Roberta Bettinetti

Bio: Roberta Bettinetti is an academic researcher from University of Insubria. The author has contributed to research in topics: Zooplankton & Biomagnification. The author has an hindex of 21, co-authored 80 publications receiving 1457 citations. Previous affiliations of Roberta Bettinetti include University of Milan.

Microplastic Contamination in Freshwater Environments: A Review, Focusing on Interactions with Sediments and Benthic Organisms

Abstract: Plastic is one of the most commonly produced and used materials in the world due to its outstanding features. However, the worldwide use of plastics and poor waste management have led to negative impacts on ecosystems. Plastic degradation in the environment leads to the generation of plastic particles with a size of <5 mm, which are defined as microplastics (MPs). These represent a global concern due to their wide dispersion in water environments and unclear potential ecotoxicological effects. Different studies have been performed with the aim of evaluating the presence and impacts of MPs in the marine environment. However, the presence of MPs in freshwater systems is still poorly investigated, making data retrieval a difficult task. The purpose of this review is to identify the main aspects concerning MPs pollution sources in lakes and rivers, with a focus on freshwater sediments as a site of accumulation and as the habitat of benthic organisms, which are key components of food webs and play a fundamental role in energy/contaminant transfer processes, but are still poorly considered. Through this review, the sources and fate of MPs in freshwater are analysed, ecotoxicological studies focused on sediments and benthic fauna are exposed, the most frequently used sampling and analysis strategies are reported, and future trends of MPs analysis in this field are proposed.

Biological Pump Control of the Fate and Distribution of Hydrophobic Organic Pollutants in Water and Plankton

Abstract: The goal of this study was to experimentally assess the coupling between primary producer biomass dynamics and the distribution and fate of persistent organic pollutants (POPs) in a lake pelagic ecosystem. This was done by following the short-term evolution of polychlorinated biphenyl (PCB) concentrations in water and biota (phytoplankton and zooplankton) and the variability of bioconcentration (BCF), biomagnification (BMF), and bioaccumulation (BAF) factors during the development of a typical spring ecological progression in which the phytoplankton bloom is followed by a peak in the zooplankton abundance. The bulk of compounds with log KOW > 6.5 in the lake epilimnion was mainly associated with primary producer biomass. The phytoplankton biological pump was a major driver of POP export from the epilimnion, causing the decline of dissolved-phase concentrations. The BCF of phytoplankton for the more hydrophobic PCBs showed minima during the period of biomass climax. The concentration in the zooplankton of all selected PCBs sharply declined from March to May, with BAFs having minima in the post algal bloom phase. Biomagnification occurred during the pre algal bloom and algal bloom phases but appeared to be absent during the post algal bloom. This study highlights the occurrence of a prompt and complex response in the fate and distribution of POPs to dynamic biogeochemical control. Within the frame of the ecological succession, phytoplankton and zooplankton biomass dynamics produced bioaccumulation metrics varying over 1–2 orders of magnitude in the time frame of a few weeks and resulted in reduced trophic web exposure.

Chemical analysis and sediment toxicity bioassays to assess the contamination of the River Lambro (Northern Italy).

Abstract: This study consisted of a 10-day whole sediment toxicity test with the chironomid Chironomus riparius and a 28-day sediment toxicity test with the oligochaete Tubifex tubifex at seven sites to assess the quality of the River Lambro (Italy), one of the most contaminated rivers of the Po Basin. Endpoints measured were survival and growth for chironomids and cocoon deposition and development of young worms for tubificid oligochaetes. Responses were evaluated in relation to the occurence of organic micropollutants (PCBs, DDT, HCB, and HCH) representative of the industrial and agricultural contamination of the area. Though survival of the organisms remained unaffected, sublethal effects were observed at all sites. The sediment sampled at the farthest upstream site differed from the control only in the number of cocoons deposited by the worms. Both test species in the next three sediments, where concentrations of PCB and DDT were in the range 21.9–39.5 ng g–1 DW and 0.6–1.3 ng g–1 DW, respectively, experienced greater toxicity in terms of growth and reproduction. Contamination was particularly high in the site closest to Milan, where the river receives untreated urban and industrial discharges. Levels of total PCBs and total DDT here were up to two orders of magnitude higher than those found at the other sampling locations, and chironomid growth and the reproductive endpoints of tubificids were significantly lower than in the control and the other sites. The test results for the next two stations showed improvement relative to that of Milan, although contamination was still evident. Sublethal effects were in agreement with the measured concentrations of the principal persistent organic pollutants and should be included as part of environmental monitoring efforts as a basis for assessing the recovery of the river.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

Abstract: The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Environmental magnetism: Principles and applications

Abstract: [1] In environmental magnetism, rock and mineral magnetic techniques are used to investigate the formation, transportation, deposition, and postdepositional alterations of magnetic minerals under the influences of a wide range of environmental processes. All materials respond in some way to an applied magnetic field, and iron-bearing minerals are sensitive to a range of environmental processes, which makes magnetic measurements extremely useful for detecting signals associated with environmental processes. Environmental magnetism has grown considerably since the mid 1970s and now contributes to research in the geosciences and in branches of physics, chemistry, and biology and environmental science, including research on climate change, pollution, iron biomineralization, and depositional and diagenetic processes in sediments to name a few applications. Magnetic parameters are used to routinely scan sediments, but interpretation is often difficult and requires understanding of the underlying physics and chemistry. Thorough examination of magnetic properties and of the environmental processes that give rise to the measured magnetic signal is needed to avoid ambiguities, complexities, and limitations to interpretations. In this review, we evaluate environmental magnetic parameters based on theory and empirical results. We describe how ambiguities can be resolved by use of combined techniques and demonstrate the power of environmental magnetism in enabling quantitative environmental interpretations. We also review recent developments that demonstrate the mutual benefit of environmental magnetism from close collaborations with biology, chemistry, and physics. Finally, we discuss directions in which environmental magnetism is likely to develop in the future.

Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain

Abstract: The tremendous increases in production of plastic materials has led to an accumulation of plastic pollution worldwide. Many studies have addressed the physical effects of large-sized plastics on organisms, whereas few have focused on plastic nanoparticles, despite their distinct chemical, physical and mechanical properties. Hence our understanding of their effects on ecosystem function, behaviour and metabolism of organisms remains elusive. Here we demonstrate that plastic nanoparticles reduce survival of aquatic zooplankton and penetrate the blood-to-brain barrier in fish and cause behavioural disorders. Hence, for the first time, we uncover direct interactions between plastic nanoparticles and brain tissue, which is the likely mechanism behind the observed behavioural disorders in the top consumer. In a broader perspective, our findings demonstrate that plastic nanoparticles are transferred up through a food chain, enter the brain of the top consumer and affect its behaviour, thereby severely disrupting the function of natural ecosystems.