Veterinary antibiotics differ in phytotoxicity on oilseed rape grown over a wide range of concentrations.

Residues of veterinary antibiotics are a worldwide problem of increasing concern due to their persistence and diverse negative effects on organisms, including crops, and limited understanding of their phytotoxicity. Therefore, this study aimed to compare the phytotoxic effects of veterinary antibiotics tetracycline (TC) and ciprofloxacin (CIP) applied in a wide range of concentrations on model plant oilseed rape (Brassica napus). Overall phytotoxicity of 1-500 mg kg-1 of TC and CIP was investigated based on morphological, biochemical, and physiological plant response. Photosystem II (PSII) performance was suppressed by TC even under environmentally relevant concentration (1 mg kg-1), with an increasing effect proportionally to TC concentration in soil. In contrast, CIP was found to be more phytotoxic than TC when applied at high concentrations, inducing a powerful oxidative burst, impairment of photosynthetic performance, collapse of antioxidative protection and sugar metabolism, and in turn, complete growth retardation at 250 and 500 mg kg-1 CIP treatments. Results of our study suggest that TC and CIP pollution do not pose a significant risk to oilseed rapes in many little anthropogenically affected agro-environments where TC or CIP concentrations do not exceed 1 mg kg-1; however, intensive application of manure with high CIP concentrations (more than 50 mg kg-1) might be detrimental to plants and, in turn, lead to diminished agricultural production and a potential risk to human health.

Heavy fuel oil-contaminated soil remediation by individual and bioaugmentation-assisted phytoremediation with Medicago sativa and with cold plasma-treated M. sativa.

Developing an optimal environmentally friendly bioremediation strategy for petroleum products is of high interest. This study investigated heavy fuel oil (HFO)-contaminated soil (4 and 6 g kg-1) remediation by individual and combined bioaugmentation-assisted phytoremediation with alfalfa (Medicago sativa L.) and with cold plasma (CP)-treated M. sativa. After 14 weeks of remediation, HFO removal efficiency was in the range between 61 and 80% depending on HFO concentration and remediation technique. Natural attenuation had the lowest HFO removal rate. As demonstrated by growth rate and biomass acquisition, M. sativa showed good tolerance to HFO contamination. Cultivation of M. sativa enhanced HFO degradation and soil quality improvement. Bioaugmentation-assisted phytoremediation was up to 18% more efficient in HFO removal through alleviated HFO stress to plants, stimulated plant growth, and biomass acquisition. Cold plasma seed treatment enhanced HFO removal by M. sativa at low HFO contamination and in combination with bioaugmentation it resulted in up to 14% better HFO removal compared to remediation with CP non-treated and non-bioaugmented M. sativa. Our results show that the combination of different remediation techniques is an effective soil rehabilitation strategy to remove HFO and improve soil quality. CP plant seed treatment could be a promising option in soil clean-up and valorization.

Drought-free future climate conditions enhance cadmium phytoremediation capacity by Brassica napus through improved physiological status.

This study aimed to assess Cd phytoextraction efficiency in well-watered and drought-stressed B. napus plants under current climate (CC, 21/14 °C, 400 ppm CO2) and future climate (FC, 25/18 °C, 800 ppm CO2) conditions. The underlying physiological mechanisms underpinning the obtained results were investigated by studying Cd (1, 10, 50, and 100 mg kg-1) effect on B. napus photosynthetic performance and nutritional status. Only the Cd-50 and Cd-100 treatments caused visible leaf lesions, growth retardation, reductions in both gas exchange and chlorophyll fluorescence-related parameters, and disturbed mineral nutrient balance. Under CC conditions, well-watered plants were affected more than under FC conditions. The most important pathway by which Cd affected B. napus photosynthetic efficiency in well-watered plants was the damage to both photosystems, lowering photosynthetic electron transport. Meanwhile, non-stomatal and stomatal limitations were responsible for the higher reduction in the photosynthetic rate (Pr) of drought-stressed compared to well-watered plants. The significantly higher shoot dry weight, which had a strong positive relationship with Pr, was the main factor determining significantly higher shoot Cd accumulation in high Cd treatments in well-watered plants under FC conditions, resulting in a 65% (p < 0.05) higher soil Cd removal rate in the Cd-50 treatment.

Self-reported behaviours and measures related to plastic waste reduction: European citizens' perspective.

Consumer attitudes and behaviour regarding consumption of plastic goods and proper waste management are of importance for reducing plastic and microplastic (MP) pollution. Therefore, based on Eurobarometer survey, this study aims to analyse European attitudes and behaviour related to plastic pollution reduction. Europeans acknowledge marine and river pollution as important environmental problems and are worried about plastics and MP environmental impacts. However, this does not translate into related plastic reduction behaviours. Regression analysis show that analysed behaviours are likely to be undertaken by women, younger, with higher incomes respondents and by those who express higher worry about plastic and MP environmental impacts. Industry and big companies are seen as having the main role in reducing plastic waste and littering, chargers for single use plastics being less important. Respondents also stress the role of education. Hence, focus on concrete steps to reduce plastic waste, highlighting the interaction of individual actions and environment should be given.

Effects of elevated temperature and decreased soil moisture content on triclosan ecotoxicity to earthworm E. fetida.

Emerging pollutants and climate change are two main challenges affecting soil organisms today. Changes in temperature and soil moisture with climate change are key factors determining activity and fitness of soil dwelling organisms. The occurrence and toxicity of antimicrobial agent triclosan (TCS) in terrestrial environment is of high concern, while no data are available on TCS toxicity changes to terrestrial organisms under global climate change. The study's aim was to assess the impact of elevated temperature, decreased soil moisture content, and their complex interaction on triclosan-induced changes in Eisenia fetida life cycle parameters (growth, reproduction, and survival). Eight-week TCS-contaminated soil (10-750 mg TCS kg-1) experiments with E. fetida were performed at four different treatments: C (21 °C + 60% water holding capacity (WHC)); D (21 °C and 30% WHC); T (25 °C + 60% WHC); and T + D (25 °C + 30% WHC). TCS had negative impact on the earthworm mortality, growth, and reproduction. Changing climate conditions have altered TCS toxicity to E. fetida. Drought and drought in combination with elevated temperature enhanced the adverse effects of TCS on earthworm survival, growth rate, and reproduction, while single elevated temperature slightly reduced TCS lethal toxicity as well as toxicity to growth rate and reproduction.

Oilseed rape (Brassica napus L.) potential to remediate Cd contaminated soil under different soil water content.

Changes in soil moisture content accompanying ongoing climate change are expected to affect plant growth and contaminants behaviour in the soil. The study was aimed at investigating soil water content impact on the energy crop oilseed rape (Brassica napus L.) efficiency to remediate Cd contaminated soil (1-250 mg kg-1). B. napus growth, Cd accumulation and removal efficiency were evaluated under optimal, reduced and elevated soil water content (SWC). B. napus showed good tolerance to Cd contamination and ability to phytoextract Cd from the soil. Cd accumulation in oilseed rape increased with Cd soil concentration, whereas removal efficiency was regulated by rape growth and Cd soil concentrations. B. napus has demonstrated good efficiency to cope with low and moderate Cd pollution (with tolerance index TI > 0.69), while high Cd soil pollution had a highly significant adverse impact on plant growth (growth was reduced up to 90%) resulting in low Cd removal efficiency. SWC governed plant growth, Cd accumulation and removal from the soil. Oilseed rapes grown under elevated SWC were of higher biomass (18%) compared to those grown under reduced SWC though the detrimental effect of Cd was more severe at elevated SWC. Reduced SWC led to decreased Cd uptake, conversely elevated SWC promoted Cd uptake. The optimal SWC ensures the highest Cd removal efficiency, whereas soil water deficit or excess restricts B. napus potential to remove Cd from the soil and prolongs remediation.

Effects of elevated CO2 concentration and temperature on the mixed-culture grown wild mustard (Sinapis arvensis L.) response to auxin herbicide.

Recently, there has been growing concern over the potential impact of CO2 concentration and temperature on herbicide efficacy. The aim of the study was to examine the influence of single elevated CO2 (400 vs. 800 ppm) and elevated CO2 in combination with temperature (21 °C vs. 25 °C) on the effects of auxin herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) (0.5-2 × field recommended rate) to wild mustard (Sinapis arvensis L.) grown in mixed-culture with spring barley (Hordeum vulgare L.). MCPA had a detrimental effect on aboveground and belowground biomass, content of chlorophylls, enzymatic and non-enzymatic antioxidants and induced oxidative stress. The significant decline in photosynthetic rate, stomatal conductance and transpiration with MCPA dose was detected. Elevated CO2 reinforced MCPA efficacy on S. arvensis: sharper decline in biomass, photosynthetic rate and antioxidant enzymes and more pronounced lipid peroxidation were detected. Under elevated CO2 and temperature, MCPA efficacy to control S. arvensis dropped due to herbicide dilution because of increased root:shoot ratio, higher activity of antioxidants and less pronounced oxidative damage. Reinforced MCPA impact on weeds under elevated CO2 resulted in higher H. vulgare biomass, while decreased MCPA efficacy under elevated CO2 and temperature reduced H. vulgare biomass.

Earthworm Eisenia fetida potential for sewage sludge amended soil valorization by heavy metal remediation and soil quality improvement.

Sewage sludge reuse in agriculture is increasing, however it can be an important route for contaminants to enter the environment. The aim of this study was to evaluate earthworm Eisenia fetida capability to reduce heavy metal content in the sewage sludge (SS) amended soil and increase soil fertility in terms of soil nutrients content. Adult earthworms were introduced into aged SS amended soil (0-200 Mg ha-1) and left for 65 days. Earthworms have stabilized soil pH and accelerated organic matter mineralization. The concentrations of most heavy metals during the vermiremediation sharply decreased, K and Mg decreased to a moderate extent, whereas Ca content has increased. The highest removal efficiency was detected for Ni, Co and Mn (> 80%), bioconcentration factors were as follows Zn > Co > Cu > Ni > Mn > Cr. The content of major nutrients (S, P) was substantially higher compared to the initial values. The most efficient remediation and soil quality improvement was achieved under the doses of 25-50 Mg ha-1. Higher (≥ 100 Mg ha-1) doses might restrict this technique application because of earthworm mortality and retarded growth. Overall, the study shows that vermiremediation might be a sustainable technique for ecological stabilization of SS amended soil and converting to usable for agricultural needs.

Physiological and Biochemical Parameters of Common Duckweed Lemna minor after the Exposure to Tetracycline and the Recovery from This Stress.

In this study, the ability of Lemna minor L. to recover to normal growth, after being degraded in a tetracycline-containing medium, was extensively investigated. The plants were exposed to tetracycline (TC) at concentrations of 1, 2.5, and 10 mM. Subsequently, their physiological status was analysed against the following criteria: rate of plant growth; free radical accumulation; antioxidant enzyme activity; chlorophyll content; HSP70 protein content; cell membrane permeability, and mitochondrial activity. The study showed that duckweed can considerably recover from the damage caused by antibiotics, within a week of cessation of stress. Of the plant properties analysed, mitochondrial activity was the most sensitive to antibiotic-induced disturbances. After transferring the plants to a tetracycline-free medium, all plant parameters improved significantly, except for the mitochondrial activity in the plants grown on the medium containing the highest dose of tetracycline. In the plants treated with this antibiotic at the concentration of 10 mM, the proportion of dead mitochondria increased and was as high as 93% after one week from the beginning of the recovery phase, even after the transfer to the tetracycline-free medium.

Physiological response of the bioindicator Ramalina farinacea in relation to atmospheric deposition in an urban environment.

Urban air pollution is one of the most important environmental problems. Lichens are good bioindicators in air pollution studies because of their dependence on the atmospheric deposition for nutrition. The present study focused on the effects of urbanization on the composition of atmospheric deposition inputs and physiological parameters of transplanted epiphytic lichen Ramalina farinacea. The status of lichens responded to urban pollutants related to vehicle and industrial activity (NO3-, Ca2+, Mg2+, NO2, PM10). The content of chlorophyll and FV/FM were positively related to the amount of precipitation (mm) and the Normalized Difference Vegetation Index (NDVI). The increase in lipid peroxidation and electrolyte conductivity, indicating damage to the cell membrane, was found in lichens transplanted to the urban environment. The high variability in electrolyte conductivity indicated that cell membrane injuries were characteristics of the investigated study area.

Do plants respond and recover from a combination of drought and heatwave in the same manner under adequate and deprived soil nutrient conditions?

Extreme climatic conditions with extended drought periods and heatwaves are predicted to increase in frequency and severity in many regions of the world. Aside from this, other abiotic stress factors such as nutrient deficiency could pose a serious problem to plants when combined with other stressors resulting in more complex underpinning mechanisms. In the present study, we evaluated the response of Brassica napus to single and combined impacts of drought and heatwave (HW) under adequate or deprived (N-A and N-D) soil nutrient conditions. In addition, to get better insights in the plant response to combined stress, a post-stress period, pointing out a degree of the recovery after the cessation of stress, was also included. The results showed a different manner of single drought and heatwave action. The adverse effect of drought on leaf gas exchange was lagged on the growth and became more apparent only after recovery period with no obvious difference between different nutrient levels. Contrary, the growth response of nutrient-deprived plants to single HW was weak and in most cases, insignificant. Heatwave applied simultaneously with drought highly exacerbated the adverse effect of drought both under N-A and N-D conditions. Combined drought and heatwave stress resulted in the sharper decline of Asat and it was attributed to both stomatal and non-stomatal limitations. Interestingly, plants underwent combined drought and HW treatment under N-D conditions showed better aboveground growth recovery, compared to those grown under N-A conditions, while displayed far more diminished photochemistry of photosystem II and badly disturbed the C/N balance. This discrepancy came from the fact that soil nutrient deficiency, by itself, evoked strong stress under control climate conditions resulting in a dramatically slower aboveground growth of nutrient-deprived plant. In turn, although combined drought and HW stress had similar effect on the aboveground growth either under N-A or N-D conditions, the recovery of later one was better. These results highlight the necessity to look at plants' performance under unfavorable environmental conditions beyond the actual event, since it can be depended not only on the duration of exposure but also on the legacy effect after treatment.

Growth and photosynthetic responses in Brassica napus differ during stress and recovery periods when exposed to combined heat, drought and elevated CO2.

This study was intended to investigate how an agronomically important crop Brassica napus will be able to cope with the combined impact of a heatwave (21/14 °C vs. 33/26 °C day/night) and drought under ambient or elevated CO2 (800 vs. 400 µmol mol-1) and to what degree their recovery will be ensured after the stress, when additional CO2 is also removed. The obtained results revealed that, in the presence of an adequate water supply, B. napus performed well under heatwave conditions. However, drought fully negated all the advantages gained from hotter climate and led to a slower and incomplete recovery of gas exchange and retarded growth after the stress, regardless mitigating the effect of elevated CO2 during the stress. The mechanism by which the elevated CO2 diminished the adverse effect of a combined heat and drought stress on photosynthetic rate at saturating light (Asat) was attributed to the improved plant water relations. However, it had little effect on the recovery of Asat. In contrast, the mechanism by which photosynthesis was more impaired under the combination of heatwave and drought, compared to single drought treatment, was attributed mainly to the faster soil drying as well as faster and sharper decrease in stomatal conductance and subsequent in Ci/Ca. Keeping in mind that photosynthesis can acclimatize by downregulation to higher CO2, the results of this study, showing a weak memory of mitigating the effect of elevated CO2, highlight a potential risk of more intense and frequent heatwaves and droughts on B. napus.

Waste of electrical and electronic equipment: Trends and awareness among youths in Lithuania.

Waste of electrical and electronic equipment (WEEE) has gained significant attention recently because of increasing consumption and related environmental impacts. This work focuses on Lithuania and analyses the trends of WEEE generation and management during the period 2008-2015. Attitudes and behaviour of students and pupils (main future consumers) regarding WEEE are also determined in this work. The analysis shows that the generation and collection of WEEE in Lithuania have been on the rise since the global economic crisis. In total, approximately 16260 metric tonnes of WEEE were collected in 2015 in Lithuania. Most of the collected WEEE consisted of large home appliances and information technology and telecommunication equipment. In addition, the survey highlights that some small WEEE is still discarded together with municipal waste. Results also report that there is a need for more information about WEEE as such, as well as the need for more collection points and possibly a refund system. The study suggests that those aspects could be of importance for the efficiency of WEEE management systems and related policy implementation.

O3 pollution in a future climate increases the competition between summer rape and wild mustard.

The initial aim of this study was to evaluate an effect of elevated CO2 concentration and air temperature (future climate) and O3 pollution on mono- and mixed-culture grown summer rape (Brassica napus L.) and wild mustard (Sinapis arvensis L.). The second task was to reveal the mechanisms of the shift in plants' competitiveness in response to single and combined environmental changes. Plants were grown in mono- and mixed-cultures under current climate (CC) (400 µmol mol-1 of CO2, 21/14 °C day/night temperature) or future climate (FC) conditions (800 µmol mol-1 of CO2, 25/18 °C day/night temperature) with and without O3 treatment (180 µg m-3). Competition had relatively little effect on growth of both species at current climate, independent of O3 treatment. In contrast, competitive effect of both plant species considerably increased under FC, and especially FC + O3 conditions, when growth of mixed-culture rape reduced up to 48% and that of wild mustard up to 80%. The mechanisms of elevated competitiveness of rape under the future climate consisted of better antioxidative protection, particularly elevated total antioxidative capacity and activities of peroxidase and ascorbate peroxidase. Whereas stronger oxidative damage, disproportionally high activities of H2O2 scavenging enzymes and lower pool of soluble sugars in mixed-culture wild mustard reduced its competitiveness under FC + O3 conditions. In conclusion it must be pointed out, that regardless improved competitive abilities of rape under FC and FC + O3 conditions, competition with wild mustard reduced growth, indicating increased weed-induced yield losses in the future climate, especially with concomitant intensification of O3 pollution.

Biochemical and life cycle effects of triclosan chronic toxicity to earthworm Eisenia fetida.

The study aimed at determining the response of adult Eisenia fetida earthworms to chronic exposure to triclosan (TCS) (10-750 mg kg-1) in soil. TCS life cycle toxicity was evaluated by the means of survival, growth rate, and reproduction assessment. Biochemical responses including changes in the activity of antioxidative enzymes (catalase, superoxide dismutase, and glutathione reductase) and concentration of malondialdehyde (MDA) were determined. Significant reduction in the earthworm survival was observed only if the exposure to TCS was longer than 4 weeks. TCS reduced the growth rate of E. fetida; the weight of the fastest growing control individuals exceeded that for the slowest growing by factor of 2.56. Reproduction was the most sensitive life cycle parameter and was affected at the very low levels of TCS in the soil. The results showed that chronic exposure to TCS levels in the soil induced a significant increase in the activity of antioxidative enzymes and MDA concentration. Present study revealed that an integrated approach combining biochemical and life cycle endpoints would provide a more comprehensive assessment of the ecological effects of chronic TCS exposure on earthworms.

Effects of cadmium and lead on the life-cycle parameters of juvenile earthworm Eisenia fetida.

Juveniles Eisenia fetida were exposed to cadmium (1-500µgCdg(-1)) and lead (20-2500µgPbg(-1)) for fourteen weeks in order to evaluate the impact on life-cycle parameters (survival, growth, sexual maturation, and cocoon production) and lipid peroxidation (expressed as concentration of malondialdehyde (MDA)). Both metals were found to significantly affect survival of the juveniles (fourteen-week LC50 296±125µgCdg(-1) and 911±164µgPbg(-1)) and alter their development. Cd and Pb severely affected the weight of the juveniles, prolonged the time to sexual maturation (at the highest concentrations, earthworms did not reach sexual maturity at all), and reduced cocoon production. LC50 significantly decreased with the time of earthworm exposure, indicating that chronic exposure to the same levels of contaminants in the soil may have more detrimental consequences than short-term exposure. A survival model showed that the survival probability for the juveniles decreased significantly with time and the concentration of metals in the soil. The metals induced a significant increase in MDA concentration (2.98-fold and 1.54-fold at 250µgCdg(-1) and 2500µgPbg(-1), respectively), and the content of MDA was negatively related to the weight of the juveniles and the percentage of mature individuals (p<0.05).