Atlas of Contaminated Sites

Site of National Interest (SIN), Balangero e Corio (TO), Piemonte, Italy

Balangero asbestos mine

Western Europe's largest chrysotile mine, 30 km from Turin. It left a benched open pit, huge fibre-rich waste-rock dumps on the Balangero and Corio slopes and asbestos-cement mill buildings still to be demolished.

PhytoremediationMycoremediation

Status
Remediation under way
Area
314 ha on land1
Activity
1917–1990
People affected
6,322 (2019)2
Media
soil, air, surface water
Kind of site
mining, asbestos
  1. Area. 314 ha according to ISPRA (perimeter of the decree of 10 January 2000); the Region's 2019 fact sheet gives a mountain area of about 400 ha plus an industrial complex of about 4 ha.
  2. People affected. Residents of the municipalities of Balangero and Corio, 2019 census (SENTIERI, Sixth Report).

Contaminants

Fibres

Status

Remediation under way

Soil characterised over 100% of the area, containment or remediation project approved for 21%, no procedure concluded; groundwater 100% characterised, no project approved (ISPRA, June 2024; work here is mainly about making asbestos safe). In 2019 the design and execution of the clean-up of the former mill buildings were under way (Regione Piemonte).

Story

Serpentine asbestos was mined on the ridge between Balangero and Corio from around 1920, first by the 'glory hole' method and then in benches. In the 1970s the mine produced on average 130–160 thousand tonnes of asbestos a year, more than 60% of it sold abroad; it also supplied the Eternit plant in Casale Monferrato. The epidemiological study of the miners gives the mine as active from 1917 to 1985; the Società Amiantifera di Balangero went bankrupt in 1990, shortly before law 257/1992 banned asbestos in Italy.

What remains are waste-rock dumps prone to landslides and erosion, with a risk of fibre release. On the Corio side the debris forms a single mass about 1 km long, with a 500 m drop and slopes of around 35°. Asbestos is also present in the roofing, in the mill machinery and in the sludge of the settling basins. In 2016 a study measured about 200,000 fibres per litre in the stream used to water a field near the mine.

The work is carried out by R.S.A. S.r.l., a publicly owned company. The first phase, up to the early 2000s, secured slopes, streams and moving dumps. After the 2007 Programme Agreement a second phase began: drainage control and stabilisation of waste rock on the Balangero side, re-profiling of the upper part of the Corio dump into benches so that it can be reforested, and a containment embankment at its foot. An on-site laboratory analyses airborne fibres daily at the work sites and in the nearby villages.

Timeline

  1. 1917Start of mining according to the miners' cohort study.
  2. 1990The Società Amiantifera di Balangero goes bankrupt; mining ends.
  3. 1998Law 426 lists Balangero among the remediation Sites of National Interest.
  4. 200010 January: decree setting the site perimeter.
  5. 2003Sampling of fungi from the mine's serpentine substrate (University of Turin).
  6. 200718 December: Programme Agreement for remediation and environmental restoration; second phase of works begins.
  7. 2019The study of mortality and mesothelioma incidence among the miners is published.

Health

In the cohort of 974 mine workers (followed to 2013) mortality was raised for all causes (SMR 1.28; 95% CI 1.17–1.40), pleural cancer (SMR 4.30; 1.58–9.37) and asbestosis (SMR 375; 263–519), with a dose-response relation (Ferrante et al. 2019). National surveillance of mesothelioma mortality for 2010–2019 lists the Balangero mine among the areas at highest risk (Fazzo et al. 2023). SENTIERI, Sixth Report (2023; mortality 2013–2017, hospital admissions 2014–2018; municipalities of Balangero and Corio, 6,322 residents at the 2019 census): among men, deaths from asbestosis and admissions for malignant tumour of the pleura are in excess; all-cause mortality is in excess in both sexes, with an uncertain estimate in men.

Remediation

  1. 2000slope stabilisationFirst phase (up to the early 2000s): hydrogeological securing of slopes, streams and moving waste-rock dumps; permanent monitoring of airborne fibres.
  2. 2007re-profiling and revegetationSecond phase, after the 2007 Agreement: drainage control and waste-rock stabilisation on the Balangero slope; benching of the top of the Corio dump for reforestation; containment embankment at the foot.
  3. 2019demolitionUnder way (2019): design and execution of the clean-up of the former mill buildings, with demolition of structures clad and roofed in asbestos cement and removal of the plant.

Plants and fungi at this site

PhytoremediationField scale, 2006–2008

Thymus humifusus, Thymus pulegioides, Thymus alpestris, Minuartia laricifolia

University of Turin. Fibre release was measured in the mine from vegetated and bare plots covered with a Plexiglas chamber and ventilated to simulate wind. Native serpentine-tolerant species collected on site were then tested: germination trials and the transplanting of 53 Thymus individuals, in November 2006, onto a bare terrace with no irrigation or soil amendment. This is phytostabilisation: the plants hold the substrate, they do not remove fibres.

Outcome With 15–40% plant cover, fibre release into the air was roughly halved. 96% of the transplanted Thymus survived, and new seedlings were present by 2008.

MycoremediationLaboratory, with soil from the site, 2003–2009

Verticillium leptobactrum, Paecilomyces lilacinus, Aspergillus fumigatus, Fusarium oxysporum

University of Turin. Soil fungi were isolated from serpentine rock and debris at two disused chrysotile mines in the Western Alps, one of them Balangero (sampled in 2003). In the laboratory the dominant species extract iron, magnesium and silicon from chrysotile fibres, partly through siderophores; iron removal is associated with a lower ability of the fibres to damage DNA. The authors propose it as a possible bioremediation route for asbestos-rich soils; no field trial is reported.

Outcome Verticillium leptobactrum, 27% of the Balangero isolates in 2003, was the most efficient; a Verticillium sp. extracted 33.6% of the iron from a Western Alps chrysotile. In a second sampling, after the environmental restoration works, the species was no longer detectable at Balangero.

Nearby

Former SIN, Torino, Piemonte

Basse di Stura (Turin)

24 km

  • Mixed waste

SIN, Émarèse (Aosta), Valle d'Aosta

Emarèse asbestos mines

49 km

  • Asbestos

SIN, Casale Monferrato (AL), Piemonte

Casale Monferrato (Eternit)

75 km

  • Asbestos

SIN, Pieve Vergonte (VB), Piemonte

Pieve Vergonte

99 km

  • DDT and breakdown products
  • Mercury
  • Arsenic
  • Dioxins and furans

Sources

  1. SENTIERI. Sesto Rapporto, Epidemiologia & Prevenzione 47(1-2) Suppl 1: risultati Nord-Ovest (scheda Balangero), Istituto Superiore di Sanità / Epidemiologia & Prevenzione, 2023
  2. Siti contaminati di interesse nazionale (indicatore, dati a giugno 2024), ISPRA, 2024
  3. Riferimenti normativi per i SIN (aggiornamento 31 dicembre 2025), ISPRA, 2025
  4. Sito di interesse nazionale ex miniera di amianto di Balangero e Corio (scheda aggiornata al febbraio 2019), Regione Piemonte, 2019
  5. Ferrante D. et al. Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: a cohort study. American Journal of Industrial Medicine 63(2):135–145, Wiley, 2019
  6. Fazzo L. et al. The Epidemiological Surveillance of Mesothelioma Mortality in Italy as a Tool for the Prevention of Asbestos Exposure. International Journal of Environmental Research and Public Health 20(11):5957, MDPI, 2023
  7. Turci F. et al. Assessment of asbestos exposure during a simulated agricultural activity in the proximity of the former asbestos mine of Balangero, Italy. Journal of Hazardous Materials, Elsevier, 2016
  8. Magnani C. et al. The Italian Experience in the Development of Mesothelioma Registries. International Journal of Environmental Research and Public Health 20(2):936, MDPI, 2023
  9. Amiantifera di Balangero (coordinate), OpenStreetMap Nominatim, 2026

Draft compiled from public sources, not yet reviewed.