Alteration of DNA,RNA and collagen synthesis in lung organ cultures exposed to mercury ions

We have examined the effect of Hg²⁺ ions on DNA, RNA and collagen synthesis in organ cultures of neo-natal rat lungs. These cultures exhibit many biochemical characteristics of lung in vivo and they continue to synthesize macromolecules at increasing rates up to 6 days. When these cultures were exposed to 1.0μM HgC1₂, the synthesis of DNA was stimulated nearly 3-fold after 72 hr of exposure followed by a decline at 120 hr reflecting cumulative cytotoxicity. Higher concentrations were inhibitory at all times. A nearly 3-fold increase in RNA synthesis occurred after 24 hr exposure to 1.0 μM HgC1₂ and at 72 hr the cultures continued to synthesize RNA at rates comparable to control. There was a decrease in RNA synthesis at 120 hr. Increased collagen synthesis was observed at concentrations up to 10 μM and at all times. The maximal increase, 2–3 fold, occurred at 120 hr in cultures exposed to 0.1 M. These studies suggest that Hg²⁺-induced cell injury in lung organ cultures elicits a reparative response characterized by increased collagen synthesis. This is similar to chemically induced tissue-injury in lungs in vivo. The relevance of these data to the mechanism of induced pulmonary fibrosis is discussed. These studies also point to the usefulness of organ cultures for studying pulmonary toxicity of environmental agents.     

Pretreatment of cyanided tailings by catalytic ozonation with Mn2+/O3

The increasing amount of cyanided tailings produced as a by-product has gained significant attention in recent years because of the rapid development of the gold industry and extensive exploitation of gold mineral resources. The effective use of these secondary resources is becoming an important and urgent problem for all environmental protection staff. Manganese-catalyzed ozonation for the pre-oxidation of cyanided tailings was studied and the effects of Mn²⁺ dosage, initial sulfuric acid concentration, ozone volume flow, temperature and agitation speed on pretreatment were examined. The optimum reaction conditions were observed to be: ore pulp density 2.5%, agitation speed 700 r/min, temperature 60 ℃, Mn²⁺ dosage 40 g/L, ozone volume flow 80 L/hr, initial sulfuric acid concentration 1 mol/L, and reaction time 6 hr. Under these conditions, the leaching rate of Fe and weight loss could reach 94.85% and 48.89% respectively. The leaching process of cyanided tailings by Mn²⁺/O³ was analyzed, and it was found that the leaching of pyrite depends on synergetic oxidation by high-valent manganese and O³, in which the former played an important part.     

Adoption of green banking practices and environmental performance in Pakistan: a demonstration of structural equation modelling

Environment, Development and Sustainability - Banking industries are blamed to be among the major factors that affect global climate change both directly and indirectly. The green banking concept...     

Is Globalization Detrimental to CO<Subscript>2</Subscript> Emissions in Japan? New Threshold Analysis

Using annual data from 1970 to 2014, this paper examines the effects of globalization on CO₂ emissions in Japan while accounting for economic growth and energy consumption as potential determinants of carbon emissions. The structural breaks and asymmetries arising due to policy shifts require attention, and hence, an asymmetric threshold version of the ARDL model is utilized. The results show the presence of threshold asymmetric cointegration between variables. Threshold-based positive and negative shocks arising from globalization increase carbon emissions, while the impact of the latter is more profound. Energy consumption (economic growth) also has a significant positive effect on carbon emissions. Globalization, economic growth, and energy consumption significantly increase carbon emissions in the short run. We suggest that policy makers in Japan consider globalization and energy consumption as policy tools in formulating their policies regarding protecting sustainable environmental quality in the long run. Otherwise, the Japanese economy may continue to face environmental consequences such as undesirable climate change and massive warming at the micro and macro levels as a result of potential shocks arising from globalization and energy consumption.     

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.     

Levels,profile and distribution of Dechloran Plus (DP) and Polybrominated Diphenyl Ethers (PBDEs) in the environment of Pakistan

No scientific data is available on emerging contaminants including Polybrominated Diphenyl Ethers (PBDEs) and Dechloran Plus (DP) levels in the environment in Pakistan. Levels of PBDEs and DP were determined in the soil, sediment and atmospheric samples along the stretch of River Ravi in Punjab Province. Average concentrations of ΣPBDEs in atmosphere, soils and sediments were 36 pg m⁻³, 40 ng g⁻¹ and 640 ng g⁻¹. BDE-209 was the most abundant PBDE congener, showing that deca-BDE accounts for most of the total PBDE emitted in the environment of Pakistan. Total DP levels were calculated as 88 pg m⁻³, 0.8 ng g⁻¹ and 1.9 ng g⁻¹ in air, soil and sediment samples, respectively. The lower average fractions of anti-DP showed significant differences to those of the technical mixtures, indicating the lack of DP production source in Pakistan.     

Water quality assessment of Lake Pandu Bodhan, Andhra Pradesh State, India

A systematic investigation of variations in some nutrient levels at Pandu Lake from August 2002 to July 2004 was carried out. The untreated domestic wastes from various parts of Bodhan town are directly discharged into Pandu Lake leading to gross pollution. Therefore present investigation was under taken to assess the magnitude of sewage pollution by monitoring key water quality parameters dissolved oxygen, biological oxygen demand, alkalinity, calcium, nitrates and phosphates etc. Monthly water samples were collected from three different sampling stations. Low Dissolved oxygen and high biological oxygen demand, elevated Nitrates and Phosphates levels were found, which gives the information about conversion of this water body from oligotrophic to eutrophic nature. Phosphates were found to be in the range of 0.9 to 4.0 mg/L. Nitrates were found to be higher in Pandu Lake and their number is more in summer, and suitable explanation was given. Nitrates were found to be in range between 24.8mg/L to 71.2mg/L. Data on various chemical characteristics vary at different sites in different months in Pandu Lake. Some of the characteristics like Dissolved Oxygen, Biological Oxygen Demand, Nitrates, Phosphates and nutrient loading are contributing to eutrophication process in this lake and the lake seems to be eutrophic through out the year.     

Determination of fecal contamination indicator sterols in an Australian water supply system

This paper reports a reconnaissance survey of the concentrations of sterol compounds (as indicators of fecal contamination) in a large water supply system in southeast Australia comprising a network of rivers, channels, and drains. Levels of coprostanol and cholestanol were determined in surface water and bottom sediment using gas chromatography–mass spectrometry analysis across 17 strategic sampling sites and over 12 months. Clear differences in the levels of fecal contamination were observed among sites. Four sites routinely contained high levels of the fecal indicator sterols indicated from surface water and sediment sample analysis. Coprostanol concentrations at each location varied from 0 ng/L at the reference site to 11,327 ng/L in a surface water sample of a drain directly downstream of a knackery. The majority of the sites contained coprostanol in the range of 500 to 800 ng/L. Since no fecal-associated sterol compounds were detected at the external reference sites, these were assumed to be free from fecal contamination. Sewage water discharge and/or substantial water runoff maybe the principal factors contributing to fecal contamination of the supply drains and channels.     

Aerobiological, clinical, and immunobiochemical studies on Alstonia scholaris pollen from eastern India

Alstonia scholaris or Indian devil tree is a common, evergreen, tropical tree of the Apocynaceae family. The objectives of this study were (a) to observe the seasonal variation of A. scholaris pollen in the atmosphere of an industrial and rural area of West Bengal, India by conducting a 2-year aerobiological survey with a Burkard personal volumetric sampler, (b) to study its allergenicity in the local population by in vivo (skin-prick test) and in vitro tests (enzyme-linked immunosorbent assay and dot blotting), (c) to identify the immunoglobulin E (IgE)-binding proteins present in the pollen extract (sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting), (d) to study its chemical composition. A. scholaris pollen were present in the air from September until November. They contained 14.3 % carbohydrate, 9.2 % lipid, and 4.3 % protein. Among 140 respiratory allergic local patients, 28.57 % showed positive skin reaction to A. scholaris pollen extract. Twelve protein bands in the range of 94.4–13.3 kDa were observed in the pollen extract. Seven IgE-binding proteins were found. Among them, one component of 29.9 kDa was the most important in A. scholaris pollen extract. This component could be purified and would be helpful in the diagnosis and therapy of A. scholaris pollen-susceptible patients.     

Heavy metals concentration in edible fishes from coastal region of Kalpakkam, southeastern part of India

Concentrations of Cu, Mn, Zn, Fe, Cr, and Pb were estimated using ICP-MS in nine commercially important and locally consumed fish species (Sarda orientalis, Scomberomorus commerson, Rastrelliger kanagurta, Sardinella longiceps, Paraplagusia bilineata, Cynoglossus lida, Cynoglossus macrostomus, Lepturacanthus savala, and Siganus javus) collected from coastal waters of Kalpakkam, eastern part of India. Their concentration (μg g(-1)) in the examined fish species ranged as follows: Cu (0.8-6.5), Zn (14.3-27.9), Mn (0.5-8.8), Fe (17.6-117.0), Cr (0.24-1.78), and Pb (0.18-2.29). Concentrations of most of the metals in the fish species studied were found to be safe for human consumption barring Mn.