Essential and toxic elements in seaweeds for human consumption.

Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, and I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by energy-dispersive polarized x-ray fluorescence spectrometry in 14 seaweeds purchased in local specialty stores in Italy and consumed by humans. The differences in elements between the algae species reached up to 2-4 orders of magnitude. Lithothamnium calcareum showed the highest levels of Ca, Al, Si, Fe, and Ti. Palmaria palmata showed the highest concentrations of K, Rb, and Cl. The highest content of S was in Chondrus crispus. Laminaria digitata contained the highest concentrations of total As, Cd, Sn, Br, and I. The highest concentration of Zn was in Chlorella pyrenoidosa. Ulva lactuca displayed the highest levels of Cu, Ni, Mn, and Pb. Iodine levels ranged from 3.4 in Chlorella pyrenoidosa to 7316 mg/kg(dry) in Laminaria digitata. The nutrimental importance of essential elements was assessed using nutritional requirements. The results showed that the consumption of algae might serve as an important source of the essential elements. Health risk due to the toxic elements present in seaweed was estimated using risk estimators. Total As, Cd, and Pb concentrations ranged from <1 to 67.6, to 7.2 and to 6.7 mg/kg(dry) respectively; therefore, their contribution to total elemental intake does not appear to pose any threat to the consumers, but the concentrations of these elements should be controlled to protect the consumer against potential adverse health risks.

Methods for radioactivity measurements in drinking water using gamma spectrometry.

In this study, three methods to measure activity concentrations of radionuclides through high resolution gamma spectrometry are developed, optimized, and tested on drinking water samples. Two pre-concentration methods (partial evaporation and ion-exchange resins) were optimized for accuracy, precision, detection limits, costs, preparation, and measurements times. A new sampling method for 222Rn was designed and optimized to directly sample water from the tap, reducing and minimizing losses of radon during the sampling. A total number of 85 water samples were collected between 2017 and 2019 in collaboration with two drinking water suppliers in a wide area (~2000 km2) of the Veneto region, northeast Italy. These are the first results of radionuclides activity concentration in drinking water concerning a large extension in the foothill Veneto region. Finally, this study provides a first attempt of determining the spatial distribution and seasonal variations of radon activity concentration in drinking water in the study area.

The use of statistical methods to separate natural background and anthropogenic concentrations of trace elements in radio-chronologically selected surface sediments of the Venice Lagoon.

A new method has been developed that predicts the natural background concentrations of microelements of interest in sediments using the concentrations of various components present in the sample. This is done by developing multiple linear regressions using a dataset which has been selected, using radiochronological dating and statistical methods, to reflect the concentration distributions of natural levels of a large number of sediment constituents. This method is demonstrated in Venice Lagoon, using data generated in a lagoon-wide sampling effort. A quantitative assessment is carried out of the variability of natural background levels at the lagoon scale for the main inorganic microelements, and distribution maps of the background and anthropogenic concentrations of a selected metal (Ni) in sediments at the lagoon scale are presented. With sufficient data, this method can be applied in other areas, allowing for a site-specific separation of natural background and anthropogenic levels of microconstituents in sediments, providing insights into regional geochemistry and aiding in the risk-based management of coastal sediments.

Elemental and radiological characterization of commercial Cetraria islandica (L.) Acharius pharmaceutical and food supplementation products.

An elemental and radiological characterization was performed on Cetraria islandica (L.) Ach. pharmaceutical and food supplementation products purchased in local specialty shops in Italy. Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by Energy Dispersive Polarized X-Ray Fluorescence Spectrometry; natural radionuclides (238U, 234U, 230Th, 210Po, 232Th, and 228Th) were determined by alpha spectrometry. The results show that C. islandica, whose nutritional value was assessed referring to recommended nutrient intakes, could serve as an important source of essential elements. Moreover, as expected, lichens concentrate airborne 210Po, whose activity ranged from 132 to 489Bqkg-1dw. This value was much higher than those reported by UNSCEAR for leafy vegetables in the world. In addition, total As and Cd were <1mgkg-1dw and Pb mean concentration was 9.25mgkg-1dw. Health risks associated with the toxic elements contained in C. islandica (L.) products were calculated using risk estimators. Their contribution to total elemental intake does not appear to pose a threat, but the concentrations of these elements should be continuously monitored to protect consumers against potential adverse health effects.

Critical analysis of radiochemical methodologies for the assessment of sediment pollution and dynamics in the lagoon of Venice (Italy).

Aquatic sediments are the ultimate sink of wastes dispersed in freshwater and soil. They are therefore a useful tool for investigating polluted ecosystems. Lagoon environments are very difficult to study due to their unstable morphology. Under these circumstances, even an excellent environmental investigation of a restricted lagoon area would still be inadequate to appreciate the characteristics of the entire system. The Venice lagoon is a very complex ecosystem whose morphology is complicated further by extensive anthropic intervention. A good environmental representation of the area was obtained with a preliminary radiochemical survey of airborne radionuclides, a unique tool in evaluating the homogeneity of the entire sedimentary system. It must be stressed, however, that the significance of the data depends substantially on the use of qualified procedures. Based on this, a detailed study was carried out on selected homogeneous areas, reconstructing the inventories and fluxes of pollutants in the sediments. In this work the radiochemical approach to the environmental study of the Venice lagoon is examined.

Moss (Bryum radiculosum) as a bioindicator of trace metal deposition around an industrialised area in Sardinia (Italy).

The moss Bryum radiculosum (Brid.), a species typical of dry and coastal environments, was used as a bioindicator for the estimation of atmospheric trace metal deposition around the industrial site of Portoscuso (Sardinia, Italy), which includes a lead-zinc smelter, two power plants, and aluminium production factories. For Cd, Pb, Zn, and V the results showed very similar patterns with extremely high values in the immediate surroundings of the industrial area. Copper and Cr showed somewhat different patterns, but still pointing to local pollution sources. The levels of metals at distance of about 13 km from the industrial site were still higher than in background samples. In order to evaluate the suitability of B. radiculosum for monitoring studies, trace metal concentrations in moss were compared with bulk deposition measurements in the same area. Correlation was significant only for Pb, Cd, and Zn. For Cr, Cu, and V the results showed high variability, mainly to be ascribed to soil factors.

Immunohistochemical distribution of collagens types IV, V, and VI and of pro-collagens types I and III in human alveolar bone and dentine.

The aim of the present study was to characterize the composition of the organic matrix in alveolar jaw bone and dentine using antibodies against pro-collagens Types I and III and collagens Types IV, V, and VI. After demineralization of oral hard tissues in 0.2 N HCl, antigenicity was well preserved and the distribution of the pro-collagens and collagens could be demonstrated. Staining for pro-collagen Type I was prominent around osteoblasts and in pre-dentine, indicating active de novo synthesis of Type I pro-collagen. Pro-collagen Type I was ubiquitous but was less abundant in bone and dentine, whereas pro-collagen Type III was seen only in areas of bone remodeling, in peritubular spaces, and in pre-dentine. Type IV collagen was limited to the basement membranes of vessels in osteons and bone marrow. Type V collagen was detected neither in pre-dentine nor in bone. In contrast, Type VI collagen was found in dentine and bone, showing a faint but homogeneous staining which, similarly to pro-collagen Type III, was pronounced around osteoblasts and in pre-dentine, areas of active bone and dentine formation. This study showed that the organic matrix of dentine and bone contains Type VI as well as Type I collagen. Pro-collagen Type III (and to a lesser extent collagen Type VI) is transiently produced during new formation and remodeling of oral hard tissues, and disappears once the matrix calcifies. Type I pro-collagen qualifies as a general marker protein for increased osteoblastic activity. We conclude that immunostaining for the different collagen/pro-collagen types can be used to assess normal or abnormal stages of bone/dentine formation.

Civilian and military uses of depleted uranium: environmental and health problems.

Depleted uranium is a by-product of the process of enrichment of natural uranium and is classified as a toxic and radioactive waste; it has a very high density (approximately 19 g cm-3), a remarkable ductility and a cost low enough to be attractive for some particular technical applications. Civilian uses are essentially related to its high density, but the prevailing use is however military (production of projectiles). From the radioactive point of view, the exposure to depleted uranium can result from both external irradiation as well as internal contamination. The associated risks are however mainly of chemical-toxicological kind and the target organ is the kidney. In the present note the recent military uses and the possible effects of its environmental diffusion are discussed.

Identification of a major hepatitis B core antigen (HBcAg) determinant by using synthetic peptides and monoclonal antibodies.

To map the location of hepatitis B core and e Ag (HBcAg and HBeAg) on the hepatitis B virus core particle, we produced and analyzed four synthetic peptides which correspond to the most hydrophilic regions of the core P22 protein. Each peptide was tested in an ELISA for the ability to inhibit the binding between rHBcAg or rHBeAg and either polyclonal or monoclonal anti-HBc or anti-HBe antibodies. The former comprised 20 antisera positive for anti-HBc (anti-HBs and anti-HBe negative) and five antisera positive for anti-HBe and anti-HBc; the latter included three anti-HBc mAb developed in independent laboratories: G6F5, C51B10, and F8, as well as two anti-HBe mAb, E2 and E6. These experiments revealed the presence of a major HBcAg epitope expressed on C3, a peptide which covers amino acids 107-118 and reacted with all polyclonal and monoclonal antibodies tested. Another peptide, C2, sequence 73-85, reacted with 26% of human antisera but none of the anti-HBc mAb. None of the peptides seemed to express HBeAg activity because they do not cause any significant inhibition of the HBeAg/anti-HBe reaction. These data indicate the expression of an immunodominant HBcAg determinant on a linear dodecapeptide and argue against a strict conformation dependency of this Ag.

Serum procollagen type III peptide levels in patients with acute viral hepatitis.

Serum levels of procollagen type III peptide were measured by radioimmunoassay in 76 consecutive patients with acute viral hepatitis, in order to see if this index of hepatic fibrogenesis is also predictive for the development of chronic active hepatitis in high-risk patients. Serum procollagen levels were high (from 14.2 to 109.2 ng/ml, median 33.7 ng/ml) in 74 (97%) patients and normal (from 4 to 14 ng/ml, median 9.1 ng/ml) in 2 (3%) patients. The baseline serum procollagen levels were similar in all the subgroups of patients independently of the type of hepatitis. In the 59 patients with resolving hepatitis, serum procollagen levels returned to normal values from 2 to 48 weeks (mean 15). In the 17 patients with unresolved hepatitis, procollagen levels remained within the normal limits in 6 of 7 patients with non-progressive chronic disease, while were elevated (from 17.4 to 22.2 ng/ml) in 4 of 5 patients with chronic active hepatitis. Unlike transaminase activity, which could not discriminate between benign and progressive liver disease, serum levels of procollagen helped in identifying patients with unresolved hepatitis, who were developing chronic active disease.