Biofouling material samples from the Arabian (Persian) Gulf, used as inocula in batch cultures, brought about crude oil and pure-hydrocarbon removal in a mineral medium. Without any added nitrogen fertilizers, the hydrocarbon-removal values were between about 10 and 50 %. Fertilization with NaNO₃alone or together with a mixture of the vitamins thiamine, pyridoxine, vitamin B12, biotin, riboflavin, and folic acid increased the hydrocarbon-removal values, to reach 90 %. Biofouling material samples harbored total bacteria in the magnitude of 10⁷cells g⁻¹, about 25 % of which were hydrocarbonoclastic. These numbers were enhanced by NaNO₃and vitamin amendment. The culture-independent analysis of the total bacterioflora revealed the predominance of the gammaproteobacterial genera Marinobacter, Acinetobacter, and Alcanivorax, the Flavobacteriia, Flavobacterium, Gaetbulibacter, and Owenweeksia, and the Alphaproteobacteria Tistrella, Zavarzinia, and others. Most of those bacteria are hydrocarbonoclastic. Culture-dependent analysis of hydrocarbonoclastic bacteria revealed that Marinobacter hydrocarbonoclasticus, Dietzia maris, and Gordonia bronchialis predominated in the fouling materials. In addition, each material had several more-specific hydrocarbonoclastic species, whose frequencies were enhanced by NaNO₃and vitamin fertilization. The same samples of fouling materials were used in four successive crude-oil-removal cycles without any dramatic loss of their hydrocarbon-removal potential nor of their associated hydrocarbonoclastic bacteria. In the fifth cycle, the oil-removal value was reduced by about 50 % in only one of the studied samples. This highlights how firmly biofouling materials were immobilizing the hydrocarbonoclastic bacteria.

Laboratory toxicity testing is the primary tool used for surface water environmental risk assessment; however, there are critical information gaps regarding the sublethal effects of pesticides. In 10-day exposures, we assessed the lethal and sublethal (motility and growth) toxicities of four commonly used pesticides, bifenthrin, permethrin, cyfluthrin, and chlorpyrifos, on two freshwater invertebrates, Chironomus dilutus and Hyalella azteca. Pyrethroids were more toxic than the organophosphate chlorpyrifos in both species. Bifenthrin was most toxic to H. azteca survival and growth. Cyfluthrin was most toxic to C. dilutus. However, cyfluthrin had the greatest effect on motility on both H. azteca and C. dilutus. The evaluated concentrations of chlorpyrifos did not affect C. dilutus motility or growth, but significantly impacted H. azteca growth. Motility served as the most sensitive endpoint in assessing sublethal effects at low concentrations for both species, while growth was a good indicator of toxicity for all four pesticides for H. azteca. The integration of sublethal endpoints in ambient water monitoring and pesticide regulation efforts could improve identification of low-level pesticide concentrations that may eventually cause negative effects on food webs and community structure in aquatic environments.

Coastal aquifers are at threat of salinization in most parts of the world. This study was carried out in coastal shallow aquifers of Aousja-Ghar El Melh and Kalâat el Andalous, northeastern of Tunisia with an objective to identify sources and processes of groundwater salinization. Groundwater samples were collected from 42 shallow dug wells during July and September 2007. Chemical parameters such as Na⁺, Ca²⁺, Mg²⁺, K⁺, Cl⁻, SO₄²⁻, HCO₃⁻, NO₃⁻, Br⁻, and F⁻were analyzed. The combination of hydrogeochemical, statistical, and GIS approaches was used to understand and to identify the main sources of salinization and contamination of these shallow coastal aquifers as follows: (i) water-rock interaction, (ii) evapotranspiration, (iii) saltwater is started to intrude before 1972 and it is still intruding continuously, (iv) irrigation return flow, (v) sea aerosol spray, and finally, (vi) agricultural fertilizers. During 2005/2006, the overexploitation of the renewable water resources of aquifers caused saline water intrusion. In 2007, the freshening of a brackish-saline groundwater occurred under natural recharge conditions by Ca-HCO₃meteoric freshwater. The cationic exchange processes are occurred at fresh-saline interfaces of mixtures along the hydraulic gradient. The sulfate reduction process and the neo-formation of clays minerals characterize the hypersaline coastal Sebkha environments. Evaporation tends to increase the concentrations of solutes in groundwater from the recharge areas to the discharge areas and leads to precipitate carbonate and sulfate minerals.

In this work, we studied the influence of air pollution on the morpho-structural, biochemical and chemical composition of Eucalyptus camaldulensis leaves. Analyses were carried out on 22 samples collected in Palermo (Italy) area. Considering the mean concentrations (in unwashed leaves) of investigated metals, nutrient elements as Fe (214 mg kg⁻¹ dry weight (d.w.)), Mn (160 mg kg⁻¹ d.w.) and Zn (39 mg kg⁻¹ d.w.) were the most abundant, whereas Pb (5.6 mg kg⁻¹ d.w.) and Cd (0.072 mg kg⁻¹ d.w.) showed the lowest concentrations. The values of metal pollution index (MPI) ranged from 6.0 (station no. 15) to 25 (station no. 8) and from 4.0 (station no. 16) to 17 (stations no. 7 and no. 15) for unwashed and washed leaves, respectively. The station no. 8, located in an area interested by traffic mostly caused by the activities of university, showed the highest value of MPI. The station no. 15 (Industrial area) showed the lowest MPI value, which is similar to those determined in the reference stations. Considering that the station considered is located in a large and open area interested only by commercial activities and there are no production activities, this data is not surprising. In this study, the washing of the leaves with distilled water has caused a little reduction of metal concentrations. Microphotography reveals a correlation between zones of necrosis, modified cuticles and accumulations of acid phosphatases in the leaves collected in polluted areas. The diaphanized leaves from the more polluted areas show irregular areolas, several idioblasts both on the ribs and scattered in the mesophyll. With polarized light, we observe many crystal deposits near the ribs.

The registration of plant protection products (PPPs) in the EU is under Regulation 1107/2009, which recommends a tiered approach to assessing the risk to non-target terrestrial plants (NTTPs). However, little information is provided on how to perform and implement higher tier studies or how to use them to refine the risk assessments. Therefore, a stakeholder workshop was organized to consolidate current knowledge and expertise to aid the further development of testing and assessment procedures for NTTPs. This brief communication highlights the agreed recommendations of the workshop, which relate to the three main themes, i.e. specific protection goals, risk assessment and mitigation. The participants of the workshop adopted the European Food Safety Authority (EFSA) approach of using an ecosystem services framework for identifying specific protection goals. First, delivery and protection of ecosystem services were discussed for in-crop, in-field and off-crop, and off-field areas. Second, lower and higher tier risk assessment methods, including modelling approaches, were evaluated. Third, options for risk mitigation of spray drift and run-off were discussed and evaluated. Several important knowledge gaps were identified, and specific data collation and literature-based tasks were actioned to begin to address them. A full workshop report is planned for the fall of 2014.

In rural environments, atmospheric CO₂ is mainly controlled by natural processes such as respiration-photosynthesis or low atmosphere evolution. This paper considers atmospheric CO₂ measurements obtained at a rural site during 2011 using the wavelength-scanned cavity ringdown spectroscopy technique and presents two clustering methods, the silhouette being calculated to evaluate procedure validity. In the first method, clusters were formed depending on the similarity of wind roses, with satisfactory silhouette values. An anticyclonic rotation of the wind direction was observed during the daily cycle and clusters were formed by consecutive directions following the mixing layer evolution. However, monthly roses revealed four quite different wind directions, mainly oriented in the E-W axis. Although CO₂ was not used in this procedure, a successful link between clusters and CO₂ was obtained. In the second procedure, clusters were formed by the similarity of CO₂ histograms calculated in intervals of one or two ancillary variables, wind direction, time of day, or month. The influence of a nearby city, the daily evolution of the low atmosphere, and the growing season were highlighted. Finally, the usefulness of the method lies in its easy extension to other gases or variables.

In this study, positive matrix factorization (PMF) and principal components analysis (PCA) were combined to identify and apportion pollution-based sources of hazardous elements in the surface sediments in the Yangtze River estuary (YRE). Source identification analysis indicated that PC1, including Al, Fe, Mn, Cr, Ni, As, Cu, and Zn, can be defined as a sewage component; PC2, including Pb and Sb, can be considered as an atmospheric deposition component; and PC3, containing Cd and Hg, can be considered as an agricultural nonpoint component. To better identify the sources and quantitatively apportion the concentrations to their sources, eight sources were identified with PMF: agricultural/industrial sewage mixed (18.6 %), mining wastewater (15.9 %), agricultural fertilizer (14.5 %), atmospheric deposition (12.8 %), agricultural nonpoint (10.6 %), industrial wastewater (9.8 %), marine activity (9.0 %), and nickel plating industry (8.8 %). Overall, the hazardous element content seems to be more connected to anthropogenic activity instead of natural sources. The PCA results laid the foundation for the PMF analysis by providing a general classification of sources. PMF resolves more factors with a higher explained variance than PCA; PMF provided both the internal analysis and the quantitative analysis. The combination of the two methods can provide more reasonable and reliable results.

The Yellow River Wetland National Nature Reserve (the Sanmenxia section) is an important area of the Yellow River for two important hydrologic gauging stations: the Sanmenxia reservoir and the Xiaolangdi reservoir. Seven sites along the section were selected: Jiziling, Dinghuwan, Houdi, Canglonghu, Shangcun, Wangguan, and Nancun. After the microwave digestion with aqua regia, concentrations of Cu, Pb, Cd, Cr, Zn, and Mn in the sediments were analyzed by flame atomic absorption spectrometry with air-acetylene flame. The results showed that all the concentrations of Cr detected were from the lithogenic source, and 63 % Mn, 48 % Pb, 41 % Cu, 20 % Cd, and 12 % Zn were from the anthropogenic source. The values of the index of geo-accumulation pointed out that there was moderate contamination of Mn at the Dinghuwan (1.04) and Houdi (1.00) sites (class 2), while the modified degree of contamination denoted that the contamination at the Houdi site (2.02) was moderate, nil to very low at the Nancun and Shangcun sites and low at the other sites, consisting with the tendency of pollution load index. For metal toxicity, the sediment pollution index indicated that the sediments of the Canglonghu site were low polluted, that of the Houdi site is nearly slightly contaminated, and those of others were natural and uncontaminated. It was vital to evaluate the degree of contamination with individual and overall elements and even with the metal toxicity. Cu, Pb, and Mn contaminations were aggravated in the Sanmenxia section, and there maybe was one of the main anthropogenic sources of these metals along the Yellow River. The findings were expected to update the current status of the heavy metal pollution in the Sanmenxia section as well as to create awareness concerning the sound condition of the whole reaches of the Yellow River.

The thermal desorption was combined with sodium hydroxide to remediate polychlorinated biphenyl (PCB)-contaminated soil. The experiments were conducted at different temperatures ranging from 300 to 600 °C with three NaOH contents of 0.1, 0.5, and 1 %. The results showed that thermal desorption was effective for PCB removal, destruction, and detoxication, and the presence of NaOH enhanced the process by significant dechlorination. After treatment with 0.1 % NaOH, the removal efficiency (RE) increased from 84.8 % at 300 °C to 98.0 % at 600 °C, corresponding to 72.7 and 91.7 % of destruction efficiency (DE). With 1 % NaOH content treated at 600 °C, the RE and DE were 99.0 and 93.6 %, respectively. The effect of NaOH content on PCB removal was significant, especially at lower temperature, yet it weakened under higher temperature. The interaction between NaOH content and temperature influenced the PCB composition. The higher temperature with the help of NaOH effectively increased the RE and DE of 12 dioxin-like PCBs (based on WHO-TEQ).

Air pollution has become a top environmental concern in China. In the present study, 9 years of PM₁₀ and PM₂.₅ data from an urban monitoring station in Beijing was analyzed relative to other gaseous pollutants and several meteorological parameters. The levels and characteristics of particulate matters as well as the sources and factors affecting them were provided in the present study. During the 9-year observation period, PM₁₀ and PM₂.₅ showed high levels, with annual mean values of 138.5 ± 92.9 and 72.3 ± 54.4 μg/m³, respectively. Slight decreasing trends of annual mean PM₁₀ and PM₂.₅ were observed; autumn was the main season that contributed to the decrease in annual mean PM₁₀ and PM₂.₅. Higher values for both PM fractions were generally observed in the spring and summer months, respectively, whereas lower values were found in the summer and spring months, respectively. Pronounced diurnal variations were found for PM₁₀ and PM₂.₅, which both displayed a bimodal pattern with peaks between 7:00 and 8:00 a.m. as well as 7:00 and 11:00 p.m.; a minimum generally appeared at approximately noon. The seasonal and diurnal variations in particulate concentration are mostly dominated by the seasonal and diurnal variability of boundary layer and source emissions. A principal components analysis revealed that both the traffic-related emissions and combustion sources were major contributions to the particles; their contributions ranged between 35.5–75.1 %. Furthermore, a directional analysis shows a stronger association between particles and the southerly winds, the PM derived from sources south of Beijing, most likely secondary PM, significantly affects concentrations at the sampling site. To improve air quality in Beijing, mitigation measures including phasing out high energy-consuming industries and prioritize the use of clean energy sources should be designed to reduce emissions from both local and regional sources.