Seveso disaster
The Seveso disaster was an industrial accident that occurred around 12:37 pm on 10 July 1976, in a small chemical manufacturing plant approximately 20 kilometres (12 mi) north of Milan in the Lombardy region of Italy.
It resulted in the highest known exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in residential populations,[1] which gave rise to numerous scientific studies and standardized industrial safety regulations, including the European Union's Seveso III Directive.
[4] Reaction temperature was achieved by passing the steam exhaust from the onsite electricity generation turbine through an external heating coil installed on the chemical reactor vessel.
The chemical-release accident occurred when a batch process was stopped prior to the completion of the final step of removal of ethylene glycol from the reaction mixture by distillation.
Other parts of the site had already started to close down as the processing of other batches finished, which reduced power consumption across the plant, causing a dramatic drop in the load on the turbine and a consequent increase in the temperature of the exhaust steam to around 300 °C.
This hotter than normal steam then heated the portion of the metal wall of the accident reactor above the level of the liquid within it to the same temperature.
With the stirrer not running, the heating was highly localised to just the portion of the upper layers of reaction mixture adjacent to the reactor wall.
[5][6] The reactor relief valve eventually opened, causing the aerial release of 6 tonnes of chemicals, which settled over 18 km2 (6.9 sq mi) of the surrounding area.
[9][clarification needed] However, in the higher-temperature conditions associated with the runaway reaction, TCDD production apparently reached 166 ppm or more.
The population who lived in the path of the aerosol cloud reportedly developed acute symptoms such as headaches, nausea, and eye irritation.
[8] After evacuation, all residents of Zone A were medically examined and laboratory tests were performed, Ultimately, 640[13] individuals living in the region were affected with chloracne.
[8] An advice center was set up for pregnant women, of whom 26[citation needed] opted for an abortion (which was legal in special cases) after consultation.
The ascertainment of other, possibly severe sequelae of dioxin exposure (e.g., birth defects) was hampered by inadequate information; however, generally, no increased risks were evident.
Results cannot be viewed as final or comprehensive, however, because of various limitations: the lack of individual exposure data, short latency period, and small population size for certain cancer types.
A 2001 study confirmed in victims of the disaster, that dioxin is carcinogenic to humans and corroborate its association with cardiovascular- and endocrine-related effects.
This result of the underlying Seveso study has been noted to provide the most pronounced evidence for prenatal exposure to an environmental chemical causing low sperm counts.
On 5 February 1980, Paolo Paoletti (the Director of Production at ICMESA) was shot and killed in Monza by a member of the Italian radical left-wing terrorist organization Prima Linea.
[18] On 19 December 1980, representatives of the Region of Lombardy/Italian Republic and Givaudan/ICMESA signed a compensation agreement in the presence of the prime minister of Italy, Arnaldo Forlani.
However, in February 1983, the programme A bon entendeur on Télévision Suisse Romande, a French language Swiss television channel, followed the route of the barrels to Saint-Quentin in northern France where they disappeared.
A public debate ensued in which numerous theories were put forward when it was found that Mannesmann Italiana had hired two subcontractors to dispose of the toxic waste.
As a result, the local population was caught unaware when the accident happened, and thus was unprepared to cope with the danger of an invisible poison.
In the context of such heightened tensions, Seveso became a microcosm where all the existing conflicts within society (political, institutional, religious, industrial) were reflected.
Moreover, the eventual disappearance of the offending factory itself and the physical exportation of the toxic substances and polluted soil enabled the community to feel cleansed.
