Decadal changes in atmospheric CO2 concentration and δ13C over two seas and two oceans: Italy to New Zealand

Continuous measurements of the CO₂ concentration were repeatedly carried out from 1996 to 2007 between Italy and New Zealand by means of a Siemens Ultramat 5E analyzer assembled for shipboard use. Along the ship routes discrete air samples were collected from 1998 to 2005 using four-litre Pyrex flasks. The δ¹³C of the CO₂ from the flask air samples was measured according to well-established techniques. The decadal changes of these two variables can now be evaluated from these results. Large variations of the CO₂ concentration were normally recorded in the Mediterranean and the Red Sea. Completely different trends of the CO₂ concentration were observed in the Red Sea (30° N to about 13° N) between 2007 (a marked southward decrease) and 2005 and 2003 when a marked southward increase is apparent, at least between 23° and 13° N. A further difference among different expeditions is related to the decrease or increase of the CO₂ concentration in the Gulf of Aden. The backward trajectories of the air masses help to explain, at least partially, these differences. In the Indian Ocean and Southern Ocean a decrease of a few ppmv of the CO₂ concentration takes place from Cape Guardafui (Northern Somaliland) to southern New Zealand, particularly during 2005 and 2007. The yearly rate of increase of the CO₂ concentration between 1996 and 2007 for the Indian Ocean is of about 1.9 ppmv yr^?1, in excellent agreement with the NOAA/CMDL measurements carried out during the same period at Mahé Isld. (Indian Ocean) and Cape Grim (Tasmania). The δ¹³C results obtained from the CO₂ of flask samples collected in the Mediterranean show the effect of anthropogenic emissions, though this is considerably smaller than expected. This inconsistency may be related to the large terrestrial biospheric sink of CO₂ in the Northern Hemisphere. The results obtained from the Red Sea are quite variable through time and space, particularly in its southern section; their interpretation is not easy. The Indian Ocean and the Southern Ocean show rather homogeneous δ¹³C results even though a variable carbon isotope shift can be calculated from period/cruise to period/cruise. In the case of the Indian Ocean the mean δ¹³C value from the flask air samples collected in 2005 is ?8.29‰ and the calculated rate of the carbon isotope shift between 1998 and 2005 is ?0.034‰ yr^?1, considerably larger than that calculated at the closest NOAA station (Mahé Isld.) of ?0.026‰ yr^?1. This discrepancy may be, at least partially, caused by the small number of measurements carried out at sea. However, the atmosphere over the Indian Ocean is less affected by anthropogenic emissions than in other areas.     

Butyltin Compounds in Sediments of the Bahía Blanca Estuary, Argentina

Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base, in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g⁻¹ were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g⁻¹ near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g⁻¹ were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g⁻¹ was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas of heavy shipyard activities.     

Population Declines and Priorities for Amphibian Conservation in Latin America

Abstract: Although dramatic amphibian population declines have been reported worldwide, our understanding of the extent of the declines in Latin America, where amphibian diversity is high, is limited to a few well-documented studies. To better understand the geographic extent of declines, their possible causes, and the measures needed to improve Latin American scientists' ability to research the phenomenon and make effective management recommendations, we convened three regional workshops with 88 Latin American herpetologists and conservationists. Population declines are widespread in Latin America. At least 13 countries have experienced declines, and in 40 cases species are now thought to be extinct or extirpated in a country where they once occurred. Declines or extinctions have affected 30 genera and nine families of amphibians. Most declines have occurred in remote highlands, above 500 m in elevation in Central America and above 1000 m in the Andes. Most documented declines occurred in the 1980s. Of the possible causes studied to date, climate change appears to be important at one site and chytrid fungal disease has been identified at sites in three countries. Although many monitoring studies are currently underway in a variety of habitats, most studies are recent and of short duration. In a signed resolution, workshop participants called for greater collaboration and communication among scientists working in Latin America to understand the geographic extent of population declines and the distribution of possible causal factors. In situ conservation is important to protect habitats, but captive-rearing programs for species subject to imminent extinction are also needed. Better understanding of the taxonomy and natural history of amphibians and more funding for research and monitoring are critical to developing a scientific basis for management action to arrest and reverse population declines.     

Characterisation of the airborne pollen spectrum in Guadalajara (central Spain) and estimation of the potential allergy risk

Aerobiological research into airborne pollen diversity and seasonal variations in pollen counts has become increasingly important over recent decades due to the growing incidence of asthma, rhinitis and other pollen-related allergic conditions. Airborne pollen in Guadalajara (Castilla-La Mancha, Spain) was studied over a 6-year period (2008–2013) using a Hirst-type volumetric spore trap. The highest pollen concentrations were recorded from February to June, coinciding with the pollen season of the pollen types that most contribute to the local airborne pollen spectrum: Cupressaceae (32.2 %), Quercus (15.1 %), Platanus (13.2 %), Olea (8.3 %), Populus (7.8 %) and Poaceae (7.2 %). These are therefore critical months for allergy sufferers. The pollen calendar was typically Mediterranean and comprised 25 pollen types. Between January and March, Cupressaceae pollen concentrations exceeded allergy risk thresholds on 38 days. Other woody species such as Olea and Platanus have a shorter pollen season, and airborne concentrations exceeded allergy risk thresholds on around 13 days in each case. Poaceae pollen concentrations attained allergy risk levels on 26 days between May and July. Other highly allergenic pollen types included Urticaceae and Chenopodiaceae-Amaranthaceae, though these are less abundant than other pollen types in Guadalajara and did not exceed risk thresholds on more than 3 and 5 days, respectively.     

Current and future suitability areas of kermes oak (<Emphasis Type="Italic">Quercus coccifera</Emphasis> L.) in the Levant under climate change

Quercus coccifera L. (Kermes oak) is an evergreen oak, typical of the maquis in the eastern and south-eastern part of the Mediterranean. It occurs almost continuously along the Syrian–Lebanese coast up to 1500 m and is more scattered inland, up to the arid southernmost area of Petra in Jordan. Human impact and global warming both strongly affect the natural distribution of the species, thus leading to a widespread forest fragmentation in the whole region. In this study, we investigate the current bioclimatic range of Kermes oak and forecast which areas are potentially most suitable over the course of the twenty-first century. Ecological niche modelling was used to retrieve the environmental envelope of the species according to 23 topographic and climate variables. Five algorithms and three general circulation models were applied to provide the potential distribution of Kermes oak at the present time and project it to the future. Results showed a current suitability area in the Middle East extending from NW of Syria, rather continuously along the Lebanese coasts and inland up to the Mediterranean western slopes of Palestine and the Golan area (Israel), encompassing the Jordan Valley towards Dana and Wadi Rum (Jordan), with an isolated patch in Jabal Al-Arab (South Syria). Future scenarios depict a significant fragmentation and restriction of Kermes oak range, especially in the north of Syria and Golan, with a general shifting in altitude. This information may be useful in helping the foresters to cope with the challenge of climate changes by identifying the most suitable areas climatically effective for successful ecosystem restoration and management, including reforestation programmes.     

Mutagenic properties of linuron and chlorbromuron evaluated by means of cytogenetic biomarkers in mammalian cell lines

Agricultural practices are usually supported by several chemical substances, such as herbicides. Linuron and chlorbromuron are phenylurea herbicides largely used to protect crops from weeds, blocking photosynthesis by inhibition of the photosystem II complex. The former, also commercially known as lorox or afalon, is selectively used to protect bean and French bean plants, fennels, and celeriacs; the second, commercially known as maloran, is selectively used for carrots, peas, potatoes, soy sprouts, and sunflowers. Considering the widespread use of herbicides and, more generally, pesticides, it is important to clarify their involvement on human health, one of them concerning the possible direct or indirect effect on the genome of exposed populations. Here, we show that these herbicides are endowed by mutagenic properties, as demonstrated by an increased number of chromosomal aberrations (CAs) in two exposed Chinese hamster cell lines derived from ovary and epithelial liver, respectively. This was also confirmed by sister chromatid exchange (SCE) and micronucleus (MN) assays. Our present and previously obtained data clearly indicate that phenylurea herbicides must be used with great caution, especially for agricultural workers who use large amounts of herbicides during their work, and particular attention should be given to residues of these herbicides and their involvement in environmental pollution.     

Pesticide removal from waste spray-tank water by organoclay adsorption after field application to vineyards

Purpose

The main objective of this work was to develop and test a pilot scheme for decontaminating pesticide-containing water derived from pesticide mixtures used to protect vineyards, in which the scheme comprises adsorption by an organoclay and includes a system where an enhanced or rapid microbial degradation of the adsorbed residues can occur.

Methods

In laboratory experiments, the Freundlich adsorption coefficients of formulations of two fungicides, penconazole and cyazofamid, onto the organoclay Cloisite 20 A were measured in order to predict the efficiency of this organoclay in removing these fungicides from the waste spray-tank water. Subsequently, the adsorption tests were repeated in the pilot system in order to test the practical operation of the depuration scheme.

Results

The adsorption tests with the pilot system show 96% removal of both fungicides over a few hours, similar to the efficiency of removal predicted from the laboratory adsorption tests. The formulation type may influence the efficiency of clay recovered after adsorption. Regarding the waste disposal, for instance, the organoclay composted after the treatment, cyazofamid showed significant dissipation after 90?days, whereas the dissipation of penconazole was negligible.

Conclusion

The depuration scheme developed showed to be efficient for decontaminating pesticide-containing water derived from vineyards, but additional treatments for the adsorbed residues still appear to be necessary for persistent pesticides. However, future decontamination research should be attempted for water contaminated with pesticides containing antifoaming agents in their formulations, in which case the present pilot system could not be applied.     

Agreement between predicted risk and prevalence of Down syndrome in first trimester nuchal translucency screening

The agreement between predicted risks of Down syndrome and observed prevalence was investigated in a population of 11 847 singleton pregnancies screened by first trimester nuchal translucency at a single institution. Twenty-seven cases of Down syndrome were observed; 20 were detected prenatally by nuchal translucency and maternal age screening, three by other means and four postnatally. The screened women were grouped according to their predicted risk of having an affected pregnancy, and this was compared with the observed prevalence. A significant correlation between predicted and observed prevalences was noted, thus demonstrating that risk estimates for Down syndrome based on first trimester nuchal translucency screening are accurate. Copyright © 2002 John Wiley & Sons, Ltd.