Worldwide occurrence and effects of antifouling paint booster biocides in the aquatic environment: a review

Organic booster biocides were recently introduced as alternatives to organotin compounds in antifouling products, after restrictions imposed on the use of tributyltin (TBT) in 1987. Replacement products are generally based on copper metal oxides and organic biocides. This ban has led to an increase in alternative coating products containing the above biocides. The most commonly used biocides in antifouling paints are: Irgarol 1051, diuron, Sea-nine 211, dichlofluanid, chlorothalonil, zinc pyrithione, TCMS (2,3,3,6-tetrachloro-4-methylsulfonyl) pyridine, TCMTB [2-(thiocyanomethylthio) benzothiazole], and zineb. Since 1993, several studies have demonstrated the presence of these biocides in European coastal environment as a result of their increased use. More recently, the presence of these biocides was also revealed in waters from Japan, United States, Singapore, Australia and Bermuda. This paper reviews the currently available data on the occurrence of these biocides in the aquatic environment. Some data dealing with the environmental fate, partitioning, behaviour and risk assessment of antifouling paint booster biocides are also reported in order to discuss the detected levels of contamination.     

Projected twenty-first-century changes in the Central American mid-summer drought using statistically downscaled climate projections

Regional Environmental Change - In addition to periodic long-term drought, much of Central America experiences a rainy season with two peaks separated by a dry period of weeks to over a month in...     

The influence of socioeconomic, environmental, and demographic factors on municipality-scale land-cover change in Mexico

Land-cover change is the result of complex multi-scale interactions between socioeconomic, demographic, and environmental factors. Demographic change, in particular, is thought to be a major driver of forest change. Most studies have evaluated these interactions at the regional or the national level, but few studies have evaluated these dynamics across multiple spatial scales within a country. In this study, we evaluated the effect of demographic, environmental, and socioeconomic variables on land-cover change between 2001 and 2010 for all Mexican municipalities (n?=?2,443) as well as by biome (n?=?4). We used a land-cover classification based on 250-m MODIS data to examine the change in cover classes (i.e., woody, mixed woody, and agriculture/herbaceous vegetation). We evaluated the trends of land-cover change and identified the major factors correlated with woody vegetation change in Mexico. At the national scale, the variation in woody vegetation was best explained by environmental variables, particularly precipitation; municipalities where woody cover increased tended to be in areas with low average annual precipitation (i.e., desert and dry forest biomes). Demographic variables did not contribute much to the model at the national scale. Elevation, temperature, and population density explained the change in woody cover when municipalities were grouped by biome (i.e., moist forest, dry forest, coniferous forest, and deserts). Land-cover change at the biome level showed two main trends: (1) the tropical moist biome lost woody vegetation to agriculture and herbaceous vegetation, and (2) the desert biome increased in woody vegetation within more open-canopy shrublands.     

Is there a density compensation effect in plant communities of anthropogenic habitats?

The occurrence of density compensation effect (DCE) has been estimated in areas occupied by synanthropic communities in the Western Caucasus. The density of dominant plant species has been estimated from their coverage, and that of subordinate species, from their frequency in 0.5-m² squares within 15 (16)-m² plots, using natural and seminatural communities as a reference standard. The factual material has been analyzed by the method of numerical experiments. The results show that the transformation of natural habitats into anthropogenic ones has led to a decrease in the species diversity of plant communities, but without causing a widespread occurrence of DCE. It is hypothesized that relatively high average values of species frequency in low-diversity synanthropic communities are more likely accounted for by random rather than compensatory processes.     

Plutonium in sheep faeces as an indicator of deposition on vegetation

In order to study the deposition on vegetation of plutonium arising from the testing of nuclear weapons and discharges from nuclear facilities, sheep faeces were collected from the South-west and North of England. The plutonium content of faeces has been shown to be a reproducible and sensitive indicator of deposition on herbage and, with this technique, plutonium discharged from the Sellafield Works of British Nuclear Fuels LImited can be detected 60 km from the site. On moorland pastures the concentration of ^239+240Pu in faeces, expressed as activity per gram of ash, is roughly equal numerically to the deposit of plutonium on 1 m² of vegetation.Some of the plutonium ingested by a grazing sheep is absorbed and the highest concentrations are found in liver. The liver of a sheep grazing on pasture where the ^239+240Pu concentration in faeces was about 2 pCi (74 mBq) g⁻¹ of ash, was found to contain <1% of the Generalised Derived Limit for mutton and offal, and the meat <0·001%.     

First-trimester diagnosis of menkes disease: Intermediate copper values in chorionic villi from three affected male fetuses

Chorionic villus samples with copper contents of 1·91, 4·2, 5·6, and 6·3 ng/mg were observed in four cases with male karyotypes. These values were outside the range for unaffected males (0·30–0·85 ng/mg), and three of them were outside the control range (0·20–2·39 ng/mg). But these three values were below the values previously observed for affected Menkes fetuses (12·0–24·8 ng/mg). Follow-up by ⁶⁴Cu uptake studies on the amniotic fluid cells was performed in three of these cases. A combination of ⁶⁴Cu uptake and chase experiments on the amniotic fluid cells showed more convincingly than ⁶⁴Cu uptake per se the direct copper values of 4·2 and 5·6 ng/mg to correspond to affected fetuses. Amniotic fluid cells from the male fetus with the CV copper value of 1·9 ng/mg showed normal results. The CV copper value of 6·3 ng/mg was considered pathognomonic for Menkes disease. The pregnancy was terminated, and the diagnosis was confirmed on fetal fibroblasts. Maternal deciduum prepared from the placentae showed in one of the cases with an affected fetus copper values ranging from 1·5 to 5·7 ng/mg. In six additional diagnostic cases, the copper content was determined in both CV samples and maternal deciduum. In three of these cases with normal CV sample copper, maternal decidua values of 4·85–7·8 ng/mg copper were observed. These results show that maternal deciduum contamination of a CV sample could cause a false-positive diagnosis.     

European scale application of atmospheric reactive nitrogen measurements in a low-cost approach to infer dry deposition fluxes

A European scale network was established in 2006 as part of the NitroEurope Integrated Project to infer reactive nitrogen (Nr) dry deposition fluxes, based on low-cost sampling of gaseous and aerosol species and inferential modelling. The network provides monthly measurements of NH₃, NH₄⁺, HNO₃ and NO₃⁻, as well as SO₂, SO₄²⁻, HCl, Cl⁻ and base cations at 58 sites. Measurements are made with an established low-cost denuder methodology (DELTA) as a basis to: (1) examine temporal trends and spatial patterns across Europe, (2) improve and calibrate inferential modelling techniques to estimate exchange of Nr species, (3) provide best estimates of atmospheric dry N deposition, and (4) permit an analysis of net GHG exchange in relation to atmospheric and agricultural N inputs at the European scale. Responsibility for measurements is shared among seven European laboratories. An inter-comparison of the DELTA implementation by 6 laboratories at 4 test sites (Montelibretti, Italy; Braunschweig, Germany; Paterna, Spain and Auchencorth, UK) from July to October 2006 provided training for the laboratories and showed that good agreement was achieved in different climatic conditions (87% of laboratory site-means within 20% of the inter-laboratory median). Results obtained from the first year of measurements show substantial spatial variability in atmospheric Nr concentrations, illustrating the major local (NH₃) and regional (HNO₃, NO₃⁻, and NH₄⁺) differences in Nr concentrations. These results provide the basis to develop future estimates of site-based Nr dry deposition fluxes across Europe, and highlight the role of NH₃, largely of agricultural origin, which was the largest single constituent and will dominate dry Nr fluxes at most sites.     

Petroleum waste biodegradation with porous biomass support system (PBSS) on rotating biological contactor

A laboratory scale study was conducted to assess the feasibility of the new coupling of rotating biological contactor (RBC) plus porous biomass support system (PBSS) using polyurethane foam as porous support media to biodegrade petroleum refinery wastewater. Polyurethane foam was attached on disks of two four-stage laboratory scale cascade connected RBC units.The two RBC units were operated simultaneously at different but constant, flowrates giving hydraulic loading rates of 0.01, 0.02, 0.03, 0.04 m3/m2/d in two runs keeping the same rotational speed 10 r/min throughout. Organic loading was a less controllable factor in this study.For all of the hydraulic loadings, it was found that the removal efficiency of total chemical oxygen demand (TCOD) and oil were above 80 percent. Ammonia nitrogen and phenol removal were above 90 and 80 percent respectively. The maximum biomass concentration within polyurethane foam was about 30 g/m2 in the first stage for 0.03 m3/m2/d hydraulic loading.The results show that t