Human and crab exposure to mercury in the Caribbean coastal shoreline of Colombia: impact from an abandoned chlor-alkali plant

Human hair samples from male and female people aged 6-85 years, as well as muscle of crabs (Callinectes sapidus and Callinectes bocourti) were collected from different fishing places along the Caribbean coastal shoreline of Colombia and analyzed for total mercury (T-Hg) in order to establish the impact of mercury-polluted sediments in Cartagena bay on the ecosystem. Hair T-Hg in inhabitants varied between 0.1 and 21.8 microg/g, with average and median of 1.52 microg/g and 1.1 microg/g, respectively. Differences between sampling locations were significant (P<0.01) and median values decreased in the order: Ca?o del Oro (1.5 microg/g)相似文献   

Discrimination of Infectious Hepatitis A Viruses by Propidium Monoazide Real-Time RT-PCR

The discrimination of infectious and inactivated viruses remains a key obstacle when using quantitative RT-PCR (RT-qPCR) to quantify enteric viruses. In this study, propidium monoazide (PMA) and RNase pretreatments were evaluated for the detection and quantification of infectious hepatitis A virus (HAV). For thermally inactivated HAV, PMA treatment was more effective than RNase treatment for differentiating infectious and inactivated viruses, with HAV titers reduced by more than 2.4 log₁₀ units. Results showed that combining 50 μM of PMA and RT-qPCR selectively quantify infectious HAV in media suspensions. Therefore, PMA treatment previous to RT-qPCR detection is a promising alternative to assess HAV infectivity.     

Assessment of anthropogenic sources of water pollution using multivariate statistical techniques: a case study of the Alqueva’s reservoir, Portugal

Multivariate statistical techniques were applied to evaluate spatial/temporal variations, and to interpret water quality data set obtained at Alqueva reservoir (south of Portugal). The water quality was monitored at nine different sites, along the water line, over a period of 18 months (from January 2006 to May 2007) using 26 water quality parameters. The cluster analysis allowed the formation of five different similarity groups between sampling sites, reflecting differences on the water quality at different locations of the Alqueva reservoir system. The PCA/FA identified six varifactors, which were responsible for 64% of total variance in water quality data set. The principal parameters, which explained the variability of quality water, were total phosphorus, oxidability, iron, parameters that at high concentrations indicate pollution from anthropogenic sources, and herbicides indicative of an intensive agricultural activity. The spatial analysis showed that the water quality was worse in the north of the reservoir.     

New frontiers for sustainability: emergy evaluation of an eco-village

The emergy analysis was used to evaluate the sustainability of a village which aims to be ecologically friendly. The choice of focusing on the use of local resources including agriculture and farm goods, photovoltaic panels, renewable heating and cooling systems, recycled water from constructed wetlands etc., aims to obtain a sustainable village. Indices and ratios based on emergy flows have been calculated and used to evaluate the behaviour of the whole system. Their dependence upon the fraction of renewable and non renewable inputs as well as locally available versus purchased inputs from outside is stressed. A new index of sustainability (SI) is also applied to the case study. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

Perfluorooctanesulfonate and related fluorochemicals in biological samples from the north coast of Colombia

Perfluorinated compounds are widespread pollutants of toxicological importance that have been detected in environmental matrices. However, little is known on their distribution in South America. In this study, distribution of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonate (PFHxS), and perfluorooctanesulfonamide (PFOSA) was determined in the bile of mullet, Mugil incilis, and in tissues of pelicans (Pelecanus occidentalis) collected from North Colombia. Analysis was performed by HPLC mass spectrometry after ion-pair extraction. PFOS was found in all bile samples and PFOA and PFHxS were detected at lower frequency. Average concentrations of PFOS, PFOA, and PFHxS in bile of fish from Cartagena Bay, an industrialized site, and Totumo marsh, a reference site, were 3673, 370, 489 and 713, 47.4, 1.27 ng/mL, respectively. PFOS concentrations in pelican organs decreased in the order of spleen>liver>lung>kidney>brain>heart>muscle. These results suggest, for the first time, that perfluorinated compounds are also found in wildlife from Latin American countries.     

Identification and chemical characterization of industrial particulate matter sources in southwest Spain

A detailed physical and chemical characterization of coarse particulate matter (PM10) and fine particulate matter (PM2.5) in the city of Huelva (in Southwestern Spain) was carried out during 2001 and 2002. To identify the major emission sources with a significant influence on PM10 and PM2.5, a methodology was developed based on the combination of: (1) real-time measurements of levels of PM10, PM2.5, and very fine particulate matter (PM1); (2) chemical characterization and source apportionment analysis of PM10 and PM2.5; and (3) intensive measurements in field campaigns to characterize the emission plumes of several point sources. Annual means of 37, 19, and 16 microg/m3 were obtained for the study period for PM10, PM2.5, and PM1, respectively. High PM episodes, characterized by a very fine grain size distribution, are frequently detected in Huelva mainly in the winter as the result of the impact of the industrial emission plumes on the city. Chemical analysis showed that PM at Huelva is characterized by high PO4(3-) and As levels, as expected from the industrial activities. Source apportionment analyses identified a crustal source (36% of PM10 and 31% of PM2.5); a traffic-related source (33% of PM10 and 29% of PM2.5), and a marine aerosol contribution (only in PM10, 4%). In addition, two industrial emission sources were identified in PM10 and PM2.5: (1) a petrochemical source, 13% in PM10 and 8% in PM2.5; and (2) a mixed metallurgical-phosphate source, which accounts for 11-12% of PM10 and PM2.5. In PM2.5 a secondary source has been also identified, which contributed to 17% of the mass. A complete characterization of industrial emission plumes during their impact on the ground allowed for the identification of tracer species for specific point sources, such as petrochemical, metallurgic, and fertilizer and phosphate production industries.     

Leaching composted lignocellulosic wastes to prepare container media: Feasibility and environmental concerns

The leaching of salt and mineral elements from three composts prepared with residual vegetable crop biomass (melon, pepper or zucchini) was studied using methacrylate columns and distilled water. The benefits of the leached composts to be used for ornamental potted plant production were also analysed. After leaching 5 container capacities of effluent, both the electrical conductivity and the concentration of soluble mineral elements in compost leachates decreased substantially and remained close to the target levels. Composts reacted differently to leaching due to differences in the raw waste sources and the composting process and hence, in their physical and chemical characteristics. At the end of the experiment, after pouring 8 container capacities of water, the leaching efficiency of the salts was 96%, 93% and 87% for melon, pepper and zucchini-based composts, respectively. Mineral elements differed in their ability to be removed from the composts; N (NH₄⁺ and NO₃^?), K⁺, Na⁺, Cl^?, and SO₄^2? were leached readily, whereas H₂PO₄^?, Ca²⁺, and Mg²⁺ were removed hardly. Leached composts showed a range of physico-chemical and chemical characteristics suitable for use as growing media constituents. Potted Calendula and Calceolaria plants grew in the substrates prepared with the leached composts better than in those made with the non-leached ones. Finally, special emphasis must be paid to the management of the effluents produced under commercial conditions to avoid environmental pollution.