Vicente Andreu

Heavy metals incidence in the application of inorganic fertilizers and pesticides to rice farming soils

The concentrations of Cd, Co, Cu, Ni, Pb, Zn, Fe and Mn in different inorganic fertilizers (urea, calcium superphosphate, iron sulphate and copper sulphate) and in pesticides (two herbicides and one fungicide) are evaluated together with the contribution of these metals in soils from their use. The study was made in rice farming areas to the north of Albufera Natural Park (Valencia, Spain). The results obtained show that superphosphate is the fertilizer that contains the highest concentrations of Cd, Co, Cu and Zn as impurities. Copper sulphate and iron sulphate have the most significant concentrations of Pb, and are the only fertilizers in which Ni was detected. The three pesticides analysed show similar Cd contents and the highest levels of Fe, Mn, Zn, Pb and Ni are found in the herbicides. The most significant additions of heavy metals as impurities that soil receives from agricultural practices, are Mn, Zn, Co and Pb. Three contamination indexes have been applied to provide a basis for comparison of potential heavy metal toxicity. These results denote the potential toxicity of heavy metals in the studied soils.

Occurrence of acidic pharmaceuticals and personal care products in Turia River Basin: From waste to drinking water

The occurrence of 21 acidic pharmaceuticals, including illicit drugs, and personal care products (PPCPs) in waste, surface and drinking water and in sediments of the Turia River Basin (Valencia, Spain) was studied. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the determination of these PPCPs with electrospray (ESI) in negative ionization (NI) mode. Ammonium fluoride in the mobile phase improved ionization efficiency by an average increase in peak area of 5 compared to ammonium formate or formic acid. All studied compounds were detected and their concentration was waste water>surface water>drinking water. PPCPs were in waste water treatment plants (WWTPs) influents up to 7.26μgL(-1), dominated by ibuprofen, naproxen and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCOOH). WWTPs were highly effective in removing most of them, with an average removal rate of >90%. PPCPs were still detected in effluents in the 6.72-940ngL(-1) range, with the THCOOH, triclocarban, gemfibrozil and diclofenac as most prevalent. Similarly, diclofenac, gemfibrozil, ibuprofen, naproxen and propylparaben were detected quite frequently from the low ngL(-1) range to 7μgL(-1) in the surface waters of Turia River. Ibuprofen, methylparaben, salicylic acid and tetrahydrocannabinol (THC) were at concentrations up to 0.85ngg(-1) d.w. in sediments. The discharge of WWTP as well as of non-treated waters to this river is a likely explanation for the significant amount of PPCPs detected in surface waters and sediments. Mineral and tap waters also presented significant amounts (approx. 100ngL(-1)) of ibuprofen, naproxen, propylparaben and butylparaben. The occurrence at trace levels of several PPCPs in drinking water raises concerns about possible implications for human health.

Determination of pharmaceuticals in soils and sediments by pressurized liquid extraction and liquid chromatography tandem mass spectrometry

The present work describes the development of a sensitive analytical method based on pressurized liquid extraction (PLE) and pre-concentration by solid-phase extraction (SPE), followed by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) for the determination of seventeen pharmaceuticals in soils and sediments. The method is based on sample homogenisation using Na(2)-EDTA washed sand and extraction with water at 90 degrees C. Special emphasis was placed on the optimization of the extraction procedure to develop a green method that reduces, at a maximum, the use of organic solvents in order to eliminate matrix components during the clean-up. The proposed method was linear in a concentration range from 0.3 to 333ngg(-1), with correlation coefficients higher than 0.993. Method detection (MDLs) and quantification (MQLs) limits ranged from 0.1 to 6.8ngg(-1) and from 0.25 to 23ngg(-1), respectively. Absolute recoveries were analyte dependent, varying between 50% and 105% at the MQL level, except for fenofibrate (40%) and diclofenac (34%). The intra-day and inter-day precision was given by RSD values from 0.7% to 7.9% and from 1.6% to 14.5%, respectively. Acetaminophen, carbamazepine, ciprofloxacin, clofibric acid, codeine, diazepam, fenofibrate, metropolol, ofloxacin and propanolol were detected at concentrations from MDL to 35.62ngg(-1) in soils and sediments from marsh areas. Due to the low recoveries, results for fenofibrate and diclofenac can only be considered as semi-quantitative. The method was fully suitable for the other 15 pharmaceuticals.

Temporal changes in soil aggregates and water erosion after a wildfire in a Mediterranean pine forest

Abstract The evolution of soil structure after a forest fire was studied on two zones representatives of a typical Mediterranean Pine forest. These zones were in opposite slope orientation but with similar topographical and pedological characteristics. Changes in soil macro-aggregation and water stable micro-aggregation were monitored seasonally during a year after the fire. The water erosion patterns were also studied from August 1993, immediately after the fire, to the end of 1996. The first 5 cm of soil depth were the most affected by fire temperature, showing clear differences on aggregate distribution and temporal variability between zones. In the north-facing soil, a substantial and gradual recovery on soil aggregation was observed mainly in the fraction greater than 5-mm diameter; this reached an increase of 27% in mass of aggregates. In the south slope, the evolution of aggregation was smooth and restricted to the fraction minor than 0.1 mm. These differences between zones are reflected also in their values on soil cohesiveness and compaction, being lesser in the south-oriented soils. Values of erosion parameters show that both zones have the higher soil losses during the immediate period (4 months) after the fire, being more important in the south zone. This zone produced more sediment and runoff (52.42% and 29.95%, respectively) than north-facing soils for the whole period studied.

Risk assessment on the presence of pharmaceuticals in sediments, soils and waters of the Pego–Oliva Marshlands (Valencia, eastern Spain)

This study is focused on the occurrence of 17 pharmaceuticals in waters (34 samples), sediments (16 samples) and soils (23 samples, at two different depths) in a typical Mediterranean coastal wetland (Pego-Oliva marsh, Spain). Soil and sediment samples were extracted by pressurized liquid extraction (PLE). Aqueous extracts from PLE and water samples were concentrated by solid-phase extraction (SPE) and determined by liquid-chromatography tandem mass spectrometry (LC-MS/MS). Pharmaceuticals were detected in concentrations up to 112 ng/L in water samples, up to 15.1 ng/g sediments and up to 8.4 ng/g in soil. In surface waters, ibuprofen and codeine were the compounds more frequently detected (up to 59 ng/L and 63 ng/L, respectively). Ground and tap water samples analyzed were also contaminated with pharmaceuticals. The 94% of sediments and the 80% of agricultural soils were polluted (mostly by carbamazepine and acetaminophen). Diffusion of codeine and fluoroquinolones to deeper soil horizons was observed. Possible relationships between variables were established by Pearson correlations and principal components analysis (PCA). An environmental risk assessment based on the available long-term data was performed. Results showed actual risk for the lowest trophic level, and for fishes, due to the presence of fluoroquinolones and ibuprofen. Nevertheless, the presence of pharmaceuticals in the environment is not limited only to an ecological problem since contamination also affects drinking water, being a potential risk to human health.

Spatial patterns of soil temperatures during experimental fires

The main objective of this paper is to assess the spatial patterns of temperature distribution at the soil surface after a shrubland fire in a typical Mediterranean environment. The study was carried out by making experimental fires at a permanent field station (La Concordia, Valencia, Spain) in a typical Mediterranean forest slope. The set up consisted of nine plots (20 m long×4 m wide) with similar morphology, slope gradient, rock outcrops, soil (Rendzic Leptosol) and vegetation cover (Rhamno lycioidis–Quercetum cocciferae association). Two different fire severities were evaluated, high (F1) and moderate (F2), created by the addition of limited amounts of biomass. To measure soil temperatures, two complementary methods were used: thermocouples and thermosensitive paints. Results show that peak temperatures on the soil surface measured by the two systems (higher than 600 °C in most cases) are quite similar and there are no statistically significant differences between them. The mean values of soil surface temperatures measured with thermosensitive paints were 240, 239 and 218 °C for F1 plots and 418, 448 and 435 °C for F2 plots. Half of the F1 plots surface showed temperature values between 170 and 235 °C, and in the F2 plots, these values ranged between 322 and 543 °C. Geostatistics were applied to analyze and describe the spatial variation of soil temperatures at the soil surface. Results showed that there are two dominant spatial patterns of temperature distribution (spherical and linear). The spherical model varied approximately between 4 and 10 m, and its pattern is related mainly to the natural biomass distribution and the time of flame persistence. In the second, the linear pattern, the temperature rise from the lower part to the upper part of the plot seems to be controlled by the meteorology at the time of burning, mainly by wind speed and wind direction. The spatial patterns of soil temperatures during the studied experimental fires affect soil properties in different ways according to the fire severity. This fact could contribute to change the spatial dynamics of soil nutrients that will play an important role in the recovery of the burned vegetation.

Postfire Effects on Soil Properties and Nutrient Losses

The effects of an August, 1992, wildfire on nutrient losses by water erosion have been studied. The fire affected an area of 9498 ha of pine forest and shrub, located in Sierra Calderona (Valencia, Spain). In the burned area, six stations of erosion measurement were set up immediately after the end of the fire. The results obtained in these stations are reported. Topographical, edaphological and vegetation characteristics of each station are described. Fourteen episodes of erosive rain with production of runoff and sediments, between August,1992, and November, 1993, were studied, mainly in relation to changes in the soil chemical characteristics. Data show that the highest soil and nutrient losses were produced in the period immediately after the fire. However, fire intensity is the factor that determines the soil status with respect to its response to nutrient losses.

Spatio-temporal patterns of pesticide residues in the Turia and Júcar Rivers (Spain)

A study was conducted on the occurrence of 50 pesticides in water and sediments of Turia and Júcar Rivers (Valencian Community, Eastern Spain) for a period of two consecutive years each, 2010/2011 and 2012/2013, respectively to assess the contribution of agriculture and urban activities on pesticide pollution. The results showed that mean concentrations of pesticides ranged from <LOQ up to 200 ng/L. Chlorpyrifos was the most frequent pesticide whereas imazalil, thiabendazole, tolclofos methyl, ethion and carbofuran were those found at higher concentrations. Ubiquitous pesticides are those with long half-lives. The most polluted parts of the rivers were the headwaters and the mouth, which could be related to the agricultural practices and rainfall. Contrarily, in the abrupt part of the rivers of difficult access the contamination is low. Other quality parameters monitored in this study also corroborate the worst water quality in the alluvial plains that coincides with higher anthropic pressure. The temporal variations also indicated a strong relation of pesticide concentrations with hydrology, the higher the river flow, the higher number and frequency of pesticides but at lower concentrations. On the contrary, at lower river flows higher pesticide concentrations were detected. The risk assessment for aquatic biota pointed out that organophosphorus and fungicides are a threat to fish and daphnia and herbicides and fungicides are hazards for algae. Thus, the strict control of pesticide concentrations is important to preserve the aquatic ecosystems health.

Testing three Mediterranean shrub species in runoff reduction and sediment transport

Runoff yield and sediment delivery are compared in three shrub species (Medicago arborea, Atriplex nummularia, and Psoralea bituminosa) with natural (matorral) vegetation in an experimental plot set. The planted species are arranged in discontinuous rows perpendicular to the slope, acting as barriers to the direction of the surface water flow. The study was carried out from 1988 to 1995, in which 56 erosive rain events were monitored in runoff production and in soil losses, together with their intrinsic characteristics (duration, intensity and rainfall). Growth of the three shrub species (height, vegetation cover, and stem diameter) and the influence on soil properties during this period were recorded. Because of certain characteristics of the study area (shallow soils, high levels of carbonates, stoniness) and the climate (an especially intense period of drought since 1990), the growth of these plants was very irregular. M. arborea gave the best protection against water erosion reducing sediment production by more than 58% compared to the bare soil. However, the protection afforded by this species never reached that obtained with natural vegetation, which reduced sediment production by almost 75%.

Determination of currently used pesticides in biota.

Although pesticides enable control of the quantity and quality of farm products and food, and help to limit diseases in humans transmitted by insects and rodents, they are regarded as among the most dangerous environmental contaminants because of their tendency to bioaccumulate, and their mobility and long-term effects on living organisms. In the past decade, more analytical methods for accurate identification and quantitative determination of traces of pesticides in biota have been developed to improve our understanding of their risk to ecosystems and humans. Because sample preparation is often the rate-determining step in analysis of pesticides in biological samples, this review first discusses extraction and clean-up procedures, after a brief introduction to the classes, and the methods used in the analysis of pesticides in biota. The analytical methods, especially chromatographic techniques and immunoassay-based methods, are reviewed in detail, and their corresponding advantages, limitations, applications, and prospects are also discussed. This review mainly covers reports published since 2008 on methods for analysis of currently used pesticides in biota.