Concentrations of trace elements in tissues of loggerhead turtles (Caretta caretta) from the Tyrrhenian and the Ionian coastlines (Calabria,Italy)

Environmental Science and Pollution Research - Toxic trace elements from both, natural and anthropogenic origin, pose a threat to aquatic environments and marine wildlife due to their long-range...     

Farmer knowledge and a priori risk analysis: pre-release evaluation of genetically modified Roundup Ready wheat across the Canadian prairies

Background, aim, and scope  

The controversy over the world’s first genetically modified (GM) wheat, Roundup Ready wheat (RRW), challenged the efficacy of ‘science-based’ risk assessment, largely because it excluded the public, particularly farmers, from meaningful input. Risk analysis, in contrast, is broader in orientation as it incorporates scientific data as well as socioeconomic, ethical, and legal concerns, and considers expert and lay input in decision-making. Local knowledge (LK) of farmers is experience-based and represents a rich and reliable source of information regarding the impacts associated with agricultural technology, thereby complementing the scientific data normally used in risk assessment. The overall goal of this study was to explore the role of farmer LK in the a priori risk analysis of RRW.     

Assessment of nitrous oxide emission from cement plants: Real data measured with both Fourier transform infrared and nondispersive infrared techniques

Nitrous oxide (N₂O) is the third most important greenhouse gas after carbon dioxide and methane, and contributes about 6% to the greenhouse effect. Nitrous oxide is a minor component of the atmosphere, and it is a thousand times less than carbon dioxide (CO₂). Nevertheless, it is much more potent than CO₂ and methane, owing to its long stay in the atmosphere of approximately 120 yr and the high global warming potential (GWP) of 298 times that of CO₂. Although greenhouse gases are natural in the atmosphere, human activities have changed the atmospheric concentrations. Most of the values of emission of nitrous oxide are still obtained by means of emission factors and not actually measured; the lack of real data may result in an underestimation of current emissions. The emission factors used for the calculation of N₂O can be obtained from the “Guidelines for the implementation of the national inventory of emissions” of the Intergovernmental Panel on Climate Change, which refer to all nations for the realization of their inventory. This study will present real data, measured in several Italian cement plants with different characteristics. The work also shows a comparison between N₂O concentration measured with in situ Fourier transform IR (FTIR) and the reference method EN ISO 21258 based on nondispersive IR (NDIR), in order to investigate the interfering compounds in the measurement with NDIR.

Implications:N₂O may arise as an unwanted by-product of nitrogen oxide (NO_x) abatement systems, in particular selective noncatalytic reduction (SNCR). Since it is applied in the cement plants, N₂O emission from cement industry is evaluated, with both FTIR and NDIR instrument. Several considerations emerged from the results. First of all, the emission from this industrial sector is not negligible, and for that reason N₂O concentration should be regulated; another observation is that the reference method based on the NDIR technique is not as selective as FTIR could be.     

On estimating Hooded crow density from line transect data through exponential mixture models

Line transect sampling is a distance sampling method widely used for estimating wildlife population density. Since the usual approach assumes a model for the detection function, the estimate depends on the shape of such a function. In particular, the estimate is influenced by the so-called shoulder condition, which ensures that detection is nearly certain at small distances from the line transect. For instance, the half-normal model satisfies this condition, whereas the negative exponential model does not. The aim of this paper is to propose the exponential mixture model of the half-normal and the negative exponential in order to estimate the population density in the case where the shoulder condition is not guaranteed. Such a case study on Hooded crow is described in the paper.     

VALIDATION OF AN ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) FOR CYPRINUS CARPIO L. VITELLOGENIN, AS A BIOMARKER OF REPRODUCTIVE DISORDERS

Vitellogenin is a female sex-specific protein, and a validated and suitable method for its assay can be applied as a biomarker of reproductive disorders in male and female aquatic animals. Therefore, the present study was designed to validate an ELISA for measuring plasma vitellogenin in wild carp ( Cyprinus carpio L.) living in the Lake of Trasimeno (Umbria, Italy); plasma samples were taken during pre-spawning, spawning, and post-spawning periods; in addition to vitellogenin, in both male and female carps, plasma changes of estradiol-17 βwere monitored together with those of estrogen receptor density in the liver.

In females, VTG showed high seasonality, reaching the highest levels in March during the pre-spawning period; the VTG levels correlated with those of estradiol-17 β( E 2 ), and with the changes of gonadosomatic index (GSI), while a non parallel trend was found in the liver estrogen receptor (ER) density. In forty percent of males, VTG was found to be present in the plasma and changes of ER density in the liver were observed.

The data here reported suggest that the common carp can be a useful sentinel species for biomonitoring studies of environmental estrogens, and of their effects on its reproductive biology.     

鼋头渚不同年龄夜鹭卵中多氯联苯污染状况及分布特征

通过对太湖鼋头渚2000年采集的2龄、3龄和4龄夜鹭所产卵中15种多氯联苯同系物残留状况的研究,发现所有样品中均检出多氯联苯,残留量最高的为PCB₁₁₈,PCB₈₇,PCB₁₀₁和PCB₁₅₃,占PCBs残留量的75%～85%.含5～6个氯原子的同系物在夜鹭卵中的PCBs残留量明显高于其它类型的同系物.同时,多氯联苯残留量随亲鸟年龄增加而明显增加.4龄卵样分别比3龄、2龄卵样中PCBs残留量高出47.5%和60.9%.统计处理结果表明:多氯联苯残留总量与亲鸟年龄呈正相关(p=0.05).PCBs总量与亲鸟年龄呈正相关(p=0.05).与欧美日等国家同类研究结果中PCB₁₅₃残留量最高的情况略有不同,本研究在夜鹭卵中发现残留量最高的是PCB₁₁₈,占PCBs残留总量的30%左右,PCB₁₅₃含量仅为PCBs残留总量的17%左右.     

不同年龄夜鹭卵中有机氯农药污染的生物指示

通过对太湖鼋头渚2000年采集的二龄、三龄和四龄夜鹭卵以及相应年龄组夜鹭的捕食物中有机氯残留的检测, 发现捕食物中HCH和DDT的平均残留量随年龄增加而增加.除γHCH外, 其它15种有机氯农药在卵样中均有检出, 残留水平最高的为p, p'DDE, 占有机氯农药残留总量的85%以上.βHCH是六六六类中持留性最强的组分, 其残留量仅次于p, p'DDE.研究发现, p, pDDT和βHCH检出率为100%, 而其它类型农药只有很低的检出率, 这与我国有机氯农药使用的历史情况相吻合.随着亲鸟年龄增加, 卵中β-HCH残留量有所提高, p, p'DDE残留量似有先升后稍降的趋势.统计结果表明:各年龄组有机氯残留量差异不明显, 因此在用夜鹭卵作有机氯污染的生物指示时可以不考虑年龄差异所带来的影响.     

Benthic-pelagic coupling in frontal system areas of the Northern Adriatic Sea: Analysis of the carbon budgets

Sediment samples were collected between 1996 and 1998 during 4 cruises in the northern sector of the Adriatic Sea, facing the Po River outflow. In each sampling period, after identification of the front line, a grid of 6 sampling stations was selected in order to cover: the coastal area (largely affected by river waters), the inner and outer front areas, and the offshore waters. The biochemical composition of sedimentary organic matter (OM, lipids, proteins, carbohydrates and photosynthetic pigments) and enzymatic activity rates were studied to provide information on the potential organic matter turnover. Tentative estimates of the organic carbon budgets (input/production versus requirement by benthic consumers) are presented. Benthic carbon requirements, estimated from bacterial plus meiofaunal secondary production, was high (897 r mg r C r m m 2 r d m 1 ). OM concentrations in the Northern and Middle Adriatic Sea displayed high values, proteins being dominant, thus suggesting inputs of freshly produced material to the sea floor. OM turnover was generally rapid (11-30 r d m 1 ) and higher during summer. The uncoupled enzymatic rates ( i.e. faster protein than carbohydrate mobilisation in February, 1997) determined a decrease of the OM quality that plays an important role in biogeochemical cycles and OM diagenesis, limiting bacterial secondary production and sedimentary organic carbon utilisation. These data suggest that the efficiency of the system in the transfer of energy through the food web is generally higher in summer, especially during mucilage production.     

Validation of an enzyme linked immunosorbent assay (elisa) for cyprinus carpio l. vitellogenin,as a biomarker of reproductive disorders

Vitellogenin is a female sex-specific protein, and a validated and suitable method for its assay can be applied as a biomarker of reproductive disorders in male and female aquatic animals. Therefore, the present study was designed to validate an ELISA for measuring plasma vitellogenin in wild carp ( Cyprinus carpio L.) living in the Lake of Trasimeno (Umbria, Italy); plasma samples were taken during pre-spawning, spawning, and post-spawning periods; in addition to vitellogenin, in both male and female carps, plasma changes of estradiol-17 g were monitored together with those of estrogen receptor density in the liver. In females, VTG showed high seasonality, reaching the highest levels in March during the pre-spawning period; the VTG levels correlated with those of estradiol-17 g ( E 2 ), and with the changes of gonadosomatic index (GSI), while a non parallel trend was found in the liver estrogen receptor (ER) density. In forty percent of males, VTG was found to be present in the plasma and changes of ER density in the liver were observed. The data here reported suggest that the common carp can be a useful sentinel species for biomonitoring studies of environmental estrogens, and of their effects on its reproductive biology.