The impact of certain chemicals and cocktails of chemicals on human health can be very gradual. Asbestos (mesothelioma) is the classic example – exposure to a single fibre can take decades to manifest as cancer. Another instance of the gradual impact of chemicals on human health was reported on March 14th by the BBC: see:http://www.bbc.co.uk/news/uk-england-cornwall-11719398
Camelford is a town of 20,000 in Cornwall. Back in July 1988 the local water authority –privatised in 1989 as South West Water PLC – was responsible for causing the UK’s worst case of water poisoning when 20 tonnes of aluminium sulphate entered the town’s domestic water supplies:http://en.wikipedia.org/wiki/Camelford_water_pollution_incident
South West Water was fined £10,000 for the incident. It is believed to have paid more than £500,000 to settle 650 claims from residents (to date).
In 2004 a local resident, Carol Cross, died of a rare form of dementia. She was found to have extremely high amounts of aluminium in her brain. After an 8 year campaign by her husband, an environmental scientist, for a coroner’s enquiry into the cause of death – and 24 years after the originating polluting incident occurred – the findings of the coroner’s enquiry have just been reported.
The coroner found:
The water authority was criticised for dereliction of duty by failing to warn residents promptly. The authority was severely criticised by the coroner for “gambling with as many as 20,000 lives” in failing to warn the public about the risks for 16 days after the incident occurred.
It is notoriously difficult to prove causation in pollution cases.
In the Corby birth defects case, for instance, the clever tactic of the plaintiff’s lawyers was to persuade the High Court judge to reach the conclusion that the contaminants, including hexavalent chromium, mobilised as a result of negligent remediation works on site, had the “ability to cause birth defects”. That was not a decisive conclusion on causation but it opened up sufficient concern on the part of the defendant district council to result in the settlement of the dispute with substantial payments for the victims (see: the blog dated April 20th 2010 regarding the “Corby birth defect pollution case”).
In the case of Camelford, the coroner said there was only a ‘slight possibility’ that the ingestion of aluminium caused Mrs Cross’s death, albeit there was a ‘very real possibility’ that it contributed to her death.
Evidently, as the Cross Case shows, harm to human health which arises from exposure to pollution can span many decades. It can pass from mother to child (birth defects) and it can be inter-generational. Speaking at a recent Castle Debate on Chemicals in the Environment (March 6th 2012), Professor Jane Plant highlighted the lack of scientific understanding of the ‘cocktail effect’ where several chemicals combine to potentially give rise to significant risks. Notwithstanding the huge societal benefits which the chemical sector has delivered, there is still much that we do not understand about the risks derived, especially from the interactions of different chemicals.
In summary, the tragic case of Mrs. Cross is a very sad reminder to all environmental professionals that we are often called upon to advise in relation to risks which have consequences over very long time scales, running into several decades if not longer. There are few short term answers in this vital field of endeavour.