Trace and rare earth elements in phytoplankton from the Tyrrhenian Sea (Italy).

Plankton plays a very crucial role in bioaccumulation and transfer of metals in the marine food web and represents a suitable bioindicator of the occurrence of trace and rare earth elements in the ecosystem. Trace elements and REEs were analyzed by ICP-MS in phytoplankton samples from the northwestern Mediterranean Sea. Metal concentrations in phytoplankton were found strongly influenced by seasons and depth of collection (- 30 m, - 50 m). Principal component analysis (PCA) has shown that Al, As, Cr, Cu, Ga, and Sn concentrations were related to summer and autumn in samples collected at 30 m depth, while Fe, Mn, Ni, V, and Zn levels related strongly with summer and spring at 50 m depth. Fe, Al, and Zn were the most represented elements in all samples (mean values respectively in the ranges 4.2-8.2, 9.6-13, and 1.0-4.4 mg kg-1) according to their widespread presence in the environment and in the earth crust. Principal component analysis (PCA) performed on REEs showed that mostly all lanthanides' concentrations strongly correlate with summer and autumn seasons (- 30 m depth); the highest ∑REE concentration (75 µg kg-1) was found in winter. Phytoplankton REE normalized profile was comparable to those of other marine biota collected in the same area according to the suitability of lanthanides as geological tracers.

Phthalate diester occurrence in marine feed and food (Mediterranean Sea).

Organic contaminants such as diesters of phthalic acid (PAEs) can be conveyed by microplastics in aquatic environment and constitute a relevant risk to marine organisms and humans that consume them. A method was developed for the identification and quantitative detection of 6 dimethyl phthalate (DMP), di-ethyl phthalate (DEP), di-n-butyl phthalate (DNBP), butyl benzyl phthalate (BBP), di-2-ethylesyl phthalate (DHEP), and di-n-octyl phthalate (DnOP). PAEs were then quantified in mesozooplankton, mollusk bivalves, and fish from the north-western Mediterranean Sea. Among all PAEs, DEHP was found in all zooplankton samples, in 30% of fish samples, and in 10% of bivalve samples. DBP was instead recovered in only 4% of samples (plankton and fish).

Microplastics as vectors of metals contamination in Mediterranean Sea.

Microplastics are contaminants of great concern all over the world. Microplastics constitute pollutants themselves; moreover, other contaminants such as metals are easily absorbed on their plastic surface, becoming bioavailable to marine biota such as zooplankton.We collected marine zooplankton from Mediterranean Sea to investigate trace elements associated with microplastics. Samples were subjected to visual sorting by a stereomicroscope, collected with sterile tweezers, pooled and subjected to sonication, filtration, and drying before being subjected to acid extraction. An ICP-MS was utilized for multi-elemental determination.Aluminum, iron, chromium, zinc, nickel, molybdenum, manganese, lead cobalt, and copper were found at concentrations of mg/kg while arsenic, vanadium, rubidium, and cadmium at level of µg kg-1. Other elements such as silver, beryllium, bismuth, selenium, tin, and thallium were under the limit of quantitation. Lower levels of iron and manganese in samples from Italy were found in comparison to England and Brazil, while aluminum, copper, and zinc registered comparable values. The presence of metals in marine waters is strictly related to sediment lithology and anthropogenic inputs, but plastic plays a key role as vectors for metal ions in the marine system, being able to concentrate metals several order of magnitude higher than in surrounding waters and exerting potential toxicity for living beings after chronic exposure.

Rare earth elements in marine and terrestrial matrices of Northwestern Italy: Implications for food safety and human health.

Rare earth elements (REEs) are central in several critical technologies; their use is constantly increasing as is their release into the environment. For this reason, it is important to investigate REE concentrations in different matrices to evaluate human exposure and environmental risk of these emerging contaminants. REEs were measured by ICP-MS in matrices of terrestrial (plant feed, fruit, honey, wildlife livers) and marine origin (seaweeds, zooplankton, bivalves, fish) collected from Northwestern Italy. Highest REE concentrations were measured at low trophic levels, both in terrestrial and marine environments, such as plants (ΣREE 1.8 mg kg-1) and seaweed (ΣREE 12 mg kg-1), the major source of exposure and transfer of REEs to food webs. REE concentrations were several orders of magnitude lower in fruit, honey, and livers from terrestrial wildlife, suggesting a negligible risk of exposure by these matrices. Marine biota, such as bivalves (ΣREE 0.16 mg kg-1) and fish (ΣREE 0.21 mg kg-1) may constitute a pathway for human or animal dietary exposure. The study confirmed that REEs have low potential for biomagnification, but instead are subject to trophic dilution. However, given the numerous sources of dietary introduction of REEs, they should be monitored for a possible harmful cumulative effect. Owing to the scarcity of data regarding REEs worldwide, our results contribute to assessment of the occurrence of these emerging contaminants.

Trace metal occurrence in Mediterranean seaweeds.

Seaweeds have been used as animal feed since a long time and are consumed as food in several cultures. In fact, macroalgae are a source of protein, fiber, polyunsaturated fat, and minerals. The concentration of trace elements was determined in dominant macroalga species from three sites of the northwestern Mediterranean Sea. A high interspecies variability was observed, with higher metal levels in brown and green than those in red seaweeds. The maximum values set by European regulations for arsenic, mercury, and cadmium in food and feed were never exceeded, but a few samples were very close to limits set for mercury. Conversely, the maximum limit for lead in feed was exceeded in all species from one of the considered sites. Analogously, lead in seaweeds could constitute a potential risk for human health, due to the exceeding of the maximum value set for food supplements.

A first report of rare earth elements in northwestern Mediterranean seaweeds.

The concentrations of rare earth elements (REE) were determined by ICP-MS in dominant seaweed species, collected from three locations of the northwestern Mediterranean Sea. This is the first study to define levels and patterns of REE in macro algae from these coastal areas. Rare elements are becoming emerging inorganic contaminants in marine ecosystems, due to their worldwide increasing applications in industry, technology, medicine and agriculture. Significant inter-site and interspecies differences were registered, with higher levels of REE in brown and green macro algae than in red seaweeds. Levels of light REE were also observed to be greater compared to heavy REE in all samples. One of the investigated locations (Bergeggi, SV) had higher REE and ΣREE concentrations, probably due to its proximity to an important commercial and touristic harbor, while the other two sites were less affected by anthropogenic contaminations, and showed comparable REE patterns and lower concentrations. CAPSULE: Rare earth elements in seaweeds.