PCDDs, PCDFs, PCBs and DDE in edible marine species from the Adriatic Sea

Edible marine species from several areas of the Adriatic sea were analyzed for their content in persistent organic pollutants (POPs), such as polychlorinated dibenzodioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and pp'-DDE (dichlorodiphenyldichloroethylene), a metabolite of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT). On the whole, PCDD/F contamination levels were low. In general, I-TEQ findings were greater for those species at higher levels in the trophic web (mackerel > red mullet > anchovy). Contamination levels were within 0.23 and 1.07 pg TEQ/g fw (fresh weight) in the aforesaid species, while all remaining species exhibited contamination levels ranging from approximately 0.07 to 0.25 pg TEQ/g fw. Besides, TEQ cumulative findings in species from the northern area were in general greater than those from the central and southern areas. PCB cumulative findings in the samples also revealed a detectable difference in contamination levels in species obtained from the northern, central, and southern sampling sites, between 7.6 and 177, 2.3 and 157, and 4.5 and 94 ng/g fw, respectively. The greatest PCB concentrations were found in mackerel (94-177 ng/g fw). Finally, DDE concentration levels varied from 0.7 to 32.4 ng/g fw. The highest levels of contamination were found in mackerel, red mullet and anchovy (17.7-32.4 ng/g fw, 8.1-9.8 ng/g fw, and 6.4-11.9 ng/g fw, respectively).     

Heavy Metals in Liver and Muscle of Bluefin Tuna (Thunnus thynnus) Caught in the Straits of Messina (Sicily, Italy)

The present investigation was carried out on the bluefin tuna (Thunnus thynnus) collected during the month of April 2003 from the Straits of Messina. The aim of this study is to determine heavy metal levels (Cd, Cu, Hg, Mn, Pb and Zn) in liver and muscle tissues of 14 Thunnus thynnus of different age and sex and to investigate the relationships between fish sex and size (length and weight and metal concentrations in the tissues. The concentrations of the various metals were determined by a Varian atomic absorption spectroscopy instrument. The results showsignificant variations (p < 0.01) for Hg and Zn concentrations in muscle than in liver samples. Concentrations of Cd and Pb are below the instrumental detection limits in almost all muscle samples. Levels of Hg (3.03 + 0.55 μg/g) are above the MRLs only in muscle (1μg/g) establishing toxicological risks for the consumer. Regression analysis shows a negative correlation between mercury level and weight and length in samples from both female and male. No significant difference between mean heavy metals concentrations and male or female tuna is seen. For greater food safety, it would be advisable to reduce the mercury intake by selecting safer fish, species and size and by the avoidance of tuna fish consumption by pregnant women, young children and old people, who are more sensitive to mercury exposure.     

Role of the natural and anthropogenic radiative forcings on global warming: evidence from cointegration–VECM analysis

Over the last few years there has been much debate about the hypothesis that anthropogenic emissions of CO₂ and other greenhouse gases increase global temperature permanently. By using recent advances in time series econometrics, this paper tries to answer the question on how human activity affects Earth’s surface temperatures. Bearing in mind this goal, we estimated the long-run cointegration relations between global temperatures and changes in radiative forcings by a set of perturbing factors. We found that the temperature response to a doubling in radiative forcing of anthropogenic greenhouse gases is + 2.94 °C [95 % CI: + 1.91, + 3.97], in perfect accordance with prior research, and that the orthogonalized cumulated effect over a 100 year time period, in response to a unit increase of size of one standard deviation in greenhouse gas radiative forcing, is + 3.86 °C [95 % CI: + 0.03, + 6.54]. Conversely, the amplitude of solar irradiance variability is hardly sufficient to explain observed variations in the Earth’s climate. Our results show that the combined effect of stochastic trends attributable to anthropogenic radiative forcing variations are driving the Earth’s climate system toward an ongoing phase of global warming, and that such long-run movement is unlikely to be transient.     

Optimal design of pump-and-treat systems under uncertain hydraulic conductivity and plume distribution

In this work, we present a stochastic optimal control framework for assisting the management of the cleanup by pump-and-treat of polluted shallow aquifers. In the problem being investigated, hydraulic conductivity distribution and dissolved contaminant plume location are considered as the uncertain variables. The framework considers the subdivision of the cleanup horizon in a number of stress periods over which the pumping policy implemented until that stage is dynamically adjusted based upon new information that has become available in the previous stages. In particular, by following a geostatistical approach, we study the idea of monitoring the cumulative contaminant mass extracted from the installed recovery wells, and using these measurements to generate conditional realizations of the hydraulic conductivity field. These realizations are thus used to obtain a more accurate evaluation of the initial plume distribution, and modify accordingly the design of the pump-and-treat system for the remainder of the remedial process. The study indicates that measurements of contaminant mass extracted from pumping wells retain valuable information about the plume location and the spatial heterogeneity characterizing the hydraulic conductivity field. However, such an information may prove quite soft, particularly in the instances where recovery wells are installed in regions where contaminant concentration is low or zero. On the other hand, integrated solute mass measurements may effectively allow for reducing parameter uncertainty and identifying the plume distribution if more recovery wells are available, in particular in the early stages of the cleanup process.     

Recovery agenda for sustainable development post COVID-19 at the country level: developing a fuzzy action priority surface

Environment, Development and Sustainability - As a response to the urgent call for recovery actions against the COVID-19 crisis, this research aims to identify action priority areas...     

The use of multilevel sampling techniques for determining shallow aquifer nitrate profiles

Nitrate is a worldwide pollutant in aquifers. Shallow aquifer nitrate concentrations generally display vertical stratification, with a maximum concentration immediately below the water level. The concentration then gradually decreases with depth. Different techniques can be used to highlight this stratification. The paper aims at comparing the advantages and limitations of three open hole multilevel sampling techniques (packer system, dialysis membrane samplers and bailer), chosen on the base of a literary review, to highlight a nitrate vertical stratification under the assumption of (sub)horizontal flow in the aquifer. The sampling systems were employed at three different times of the year in a shallow aquifer piezometer in northern Italy. The optimal purge time, equilibration time and water volume losses during the time in the piezometer were evaluated. Multilevel techniques highlighted a similar vertical nitrate stratification, present throughout the year. Indeed, nitrate concentrations generally decreased with depth downwards, but with significantly different levels in the sampling campaigns. Moreover, the sampling techniques produced different degrees of accuracy. More specifically, the dialysis membrane samplers provided the most accurate hydrochemical profile of the shallow aquifer and they appear to be necessary when the objective is to detect the discontinuities in the nitrate profile. Bailer and packer system showed the same nitrate profile with little differences of concentration. However, the bailer resulted much more easier to use.

     

Outbreak of fatal nitrate toxicosis associated with consumption of fennels (Foeniculum vulgare) in cattle farmed in Campania region (southern Italy)

Nitrate and nitrite are toxicants that have become increasingly significant environmental chemicals. Increase in environmental distribution of nitrogenous compounds, especially in surface and ground water, has been attributed to the intensive use of nitrate as agricultural fertilizers and to increasing amounts of nitrogenous wastes produced by municipalities, industries, and feedlots. The purpose of this study is to illustrate a fatal nitrate toxicosis in cattle associated with the consumption of fennels (Foeniculum vulgare). Fifteen cows from the same farm suddenly developed weakness, muscular tremors, respiratory distress, and finally convulsions. The affected animals died within 24 to 48 h from the onset of the clinical signs. Five cows underwent a complete post-mortem examination. In all examined animals, gross lesions included presence of dark unclotted blood around the nostrils and the anal region, moderate inflammation of the gastrointestinal mucosa, and brown discoloration of the skeletal muscles and kidneys. The histological examination showed tubular degeneration and congestion of glomerular vessels in the kidney. Toxicological analysis detected nitrates at 4 672.2 ppm in the fennels used to feed the animals. The source of exposure to nitrates was identified in the fennels. The fennels were grown in a polluted area of the Campania region in southern Italy and distributed in a public market for human consumption. The waste from the sale of the fennels was fed to the cows. The accumulation of nitrates in some vegetables poses a risk not only for animal health but also for human and environmental safety.     

Regression Analysis Model Applied to Biomonitoring Studies

A regression model is proposed for studying the relationship between trace metals concentrations and weights of individuals of Monodonta turbinata (Born), a gastropod mollusc used as a trace metal biomonitor of marine coastal areas. The model herein presented was developed including sites as reference factors and showed very good correlations. The prevision model of contamination gave good results for this kind of pollutants, and it can be used as a tool for monitoring programmes.     

Characterization and identification of trends in average ambient ozone and fine particulate matter levels through trajectory cluster analysis in eastern Canada

In many locations in Eastern Canada, ambient levels of fine particulate matter (PM,25) and surface ozone (O3) depend on airflow direction and synoptic scale meteorological conditions. In this study, a cluster analysis was performed on 10 yr (1994-2003) of back-trajectory data for 11 locations in Eastern Canada, resulting in the identification of 10 unique back-trajectory clusters (or airflows) for each location. The airflows were then used to characterize and identify spatial and temporal trends in the daily maximum 8-hr average O3 (dmax 8-hr O3) and the daily average PM2.5 levels. Results showed that airflows from the southwest passing over Michigan and Southern Ontario were associated, on average, with the highest O3 levels at most locations in Eastern Canada. For PM2.5, the highest levels occurred with airflows from the Eastern Ohio River Valley. At major urban locations in Ontario and Quebec, the warm season mean (May to September) dmax 8-hr O3 and the annual mean PM2.5 were, on average, 12 parts per billion and 7.6 microg/m3 higher, respectively, than airflows from the north. Elevated levels of O3 and PM2.5 also occurred under light airflows, and, on average, the levels under light airflows were higher than their nonlight counterparts. At several locations in Canada, including Toronto, Montreal, Quebec City, and Kejimkujik, the annual warm season mean dmax 8-hr O3 experienced a statistically significant (95% confidence) increasing trend over the 10-yr period. When airflow direction was considered, a number of locations experienced statistically significant upward trends in O3 for airflow from the north and northwest. Several locations also showed significant upward trends associated with airflow from the southwest passing over Michigan and Southwestern Ontario. Although there are no statistically significant downward trends, airflows from the southwest have shown a reduction in O3 levels in Southwestern Ontario in more recent years.