CATASTROPHIC EPISODES

There is a well documented history of ‘catastrophic’ pollution incidents over the past 40 years or so and some of the most infamous are outlined here.

2.2.1 Seveso, Italy

On 10th July 1976 there was a massive release of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD, ‘dioxin’) from a chemical plant in Seveso near Milan, Italy, which was manufacturing 2,4,5-trichlorophenol (2,4,5-TCP). A safety disc in a reaction vessel ruptured and a plume of chemicals containing 2,4,5-TCP and dioxin rose 30 to 50 m above the factory. The plume then grounded downwind of the factory, contaminating an area approximately 2 km long and 700 m wide. An estimated 3 to 16 kg of dioxin was released. Almost 28,00 people lived in the vicinity of the factory (Harrison, 2001).

Dioxin is both extremely toxic and chemically stable; it is known to cause the skin condition chloracne and affect foetal development. The population of Seveso was screened shortly after the accident and 176 individuals, mostly children, were found to have chloracne. A further round of medical screening six months later revealed a further 137 cases, but subsequent follow-ups showed the incidence to have lessened and symptoms improved. In addition to the chloracne, some neurological abnormalities were noted, including polyneuropathy, especially amongst people living in the most contaminated area of the city. Also, there was evidence of liver enlargement in about 8% of the population, which again was most noticeable amongst the most exposed population. However, there was no evidence of effects on the immune system or of chromosomal abnormalities or damage to foetuses. While no deaths were recorded as being due to the incident, a later analysis of cancer incidence in the exposed population found increased liver cancer and elevated incidences of leukaemia and other blood neoplasms in men and increased bone marrow cancers in women, as well as higher incidences of soft tissue tumours and non-Hodgkins lymphoma. Interestingly – and aligned with the fact that dioxin is an anti-oestrogen – breast cancer and endometrial cancer in women were reduced, and a changed sex ratio in the offspring of exposed men was reported (Harrison, 2001).

There were impacts too on the natural and agricultural environment. Many plants and herbivorous animals died (through oral uptake of contaminated vegetation) and large amounts of top-soil were removed from the site. Agricultural and horticultural activities were suspended over an area of approximately 1700 ha (Wipf & Schmid, 1983). It is known that TCDD becomes strongly absorbed to soil – hence its large-scale removal in contaminated areas – but the longer-term impacts of the incident on the natural environment remain largely unknown. TCDD is a proven endocrine disrupter with anti-oestrogenic properties, and hence reproductive effects in wildlife

Accidents and pollution: industry impacts 27 cannot be discounted (Institute for Environment and Health [IEH], 1995; Harrison et al. 1997). The devastation and public alarm engendered by the incident prompted the European Commission to adopt, in 1982, a Directive on the control of major accident hazards involving dangerous substances. Known as the Seveso Directive (presently amended and adopted as Directive 2012/18/EU, or ‘Seveso III’), this is aimed at preventing such major chemical accidents.

2.2.2 Bhopal, India

The Bhopal disaster has been described as ‘the worst industrial accident in history’

(Broughton, 2005) and a true industrial catastrophe (MacKenzie, 2002).

This tragic event occurred on 3rd December 1984 and involved a catastrophic release of methyl isocyanate (MIC) from the Union Carbide factory that had been producing the insecticide carbaryl, MIC being one of the main ingredients. MIC itself was manufactured from monomethylamine and phosgene – a highly toxic gas that was produced on site by reacting chlorine and carbon monoxide. There was therefore at this site a variety of toxic substances in use or stored ready for use.

It is believed that the accident was caused by water entering a tank where 41 tonnes of MIC were being stored, causing a runaway chemical reaction. This resulted in rapid vaporisation of the tank contents, causing the safety valve to burst open. It remained open for about two hours, allowing MIC in liquid and vapour form – as well as other reaction products and contaminants – to escape into the immediate environment.

Many people lived in the vicinity of the factory and as a consequence at least 2000 people died from exposure to the cocktail of extremely toxic substances. The most frequent symptoms amongst the individuals who survived were burning and watering eyes, coughing and vomiting. A great many more individuals continued to suffer physical and mental trauma as a result of this tragedy. In the eventual settlement between the company (Union Carbide Corporation) and the Indian Government, 3000 people were acknowledged to have died and 102,000 suffered permanent disabilities (Broughton, 2005), although the numbers have been disputed (e.g., Kumar, 2004). Subsequently, the Bhopal Gas Tragedy Relief and Rehabilitation Department reported that by the end of October 2003, compensation had been awarded to 554,895 people for injuries received, and to 15,310 survivors of those killed.

With such a catalogue of human deaths and disabilities, it is not surprising that impacts on wildlife and ecology have not been a major focus of the published literature. But the effects are likely to have been significant, given the human impact.

Groundwater contamination has certainly been recognised as one of the environmental consequences of the incident at Bhopal, a local aquifer having been contaminated (Fortun, 2001; Health and Safety Executive, 2004). The contamination of local aquifers by toxic organic chemicals and heavy metals has been linked with a failure to clean up completely after the incident (Broughton, 2005). Goodman (2009) reported that 25 years after the incident, the local groundwater – which provides a potable water supply for 15 communities – remained contaminated.

2.2.3 Sweizerhalle, Switzerland – the Rhine Incident

In 1986, a major fire at a pesticides factory near Basel, Switzerland, resulted in 30 tonnes of pesticides being washed into the River Rhine, carried in fire-water runoff. The fire broke out in a warehouse where a wide variety of chemicals, including mercury, were being stored. The factory was owned by Sandoz, one of the largest pesticide manufacturers in Switzerland. The inhabitants of Basel and the surrounding area on the border between France and Germany were told to stay indoors, as witnesses had reported a foul smell of rotten eggs and burning rubber. Fourteen people were admitted to hospital after inhaling the fumes (BBC, 1986). The runoff turned the river red and the toxic contaminants caused extensive fish mortalities in the tributary river and in the Rhine itself (Giger, 2009). One year after the event, a review paper written by the Head of Corporate Safety and Environmental Protection, Sandoz Group, reported that severe ecological damage had occurred over about 250 km of river, including the death of ‘a great number of fish’. Eels (Anguilla spp.) predominated in this mortality. In the Upper Rhine region of Germany, downriver of Basel, dead fish were also found, with eels again worst affected. Toxic residues were detected in fish shortly after the incident, but not when measured one year later (Salzmann, 1987).

Lessons from the 1986 Rhine incident in relation to the storing of toxic and flammable substances included recognition of the importance of:

• The characteristics of buildings and their equipment (melting point, composition and formation of toxics on combustion, structural and functional integrity in the event of a fire involving the kinds of materials stored there)

• Storage density, storage volume and storage procedures

• Packaging materials and storage records

• Retention of fire-extinguishing water in case of fire.

The factory involved in the Rhine incident responded by addressing all the above points, building two catch basins of 15,000 m³ and 2500 m³ within the site, and modifying warehouse design to specify concrete fireproof walls, dividing walls and internal catchpits and sumps. Local fire officers recommended a storage volume of 3 m³/tonne of warehoused material, based on their estimates of the volume of water normally dispersed into a fire (Salzmann, 1987).

During this incident the contaminated fire water passed down the river from Switzerland, through Germany and France, to the Netherlands, before discharging into the North Sea (Giger, 2009). This event set back a decade of intensive clean-up efforts for the Rhine, and had a major influence on European regulatory philosophy.

The Rhine incident highlighted the trans-boundary nature of Europe’s largest rivers and the need for river basin management, rather than attending simply to national interests. This ultimately led to the EU Water Framework Directive (Directive 2000/60/EC establishing a framework for Community action in the field of water policy).

Accidents and pollution: industry impacts 29

2.2.4 Tianjin, China

Beginning on the night of 12th August 2015, a series of explosions of increasing magnitude occurred at a chemicals store at the Port of Tianjin, China. The store was operated by Ruihai Logistics, a privately held company established in 2011, handling hazardous chemicals including flammable and corrosive substances, oxidising agents and other toxic chemicals. The 46,000 m² site contained multiple warehouses for hazardous goods, a fire pump and a fire pond. The business was operating in breach of several requirements relating to storage quantities, licences and safety regulations.

The first reported fire was apparently due to auto-ignition of nitrocellulose which had become warm; the fire then led to a series of explosions, the biggest of which involved 800 tonnes of ammonium nitrate. The last explosions continued into 15th August. There was some uncertainty about the chemicals stored at the site, but there were over 40 kinds of hazardous substances present, totalling about 3000 tonnes (Zeng, 2015), including calcium carbide as well as nitrates and at least 700 tonnes of toxic sodium cyanide (about 10 times the legal limit there). Firefighters were unaware of the presence of calcium carbide, which releases the flammable gas acetylene on contact with water, hence contributing to the fires and explosions.

A total of 173 people died in the disaster, with 797 non-fatal injuries. Over one thousand firefighters attended the incident, of whom 95 died – the biggest loss of life of first-response staff in China since the founding of the People’s Republic of China in 1947. As well as destroying the site, damage to nearby buildings and property was serious, including over 8000 new cars. Groundwater contamination, for example by cyanide, was a major concern. Fish mortality occurred when the first rain fell after the incident, washing contaminating chemicals either from the atmosphere or from the surfaces of the area affected by dry deposition, or both.

Local officials suggested the mortality (of sticklebacks, one of the most resilient fish species, able to tolerate poor quality conditions) could have been due to low oxygen concentrations (it was August, following a dry period when this would be likely in an urban watercourse). People reported white chemical foam covering the streets when it rained, and burning sensations and skin rashes when in contact with rain droplets (China Daily, 2015a; Phillips, 2015; Varghese, 2015).