In July 1976, Seveso was the epicentre of the worst environmental disaster ever to occur in Italy. Today, a motorway is bringing old memories and fears back to the surface.
Only a wall remains to recall one of the most serious environmental tragedies caused by human beings: the Seveso disaster. The worst in Italy. That wall — built of exposed reddish brick — stands on the street that, even today, still bears the name of the company that caused the catastrophe: via Icmesa. We are in Meda, in the province of Monza e Brianza, in Lombardy. A plaque bearing a short text and two photographs stands on the small road that ends at the gate which once served as the entrance to the chemical plant. That plant stood on the border with another municipality, one that went down in history for having suffered the worst consequences of the accident: Seveso, a town of 16,000 souls at the time of the events.
Its name, 49 years ago, travelled around the world, after a toxic cloud escaped from a chemical reactor, poisoning 40,000 people. Besides those in Seveso and Meda, the municipalities of Cesano Maderno, Bovisio, Varedo and Desio were also affected. And yet today it seems as though everything has gone quiet, everything forgotten. Almost as if to erase a stain, a stigma on the territory.
"A logic of erasure has taken hold — nobody talks about it anymore. The institutions gave us the Bosco delle Querce where we commemorate this tragedy every year, but nobody talks about it anymore," explains Davide Biggi, who in that July of 1976 was just twelve years old. "Ever since work began on building the Pedemontana lombarda, though, people have come back to life — none of us wants to breathe dioxin again," he adds. It is a new motorway, then, that is reigniting fear today over a toxic substance that fell upon people's homes while they sat down to a summer lunch.
It is midday on Saturday 10 July when a safety disc on reactor A 101 at the Icmesa plant in Meda fails. The final link in a chain of negligence, carelessness and permits granted far too easily to a company that produced, among other things, even the defoliant used by the United States during the war in Vietnam: Agent Orange. According to the most widely accepted reconstruction, the reactor was left without its cooling system and the trichlorophenol molecules inside bonded together, forming a devastating cloud laden with tetrachlorodibenzo-para-dioxin (TCDD). Better known by its common name, dioxin: an extremely toxic and carcinogenic substance.
Inside the plant at that hour on a Saturday there were few workers, all concentrated in a different section. One of them, however, fortunately stepped in: his name was Carlo Galante, head of the department where herbicides were produced. He was having lunch with his family a few metres from the factory when he heard a strange noise. Looking out of the window, he saw coloured smoke rising from his very own workplace. Without thinking too much about the possible consequences, Galante left the house and approached the reactor to manually trigger the cooling system, which had failed to activate automatically due to a fault.
That manoeuvre succeeded in preventing further releases of dioxin, and for this the worker was awarded a silver medal for civil merit, twenty years after his death. But the catastrophe was now inevitable. The wind was already pushing that first cloud south-eastward, engulfing dozens of homes, vegetable gardens and roads. Silently, without any warning. Because Icmesa itself tried to conceal the accident for days. As a result, no immediate alerts reached the population.
The prompt action of the department head was not, in fact, matched by the parent company of the Icmesa plant, the Swiss firm Givaudan, itself controlled by La Roche. Only the following day, Sunday 11 July, did two of the company's technicians inform the mayor of Seveso, Francesco Rocca, of what had happened. But it was not yet possible to understand the actual environmental damage: it was hypothesised that the cloud released might have contained dioxin, but confirmation was awaited from the company's laboratory in Lugano. Mayor Rocca decided, however, to immediately call his counterpart in Meda to work out what to do.
Already that Sunday, trees that had suddenly withered and the first dead wild birds were being noticed. In the days that followed, the first attendances at the emergency departments of Meda and Seveso began, for dermatitis and eye problems. "My parents were in the garden that Saturday — it was hot — and they immediately noticed a strange smell and irritation on their skin. In the days that followed, my father developed severe dermatitis on his arms, and the doctors who treated him explained what had happened. He and my mother died of haematological cancers a few years ago; it is only logical to think it was that wretched cloud," recalls Enrica, who was spared at the time because she was away on holiday.
Only five days after the accident, on 15 July, the public health officer for the municipality of Seveso, Dr Uberti, recommended that the authorities take "immediate measures to protect the health of the population." The mayors of the two municipalities were to "mark off the area with posts bearing the following wording: Municipalities of Seveso and Meda. Warning. Area contaminated by toxic substances. Impose a ban on touching or ingesting fruit and vegetable produce, avoiding contact with vegetation, soil and plants in general."
It was at that point that residents of the area were warned, through notices posted in the streets, of the need to avoid touching vegetables, soil, grass or animals in the likely contamination zone, and to maintain the most scrupulous hygiene of hands and clothing, using water as the best detergent.
It took a further two days before, on 17 July, newspapers began to report on the event, following the arrests of the plant's then director and deputy director. And only on the 18th was the Icmesa plant shut down, at the behest of the Swiss management. In the meantime, the dozens of emergency department attendances now left no doubt whatsoever about exposure to dioxin, with dozens of cases of childhood chloracne.
Faces eaten away by dioxin: the skin was reacting with a rash caused by the presence of certain halogenated compounds, such as chlorinated dioxins. Furthermore, the Clinica Mangiagalli in Milan also opened the door to the possibility of performing abortions, at a time when an absolute ban was still in force (by virtue of a special exemption approved by the government). Dioxin does, in fact, cause deformities in the foetus.
Meanwhile, farm and domestic animals also began to die. In the weeks that followed, 2,953 carcasses were counted. The mayors of Meda and Seveso issued orders published in local newspapers: the ban on touching animals and vegetables became mandatory on 22 July, when the territory was divided into three zones: A, B and a buffer zone (R), based on the presence of TCDD in the soil. On 26 July, the first 200 people were evacuated from the San Pietro neighbourhood bordering the factory, while soldiers cordoned off the isolated area with barbed wire and no-entry signs. Within days, 736 people had been relocated to other neighbourhoods or hotels; many children were taken to summer camps on Lake Maggiore for several weeks.
In the months that followed, discussions began about remediation through an initial incinerator project, blocked by the local mayors themselves, and then about removing the contaminated soil and relocating it into concrete tanks. Protests by displaced residents came several months later, with the first demonstration on 11 October 1976, when a group of residents from Zone A — the most heavily exposed area — broke the seals and peacefully occupied their homes and the Milan–Meda expressway. The population demanded to be allowed to return home, to return to normality. But none of them succeeded, as it was decided to demolish and bury all exposed material — houses, trees and land — in specially designed containment tanks. Between 1981 and 1984, a vast stretch of territory was excavated, and a containment zone for the contaminated soil was built on the site of Icmesa and Zone A, giving rise to the Bosco delle querce. Those who had been expropriated were relocated to new homes in the mid-1980s, while the Icmesa plant was razed to the ground and its workers placed in other employment. The entire tragedy thus vanished from sight. Regione Lombardia itself set up health surveillance and acknowledged that the risk of errors was high, precisely because of the dispersal across the territory of those affected by the dioxin.
On 16 June 1977, Parliament approved the establishment of a parliamentary commission of inquiry into the release of toxic substances from Icmesa, tasked with investigating the activities of the factory in Meda, the administrative responsibilities relating to the industrial plant, and the consequences of the accident on the health of citizens, the environment, the territory and the local economy. The Commission was also to identify measures to be taken "to compensate citizens harmed by the accident of 10 July 1976 and to obtain from those responsible the payment of damages". Until 1978, the parliamentary body collected dozens of testimonies and data on exposure to dioxin.
The final report, presented in July of that same year, identified the Swiss company as the principal party responsible, while leaving local institutions free of any objective liability. During the two years of work, several company executives were targeted in terrorist-style attacks. Notable examples include the attack on Seveso's medical officer Giuseppe Ghetti, who was kneecapped, and the parcel bomb that exploded at the front door of the Roche deputy director, Rudolf Rupp. The most disruptive act against Icmesa, however, came on 5 February 1980, when a commando unit from the extremist political group Prima Linea assassinated the then director of the company, Paolo Poletti, who was overseeing the remediation.
While the municipalities affected by the disaster opened legal proceedings to seek damages from the multinational La Roche, the Ministry of the Interior and Regione Lombardia reached an agreement with the company under which it would bear the cost of paying the sum of 103 billion lire and 634 million for the "Seveso disaster". In the end, the Swiss multinational paid over 200 billion lire in personal compensation and remediation costs. The final rulings date back to the early 2000s, when the courts of Monza and Milan upheld the convictions and compensation claims, including for the psychological and moral harm suffered by residents of the red zone. Of the five executives originally charged, by 1986 only the technical managers of Icmesa, Jorg Sambeth and Herwig von Zwehl, were convicted, sentenced to one and a half and two years' imprisonment respectively.
But the disaster also had a profound impact at the judicial level. Before 10 July 1976, no national or supranational regulations existed obliging the chemical industry to prevent potentially disastrous events, whether for the environment or for communities living near chemical plants. In the wake of the Seveso tragedy, European states as early as 1982 issued a first supranational directive applicable to large chemical installations, introducing the obligation to notify local authorities of the substances being produced and the emergency plans in the event of accidents. The directive takes its name from Seveso, precisely because of the enormous social and environmental significance that the Icmesa disaster provoked in those years. The regulation has undergone several amendments in recent years, culminating in the Seveso III directive, transposed into Italian law in 2015.
On 9 July 2024, one day before the anniversary of the disaster, at a closed-door meeting at the Bosco delle querce, the company Pedemontana lombarda discussed the new remediation plan for contaminated land in preparation for the construction of lot B2 of the motorway that will connect Gallarate with Trezzo sull'Adda. The land in question is that contaminated by dioxin within Zone B, where levels of up to four micrograms of dioxin had been recorded. The aim is to remove it without dispersing the contaminant into the atmosphere and to store it in authorised landfill sites (in the provinces of Bergamo, Brescia, Milano, Pavia, Vicenza, Pisa, Como, Novara, Alessandria, Reggio Emilia, Massa Carrara and Verona). The Pedemontana motorway project runs directly through the area affected in 1976, taking some plots of land from the Bosco delle querce itself.
"Almost fifty years after our tragedy, institutions are still not being transparent about the dioxin issue — they make decisions about our territory without opening up to the affected population. We refuse to accept this," declared the protesters picketing outside the doors of the civic centre at the Parco delle Querce.
Since Pedemontana came back onto the agenda in 2006, several mayors in the area have included dioxin monitoring in their Municipal Land Use Plans, because people are afraid of once again breathing in toxic substances.
Davide Biggi, one of the driving forces behind the Usciamone vivi movement
The company Pedemontana assures that it will operate with the utmost care in moving the 44,000 cubic metres of contaminated soil, but for the time being the data produced by Arpa Lombardia to determine exactly how much dioxin lies beneath those plots of land are still not available.
On the wall of Icmesa that still stands, the municipality of Meda has displayed a sign bearing the inscription "1948, 1949, 1953, 1957, 1961, 1963, 1969, 1970, 1972, 1974": these are the years in which the pollution caused by the factory was reported prior to the disaster. Reports made by individual citizens, municipal councillors, and the mayors of Seveso and Meda. In response to requests from the municipalities, the Province and the Civil Engineering Authority to make the plants safe, Icmesa proposed, planned and outlined options. But no changes were ever made. And the pollution of the surrounding territory continued undisturbed. Today, around what was once Icmesa, there is
