Modeling of agricultural drought risk pattern using Markov chain and GIS in the western part of Bangladesh

The aim of the study is to assess the agricultural drought risk condition in the context of global climate change in the western part of Bangladesh that covers about 45% area of the country for the period of 1960–2011. Drought Index (DI) and Drought Hazard Index (DHI) have been calculated by Markov Chain analysis and that of Drought Vulnerability Index (DVI) from socioeconomic and physical indicators. The DI values show that the northern part in general is more drought-prone, having less crops prospect, whereas the southern part is less drought-prone with high crop potentiality. The probability of extreme drought occurrence increases in recent decades in some parts as a result the drought events become more frequent in the areas. The DHI ranges from 15 to 32, and northern part suffers from more extreme drought hazards than that of southern part. DVI also indicates that northern part is exposed to high to very high drought vulnerability as higher percentage of illiterate people are involved in agricultural practices and high percentage of irrigation to cultivable land, but southern part exposed to moderate to low vulnerability because of low values of vulnerability indicators. Finally, agricultural drought exists at high risk condition in northern part and low in southern parts and 21.63, 26.54 and 29.68% of the area poses very high, high and moderate risk, respectively. So, immediate adaptation measures are needed keeping in mind climate features like rainfall and temperature variability, drought risk and risk ranking to make viable adaptation measures.     

Determination of heavy metal contents in water,sediments, and fish tissues of Shizothorax plagiostomus in river Panjkora at Lower Dir,Khyber Pakhtunkhwa,Pakistan

The present study was conducted to investigate the contamination of water, sediments, and fish tissues with heavy metals in river Panjkora at Lower Dir, Khyber Pakhtunkhwa, Pakistan. Water, sediments, and fish (Shizothorax plagiostomus) samples were collected from September 2012 to January 2013 at three different sites (upstream site at Sharigut, sewage site at Timergara, and downstream site at Sadoo) of river Panjkora. The concentrations of heavy metals in water were in the order Zn?>?Cu?≈?Pb?>?Ni?≈?Cd with mean values of 0.30, 0.01, 0.01, 0.0 and 0.0 mg/l, respectively, which were below the maximum permissible limits of WHO for drinking water. In sediments, heavy metals were found in the order Cu?>?Zn?>?Ni?>?Pb?>?Cd with mean concentrations of 50.6, 38.7, 9.3, 8, and 0.4 mg/kg, respectively. Ni and Cd were not found in any fish tissues, but Zn, Cu, and Pb were detected with the mean concentration ranges of 0.04–1.19, 0.03–0.12, and 0.01–0.09 μg/g, respectively. The present study demonstrates that disposal of waste effluents causes a slight increase in the concentration of heavy metals in river Panjkora as revealed by variation in metal concentrations from upstream to downstream site. Sewage disposal was also found to change physicochemical characteristics of Panjkora water. At present, water and fish of river Panjkora are safe for human consumption, but the continuous sewage disposal may create problems in the future.     

Effect of Tinospora cordifolia on the reduction of ultraviolet radiation‐induced cytotoxicity and DNA damage in PC12 cells

The safety of Tinospora cordifolia and its potential to protect against ultraviolet radiation‐induced cytotoxicity and DNA damage in PC12 cells were investigated. To evaluate the safety of T. cordifolia, cell viability and agarose gel electrophoresis were carried out using PC12 cells treated with 0 to 100 μg mL^?1 of methanol extract of T. cordifolia. T. cordifolia extracts did not show cytotoxicity ranging 0 to 100 μg mL^?1. In addition, T. cordifolia extracts significantly increased cell viability at 1 ng, 10 ng and 1 μg mL^?1 concentrations in serum‐deprived medium compared to control. To confirm the protective role against UV‐induced damage, PC12 cells alone or in the presence of 10 ng, 100 ng, or 1 μg mL^?1 of T. cordifolia extract were exposed to 250, 270 and 290 nm of UV radiation, which corresponded to doses of 120, 150 and 300 mJ cm^?2, respectively. Treatment with T. cordifolia extracts significantly increased the cell survival rate irradiated at 290 nm. In addition, T. cordifolia extracts significantly reduced cyclobutane pyrimidine dimer formation induced by UV irradiation at all wavelengths. In conclusion, T. cordifolia is not toxic and safe for cells. Our findings can support its application as phototherapy in the medical sector.     

An on-line analysis of 7 odorous volatile organic compounds in the ambient air surrounding a large industrial complex

The concentrations of seven odorous volatile organic compounds (VOCs) including styrene (S), toluene (T), xylene (X), methyl ethyl ketone (MEK), isobutyl alcohol (i-BuAl), methyl isobutyl ketone (MIBK), and butyl acetate (BuAc) were measured continuously at hourly intervals from an on-line odor monitoring station in Ansan city, Korea (August 2005 to December 2007). Their concentration data (ppb) exhibited a narrow range of mean values despite large variabilities: 1.33 ± 8.81, 16.1 ± 96.6, 3.32 ± 11.5, 7.45 ± 10.3, 20.4 ± 2.38, 1.31 ± 1.16, and 2.43 ± 3.02, respectively. However, unlike aromatics, the distribution of other VOCs was characterized by infrequent occurrences, e.g., as large as 97.5% of i-BuAl data below detection limit. Comparison of temporal patterns indicates that aromatic VOCs are the highest in summer, while others tend to peak during fall (or summer). If the relative compositions of these VOCs were compared in terms of odor intensity, their contribution in the study area is unlikely significant as the malodor components. Evaluation of the data suggests that the distribution of the target VOCs should be affected more sensitively by local traffic activities rather than industrial processes in the surrounding area. Nonetheless, the potent roles of these volatile components should not be underestimated with respect to human health.     

Method to recover and reuse chromated copper arsenate wood preservative from spent treated wood

The volume of chromated copper arsenate (CCA) treated wood products coming out of service is expected to increase dramatically during the next decade. There is a need for an alternative waste management approach to landfilling. This paper investigates the variables affecting extraction of CCA components from wood particles and the potential to oxidize and reuse the recovered chemicals. Most of the CCA components could be extracted by 10% H2O2 at 50 degrees C in 6 h with an average extraction efficiency of 95% for Cr, 94% for Cu and 98% for As. The extract containing Cr(III), Cu(II) and As(V) could be oxidized in several stages by aqueous 2.5% w/w H2O2 in less than 2 h to a condition where it was compatible with CCA treating solutions and could be reused for treating new wood. When the recovered extract was mixed with fresh CCA solution in different ratios, the mixed CCA-C solutions had similar solution stability as freshly prepared CCA-C solution and treated wood had similar leaching properties as wood treated with fresh solution.     

Indoor air quality assessment in child care and medical facilities in Korea

In order to characterize the status of indoor air pollution in some important facilities, a list of key criteria pollutants [particulate matter (PM(10)), carbon dioxide (CO(2)), carbon monoxide (CO), formaldehyde (HCHO), and bioaerosol] was measured from a total of 91 randomly selected sites in 18 different cities, Korea (February 2006 to December 2009). The target facilities include 43 child care facilities, 38 medical facilities, 6 elementary schools, and 4 postnatal care centers. The results showed that some air pollutants (e.g., CO and HCHO) did not exceed the recommended guideline [e.g., the Korean indoor air standard (KIAS) values of 10 ppm and 100 ppb, respectively]. However, concentration of PM(10), CO(2), and bioaerosol occasionally exceeded their respective guidelines (e.g., seven, three, and two cases). Discrete seasonalities were observed from indoor pollutants because of varying ventilation practice (e.g., summer time dominance of PM(10), HCHO, and bioaerosol or winter dominance of CO(2) and CO). However, as the concentrations of the indoor pollutants were scarcely above the recommended guideline level, more diversified approaches are desirable to diagnose the status of indoor pollution and to provide a realistic strategy for the improvement of IAQ.     

Yard waste prediction from estimated municipal solid waste using the grey theory to achieve a zero-waste strategy

Environmental Science and Pollution Research - Yard waste is one of the key components of municipal solid waste and can play a vital role in implementing zero-waste strategy to achieve sustainable...