Organochlorine pesticide residue levels in blood serum of inhabitants from Veracruz, Mexico

The objective of the present study was to monitor the levels of organochlorine pesticides HCB; α-, β-, γ-HCH; pp'DDE; op'DDT; and pp'DDT in blood serum of Veracruz, Mexico inhabitants. Organochlorine pesticides were analyzed in 150 blood serum samples that constituted that which remained after clinical analyses, using gas chromatography-electron-capture detection (GC-ECD). The results were expressed as milligrams per kilogram on fat basis and micrograms per liter on wet weight. Only the following pesticides were detected: p,p'-DDE was the major organochlorine component, detected in 100% of samples at mean 15.8 mg/kg and 8.4 μg/L; p,p'-DDT was presented in 41.3.% of monitored samples at mean 3.1 mg/kg and 1.4 μg/L; β-HCH was found in 48.6% of the samples at mean 4.9 mg/kg and 2.7 μg/L; op'DDT was determined to be in only 3.3% of monitored samples at mean 2.7 mg/kg and 1.4 μg/L. The pooled samples divided according to sex showed significant differences of β-HCH and pp'DDE concentrations in females. The samples grouped according to age presented the third tertile as more contaminated in both sexes, indicating age as a positively associated factor with serum organochlorine pesticide levels in Veracruz inhabitants.     

Characterization of As and trace metals embedded in PM10 particles in Puebla City, México

Forty-eight air-filter samples (PM₁₀) were analysed to identify the concentration level of partially leached metals (PLMs; As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and V) from Puebla City, México. Samples were collected during 2008 from four monitoring sites: (1) Tecnológico (TEC), (2) Ninfas (NIN), (3) Hermanos Serdán (HS) and (4) Agua Santa (AS). The results indicate that in TEC, As (avg. 424 ng m^?3), V (avg. 19.2 ng m^?3), Fe (avg. 1,202 ng m^?3), Cu (avg. 86.6 ng m^?3), Cr (41.9 ng m^?3) and Ni (18.6 ng m^?3) are on the higher side than other populated regions around the world. The enrichment of PLMs is due to the industrial complexes generating huge dust particles involving various operations. The results are supported by the correlation of metals (Mn, Cd and Co) with Fe indicating its anthropogenic origin and likewise, As with Cd, Co, Fe, Mn, Pb and V. The separate cluster of As, Fe and Mn clearly signifies that it is due to continuous eruption of fumaroles from the active volcano Popocatépetl in the region.     

Acute and reproductive toxicity of nano-sized metal oxides (ZnO and TiO₂) to earthworms (Eisenia fetida)

An increase in nanomaterial applications will likely lead to an increased probability of environmental exposures, raising concerns regarding the safety of these materials. Recent studies have indicated that manufactured nanomaterials, such as metal oxides, have the potential to be harmful to aquatic and terrestrial organisms. The majority of nano-metal oxide research addressing potential toxicological issues has been focused in aquatic environments with very little terrestrial data. This study characterized the acute and reproductive toxicity of zinc oxide (ZnO) and titanium dioxide (TiO(2)) to earthworms (Eisenia fetida) in a terrestrial system. Following a 14 d exposure, nano-sized ZnO on filter paper was acutely toxic to E. fetida, while nano-sized TiO(2) did not exhibit acute toxicity. In contrast, neither nano-sized ZnO nor TiO(2) exhibited acute toxicity to earthworms in sand. Both nano-sized ZnO and TiO(2), following a 4 week exposure, caused reproductive effects in earthworms in artificial soil. Overall, nano-sized ZnO exhibited greater toxicity than nano-sized TiO(2) in Eisenia fetida.     

Monitoring of pharmaceutically active compounds on the Guadalquivir River basin (Spain): occurrence and risk assessment

Guadalquivir River (South of Spain) is among the major freshwater sources of the European Atlantic basin. Until now scientific efforts have been focused on contamination by heavy metals and some priority pollutants in Guadalquivir River. However, the presence of "emerging contaminants", such as pharmaceutically active compounds, has not yet been studied. In this work the occurrence and risk assessment of sixteen pharmaceutically active compounds, belonging to different therapeutic groups, in Guadalquivir River during its course through Seville city are reported. Wastewater effluents from four wastewater treatment plants discharging into Guadalquivir River and river water samples were analyzed. All studied pharmaceutically active compounds, except sulfamethoxazole, trimethoprim, estrone and clofibric acid, were detected in effluent wastewaters at concentration levels up to 28.9 μg L(-1). Among the pharmaceutically active compounds found in effluent wastewater, seven were present in Guadalquivir River samples at concentration levels up to 0.75 μg L(-1), which indicated an important dilution from effluent discharge. Environmental risk assessment reveals that potential ecotoxicological risk cannot be expected on Guadalquivir River at measured concentration levels. Only, the lipid regulator gemfibrozil showed a medium risk for the environment. The risk for acute toxic effects in the environment with the current use of active pharmaceutical ingredients is unlikely. However, the results do not rule out the potential for chronic environmental effects.     

The spatial statistics formalism applied to mapping electromagnetic radiation in urban areas

Determining the electromagnetic radiation levels in urban areas is a complicated task. Various approaches have been taken, including numerical simulations using different models of propagation, sampling campaigns to measure field values with which to validate theoretical models, and the formalism of spatial statistics. In the work, we present here that this latter technique was used to construct maps of electric field and its associated uncertainty from experimental data. For this purpose, a field meter and a broadband probe sensitive in the 100-kHz–3-GHz frequency range were used to take 1,020 measurements around buildings and along the perimeter of the area. The distance between sampling points was 5 m. The results were stored in a geographic information system to facilitate data handling and analysis, in particular, the application of the formalism of spatial statistical to the analysis of the distribution of the field levels over the study area. The spatial structure was analyzed using the variographic technique, with the field levels at non-sampled points being interpolated by kriging. The results indicated that, in the urban area analyzed in the present work, the linear density of sampling points could be reduced to a distance which coincides with the length of the blocks of buildings without the statistical parameters varying significantly and with the field level maps being reproduced qualitatively and quantitatively.     

Sand as a relevant fraction in geochemical studies in intertidal environments

Soil and sediment samples from several intertidal environment exposed to different types of contamination were studied to investigate the importance of grain size in relation to the capacity of the substrates to retain trace metals. The unfractionated samples (referred to as bulk samples) were separated into the following grain/size fractions: fine–coarse sand (2?0.100 mm), very fine sand (0.100?0.050 mm), silt (0.050?0.002 mm), and clay (0.002 mm). The sample into its fractions was carried out was in a glove box under high-purity N₂ atmosphere in order to minimize any alterations to the samples. The bulk samples were characterized in terms of physicochemical properties such as pH, redox potential, and grain size. The total organic carbon (TOC), total sulfur (S), iron (Fe) pyrite, Fe, and manganese (Mn), and trace metals lead (Pb), mercury (Hg), chromium (Cr), and nickel (Ni) were analyzed in the bulk samples and in each fraction. The sand fractions were also examined by scanning electron microscopy (SEM). Comparisons of the above parameters were made between fractions and between each fraction and the corresponding bulk sample. The fine–coarse sand fraction contained high levels of the primary elements of the geochemical processes that occur in marine sedimentary environments such as TOC, total Fe, Mn, and S. The net concentrations of these four elements were higher in the fine-coarse sand fraction than in the very fine sand fraction and were similar to the net concentrations in the silt and clay fractions. Detailed SEM analysis of the sand coarse fraction revealed the presence of Fe and aluminum oxyhydroxide coatings in the oxic layers, whereas the framboidal pyrites and coatings observed in the anoxic layers were Fe sulfides. The presence of the various coatings explains why the trace metal concentrations in the sand fine–coarse fraction were similar to those in the clay fraction and higher than those in the very fine sand fraction. The present results highlight the importance of the sand fraction, which is generally disregarded in geochemical and environmental studies of sedimentary layers.     

Competitive Retention of Lead and Cadmium on an Agricultural Soil

Lead and cadmium contamination of an agricultural soil has been studied using batch and column experiments. Thermodynamics of theretention phenomena may be represented by a Langmuir isotherm foran aqueous metal concentration up to 100 mg L^-1. First order kinetics with respect to the solid phase yield good predictabilityfor both batch and column experiments. Kinetics and thermodynamics of lead retention predominate over those ofcadmium. As a consequence, lead is preferentially retainedand can even displace sorbed cadmium. In the event of anspill involving both metals, cadmium would move further inthe soil and its aqueous concentration downstream could beeven higher than that of the influent solution, increasingpotential risks. A two-region model has been used to fit all the experimental results. Satisfactory predictions for column experiments are obtained with parameters which are consistent with those obtained for the batch experiments, for which sorption is described by a Langmuir isotherm including competitive retention.     

Arsenic and antimony distribution in the Ría de Arousa: before and after the Prestige oil tanker sinking

The behaviour of arsenic and antimony in the Ría de Arousa (Galicia, north west of Spain) and the influence of the Prestige accident in the estuary is evaluated. As and Sb were simultaneously determined by HG-ICPOES in seawater samples after a preconcentration with La in a knotted reactor. The highest As concentration is in the inner and middle parts of the ría where the current is weaker and next to the main ports of the area. The largest Sb concentrations were found in the bay of the ría. Linear variation of concentration vs. salinity for As and As/Sb ratios indicated that there was no pollution in the waters of Arousa. The Prestige oil spillage had no serious influence and the values of arsenic (most of them <1.5 microg L(-1)) are similar to the average oceanic concentration, whereas concentrations for antimony (most of them <0.15 microg L(-1)) are less than the oceanic ones.     

Sardine (Sardina pilchardus) spawning seasonality in European waters of the northeast Atlantic

Egg data from ichthyoplankton monitoring sites in the western English Channel (1988–2003) and northern Spain (1990–2000) and macroscopic maturity data from biological samples of purse seine landings in western and southern Iberia (1980–2004) are used to describe the spawning seasonality of sardine (Sardina pilchardus) in European waters of the northeast Atlantic using generalised additive models. The fitted models reveal a double peak in spawning activity during early summer and autumn in the western Channel, a wider spring peak off northern Spain and a broad winter season in the western and southern Iberian Peninsula. At all sites, a high probability of spawning activity was observed over at least 3 months of the year, with the duration of the season increasing with both decreasing latitude and increasing fish size. Off western and southern Iberia there are indications that the spawning season has been of longer duration in recent years for all size classes (reaching in some cases 8 months of the year for large fish). These patterns are in general agreement with existing literature and theoretical expectations of sardine spawning being driven locally by the seasonal cycle of water temperature, assuming preferences for spawning at 14 –15°C and avoidance for temperatures below 12°C and above 16°C. Regional quotient plots indicated that spawning tolerance to higher temperatures increases progressively with decreasing latitude. Despite the weak evidence for geographical differences in temperature tolerance that may have some genetic origin, the degree of spatio-temporal overlap in sardine-spawning activity within Atlantic European waters is unlikely to promote any reproductive isolation in that area.     

Erratum to: Accumulation of Cr,Cd, Pb,Cu, and Zn by plants in tanning sludge storage sites: opportunities for contamination bioindication and phytoremediation

Environmental Science and Pollution Research -