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Suspended load and mercury pollution: towards a simple method to measure Hg flux from the Monte Amiata Mining District (Southern Tuscany, Italy)
No full textMining activities produce huge amounts of waste material heavily polluted by toxic elements. Over
time, these wastes can pollute fluvial ecosystems due to runoff. Moreover, mining can significantly alter
river morphology by modifying sediments supply, erosion, transport, and (re-) deposition. The interplay
between geomorphic processes (e.g., flooding events) and anthropic activities plays an important role in the
contaminants redistribution across the environment, even at long range. Mercury (Hg) is listed as a critical
contaminant due to its high toxicity, mobility, and persistence in the environment. Its use is progressively
banned, and Hg mining is limited to a few countries. However, legacy mine wastes are still releasing Hg into
the environment, particularly to fluvial ecosystems. The Monte Amiata Mining District (MAMD, Southern
Tuscany) was the 3rd largest Hg producer worldwide. The Paglia River (PR) drains the SE sector of the MAMD
and its catchment covers an area of 1320 km2. The widespread Hg pollution of this river basin and its low
resilience to contamination was demonstrated in previous studies. Disastrous flooding events remobilized and
redistributed massive amounts of polluted sediments across the catchment (Colica et al., 2019). The Hg flux
discharged by PR to the Tiber River, and ultimately to the Mediterranean Sea, was estimated around 11kg/y
(Rimondi et al., 2019; Fornasaro et al., 2022a; Fornasaro et al., 2022b). However, this estimate is based on
spot samplings throughout the year. In this study, the relationship between Hg transported by particulate (Hgp)
and total suspended solids (TSS) for PR was investigated to set up a method for the calculation of Hg fluxes
from TSS monitoring. Water samples were collected during low and high river discharge. Samples were taken
along the PR, upstream and downstream of the Elvella creek confluence (ECC), a tributary that is not polluted
by Hg, in order to evaluate its effects on the Hg budget. The samples were filtered and the TSS collected on
the filters were analyzed for Hg. TSS ranged between 1.3 and 621.4 mg/L, whereas Hg varied between 0.8
and 321.8 ng/L. The highest Hg and TSS values were measured during the recession phase of flooding events,
whereas the lowest ones were found during low flow conditions. A linear relationship was found between Hg
and TSS. Hg was higher in the upstream samples than in those collected downstream the ECC, confirming
that Hg source is the heavily polluted PR basin. The relationship between the two parameters could be applied
to the indirect, continuous measurement of Hg fluxes discharged by PR with an automated TSS/turbidity
sensor. Such monitoring would allow assessing the variability of Hg pollution across the PR basin in real time
especially in case of flooding, that are expected to become more frequent due to climate change, leading to an
increase of Hg delivery to the Tiber River and ultimately to the Mediterranean Sea.
Colica A., Benvenuti M., Chiarantini L., Costagliola P., Lattanzi P., Rimondi V. & Rinaldi M. (2019) - From point source
to diffuse source of contaminants: The example of mercury dispersion in the Paglia River (Central Italy). Catena, 172,
488-500.
Fornasaro S., Morelli G., Costagliola P., Rimondi V., Lattanzi P. & Fagotti C. (2022a) - Total Mercury Mass Load from
the Paglia–Tiber River System: The Contribution to Mediterranean Sea Hg Budget. Toxics, 10(7), 395.
Fornasaro S., Morelli G., Rimondi V., Fagotti C., Friani R., Lattanzi P. & Costagliola P. (2022b) - The extensive mercury
contamination in soil and legacy sediments of the Paglia River basin (Tuscany, Italy): interplay between Hg-mining
waste discharge along rivers, 1960s economic boom, and ongoing climate change. J. Soils Sediments, 22(2), 656-671.
Rimondi V., Costagliola P., Lattanzi P., Morelli G., Cara G., Cencetti C., Fagotti C., Fredduzzi A., Marchetti G., Sconocchia
A. & Torricelli S. (2019) - A 200 km-long mercury contamination of the Paglia and Tiber floodplain: Monitoring
results and implications for environmental management. Environ. Pollut., 255, 113191
Mercury transport in stream sediments from a former mining area to the sea: the case of the Fiora River basin, Southern Tuscany, Italy
No full textMercury (Hg) is a top-priority contaminant at a global scale due to its high toxicity, mobility, and persistence
in the environment. It was observed that remobilization of Hg polluted soils and sediments represents the
main source of Hg release in mining areas. The Monte Amiata Mining District (MAMD, Southern Tuscany)
represented the 3rd largest Hg producer worldwide (Nannoni et al., 2022). Previous works studied Hg dispersion
into fluvial ecosystem from the MAMD through the Paglia River catchment (SE sector of the MAMD) and to
the Mediterranean Sea, proving that this mining area is a persistent source of pollution and that the Paglia River
has a low resilience to Hg pollution (Rimondi et al., 2019; Fornasaro et al., 2022a, Fornasaro et al., 2022b). The
contribution of the Fiora River basin (S sector of the MAMD) to the dispersion of Hg-polluted sediments and
its temporal variability is presented here. The Fiora River originates on the S flank of Mount Amiata and flows
for 80 km towards the Mediterranean Sea. Fifty-one stream sediment samples were collected in 2022: a) 15
samples were taken along the main course of the Fiora River, b) 27 on the secondary creeks draining abandoned
mining areas, and c) 9 samples along the Fiora River tributaries that do not drain the mining areas. The total
Hg content (Hgt) of the samples were compared with the data obtained in 1985 by the RIMIN company (E.N.I.
Group) in the Tuscan section of the river catchment. The 2022 sampling also included the downstream part of
the Fiora River down to the outlet in the Latium region. Hgt varied between 0.4 and 3300 mg/kg, with mean
and median values of 111.1 and 3.7 mg/kg, respectively. The RIMIN data in the same sites showed a wider
range of Hgt (0.5-6450 mg/kg), a higher mean value (592 mg/kg) and a median (3.8 mg/kg) similar to that of
the 2022 sampling campaign. Both samplings showed that Hgt frequently exceeded the Italian law limit for
residential, public green and agricultural soil (1 mg/kg) and the highest Hgt values were found in the NE part
of the catchment, i.e., along the tributaries that drain the Abetina-Solforate (AS) mining site (up to 3300 mg/kg
in 2022). Between 1985 and 2022, Hgt decreased in the AS area and along the secondary tributaries that drain
the other former mines. The samples collected in the non-mining areas showed Hgt ranging from 0.4 to 3.5 mg/
kg. Sediments along the main course of the Fiora River showed Hgt above 1 mg/kg, with most of the highest
values (30-39 mg/kg) in the downstream segment, close to the outflow in the Mediterranean Sea.
This study demonstrates that a) the Fiora River gives a significant contribution to the transport of Hg
towards the sea, and b) this river catchment has a low resilience to Hg pollution, similarly to the Paglia River,
since the contamination did not decrease significantly in the last 40 years.
Fornasaro S., Morelli G., Rimondi V., Fagotti C., Friani R., Lattanzi P. & Costagliola P. (2022a) - Mercury distribution
around the Siele Hg mine (Mt. Amiata district, Italy) twenty years after reclamation: Spatial and temporal variability
in soil, stream sediments, and air. J. Geochem. Explor., 232, 106886.
Fornasaro S., Morelli G., Rimondi V., Fagotti C., Friani R., Lattanzi P. & Costagliola P. (2022b) - The extensive mercury
contamination in soil and legacy sediments of the Paglia River basin (Tuscany, Italy): interplay between Hg-mining
waste discharge along rivers, 1960s economic boom, and ongoing climate change. J. Soils Sediments, 22(2), 656-671.
Nannoni A., Meloni F., Benvenuti M., Cabassi J., Ciani F., Costagliola P., Fornasaro S., Lattanzi P., Lazzaroni M., Nisi B.,
Morelli G., Rimondi V. & Vaselli O. (2022) - Environmental impact of past Hg mining activities in the Monte Amiata
district, Italy: A summary of recent studies. AIMS Geosci., 8(4), 525-551.
Rimondi V., Costagliola P., Lattanzi P., Morelli G., Cara G., Cencetti C., Fagotti C., Fredduzzi A., Marchetti G., Sconocchia
A. & Torricelli S. (2019) - A 200 km-long mercury contamination of the Paglia and Tiber floodplain: Monitoring
results and implications for environmental management. Environ. Pollut., 255, 113191
The complex handling of historical contaminated sites: the case of the world-class Mt. Amiata district (Italy)
No full textGlobal population growth and industrialization have driven the demand for material resources with a
staggering growth in the decades after the World War II and at the beginning of 21st century. However, mining
activities inevitably cause environmental degradation, including contamination of watersheds by mercury
(Hg). Mercury affects human health as well as the terrestrial and marine biodiversity.
Close to historical mining sites, river self-restoration (i.e., without any management) is incompatible
to human timescales, because Hg remains stored within floodplains for decades to millennia. In contrast,
complete remediation of watersheds is often economically unstainable because of the extent of contamination
that crosses regional and national borders (e.g., Grygar et al., 2022). This paper presents results of recent
studies on the Paglia-Tiber River (PTR, Italy) watershed, affected by a long and intense mining exploitation,
as an example of environmental degradation due to lack of management strategies. The nature and the extent
of contamination suggest that no clean-up strategies are feasible from an economic and social point of view.
The PTR receives part of the drainage from the world-class Mt. Amiata Hg district, where production ended in
1980s. Longitudinally, sediments of PTR are contaminated (Hg >1 mg/kg, as defined by the Italian law) for 200
km up to the city of Rome (Rimondi et al., 2019). Transversally, the Hg contamination area affects all the Paglia
River floodplain, and extends up to the pre-anthropic Pleistocene fluvial terraces. Such distribution resulted from
the interplay of Hg mining, that fed the floodplain with large amounts of Hg-contaminated sediments during
the braided stage of the river (end of 1800-mid-1950s), and the subsequent morphological changes of the river
after 1960, induced by anthropogenic activities like gravel mining, that led to the present-day single-channel
morphology (Fornasaro et al., 2022). Most of Hg is now stacked in overbank sediments at a higher level than
the present-day watercourse. Conservative estimates indicate that at least 60 tons of Hg are contained in the
sediments of the first 40 km of the Paglia River course (Colica et al., 2019). Under high flow conditions, and
especially in coincidence with intense rain events, large amounts of Hg stored in the overbank sediments are
physically mobilized and redistributed along the PTR and eventually to the Mediterranean Sea. Extreme weather
events, expected to intensify for climate change, will further exacerbate these processes. In similar settings,
given the impossibility of total remediation, mitigation strategies must be found to guarantee that the coexistence
between humans and Hg contamination occurs at minimum risk. With respect to the PRT, ongoing studies are
evaluating the potential role of poplar trees plantation along the riverbanks to favour the physical retention of Hgrich
particles from the overbanks. A side benefit would be biomass recovery for energy production.
Colica A., Benvenuti M., Chiarantini L., Costagliola P., Lattanzi P., Rimondi V. & Rinaldi M. (2019) - From point source
to diffuse source of contaminants: the example of mercury dispersion in the Paglia River (Central Italy). Catena, 172,
488-500. https://doi.org/10.1016/j.catena.2018.08.043.
Fornasaro S., Morelli G., Rimondi V., Fagotti C., Friani R., Lattanzi P. & Costagliola P. (2022) -The extensive mercury
contamination in soil and legacy sediments of the Paglia River basin (Tuscany, Italy): interplay between Hg-mining
waste discharge along rivers, 1960s economic boom,and ongoing climate change. J. Soil. Sediment., 22(2), 656-671.
https://doi.org/10.1007/s11368-021-03129-0.
Grygar T.M., Hošek M., Navrátil T., Bednárek J., Hönig J., Elznicová J., Pacina J., Rohovec J., Sedláček J. & Sass O.
(2022) - Lessons learnt from the revitalisation of chemical factory in Marktredwitz and riverbanks downstream: when
‘renaturation’ can be harmful. Water-SUI, 14, 3481. https://doi.org/10.3390/w14213481.
Rimondi V., Costagliola P., Lattanzi P., Morelli G., Cara G., Cencetti C., Fagotti C., Fredduzzi A., Marchetti G., Sconocchia
A. & Torricelli S. (2019) - A 200 km-long mercury contamination of the Paglia and Tiber floodplain: Monitoring
results and implications for environmental management. Environ. Pollut., 255(1), 113191. https://doi.org/10.1016/j.
envpol.2019.113191
Risk assessment to atmospheric mercury pollution in workplace indoor air: the case of Central Italian Herbarium (Museum of Natural History of Florence, Italy).
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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