The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence from a panel of developed countries

The objective of the study is to investigate the long-run relationship between climatic factors (i.e., greenhouse gas emissions, agricultural methane emissions, and industrial nitrous oxide emission), air pollution (i.e., carbon dioxide emissions), and energy sources (i.e., nuclear energy; oil, gas, and coal energy; and fossil fuel energy) in the panel of 35 developed countries (including EU-15, new EU member states, G-7, and other countries) over a period of 1975–2012. In order to achieve this objective, the present study uses sophisticated panel econometric techniques including panel cointegration, panel fully modified OLS (FMOLS), and dynamic OLS (DOLS). The results show that there is a long-run relationship between the variables. Nuclear energy reduces greenhouse gases and carbon emissions; however, the other emissions, i.e., agricultural methane emissions and industrial nitrous oxide, are still to increase during the study period. Electricity production from oil, gas, and coal sources increases the greenhouse gases and carbon emissions; however, the intensity to increase emissions is far less than the intensity to increase emissions through fossil fuel. Policies that reduce emissions of greenhouse gases can simultaneously alter emissions of conventional pollutants that have deleterious effects on human health and the environment.     

Microbial contamination of drinking water in Pakistan—a review

Water pollution with pathogenic microorganisms is one of the serious threats to human health, particularly in developing countries. The main objective of this article is to highlight microbial contamination of drinking water, the major factors responsible for microbial contamination, and the resulting health problems in Pakistan. Furthermore, this study will be helpful for researchers and administrative agencies to initiate relevant studies and develop new policies to protect further deterioration of water supply with pathogenic microbes and ensure clean and safe drinking water to the public in Pakistan. In Pakistan, water at the source, in the distribution network, and at the consumer tap is heavily polluted with coliforms and fecal coliforms all over the country. An overview of more than 7,000 water samples reviewed here reveals that an average of over 71 and 58 % samples in the country was contaminated with total coliforms and fecal coliforms, respectively. Drinking water contamination accounts for 20 to 40 % of all diseases in the country, which causes national income losses of Rs 25–58 billion annually (US$0.25–0.58 billion, approximately 0.6–1.44 % of the country’s GDP). Improper disposal of industrial and municipal wastes is the most important factor responsible for water pollution in the country followed by cross-contamination due to old and leaking pipes and lack of water filtration and disinfection facilities. There is an urgent need for emergency steps to stop further deterioration of water quality and improve the existing water quality so as to protect the public from widespread waterborne diseases.     

Effects of Cd and Pb on soil microbial community structure and activities

Background, aim, and scope  

Soil contamination with heavy metals occurs as a result of both anthropogenic and natural activities. Heavy metals could have long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. Soil enzymatic activities are recognized as sensors towards any natural and anthropogenic disturbance occurring in the soil ecosystem. Similarly, microbial biomass carbon (MBC) is also considered as one of the important soil biological activities frequently influenced by heavy metal contamination. The polymerase chain reaction–denaturing gradient gel electrophoresis (DGGE) has recently been used to investigate changes in soil microbial community composition in response to environmental stresses. Soil microbial community structure and activities are difficult to elucidate using single monitoring approach; therefore, for a better insight and complete depiction of the soil microbial situation, different approaches need to be used. This study was conducted in a greenhouse for a period of 12 weeks to evaluate the changes in indigenous microbial community structure and activities in the soil amended with different application rates of Cd, Pb, and Cd/Pb mix. In a field environment, soil is contaminated with single or mixed heavy metals; so that, in this research, we used the selected metals in both single and mixed forms at different application rates and investigated their toxic effects on microbial community structure and activities, using soil enzyme assays, plate counting, and advanced molecular DGGE technique. Soil microbial activities, including acid phosphatase (ACP), urease (URE), and MBC, and microbial community structure were studied.     

Development of a variable configuration cascade impactor for aerosol size distribution measurement

In atmospheric aerosol studies, it is often required to use two different impactors, namely, the normal pressure and the low-pressure impactor, to measure the mass-size distribution over a wide size range. From the perspective of rendering the system compact for such measurements, it may be more advantageous to combine the two features in a single instrument. In an effort towards exploring this option, a variable configuration cascade impactor (VCCI) comprising of 7 normal pressure and 4 low-pressure stages has been designed and developed. In configuration-1, it operates as a low-pressure impactor, with a sampling flow rate of 10 L min^?1 and classifies the particles from 0.1 to 21 μm in eleven size classes. In configuration-2, it operates as a normal pressure impactor, with a sampling flow rate of 45 L min^?1, and classifies the particles from 0.53 to 10 μm in seven size classes. As part of performance evaluation of the system, the deposit patterns and the integral performance have been studied. For integral performance, a comparative mass-size distribution measurement between VCCI and standard Andersen impactor was carried out. Its performance was also evaluated against the GRIMM Scanning Mobility Particle Sizer (SMPS) in the common size range of both these instruments and against GRIMM Optical Particle Counter (OPC). In addition to this, VCCI was evaluated for its performance in the PM_x configuration obtained by removing a few of the impactor stages sequentially and measuring corresponding size distribution for every stage removed. Changes in the distribution parameters due to spillover of the deposits of previous stage to remaining stages were within 10%. This variation is well within the generally accepted value for all environmental measurement related applications.     

Interaction of ions in water affects water quality of freshwater lake: a case study of major lakes of North India

The influence of ionic composition on the water chemistry and thereby on aquatic flora was investigated. Two major wetlands of North India were taken for the study. Quality parameters of the lakes showed the enrichment of the water especially in the month of September with higher values of P and BOD in almost all of the lakes viz., LSJ, LCH, LSN, and LHT as <5.0, 9.0, 1.0, 1.7 and <7.3, 6.0, 6.3, and 4.0, respectively. Statistically correlated values of the ions in the water quality showed an effect of one on another. An attempt has also been made to investigate if ionic constituent is one of the major causes affecting the aquatic floral diversity.     

Effect of liming on the distribution of heavy metals in untreated industrial sewage sludge produced in Pakistan for the cultivation of <Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.)

The recycling of sewage sludge on agriculture land represents an alternative, advantageous, disposal of this waste material. The aim of the present study was to evaluate the feasibility of using industrial sewage sludge, produced in Pakistan, as a fertiliser. Agricultural soil amended with 25% (w/w) sewage sludge with or without lime treatment was used for growing a variety of sorghum (PARC-SS-1). The mobility of the heavy metals (HMs) (Cd, Cu, Cr, Ni, Pb and Zn) and metalloid (As) in the untreated industrial waste water sewage sludge (UIWS) samples were assessed by applying a modified BCR (Community Bureau of Reference) sequential extraction procedure. The single extraction procedure comprised of the application of mild extractant (CaCl₂) and water for the estimation of the proportion of easily soluble metal fractions. The precision and accuracy of BCR was evaluated by using a certified reference material of soil amended with sewage sludge BCR 483. The plant available metal contents, as extracted by the deionised water and 0.01 M CaCl₂ solution and exchangeable fraction of BCR sequential, decreased with lime application in the range of 10–44% for As, Cr, Ni, Pb and Zn, except in the cases of Cd and Cu, where their mobility was increased by 10% and 24%, respectively. Sludge amendment enhanced the dry weight yield of sorghum and the increase was more obvious after liming up to 25%. The uptake of HMs were lower in test samples (3.2–21.8%), except for Cu and Cd, which was higher (4%), while they were below the permissible limit of these metals. The present experiment demonstrates that liming was important in factors facilitating the growth of sorghum in sludge-amended soil.     

A study on the combined effect of noise and vibration on operators' performance of a readability task in a mobile driving environment.

This paper presents a study in which the main objective was to investigate the combined effect of noise and vibration on the performance of a readability task in a mobile driving environment. Subjects performed a readability task on a laptop computer in a sitting posture with their backs supported with a backrest under varying levels of noise and vibration. The data in terms of the mean number of characters read per minute were collected and statistically analyzed. Results showed that the individual effect of noise, vibration, and the operators' gender as well as the interaction between gender and noise, and gender and vibration were statistically significant. However, the combined effect of noise and vibration was not found to be statistically significant. Results also indicated that gender was statistically significant at all levels of noise as well as vibration, and noise and vibration were statistically significant at both levels of gender.     

Chromium Removal from Soil by Phytoremediation with Weed Plant Species in Thailand

The possibility of using phytoremediation with weed plant species in Thailand to remove chromium (Cr) from soil was investigated. Six plant species, Cynodon dactylon, Pluchea indica, Phyllanthus reticulatus, Echinochloa colonum, Vetiveria nemoralis, and Amaranthus viridis, were chosen for their abilities to accumulate total chromium (TCr) at tanning industry sites. These plant species were studied in pots at a nursery. Cynodon dactylon and Pluchea indica provided highest TCr accumulation capacities of 152.1 and 151.8 mg/kg of plant on a dry weight basis, respectively, at a pulse hexavalent Cr [Cr(VI)] input of 100 mg Cr(VI)/kg soil. Most of the Cr uptake occurred within 30 days after the input. The TCr accumulation by Pluchea indica was observed in roots, stems, and leaves at 27%, 38%, and 35% of the TCr mass uptake, respectively, whereas 51%, 49% and 0% of the TCr mass uptake accumulated in roots, stems, and leaves of Cynodon dactylon, respectively. The results on Cr accumulation and translocation in plant tissues suggest that Cr was removed mainly via phytoaccumulation and Pluchea indica is more suitable than Cynodon dactylon for the phytoremediation of Cr contaminated soil.     

Reproduction and growth of progeny of female mice mated after treatment with crufomate

Effects on reproduction and litter growth were studied for two successive reproductive periods (RP)--interval between caging females with males and whelping--in female mice treated dermally with crufomate at 100 or 50 mg/kg on days 35 and 21 before caging with untreated males. Each treatment with crufomate caused about 50% reversible inhibition of cholinesterase activity without inducing any signs of toxicity. The higher dose reduced the conception rate and the number of litters and young born and weaned during the two RPs. It also reduced the lactation index, weaning weight of males and females, and mature weight of males in the first litter. The lower dose prolonged the gestation period and reduced the lactation index and the number of litters and young weaned in the first RP and conception rate and number of litters and young born and weaned in the second RP. The lower dose reduced the weaning and mature weights of the first litter and mature weight of males in the second litter. The higher dose reduced the body weight and the lower dose increased the adrenal weight of the treated females.