The influence of metal speciation on the bioavailability and sub-cellular distribution of cadmium to the terrestrial isopod, Porcellio dilatatus

Cadmium is a non-essential toxic metal that is able to bioaccumulate in both flora fauna and has the potential to biomagnify in some food chains. However, the form in which cadmium is presented to consumers can alter the bioavailability and possibly the internal distribution of assimilated Cd. Previous studies in our laboratory highlighted differences in Cd assimilation among isopods when they were provided with a plant-based food with either Cd biologically incorporated into plant tissue or superficially amended with ionic Cd(2+). Cd is known for its high affinity for sulphur ligands in cysteine residues which form the basis for metal-binding proteins such as metallothionein. This study compares Cd assimilation efficiency (AE) in Porcellio dilatatus fed with food amended with either cadmium cysteinate or cadmium nitrate in an examination of the influence of Cd speciation on metal bioavailability followed by an examination of the sub-cellular distribution using a centrifugal fractionation protocol. As hypothesized the AE of Cd among isopods fed with Cd(NO(3))(2) (64%, SE=5%) was higher than AE for isopods fed with Cd(Cys)(2) (20%, SE=3%). The sub-cellular distribution also depended on the Cd species provided. Those isopods fed Cd(Cys)(2) allocated significantly more Cd to the cell debris and organelles fractions at the expense of allocation to metal-rich granules (MRG). The significance of the difference in sub-cellular distribution with regard to toxicity is discussed. This paper demonstrates that the assimilation and internal detoxification of Cd is dependent on the chemical form of Cd presented to the isopod.     

Cocaine and other illicit drugs in airborne particulates in urban environments: a reflection of social conduct and population size

Levels of cocaine and other psychoactive substances in atmospheric particulate matter (PM) were determined in urban environments representing distinct social behaviours with regard to drug abuse: night-life, university and residential areas. Three cities (with population >1 million and <0.3 million inhabitants) were selected. Mean daily levels of drugs in PM were 11-336 pg/m³ for cocaine, 23-34 pg/m³ for cannabinoids, and 5-90 pg/m³ for heroin. The highest levels were recorded on weekends, with factors with respect to weekdays of 1-3 for cocaine, 1-2 for cannabinoids and 1.1-1.7 for heroin. Higher levels were detected in the night-life areas, pointing towards consumption and trafficking as major emission sources, and possibly ruling out drug manufacture. The similarities in temporal trends at all sites suggested a city-scale transport of psychoactive substances. Correlations were detected between cocaine and amphetamine consumption (r² = 0.98), and between heroin and cannabinoids (r²>0.82).     

Printed wiring boards for mobile phones: characterization and recycling of copper

The popularization of mobile phones, combined with a technological evolution, means a large number of scrap and obsolete equipment are discarded every year, thereby causing economic losses and environmental pollution. In the present study, the printed wiring boards scrap of mobile phones were characterized in order to recycle some of the device components, using techniques of mechanical processing, hydrometallurgy and electrometallurgy. The use of the techniques of mechanical processing (milling, particle size classification, magnetic and electrostatic separation) was an efficient alternative to obtain a concentrated fraction (mainly iron in the magnetic fraction and copper in the conductive fraction) and another fraction containing polymers and ceramics. At the end of mechanical processing, a concentrated fraction of metals could be obtained with an average concentration of 60% copper. This concentrated fraction in metals was dissolved in aqua regia and sent to electrowinning to recover 92% of the dissolved copper. The obtained cathodes have a copper content above 95%, which demonstrates the technical feasibility of recovery of copper using the techniques of mechanical processing, hydrometallurgy and electrometallurgy.     

Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adélie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g⁻¹ dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g⁻¹ dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine.     

Analysis and fit of surface CO2 concentrations at a rural site

Purpose

The impact of CO₂ urban plume in a rural area was investigated by concentrations recorded near surface.

Methods

CO₂ dry concentrations at three levels near surface were recorded for about 8 months at a rural site. Daily cycles were obtained and directional analysis was made with percentiles. Several functions were used to fit background and plume concentrations and the goodness of fit was evaluated with different statistics, which were also compared.

Results

Daily cycle showed a difference of around 2 ppm during the night between the lowest (1.8 m) and the highest (8.3 m) levels. Weighting functions of the directional analysis revealed the influence of the Valladolid urban plume. Two regions were established, with local factors prevailing below 3 m?s^?1 and transport dominating above 6 m?s^?1. The best fit was achieved with a quadratic function for the background and a cubic function for the plume due to the lack of symmetry observed. Gamma and Weibull distributions were also successfully used. Some statistics, such as the root mean square error (RMSE), stood out when evaluating the goodness of fit, whilst others were discarded due to their extremely low values and the lack of sensitivity against the functions used. Finally, a comprehensive metric merging several statistics was also tested with slight differences against RMSE.     

Mercury distribution in seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system

Background and purpose  

More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation.     

Hexachlorocyclohexane (HCH) as new Stockholm Convention POPs��a global perspective on the management of Lindane and its waste isomers

Purpose

Hexachlorocyclohexane (HCH) isomers (??-, ??- and ??- (Lindane)) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention, and therefore, the legacy of HCH and Lindane production became a contemporary topic of global relevance. This article wants to briefly summarise the outcomes of the Stockholm Convention process and make an estimation of the amount of HCH waste generated and dumped in the former Lindane/HCH-producing countries.

Results

In a preliminary assessment, the countries and the respective amount of HCH residues stored and deposited from Lindane production are estimated. Between 4 and 7 million tonnes of wastes of toxic, persistent and bioaccumulative residues (largely consisting of alpha- (approx. 80%) and beta-HCH) are estimated to have been produced and discarded around the globe during 60 years of Lindane production. For approximately 1.9 million tonnes, information is available regarding deposition. Countries are: Austria, Brazil, China, Czech Republic, France, Germany, Hungary, India, Italy, Japan, Macedonia, Nigeria, Poland, Romania, Slovakia, South Africa, Spain, Switzerland, Turkey, The Netherlands, UK, USA, and former USSR. The paper highlights the environmental relevance of deposited HCH wastes and the related POPs?? contaminated sites and provides suggestions for further steps to address the challenge of the legacy of HCH/Lindane production.

Conclusion

It can be expected that most locations where HCH waste was discarded/stockpiled are not secured and that critical environmental impacts are resulting from leaching and volatilisation. As parties to the Stockholm Convention are legally required to take action to stop further POPs pollution, identification and evaluation of such sites are necessary.     

World poverty,another look

The World Bank used the Consumer Price Index (CPI) to calculate changes in the world poverty level (measured in U.S. dollars) prior to 1982. In 1983, the U.S. Bureau of Labor Statistics (BLS) replaced the CPI with several indices including CPI-W which was then adopted by the World Bank. This caused the inflated rate of the U.S. dollars and the percentage of the world population in poverty to be dramatically underestimated. This new incorrect procedure gives 25% (1.5 million) below the poverty line in 2005, while the more appropriate procedure (described herein) gives 52% (3.3 million in 2005). The rapid rise of the poverty line (using the preferable CPI) starting in 1987 occurred at nearly the same time as the peak in per capita annual cereal production.     

Pesticide use among smallholder rice farmers in Tanzania

In an interview study conducted among smallholder rice farmers in Rufiji, Tanzania coastal mainland, and in Cheju, Zanzibar, farmer??s pesticide use and risk awareness were assessed. The farmers generally lacked knowledge or possibilities to manage the pesticides as prescribed by the manufacturers. Few farmers knew what kind of pesticides they were using and had never seen the original packages, as pesticides were usually sold per weight or already diluted without labeling. Protective equipment was rarely used since they were not aware of risks associated with pesticides or did not know where to purchase protective gear. Only half of the farmers were aware of pesticides?? health hazards and few associated pesticides with environmental problems. The pesticide use was relatively low, but based on farmers?? pesticide handling and application practices, health risks were a major concern. Most farmers did not believe in successful rice cultivation without using pesticides to control pests. However, estimated yields did not differ between pesticide users or farmers using conventional methods or neem tree extract. To avoid negative effects on human health and the environment, the farmers need basic education and better assistance in their farming practices and pesticide management.     

The Properties of Poly(<Emphasis Type="SmallCaps">l</Emphasis>-Lactide) Prepared by Different Synthesis Procedure

Different synthesis methods were applied to determine optimal conditions for polymerization of (3S)-cis-3,6-dimethyl-1,4-dioxane-2,5-dione (l-lactide), in order to obtain poly(l-lactide) (PLLA). Bulk polymerizations (in vacuum sealed vessel, high pressure reactor and in microwave field) were performed with tin(II) 2-ethylhexanoate as the initiator. Synthesis in the vacuum sealed vessel was carried out at the temperature of 150 °C. To reduce the reaction time second polymerization process was carried out in the high pressure reactor at 100 °C and at the pressure of 138 kPa. The third type of rapid synthesis was done in the microwave reactor at 100 °C, using frequency of 2.45 GHz and power of 150 W at the temperature of 100 °C. The temperature in this method was controlled via infrared system for in-bulk measuring. The solution polymerization (with trifluoromethanesulfonic acid as initiator) was possible even at the temperature of 40 °C, yielding PLLA with narrow molecular weight distribution in a very short period of time (less than 6 h). The obtained polymers had the number-average molecular weights ranging from 43,000 to 178,000 g mol⁻¹ (polydispersity index ranging from 1 to 3) according to the gel permeation chromatography measurements. The polymer structure was characterized by Fourier transform infrared and NMR spectroscopy. Thermal properties of the obtained polymers were investigated using thermogravimetry and differential scanning calorimetry.