Passive air monitoring of PCBs and PCNs across East Asia: a comprehensive congener evaluation for source characterization

A comprehensive congener specific evaluation of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in the atmosphere was conducted across East Asia in spring 2008, applying polyurethane foam (PUF) disk passive air sampler (PAS) as monitoring device. Mean concentrations derived for Japan, China and Korea were 184 ± 24, 1100 ± 118, and 156 ± 20 pg m⁻³ for ∑₂₀₂ PCBs, and 9.5 ± 1.5, 61 ± 6, and 16 ± 2.4 pg m⁻³ for ∑₆₃ PCNs, respectively. Relative to reported data from 2004, the present results suggest that air PCBs concentrations have not changed much in Japan and Korea, while it has increased by one order of magnitude in China. From principal component analysis, combustion emerged highly culpable in contemporary emissions of both PCBs and PCNs across the East Asian sub-region. Another factor derived as important to air PCBs was re-emissions/volatilization. Signals from PCBs formulations were also picked, but their general importance was virtually consigned to the re-emissions/volatilization tendencies. On the contrary, counterpart PCNs formulations did not appear to contribute much to air PCNs.     

Pesticide residues in fruits and vegetables from Pakistan: a review of the occurrence and associated human health risks

The main objective of the review is to document, assess and analyze the results of the previously reported data on levels of different pesticides in selected fruits and vegetables from Pakistan. The findings of the previous studies clearly indicated that more than 50 % of the samples were contaminated with organophosphate, pyrethroids and organochlorine pesticides. Many studies reported that among fresh fruits and vegetables tomato, apple, melon, mango, grapes, and plum crossed the FAO/WHO permissible limits for these contaminants residual levels. The comparison of other regions showed that observed levels were found above maximum residue limits (MRLs) in 50 % of the samples but were in agreement with the studies from neighboring countries like China and Bangladesh. Higher hazard risk index (HRI) values were calculated for dieldrin, methamidophos, o,p′-DDT, diazinon and p,p′-DDT in apple, mango, banana, melon, potato and onion. The review also highlights that data on pesticide residues in foodstuff is scarce which should be overcome by further extending studies from different areas of Pakistan. In order to ascertain the provision of food suitable for human consumption, it is imperative to monitor pesticides in food commodities by the country’s authorities and enforce guidelines based on permissible limits.     

Optimized Removal of Acid Blue 62 from Textile Waste Water by SBA-15/PAMAM Dendrimer Hybrid Using Response Surface Methodology

SBA-15/PAMAM Nano adsorbent was synthesized by the proficiency of SBA-15 as an original compound, 3-chloropropyltrimethoxysilane as a bridge chemical compound and polyamidoamine dendrimer (PAMAM) in the role of a multifunctional amine end group for adsorption of acid blue 62 (AB62) from aqueous media. The synthesized adsorbent was characterized by transmission electron microscope, field emission scanning electron microscope and Fourier-transform infrared spectroscope. A response surface methodology was employed to evaluate the simple and amalgamated factors of the operating variables subtending initial pH (2–12), adsorbent dosage(0.01–0.03 g), contact time (5–120 min), initial dye concentration (40–600 ppm) and temperature (25–45?°C) to optimize the operating statues of the treatment method. These parameters were altered at five levels pursuant to the central composite design to appraise their effects on AB62 removal through analysis of variance. Analysis of variance represented a high coefficient of definition amount (R²?=?0.9999) and acceptable prediction quadratic polynomial model was concluded which ascertain the suitability of the model and a high correlation among the predicted and empirical amounts. Utmost color removal efficiency was auspicated and empirically accredited. The optimum conditions relied on acquired results for AB62 removal were at an initial pH of 2, adsorbent dosage of 0.03 g SBA-15/PAMAM, dye concentration of 40 mg l^?1, time contact of 60 min and temperature of 25?°C.     

Carbaryl stress induced cellular changes in Calothrix brevissima

Cyanobacterial biofertilizers are affected by paddy field pesticides as nontarget organism. Carbaryl is a carbamate pesticide and is commonly used against rice thrip pest in paddy fields. In the present work, cellular changes caused by exposure of the cyanobacterial biofertilizer namely Calothrix brevissima to carbaryl were studied with special reference to fatty acids, electrolyte leakage, sulfur metabolism, and osmolytes. To study the toxic effect of carbaryl, the test cyanobacterium was exposed to varying concentrations of pesticide (0, 10, 20, 30, and 40 mg L^?1) for biochemical analyses. At 40 mg L^?1 carbaryl, polyunsaturated fatty acids were reduced by 32 % and membrane leakage was increased by 27 % suggesting that free radical-mediated lipid peroxidation took place. The sulfur-containing metabolites namely cysteine, cystine, and methionine were increased by 79, 64, and 52 %, respectively. The enzymatic and nonenzymatic antioxidants namely glutathione S-transferase, glutathione reductase, reduced glutathione, and oxidized glutathione were increased to 56, 71, 72, and 60 %, respectively. Osmolytes that serve as stress enzyme protectors as well as nonenzymatic free radical scavenger were also increased, indicating their protective nature in context with carbaryl-induced stress. The respective increase in mannitol, trehalose, and glycogen were 158, 98, and 159 %. In C. brevissima, carbaryl-induced membrane leakage was counteracted by increasing enzymatic and nonenzymatic parameters that helped in scavenging free radicals.     

Impact of treated urban wastewater for reuse in agriculture on crop response and soil ecotoxicity

The scarcity of freshwater resources is a serious problem in arid regions, such as Tunisia, and marginal quality water is gradually being used in agriculture. This study aims to study the impact of treated urban wastewater for reuse in agriculture on the health of soil and food crops. The key findings are that the effluents of Sfax wastewater treatment plant (WWTP) did not meet the relevant guidelines, therefore emitting a range of organic (e.g., up to 90 mg L^?1 COD and 30 mg L^?1 BOD₅) and inorganic pollutants (e.g., up to 0.5 mg L^?1 Cu and 0.1 mg L^?1 Cd) in the receiving aquatic environments. Greenhouse experiments examining the effects of wastewater reuse on food plants such as tomato, lettuce, and radish showed that the treated effluent adversely affected plant growth, photosynthesis, and antioxidant enzyme contents. However, the pollution burden and biological effects on plants were substantially reduced by using a 50 % dilution of treated sewage effluent, suggesting the potential of reusing treated effluent in agriculture so long as appropriate monitoring and control is in place.     

Size fraction of hazardous particulate matter governing the respiratory deposition and inhalation risk in the highly polluted city Delhi

Environmental Science and Pollution Research - Delhi has been identified as one of the highly polluted cities in the world and recently associated with the highest population weighted PM2.5...     

Microplastics in water,sediments, and fish at Alpine River,originating from the Hindu Kush Mountain,Pakistan: implications for conservation

Environmental Science and Pollution Research - Microplastics (MP) pollution is an emerging threat to life and the environment. These particles are not restricted to human-inhabited lands but also...     

Indigenous knowledge on use values of Karvan district plants,Iran

Traditional and indigenous knowledge on plants usage is a valuable source of information from cultural and natural perspectives, reflecting society’s complicated and close relationship with the environment. Communities have a valuable source of traditional knowledge on the utilization of natural resources, and it is worth to be documented and preserved for current and future applications. We conducted this research to collect and identify plant species of Karvan District and document the traditional knowledge on their use and consumption values. Regarding the results, 150 plant species are used by local communities, more than 30 % of which are directly consumed as food, 24 % (37 species) are used as medicinal plants, and 16.3 % are applied for decoration purposes; 58.6 % of the species are consumed in the raw form, and the remaining is processed before consumption. Leaves (35 %), seeds (21 %) and flowers (21 %) are the most frequent parts of the plants that are used. High number of young emigrants to industrialized areas in seek of job opportunities is threatening this precious source of indigenous knowledge. Attempts to preserve this empirical source of information by encouraging trans-generational knowledge transmission would help to maintain it for future applications.     

A historical perspective of Global Warming Potential from Municipal Solid Waste Management

The Municipal Solid Waste Management (MSWM) sector has developed considerably during the past century, paving the way for maximum resource (materials and energy) recovery and minimising environmental impacts such as global warming associated with it. The current study is assessing the historical development of MSWM in the municipality of Aalborg, Denmark throughout the period of 1970 to 2010, and its implications regarding Global Warming Potential (GWP₁₀₀), using the Life Cycle Assessment (LCA) approach. Historical data regarding MSW composition, and different treatment technologies such as incineration, recycling and composting has been used in order to perform the analysis. The LCA results show a continuous improvement in environmental performance of MSWM from 1970 to 2010 mainly due to the changes in treatment options, improved efficiency of various treatment technologies and increasing focus on recycling, resulting in a shift from net emission of 618 kg CO₂-eq. tonne^?1 to net saving of 670 kg CO₂-eq. tonne^?1 of MSWM.     

Monitoring landscape metrics by point sampling: accuracy in estimating Shannon’s diversity and edge density

Environmental monitoring of landscapes is of increasing interest. To quantify landscape patterns, a number of metrics are used, of which Shannon’s diversity, edge length, and density are studied here. As an alternative to complete mapping, point sampling was applied to estimate the metrics for already mapped landscapes selected from the National Inventory of Landscapes in Sweden (NILS). Monte-Carlo simulation was applied to study the performance of different designs. Random and systematic samplings were applied for four sample sizes and five buffer widths. The latter feature was relevant for edge length, since length was estimated through the number of points falling in buffer areas around edges. In addition, two landscape complexities were tested by applying two classification schemes with seven or 20 land cover classes to the NILS data. As expected, the root mean square error (RMSE) of the estimators decreased with increasing sample size. The estimators of both metrics were slightly biased, but the bias of Shannon’s diversity estimator was shown to decrease when sample size increased. In the edge length case, an increasing buffer width resulted in larger bias due to the increased impact of boundary conditions; this effect was shown to be independent of sample size. However, we also developed adjusted estimators that eliminate the bias of the edge length estimator. The rates of decrease of RMSE with increasing sample size and buffer width were quantified by a regression model. Finally, indicative cost–accuracy relationships were derived showing that point sampling could be a competitive alternative to complete wall-to-wall mapping.