The main objective of the present study is to measure the levels of heavy metals in important fruit species such as apple, apricot, and nectarine and their nine, five, and six cultivars, respectively. This work investigates the accumulation of Fe, Cu, Zn, Ni, Cd, Pb, and Cr in flowers of above species, to measure the levels of heavy metal contamination. The obtained results revealed that amounts of heavy metals significantly varied among cultivars at the same species and were within the permissible amounts in general. The Cd was not detected in apricot, nectarine, and the most of apple cultivars. Results for floral Fe, and also for Cu and Zn, which are the most important micronutrients for fruit production, suggest that levels of these elements might be used for assessing the storage of these elements during the previous season. We assume that the production of apple, apricot, and nectarine is safe, and there is no risk of contamination with heavy metals.

The scope of this study was to investigate the uptake of chromium and nickel by onions (Allium cepa) and potatoes (Solanum tuberosum) and their impact on plant enzymes catalase (CAT, E.C. 1.11.1.6) and peroxidase (POX, E.C. 1.11.1.7). A greenhouse experiment was conducted, simulating the irrigating conditions existing in the two biggest tuber-producing regions of Greece (Asopos and Messapia). Plants were cultivated for 4 months in six irrigation lines, each one supplied by an aqueous solution, containing levels of Cr(VI) and Ni(II) ranging from 0 μg/L (control) to 1,000 μg/L. Significant statistical correlations were observed between (i) the levels of heavy metals in plants, (ii) the levels of heavy metals in plants and in irrigation water, and (iii) the levels of heavy metals and the enzymatic activities in plants. The existing EU legislation has no legal limits for Ni and Cr in food, and the nutritional implications of this study are discussed.

Studying the toxic risk of pesticide exposure to ladybird beetles is important from an agronomical and ecological perspective since larval and adult ladybirds are dominant predators of herbivorous pest insects (e.g., aphids) in various crops in China. This article mainly deals with the long-term effects of a single application of the insect growth regulator hexaflumuron on Coccinella septempunctata. A 72- h and a 33-day toxicity test with hexaflumuron (single application) were performed, starting with the second instar larvae of C. septempunctata. Exposure doses in the long-term experiment were based on the estimated 72-h acute LR50 (application rate causing 50 % mortality) value of 304 g active ingredient (a.i.) ha-1 for second instar larvae of C. septempunctata. The long-term test used five hexaflumuron doses as treatment levels (1/50, 1/100, 1/200, 1/400, and 1/800 of the 72-h acute LR50), as well as a solvent control and blank control treatment. The measurement endpoints used to calculate no observed effect application rates (NOERs) included development time, hatching, pupation, adult emergence, survival, and number of eggs produced. Analyzing the experimental data with one-way analysis of variance showed that the single hexaflumuron application had significant effects on C. septempunctata endpoints in the 33-day test, including effects on development duration (NOER 1.52 g a.i. ha-1), hatching (NOER 3.04 g a.i. ha-1), pupation (NOER 3.04 g a.i. ha-1), and survival (NOER 1.52 g a.i. ha-1). These NOERs are lower than the reported maximum field application rate of hexaflumuron (135 g a.i. ha-1) in cotton cultivation, suggesting potential risks to beneficial arthropods.

Artemisinin, an antimalarial compound derivated from the cultivated plant Artemisia annua L., is produced in situ through cultivation of A. annua under different climatic conditions. The bioactive compound artemisinin has been observed to spread to the surroundings as well as to leach to surface- and groundwater. To make better risk assessments of A. annua which is cultivated under varying climatic conditions, the temperature-dependent toxicity of artemisinin toward the green algae Pseudokirchneriella subcapitata and the macrophyte Lemna minor was evaluated at temperatures ranging from 10 to 30 °C. To include a possible effect of temperature on the degradation rate of artemisinin, artemisinin concentrations were measured during the experiment and toxicity was related to the time-weighted averages of exposure concentrations. The toxicity of artemisinin toward the macrophyte L. minor and the algae P. subcapitata increased with increasing growth rates, and we conclude that bioavailability plays a minor role in the observed relation between temperature and toxicity of artemisinin. The obtained results are important for possible future risk assessment of A. annua cultivation.

Considerable amount of gasoline from natural and anthropogenic sources, such as urban runoff during hurricanes and oil discharges from pleasure crafts, has been released into Lake Pontchartrain, Louisiana, which poses a threat to the lake marsh ecosystems. In this research, we evaluated the impact of gasoline on indigenous bacterial communities in three types of marsh sediments collected from the Lake Pontchartrain. Our data show that several bacterial species are significantly enriched in gasoline-treated sediments. DNA sequencing data indicate that the enriched bacteria in response to the gasoline treatment are Acidocella and Burkholderia spp. in freshwater marsh; Mariprofundus, Nitrosospira, and Ferrimicrobium spp. in brackish marsh; and three Pseudomonas spp. in salt marsh. Our research will help to understand a gasoline bioremediation by indigenous bacteria and to develop site-specific bioremediation strategies for the Lake Pontchartrain.

In this research, different inlet concentrations of n-hexane vapor (1–11 g m⁻³) corresponds to the inlet loading rates of 9–598 g m⁻³ h⁻¹at different temperatures (35–45 °C) were eliminated from air under continuous and intermittent loading (10-h feeding per day) in a biofilter packed with compost and lava rock. Loading type had minor effect on the n-hexane removal at 35 °C and the removal efficiency (RE) was in the range of 70 to 100 % at an inlet concentration of 11 gm⁻³. On the contrary, RE dropped significantly to 25 % at 40 °C under intermittent loading while it was 77 % under continuous loading with the inlet concentration of 9 g m⁻³and empty bed residence time (EBRT) of 2 min. Increasing the temperature to 45 °C significantly reduced the RE at both types of loading at both EBRTs of 2 and 1.3 min; however, intermittent loading was led to a slightly greater removal. According to transient-state experiment under intermittent loading at EBRT of 2 min, the biochemical reaction became the dominant mechanism, after an initial short period, every day to remove n-hexane rather than adsorption on bed. Kinetic modeling showed that the biodegradation rates changed linearly with increase in the logarithmic mean n-hexane concentration during intermittent loading at different temperatures while the order of reaction was higher at continuous loading.

Water pollution through natural and anthropogenic activities has become a global problem causing short-and long-term impact on human and ecosystems. Substantial quantity of individual or mixtures of organic pollutants enter the surface water via point and nonpoint sources and thus affect the quality of freshwater. These pollutants are known to be toxic and difficult to remove by mere biological treatment. To date, most researches on the removal of organic pollutants from wastewater were based on the exploitation of individual treatment process. This single-treatment technology has inherent challenges and shortcomings with respect to efficiency and economics. Thus, application of two advanced treatment technologies characterized with high efficiency with respect to removal of primary and disinfection by-products in wastewater is desirable. This review article focuses on the application of integrated technologies such as electrohydraulic discharge with heterogeneous photocatalysts or sonophotocatalysis to remove target pollutants. The information gathered from more than 100 published articles, mostly laboratories studies, shows that process integration effectively remove and degrade recalcitrant toxic contaminants in wastewater better than single-technology processing. This review recommends an improvement on this technology (integrated electrohydraulic discharge with heterogeneous photocatalysts) viz-a-vis cost reduction in order to make it accessible and available in the rural and semi-urban settlement. Further recommendation includes development of an economic model to establish the cost implications of the combined technology. Proper monitoring, enforcement of the existing environmental regulations, and upgrading of current wastewater treatment plants with additional treatment steps such as photocatalysis and ozonation will greatly assist in the removal of environmental toxicants.

The relationship between ambient concentrations of fine particulate matter (PM2.5) and detrimental effects on fauna remains a highly controversial issue. The present study has determined the levels of fine particulate matter and trace metals in the particulate matter as well as in soil and plants in an oil field of Assam in northeastern India in order to assess the effects of oil exploration on muga (Antheraea assama) silk worms. Ambient PM2.5 concentration was monitored daily at two sites during November (one of the driest months) along with the trace metals, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn. The distance variation of the trace metals was determined by factors related to dispersion and the emission sources. Higher levels of PM2.5 were measured during the night. This might be due to increased emissions from the group gathering station of crude oil done during the night. Significant correlations were observed among the trace metal compositions of the fine particulate matter in ambient air, soil, and plants of the oil field area, and the same were related to the oil exploration activities. Meteorological data and statistical analysis further confirmed the influence of the oil field activities on the levels of PM2.5 and the trace metals.

Soils that are exposed to floodwaters because of shallow groundwater and periodical wetlands are, to a large extent, exposed to contamination by organic and inorganic compounds. These are mainly compounds that have drifted along with the inflow of heavily laden floodwater and are produced within the soil profile by the anaerobic transformation of organic matter. Heavy metals and polycyclic aromatic hydrocarbon (PAH) compounds are absorbed by the soil of the floodwaters, and moving in the soil profile, they pose a threat to groundwater. What is more, after a flood, they may be absorbed by the crops. This paper focuses on the effects of Odra River (Poland) floods, heavy metals, and PAHs on soil and the possibilities of the migration of these pollutants into the soil profile. In the tested sludge samples of floodwater and soil, there were no abnormal concentrations of heavy metals, but the flooding time positively affected the amount listed in the test samples. Concentrations of PAHs increased, but they also exceeded the standards for arable soils in the case of single compounds.