Determination of heavy metals in fresh water fish species of the River Ravi, Pakistan compared to farmed fish varieties

The untreated industrial and sewage wastes arising from industries and metropolitan activities make their passage to the River Ravi, Pakistan, where Balloki Headworks is one of the major sites of effluent concentration. This study was designed to evaluate the concentration of various toxic elements in fishes of that area compared to a nearby fish farm. The concentrations of heavy metals, such as As, Cd, Cu, Pb, Hg, and Zn, and electrolytes Ca, K, and Na were determined in different edible and non-edible fresh water fish varieties. Fish samples were collected from two selected sites and were analyzed for aforementioned elements. Higher levels of As (35.74–45.33 ppm), Cd (0.35–0.45 ppm), Pb (2.1–3.0 ppm), Hg (83.03–92.35 ppm) while normal levels of Zn (37.85–40.74 ppm) and Cu (1.39–2.93 ppm) were observed. Mercury, higher levels of which trigger cough, impairment of pulmonary function, and psychotic reactions, was significantly higher in all studied categories. At the sites under study, there has been observed alarming levels of toxic metals which are needed to be monitored regularly.     

Monitoring the impact of urban effluents on mineral contents of water and sediments of four sites of the river Ravi, Lahore

We assessed the impact of urban effluents on the concentrations of selected minerals (Cd, Cr, Cu, Fe, Pb, Zn, Mn, Ni, and Hg) in river Ravi before and after its passage through Lahore city. Water and sediment samples were collected from three lowly to highly polluted downstream sites (Shahdera (B), Sunder (C), and Balloki (D)) alongside the least polluted upstream site (Siphon (A)) during high and low river flow seasons. All the mineral concentrations increased up to site C but stabilized at site D, showing some recovery as compared to the third sampling site. The trend of mean mineral concentration was significantly higher during the low than the high flow season at all the sites. The mean Hg concentrations approached 0.14 and 0.12 mg/l at site A which increased (%) up to 107 and 25 % at site B, 1,700 and 1,317 % at site C, and 1,185 and 1,177 % at site D during low and high river flows, respectively. All mineral concentrations were much higher in the sediment than the water samples. Mean Cd (917 %), Cr (461 %), Cu (300 %), Fe (254 %), Pb (179 %), Zn (170 %), Mn (723 %), Ni (853 %), and Hg (1,699 %) concentrations were higher in riverbed sediments sampled from site C in comparison with the sample collected at site A during low flow season. The domestic and industrial discharges from Lahore city have created undesirable water qualities during the low river flow season. As majority of the mineral levels in the river Ravi were higher than the permissible and safe levels, this is of immediate concern for riverine fish consumers and the users of water for recreation and even irrigation. The use of these waters may pose health risks, and therefore, urgent intervention strategies are needed to minimize river water pollution and its impact on fish-consuming communities of this study area and beyond.     

Evaluation of the mutagenic potential of chlorpyrifos (CPF) using polytene chromosomes of Anopheles mosquito

Diverse cytogenetic tests are employed for short term screening of suspect environmental mutagens by using insects and mammals as models. In the present paper the polytene chromosomes of a mosquito Anopheles maculatus were used to evaluate the mutagenic potential of a widely used organophosphate pesticide chlorpyrifos-[o, o-diethyl-o-(3, 5, 6-trichloro-2-pyridyl) phosphothioate]. The results are based on the frequency of various structural aberrations encountered in the polytene chromosomes of the larvae treated with LC20 of chlorpyrifos (CPF). These aberrations were dominated by inversions, stickiness of the chromosomes, heterochromatinization of the bands and lack of polyteny. The frequency of various aberrations was highest in the left arm of chromosome number 2L followed by 2R, 3L, 3R, and X-chromosomes i.e. 2.10 +/- 0.44, 1.84 +/- 0.44, 1.57 +/- 0.54, 1.31 +/- 0.50, and 0.22 +/- 0.27 respectively. The susceptibility of different chromosomal arms to this pesticide was 2L > 2R > 3L > 3R > X and the regions prone to these aberrations have been marked on the polytene chromosome map of Anopheles maculatus.     

Optimization of alkaline extraction of natural dye from Henna leaves and its dyeing on cotton by exhaust method

The alkaline conditions for extraction of natural dye from Henna leaves were optimized and the resulting extract was used to further optimize its dyeing conditions on cotton by exhaust method. Dyeings without any mordant were compared with those obtained with premordanting and postmordanting with alum and iron. It was found that dyeings produced with alkaline extracts of Henna leaves have better colour strength than the dye extracts obtained in distilled water. Furthermore, dyeings with alkaline extracts have moderate to good fastness properties and that mordanting did not result in any significant improvement in fastness properties. Finally, in comparative studies between synthetic and this natural dye, it was inferred that natural dye has good potential to act as co-partner with synthetic dye.     

Industrialization,Freight Transport and Environmental Quality: Evidence from Belt and Road Initiative Economies

Environmental Science and Pollution Research - Belt and Road initiative has been proposed by China to initiate the cooperation among relevant countries in sector of energy and Trade. The...     

Estimation of bacteriological levels in surface water samples to evaluate their contamination profile

The present work deals with the assessment of bacteriological contamination along with some physico-chemical parameters of water samples from Lahore canal. ANOVA showed that the observed p values of log-transformed viable plate counts, total suspended solids, turbidity, and biological oxygen demand are 0.000, 0.000, 0.000, and 0.000, respectively, which are <0.05, while the p value of total coliforms, total fecal coliforms, and Escherichia coli are 0.728, 0.827, and 0.081, respectively which are >0.05. Significant correlation was observed between log-transformed viable plate counts (CFU), biological oxygen demand, total suspended solids, and turbidity. Further regression analysis revealed that simple line regression model is fit for log-transformed viable plate counts and total suspended solids, log-transformed viable plate counts and turbidity, turbidity and total suspended solids, biological oxygen demand and total suspended solids, biological oxygen demand and log-transformed viable plate counts, and biological oxygen demand and turbidity.     

Nexus between green logistic operations and triple bottom line: evidence from infrastructure-led Chinese outward foreign direct investment in Belt and Road host countries

Environmental Science and Pollution Research - The Belt and Road initiative (BRI) mainly relies on the traditional and underdeveloped logistical trade routes including the terrestrial and oceanic...     

Silver recovery as Ag0 nanoparticles from ion-exchange regenerant solution using electrolysis

Many silver(Ag)containing consumer-products(e.g.textiles)release Ag into the environment,posing ecotoxicological risks.Ag recovery mitigates environmental hazards,recycles Ag,and leads to sustainability.In the present work,Ag has been recovered as Ag~0nanoparticles from the spent solution(thiourea(TU)～0.5 mol/L pH～1.1–1.2,and Ag～550 mg/L)obtained from the regeneration of an Ag-loaded resin using a simple undivided electrolytic cell.The reclaimed regenerant solution has been recycled and reused in a closed-loop scheme over multiple cycles.The process parameters,i.e.,current(0.05 A)and stirring speed(600 r/min),have been optimized for Ag recovery of～94%and TU loss of～2%.The reclaimed regenerant solution has been shown to regenerate Ag-loaded resin samples with90%regeneration efficiency over 4 cycles of consecutive extraction and regeneration.The recovered Ag~0nanoparticles are monodisperse,consistently spherical in shape,and have a mean diameter of～6 nm with standard deviation of the Gaussian fit as～2.66 nm.     

Occupational health and safety issues in the informal economic segment of Pakistan: a survey of construction sites

This research covers the current status of occupational health and safety (OHS)-related practices in the informal construction segment of Pakistan. Data were collected, through interviews, from 316 construction sites employing 3577 workers. The results of the study reveal that both employers and workers lack knowledge of OHS laws/standards and no practices of this nature are enacted at these construction sites. Alarmingly, work-related accidents, whenever they happen, are not given due attention and there is no formal injury-report system. The informal construction industry employs a huge portion of the informal workforce, and lack of OHS happens at tremendous human cost. These research findings may thus play their role in strengthening the case for reforms in the sector. This study, if properly utilized, may also enable employers of the sector by increasing their knowledge about OHS practices and, as a result, trying to offer safer environments for their workers.