Chemicals

The Buncefield fire

Just after 6.00am on Sunday 11 December 2005, the fifth largest oil depot in the UK exploded into flames. It took four days to bring the fire under control, by which time 22 tanks of diesel, kerosene and aviation fuel at the Buncefield oil depot in Hemel Hempstead had been destroyed. Fumes from the fire caused a black plume of smoke that reached nearly three kilometres above the ground and stretched over an area from East Anglia to Wiltshire. Hundreds of people living locally had to leave their homes.

While there were no fatalities, 43 people were reported injured. It was the largest fire in peacetime Europe and the most complex incident to which the Health Protection Agency had responded.

The Agency's immediate concern was to assess the risk to health and provide advice on how to reduce any threat to people in the vicinity or those fighting the fire. Many Agency staff were involved, including specialists in chemical hazards, experts in emergency response and doctors with expertise in public health. Some staff joined the police, fire and other emergency services to provide information on toxic substances that could be released by the fire and the possible health effects of breathing in smoke particulates.

The initial risk assessment, based on previous experience, was that the plume of smoke was likely to pose a minimal risk to health. In the very high temperatures of the fire, it was thought that all organic chemicals in the fuel would be completely destroyed, leaving few pollutants. However, the Agency advised people in the Hemel Hempstead area to "stay indoors, keep windows closed and tune into local media for further updates."

Later, air quality monitoring indicated that the plume was not significantly adding to background air pollution, with particulate levels no worse than that found near a busy main road. The Agency therefore advised the public that the risk to health was low and should not be associated with increased illness. However, caution was still recommended. People with respiratory or heart conditions were advised to be especially careful and to remain inside if they saw smoke or soot particles on window sills and other surfaces outside. Air monitoring and environmental sampling continued throughout the incident and did not identify any pollutants at levels outside the normal range. This supported the initial findings and the appropriateness of the advice given.

The Agency's communications staff worked with local primary care trusts to make sure the health advice was widely disseminated by local and national media. In addition to press releases, a list of frequently asked questions and answers was made available through the Agency's website. Other issues staff had to address included assessing the oil depot site as a public health risk and concerns about ground water contamination. Work continued round-the-clock, with staff taking on night shifts until Friday 16 December when the plume had dispersed.

The Agency's response was led by the East of England Local and Regional Services, working closely with the Centre for Radiation, Chemical and Environmental Hazards, the London and South East Regions and the Centre for Emergency Response and Preparedness. Epidemiologists from the East of England monitored the impact on health, using reports from hospital A&E departments and GPs to determine whether people were suffering from breathing problems.

The incident demonstrated the value of an integrated health protection service, able to work across different sectors and provide comprehensive advice and support. The fire also underlined the importance of planning and preparing for emergencies, which is a core part of the Agency's work.

The Buncefield fire was the first major environmental incident faced by the Agency. Although the response was effective, valuable lessons were learned about how to improve future Agency response. Following the fire, a multi-agency steering group, chaired by the Agency, was set up to review and monitor the impact on the health of the local population and frontline workers at Buncefield. This follow-up study aimed to establish whether any long-term effects-physical, psychological or toxic-were experienced and to identify any public concerns.

 

The study involved:

 

• An occupational health questionnaire for people who responded to the fire, including fire and rescue services, ambulance services, local authority staff, police departments and those involved in caring for casualties, construction and engineering work and environmental sampling .

• Records from Watford and Hemel Hempstead A&E departments were reviewed to identify individuals who had health issues related to the fire.

• To determine whether local people had ongoing concerns, a questionnaire was sent to 5,000 residents, including 500 people who were evacuated from homes within one kilometre of the site.

• The first risk assessment, made at the peak of the crisis, that concluded that there was negligible risk from the plume was also reviewed.

• A detailed analysis of all exposure data was also carried out to help organisations conduct similar assessments in the future.

 

 

Personal Perspectives

Dr Sue Ibbotson: Interim Regional Director for the East of England

"This incident used resources from five regions and four national divisions in the immediate response and for a week in total. The follow-up work continues to involve a large number of individuals from across the Agency, and will do for a long time to come."

 

Dr Marian McEvoy, Consultant in Communicable Disease Control, Acting Director Bedfordshire and Hertfordshire Health Protection Unit

"Buncefield emphasised the absolute necessity of working with partner organisations and the fact that we still have some way to go in understanding each others' methods and cultures. Building up strong working relationships before disasters happen is increasingly important in today's world "

 

Professor Virginia Murray, a Medical Toxicology Consultant and Head of the London unit of the Chemical Hazards and Poisons Division ,

"Our initial discussions centred around the temperatures the fire might reach, likely materials that might be burning and products of combustion that might be produced, and who we should be worried the fire might affect, for example people with breathing conditions such as asthma."

 

Mike Saunders, Regional Health Emergency Planning Adviser, East of England.

"On the morning of the Buncefield incident, I was woken at around 6am by a loud 'whooshing' sound. I went to investigate but found nothing. Soon afterwards my colleague who was on-call contacted me to tell me about the explosion which was unbelievably some 40 miles from my home. Within the next hour I found myself at Police HQ in Welwyn Garden City and the rest is as they say history."

 

Broomfield Tip Fire

In 2003, excavation work began at Broomfield tip in the Wigan area to tackle a coal-tip fire which had probably been burning for about 18 months before excavation.

As part of the treatment which was organised by the local authority, burning material was dug out and laid out to cool. During this process, which lasted for twelve months, the local population was sometimes exposed to high levels of smoke and fine particles.

The local health protection unit (HPU), along with the local Primary Care Trust (PCT) provided advice to the local authority on the best way to manage the excavation and reduce dust exposure to residents, for example, by working on days when the wind was blowing away from people's homes and giving practical advice to residents to avoid exposure.

To address the concerns of local residents the Agency investigated whether the elevated exposures could cause damage to people's health. A steering group was established with representation and input from the HPU, the PCT, the residents' group, the Council, the epidemiology function of Chemical Hazards and Poisons Division and a university statistician.

The steering group designed a questionnaire which was distributed to thousands of residents. It asked about events such as health symptoms; additionally, data on hospital admissions, prescriptions, GP consultations, and visits to A&E departments and absences from school were studied.

Computer programmes taking into account information on wind direction, wind speed, temperature, the local topography and actual measurements of airborne dust levels were used to produce maps of which residents would be expected to have high, medium and low levels of exposure.

Work by the HPU in collaboration with staff from the Agency's Chemical Hazards and Poisons Division, London , and advisors from the Institute of Occupational Medicine in Edinburgh judged that there is no significant long-term risk to the health of the local population, and that a further long term study of health was not needed.