Roberta Selvaggi

Deformities of chironomid larvae and heavy metal pollution: From laboratory to field studies

Mouthpart deformities of Chironomus riparius larvae (Diptera) have been investigated to evaluate the toxic effects of contamination by heavy metals in the Genna Stream (Central Italy), situated in an area subjected to intensive swine farms (40000 heads). The livestock farming (fertirrigation) contributes to metal pollution of the Genna Stream with an increase of copper, zinc, cadmium, chromium and nickel in the sediments of the downstream stations. The incidence of mentum deformities was very high at all sampling stations, about 56%. The highest values of deformities were found in the intermediate river reach (St. 3: 65%) and in March (66%), mainly due to an increase in severe deformities. The high incidence of severe deformities (30%) is attributed to the high pollution level by heavy metals in the sediments, in particular to copper and zinc, which showed the highest average value at St. 3 and in March. This field study reflected the relationships between sediment metal concentrations and chironomid mouthpart deformities, previously observed in laboratory tests, and highlighted these deformities as toxicity endpoints. This feature paves the way for their use as an effective tool in freshwater bioassessment monitoring programs to evaluate the toxic effects of metal contamination in freshwater ecosystems.

Sediment toxicity and deformities of chironomid larvae in Lake Piediluco (Central Italy).

The chemical analysis of the bottom sediments of the Lake Piediluco (Central Italy) has been carried out in order to individuate the potential correlation between the sediment toxicity and the high incidence of mouthpart deformities in chironomid larvae (biological indicators) found in this lake. The environmental contamination has been analyzed by determining the concentrations of the main heavy metals (lead, copper, cadmium, chromium, zinc and nickel), and the concentrations of organic compounds of anthropic source: PAHs, NPPs and OCPs. Heavy metals concentrations have pointed out a non-elevated contamination grade for the Lake Piediluco. The highest level of metals has been detected in the western area that feels the effect of the continuous tributaries incoming load. Also, concerning PAHs, NPPs and OCPs the lake does not present high values of pollution. The highest concentrations of the organic toxicants has been observed in the eastern sector of the lake, which presents typical lentic characteristics. A clear relationship has not found between the toxic substances present in the lacustrine sediments and the deformities incidence for chironomid larvae, which represent an index of environmental alteration. Probably, the mouthpart deformities found in the chironomid larvae of Chironomus plumosus are affected by a synergic action due to the whole toxic mixture present in the sediments of the Lake Piediluco.

Heavy metals bioaccumulation in selected tissues of red swamp crayfish: An easy tool for monitoring environmental contamination levels

In this paper we explored the heavy metal bioaccumulation (Cd, Cu, Pb and Zn) in Procambarus clarkii, a crayfish recently suggested as a potential bioindicator for metals pollution in freshwater systems. The present study is focused on crayfishes populations caught in a heavily polluted industrial and in a reference sites (Central Italy), though the results are generalized with a thorough analysis of literature metadata. In agreement with the literature, the hepatopancreas (Hep, detoxification tissues) of the red swamp crayfish showed a higher concentration of heavy metals in comparison to the abdominal muscle (AbM, not detoxification tissues) in the sites under scrutiny. Hep/AbM concentration ratio was dependent on the specific metal investigated and on its sediment contamination level. Specifically we found that Hep/AbM ratio decreases as follows: Cd (11.7)>Cu (5.5)>Pb (3.6)>Zn (1.0) and Pb (4.34)>Cd (3.66)>Zn (1.69)>Cu (0.87) for the industrial and reference sites, respectively. The analysis of our bioaccumulation data as well as of literature metadata allowed to elaborate a specific contamination index (Toxic Contamination Index, TCI), dependent only on the bioaccumulation data of hepatopancreas and abdominal muscle. In the industrial site, TCI expressed values much higher than the unit for Cd and Cu, confirming that these metals were the main contaminants; in contrast for lower levels of heavy metals, as those observed in the reference site for Cu, Zn and Pb, the index provided values below unit. TCI is proposed as a useful and easy tool to assess the toxicity level of contaminated sites by heavy metals in the environmental management.

Tandem diels-alder reaction of 4-oxo-2-cyclopentenyl acetate. A facile one-pot synthesis of hydrofluorenones

Abstract 4-Oxo-2-cyclopentenyl acetate has been shown to behave as a conjunctive reagent for Tandem Diels-Alder Reaction under aluminum chloride catalysis. This methodology represents a mild and convenient elaboration of hydrofluorenones. Structure analysis of the reaction products by NMR spectroscopy is discussed.

Regiochemistry of the Diels-Alder Reaction of 1-Ethenyl-hydronaphthalenes and 2-Methyl-2-cyclopenten-1-one

Abstract Diels-Alder reactions of 2-methyl-2-cyclopenten-l-one with l-ethenylhydronaphthalenes are described. The structure analysis of the reaction products by NMR spectroscopy is reported. The regioselectivity as well as the diastereoselectivity of the cycloadditions are discussed.

Solid-Phase Analysis of Polycyclic Aromatic Hydrocarbons by Fluorimetric Methods

Polycyclic aromatic hydrocarbons (PAHs) adsorbed on the surface of particulates collected in a working environment have been analyzed using fluorescence techniques. In particular, fluorescence measurements were carried out directly on the sampling filters, in solid phase, and for comparison, on the extract samples in solution. Fluorescence synchronous acquisitions allowed the detection of signals from different PAH compounds and, on the basis of the 0–0 transition energy, the assignment of the emission signals to chemical structures. In particular, the contribution of benzo-α-pyrene was easily detected and used to evaluate the sensitivity of the measurements, which is a few nanograms per milliliter, comparable with other analytical tools. The results of the fluorimetric investigation were validated through the comparison with the data obtained by gas chromatography (GC) analysis on the extracted samples, which allowed identification of the PAHs and the quantification of their distribution on the filters with different cut sizes. The agreement between the two series of data led to the conclusion that fluorimetric analysis directly on the sampling filter could be a new and cost-effective approach for the analysis of PAHs.

A One-step Regioselective Construction of the Steroid Skeleton by Lewis Acid Catalyzed High Pressure Diels-Alder Reaction1

Abstract The one-step regioselective construction of the steroid skeleton by high pressure EtAlCl2 catalyzed Diels-Alder reaction of 3-methyl-2-cyclopenten-1-one with a 1-ethenyl-hexahydronaphthalene is described. Structure analysis of the reaction products by NMR spectroscopy is presented.

HIGH PRESSURE LEWIS-ACID CATALYZED DIELS-ALDER REACTIONS OF 3-METHYL-2-CYCLOPENTEN-1-ONE. A NEW CONSTRUCTION OF ANGULARLY METHYLATED HYDRINDANONES

Abstract The Diels-Alder reactions of 3-methyl-2-cyclopenten-1-one with simple acyclic dienes under high pressure in combination with EtAlCl2 are described. Angularly methylated hydrindanones were isolated in reasonably to good yields. Structure analysis of the reaction products by NMR spectroscopy is presented.

AFLP Approach Reveals Variability in Phragmites australis: Implications for its Die-back and Evidence for Genotoxic Effects

Phragmites australis is a subcosmopolitan species typical of wetlands being studied in Europe for its disappearance from natural stands, a phenomenon called reed die-back syndrome (RDBS). Although it is conjectured that low genetic variability contributes to RDBS, this aspect remains neglected to this day. Using a molecular fingerprinting approach and a sequence analysis of the trnT-trnL/rbcL-psaI regions of cpDNA, this study aimed to compare the genetic structure of stable vs. RDBS-affected P. australis stands from five wetlands of central Italy. Beforehand, in order to characterize the health condition of reed populations, the occurrence of the main macromorphological descriptors for RDBS was considered on 40 reed stands. Soil samples were also collected to examine the total content of heavy metals. The current study analyzed cpDNA in 19 samples and AFLP profiles in 381 samples to investigate the genetic structure of Phragmites populations. Based on the multinomial-Dirichlet model, an analysis of candidate loci under selective pressure was also performed. The relationships among AFLP data, RDBS descriptors and chemicals were evaluated with the use of Linear Mixed Models. The analysis of the cpDNA shows the occurrence of the haplotypes M (the most widespread), and K here recorded for the first time in Italy. Three new haplotypes were also described. The DNA fingerprinting analysis has produced a total of 322 loci (98% polymorphic) and shows the medium-to-high amount of genetic diversity. The significant genetic differentiation among wetlands (Fst = 0.337) suggests either low gene flow or small effective population size. Moreover, the low amount of outlier loci (only 5; l.5% of the total), seems to indicate the scarce occurrence of selective pressure upon the reed’s genome. Genetic diversity increased in relationship to the decrease in diameter and of flowering buds of the reed, two of the trends associated with the die-back. The current study rejects the hypothesis that genetic diversity massively contributed to RDBS. Moreover, significant relationships between genetic diversity and the total concentration of some heavy metals (Cr, Cu, and Zn) were highlighted, indicating possible genotoxic effects on P. australis. The current study represents a fact-finding background useful for the conservation of common reed.

Invertebrate diversity in relation to chemical pollution in an Umbrian stream system (Italy)

We used self-organizing maps (SOM, neural network) to bring out patterns of benthic macroinvertebrate diversity in relation to river pollution. Fourteen stations were sampled over various seasons in the Nestore drainage basin (Central Italy) and characterized for macroinvertebrate communities, nutrient and heavy metal concentrations. Physicochemical variables were introduced into a SOM previously trained with macroinvertebrate data. Patterns of communities matched spatial and seasonal changes in environmental conditions, including water chemistry related to economic activities in the catchment. Although our analyses did not allow us to establish the specific effect of any given environmental parameter upon macroinvertebrate community composition based on the field study, they enabled us to map the ecological health of river ecosystems in a readily interpretable manner.