japan. ► Beech is more sensitive to ozone than oak. ► Decrease of photosynthesis in beech was mainly due to biochemical limitation. -- Photosynthesis of beech is more sensitive to free air ozone exposure than that of oak
[en] Bromide is a conservative tracer that is often applied with non-conservative solutes such as pesticides to estimate their retardation in the soil. It has been applied in concentrations of up to 250 g Br L−1, levels at which the growth of single-celled organisms can be inhibited. Bromide applications may therefore affect the biodegradation of non-conservative solutes in soil. The present study investigated the effect of potassium bromide (KBr) on the mineralisation of three pesticides – glyphosate, MCPA and metribuzin – in four agricultural A-horizon soils. KBr was added to soil microcosms at concentrations of 0, 0.5, 2.5 and 5 g Br− L−1 in the soil solution. The study concluded that KBr had a negative effect on pesticide mineralisation. The inhibitory effect varied depending on the KBr concentration, the type of pesticide and the type of soil. Furthermore, 16 S amplicon sequencing revealed that the KBr treatment generally reduced the abundance of bacteroidetes and proteobacteria on both an RNA and DNA level. Therefore, in order to reduce the effect of KBr on the soil bacterial community and consequently also on xenobiotic degradation, it is recommended that KBr be applied in a concentration that does not exceed 0.5 g Br− L−1 in the soil water. - Highlights: • Conservative tracer KBr inhibits pesticide degradation. • The inhibitory effect depends on KBr concentration, type of pesticide and soil type. • KBr treatments generally reduced soil bacterial presence and activity. - This study reveals that KBr has a negative effect on herbicide mineralization, hence questioning if KBr should be considered concervative when used alongside xenobiotics in leaching experiments.
[en] The odd-even car trial scheme, which reduced car traffic between 08.00 and 20.00 h daily, was applied from 1 to 15 January 2016 (winter scheme, WS) and 15–30 April 2016 (summer scheme, SS). The daily average PM2.5 and PM10 exceeded national standards, with highest concentrations (313 μg m−3 and 639 μg m−3, respectively) during winter and lowest (53 μg m−3 and 130 μg m−3) during the monsoon (June–August). PM concentrations during the trials can be interpreted either as reduced or increased, depending on the periods used for comparison purposes. For example, hourly average net PM2.5 and PM10 (after subtracting the baseline concentrations) reduced by up to 74% during the majority (after 1100 h) of trial hours compared with the corresponding hours during the previous year. Conversely, daily average PM2.5 and PM10 were higher by up to 3–times during the trial periods when compared with the pre–trial days. A careful analysis of the data shows that the trials generated cleaner air for certain hours of the day but the persistence of overnight emissions from heavy goods vehicles into the morning odd–even hours (0800–1100 h) made them probably ineffective at this time. Any further trial will need to be planned very carefully if an effect due to traffic alone is to be differentiated from the larger effect caused by changes in meteorology and especially wind direction. - Highlights: • Effect of odd–even traffic trial on PM2.5 and PM10 concentrations in Delhi are analysed. • PM2.5 and PM10 were the highest during winter and lowest during monsoon season. • High tempo–spatial variability in baseline PM was observed at different sites. • Unlike PM10, the effect of odd–even was highest on PM2.5 during peak traffic hours. • Persistence of overnight emissions from heavy goods vehicles made early odd–even hours ineffective. - The odd–even car trial in Delhi reduced PM levels in certain hours but the persistence of overnight emissions from trucks made them ineffective during the morning odd–even hours.
[en] Polybrominated diphenyl ethers (PBDEs) may enter the environment because of accumulation in biosolids followed by application to agricultural lands. No published dissipation studies are available for PBDEs in agricultural soils after biosolids application. Therefore, we conducted a 3-year study to examine the fate of PBDEs in a small-scale 0.24-ha continuously cropped field after a single biosolids application at 72.3 wet tons/ha and determined dissipation half-lives for BDE-47+BDE-99 and BDE-209. In addition, we conducted a large-scale survey of soils from 26 mostly pasture fields at 10 farms with detailed information on timing and rate of biosolids applications. In the small-scale experiment, maximum soil PBDE concentrations of 43.7 ± 42.7 μg kg−1 d.w. for BDE-209 and 6.05 ± 7.15 μg kg−1 d.w. for BDE-47+BDE-99 were reached 1 year after application. We hypothesized that PBDEs were slowly released from the biosolids matrix into the soil over the first year. After 3 years, median BDE-47+BDE-99 concentrations were approximately equal to preapplication levels, whereas median BDE-209 concentrations remained ∼129% above preapplication levels. The estimated residence time from the small-scale experiment was 342 d for BDE-47+BDE-99 and 861 d for BDE-209. In the large-scale study, a subset of fields that received a single biosolids application was used to generate another estimate of residence time: 704 d for BDE-47+BDE-99 and 1440 d for BDE-209. These longer residence time estimates were used in three different first-order decay dissipation scenarios (continuous, limited, and no dissipation) to predict PBDE concentration in fields with single and multiple biosolids applications. Results indicate that dissipation occurs primarily in the first 2 years after application, but residues remaining in the soil after this period are likely to be much more tightly bound and less available for degradation. - Highlights: • PBDE soil concentrations increased and peaked one year after biosolids application. • Fields with a single application had residence time of 1440d for BDE-209. • No dissipation scenario best estimated PBDE concentrations in 23 fields. - The study calculates PBDE soil residence times in agricultural fields that received biosolids applications; these residence times may be used in the terrestrial risk assessments of PBDEs.
[en] The toxicity of three biocides, esfenvalerate, picoxystrobin and triclosan, on adult survival and recruitment of juveniles was studied in the springtail Folsomia fimetaria, both in single and mixture experiments. Recruitment of juveniles was more sensitive to biocide exposure than adult survival. The concepts of concentration addition and independent action returned almost identical toxicity predictions, though both models failed to predict the observed toxicity due to synergistic deviations at high exposure concentrations. A comparison with a similar study on earthworms showed that response-patterns were species-specific. Consequently, there is no single reference concept which is applicable for all species of one ecosystem, which in turn questions the usefulness of such mixture prediction concepts in ecological risk assessment. -- Highlights: • Toxicity of esfenvalerate, picoxystrobin and triclosan to Folsomia fimetaria was assessed. • Both, the single biocides and the mixture affected recruitment stronger than survival. • Concentration addition and independent action predictions were almost identical. • Inhibition of recruitment after mixture exposure was stronger than predicted. • Comparison with an earthworm study showed that responses are species-specific. -- The concepts of concentration addition and independent action failed to predict mixture toxicity due to dose-dependent synergistic effects
[en] Concentrations of halogenated pesticides in freshwater fish can be affected by age, size, trophic position, and exposure history. Exposure history may vary for individual fish caught at a single location due to different life histories, e.g. they may have hatched in different tributaries before migrating to a specific lake. We evaluated correlations of pesticide concentrations in freshwater brown trout (Salmo trutta) from the Clutha River, New Zealand, with potential predictors including capture site, age, length, trophic level, and life history. Life history was determined from otolith (fish ear bone) strontium isotope signatures, which vary among tributaries in the region of our study. Variability in pesticide concentrations between individual fish was not well explained by capture site, age, length, or trophic level. However, hexachlorobenzene (HCB) and chlorpyrifos concentrations were distinct in lake-based trout with different life histories. Additionally, one of the riverine life histories was associated with relatively high concentrations of total endosulfans. Linear models that included all potential predictor variables were evaluated and the resulting best models for HCB, chlorpyrifos, and total endosulfans included life history. These findings show that in cases where otolith isotope signatures vary geographically, they can be used to help explain contaminant concentration variations in fish caught from a single location. - Highlights: • Halogenated pesticides were found in trout from a New Zealand river catchment. • Concentrations were not well explained by capture site, age/size, or trophic level. • Life history was determined from strontium isotopes in trout otoliths (ear bones). • In some cases, variations in pesticide concentrations were linked to life history. - Strontium isotopes were used to identify differences in the migratory histories of freshwater trout, and therefore differences in their pesticide exposure histories, from a single capture location.