Reactivity of secondary phases in weathered limestone using isotopic tracers (D and 18O)

Environmental Science and Pollution Research - For a long time, limestone has been massively used in stone building and monuments because of its easy extraction and common presence in the...     

Treatment of a clinical analysis laboratory wastewater from a hospital by photo-Fenton process at four radiation settings and toxicity response

Environmental Science and Pollution Research - The photo-Fenton process was performed with four radiation settings to treat clinical analysis laboratory wastewater (CALWW) from a hospital, with the...     

Trace Element Contaminants in Sediments From the Noaa National Status and Trends Programme Compared to Data From Throughout the World

The National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends (NS&T) Programme has analyzed samples of surface sediment collected at almost 300 coastal and estuarine sites throughout the United States since 1984. the overall distributions for concentrations of each element are approximately lognormal allowing a definition of geometric means and of “high” concentrations as those exceeding the mean plus one standard deviation of the lognormal distribution. Those mean and “high” concentrations should be useful for comparing the NS&T data set and with other reports on sediment contamination. A world-wide data set, constructed from data in the literature, was summarized in an identical manner. It was found, after excluding locally extreme values, that the NS&T and world-wide data sets yielded very similar mean and “high” concentrations for Cu, Ni, Pb and Zn. Chromium was the sole element showing higher summary statistics in the NS&T data set, a result attributed to NS&T sampling in areas of naturally (not contaminated) elevated Cr content. It remains undetermined, however, why the world-wide data set, even with exclusion of “hot spots”, yielded higher means and “highs” for Cd, Hg, As, and Ag.     

Organochlorine contaminants in hair of adolescents from Iassy, Romania

Human hair samples (n=42) from Iassy county (Eastern Romania) collected in 2002-2003 from adolescents were analyzed for hexachlorocyclohexane (HCH) isomers, p,p'-DDT and its metabolites, hexachlorobenzene (HCB), chlordane and metabolites and 5 polychlorinated biphenyl (PCB) congeners. Very low levels were found for HCB and oxychlordane (0.8 and 2.5 ng g(-1)) indicating a low usage of these pesticide formulations in the studied area. In case of HCHs, gamma-HCH isomer was measured at higher median concentrations (79 ng g(-1) hair) compared to the beta-HCH isomer (55 ng g(-1)), which generally is the most prevalent from HCHs. The DDTs profile consisted in p,p'-DDE and p,p'-DDT which levels correspond to 81% of sum DDTs. Very high median concentrations measured for p,p'-DDT (192 ng g(-1)) combined with lower values for p,p'-DDE/p,p'-DDT of 0.4 (from 0.20 to 2.0) in all hair samples suggest recent exposure to "fresh" DDT. When gender was considered, significantly higher concentrations for most of the investigated contaminants were found in girls hair compared to boys. Very high levels were found in the present study for HCHs and DDTs compared to samples from Greece, Western Europe and China. In case of PCBs, the levels found in Romanian samples were found to be in the same range compared to other previously published data.     

Distribution of polychlorinated biphenyls (PCBs) and organochlorine pesticides in soils from the East Antarctic coast

Concentrations of hexachlorobenzene (HCB), alpha-, beta- and gamma-hexachlorocyclohexane (HCH) isomers, 6 o,p'-and p,p'-isomers of DDT and 28 PCB congeners have been measured in eleven soil samples and one lichen collected on the Eastern coast of Antarctica from 5 Russian stations. For samples with low concentrations of PCBs (range 0.20-0.41 ng g(-1) dry weight) and pesticides (0.86-4.69 ng g(-1) and 0.11-1.22 ng g(-1) dry weight for HCHs and DDTs, respectively), atmospheric long-range transport from Africa, South America or Australia was suggested as the sole source of contamination. The profile of PCB congeners was dominated by the more volatile tri-, tetra- and penta-PCBs congeners, thus supporting long-range transport hypothesis. Four samples contained moderate levels of PCBs (range 1.98-6.94 ng g(-1) dry weight) and variable concentrations of pesticides (gamma-HCH, p,p'-DDT and o,p'-DDT being the main contaminants). For samples with high concentrations of PCBs (range 90.26-157.45 ng g(-1)) and high concentrations of pesticides, the presence of high molecular weight PCB congeners such as: 153, 180, 187, 170 etc, strongly suggest a local source (biotic) of PCBs rather than atmospheric transport. It is likely that on a local scale, biotic focussing of pollutants, due to bird activities (nesting and excrement) can cause high contamination levels and become more significant than contaminant input via abiotic pathways.     

Pollution by organochlorine pesticides in Navachiste-Macapule,Sinaloa, Mexico

The lagoon system of Navachiste-Macapule is located in northern Mexico, in the state of Sinaloa, with an area of 24,000 ha. The main economic activity in the area is agriculture, and the lagoon lies next to the irrigation district ID-063 which covers 116,615 ha. The purpose of this study is to evaluate the levels of pollution generated by organochlorine pesticides (OC) in the surface sediments of the lagoon and in the agricultural drains of the ID-063 that are supposedly transported into the system as a result of agricultural activities and runoff from adjacent land. For this, between 2006 and 2007, 45 surface sediment samples were collected (warm dry, rainy and cold dry) from 15 sampling sites, during the three climatic seasons. Of these, eight were located inside the lagoon in marine conditions (salinity >31 PSU) and seven in the agricultural drains of the ID-063 in freshwater conditions (salinity <5 PSU). The average concentration of the OC in the sediments was 44.75 ng g^− 1, among which the group of the alicyclic compounds presented the greatest concentrations. The average value of the total organic carbon (TOC) in the sediments of the system was 0.90%. The sediments collected inside the lagoon had an average OC concentration of 18.97 ng g^− 1, and the predominant type of sediment was fine to very fine sand. The average OC concentration in the sediments collected in the agricultural drains was 75.69 ng g^− 1, where fine sediments (silt) were predominant. The presence of methoxychlor, endrin and heptachlor suggested that these compounds were continuously used in the system, even though their use is forbidden in Mexico.     

HPLC-FLD determination of 4-nonylphenol and 4-<Emphasis Type="Italic">tert</Emphasis>-octylphenol in surface water samples

A simple, sensitive and reliable HPLC-FLD method for the routine determination of 4-nonylphenol, 4-NP and 4-tert-octylphenol, 4-t-OP content in water samples was developed. The method consists in a liquid–liquid extraction of the target analytes with dichloromethane at pH  3.0–3.5 followed by the HPLC-FLD analysis of the organic extract using a Zorbax Eclipse XDB C8 column, isocratic elution with a mixed solvent acetonitrile/water 65:35, at a flow rate of 1.0 mL/min and applying a column temperature of 40°C. The method was validated and then applied with good results for the determination of 4-NP and 4-t-OP in Ialomi?a River water samples collected each month during 2006. The concentration levels of 4-NP and 4-t-OP vary between 0.08–0.17 μg/L with higher values of 0.24–0.37 μg/L in the summer months for 4-NP, and frequently <0.05 μg/L but also between 0.06–0.09 μg/L with higher values of 0.12–0.16 μg/L in July and August for 4-t-OP and were strongly influenced by sesonial and anthropic factors. The method was also applied on samples collected over 2 years 2007 and 2008 from urban wastewaters discharged into sewage or directly into the rivers by economic agents located in 30 Romanian towns. Good results were obtained when the method was used for analysis of effluents discharged into surface waters by 16 municipal wastewater treatment plants, during the year 2008.     

Cytogenetic biomonitoring of oral mucosa cells of crack cocaine users

The aim of the present study was to comparatively evaluate genomic damage (micronucleus) and cellular death (pyknosis, karyolysis, and karyorrhexis) in exfoliated oral mucosa cells from crack cocaine users by micronucleus test. A total of 30 crack cocaine users and 30 health controls (non-exposed individuals) were included in this setting. Individuals had epithelial cells from cheek mechanically exfoliated, placed in fixative, and dropped in clean slides, which were checked for the above nuclear phenotypes. The results pointed out significant statistical differences (p?<?0.05) of micronucleated oral mucosa cells from crack cocaine users. Exposure to crack cocaine caused an increase of other nuclear alterations closely related to cytotoxicity such as karyolysis in oral cells as well. In summary, these data indicate that crack cocaine is able to induce chromosomal breakage and cellular death in oral mucosa cells of users.     

Effect of biosolid incorporation to mollisol soils on Cr, Cu, Ni, Pb, and Zn fractionation, and relationship with their bioavailability

Biosolid application to soil may be a supply of nutrients and micronutrients but it may also accumulate toxic compounds which would be absorbed by crops and through them be incorporated to the trophic chain.

The present study deals with the effect of biosolid application on Cr, Cu, Pb, Ni, and Zn in agricultural soils. The procedure used is sequential extraction so that the availability of those metals may be estimated and related to their bioavailability as determined through two indicator plants grown in greenhouse: ryegrass (Lolium perenne L.) and red clover (Trifolium pratense). Results showed that biosolid application to soil increased total Cu and Zn content. Sequential extraction showed that the more labile Zn fractions increased after biosolid application to soil. This was confirmed when assessing the total content of this metal in shoot and root of the plants under study, since a higher content was found in plant tissues, while no significant differences were found for Cu, Cr, Ni, and Pb.     

Relative influence of the dissolved humic material on the solid-phase extraction efficiency of pesticides from environmental water

The effect of organic matter on the solid-phase extraction (SPE) efficiency for pesticides belonging to different chemical groups (urea-derivatives, carbamates and triazines) and having different polarities, was simultaneously studied for the first time in pure and simulated water samples. SPE was carried out in precolumns packed with C18 silica or styrene-divinylbenzene copolymer PLRP-S phases on-line coupled to high performance liquid chromatography (HPLC) analysis. Retention factors in water (k'(W)) were estimated for 25 compounds and used for the calculation of the theoretical breakthrough volume (Vb(T)) in pure water. Experimental breakthrough volumes (Vb(E)) were first determined using purified and deionized water as the matrix for selected compounds having Vb(T) < 500 mL; then, the same water with an added humic acid sodium salt (HA) at 0.4-5.6 mg/L of dissolved organic carbon (DOC) content, was used as the matrix for compounds having VbE < 500 mL in pure water. Several polar pesticides showed negative linear or logarithmic Vb(E) curves depending on HA content; their recoveries were also determined in environmental samples having low dissolved organic carbon values, between 0.5-6.4 mg/L. A similar behavior was observed for these compounds in simulated and natural water samples, where DOC concentration and the percolated volume (Vp) mainly determine the solute recoveries values. However, the variation of recoveries as a function of DOC content could be negative or null depending on the two examined conditions (Vp lower or larger than Vb(E) in pure water). Results demonstrated that breakthrough volume must always be considered to correctly interpret the participation of dissolved humic material on the SPE efficiency of organic micropollutants in water.