Dr David Russell1 BSc (Hons) MSc MBBCh Dip Med Tox (Dist) FRCPath, Andrew P Jones2 BSc (Hons) MPH FFPH, Peter G Davies1 MSc (Dist) FCIEH, Dr Lynne Harris3 LRCP MRCS, FFPHM, Dr Ciaran Humphreys3 MB BAO BCh B(Med)Sci (Hons) MPH (Dist) MRCSI MFPH; Dr Simon Wilkinson4 BSc (Hons) Ph.D, Edwin Huckle1 MSc, Dr Raquel Duarte-Davidson1 BSc (Hons) MSc Ph.D and Dr Channa V Krishna5 MBBS MD MRCP Dip Med Tox Dip in Therapeutics.
1 Chemical Hazards and Poisons Division, The Health Protection Agency, UWIC.
2 National Public Health Service For Wales, Ardudwy, University of Wales.
3 National Public Health Service for Wales, Carmarthen.
4 Medical Toxicology Centre, Newcastle University.
5 Cardiff and Vale NHS Trust, LLandough Hospital, Penarth.
Correspondence: Dr David Russell, Head Of Unit, Chemical Hazards and Poisons Division, The Health Protection Agency, UWIC, Colchester Avenue, Cardiff CF23 9XR, Wales, UK.
Petroleum hydrocarbons are an integral part of modern developed society, as evidenced by the global petrochemical industry. The various petroleum fractions provide essential resources for energy, transportation, agricultural feed stock and the synthesis of plastics.
Accidental release of petroleum hydrocarbons is not uncommon. When such accidents do occur, widespread environmental contamination is likely and owing to the toxicological properties of petroleum hydrocarbons significant detrimental impacts on public health may arise. In the incident reported here, a spillage of chemically complex aviation fuel – jet propulsion 8 (JP-8) – occurred in rural Pembrokeshire, Wales, UK. The spill resulted in widespread contamination of the environment including groundwater, a surface stream and the sewage system, and the pooling of petroleum hydrocarbons on lawns was observed. Several residents complained of symptoms consistent with exposure to petroleum hydrocarbons.
The response to the incident involved a co-ordinated, multi-disciplinary/multi-agency response. The Welsh Assembly Government convened a Health Advisory Group, consisting of all major allied organisations and agencies in Wales to provide holistic and integrated advice on the management of the incident. Thus, as part of a multi-disciplinary, multi-agency approach to chemical incidents in Wales, the local public health strategy was enhanced by access to authoritative advice on clinical, toxicological, risk assessment, chemical and environmental issues.
A suite of public health measures was instigated. Environmental monitoring detected raised levels of kerosene vapours in several houses. Clinical examination demonstrated that the reported symptoms were transient. Monitoring of the public water supply led to a temporary potable supply being provided for one household. The risk was communicated to the public by means of posters and letters, supplemented by direct community meetings.
Advice was provided on possible food contamination, especially home grown vegetables, and residents in the worst affected houses were advised to ventilate their properties and were offered temporary accommodation. Environmental decontamination was carried out together with the deployment of in-stream interceptors, the placement of oil absorbent booms and pads and the pumping out of contaminated water.
Key words: Aviation Fuel; Chemical Incidents; Environmental Health; Integrated Emergency Management; Petroleum hydrocarbons; Public Health Response.
Petroleum is found in many sedimentary rocks, the product of the decomposition of organic matter at high temperature over a period of millions of years, resulting in a complex mixture of gaseous, solid and liquid hydrocarbons. Processed petroleum products contribute up to 50% of the world’s total energy, transportation, electrical utility and heating requirements. Petroleum products are also utilised for the production of lubricants, solvents, the surfacing of highways, waterproofing, and in the manufacture of a range of plastics and feed stocks (ATSDR, 1998).
The aviation sector is a significant consumer of petroleum products. Jet-Propulsion 8 (JP-8) is the product of distillation, the exact chemical composition varying according to the crude petroleum from which it is refined, but is typically composed of kerosenes, consisting of aliphatic and aromatic hydrocarbons, paraffins (aliphatic alkanes) and napthalenes (cycloalkanes), while aromatic hydrocarbons constitute less than 20% and olefins comprise less than 1% of such mixtures (ATSDR, 1998). More than 200 hydrocarbon constituents may be identified analytically. The addition of anti-oxidants, static and corrosion inhibitors, thermal stabilants, lubrication improvers, icing inhibitors and biocides add to its toxicological complexity (ATSDR 1998, IARC 1989a).
The physico-chemical properties of such mixtures are not surprisingly, extremely complex. Lighter fractions volatilise readily following release, hydrophilic and amphipathic fractions dissolve in water and lipophilic fractions are likely to be bound to soil particles, vegetables and crops and stream sediment. Therefore, it is likely that the inadvertent release of petroleum hydrocarbons will result in all major environmental compartments becoming contaminated. This, coupled with the potential toxicity of such mixtures, illustrates the complex nature of such releases and the potential for serious impacts on public health following any inhalation, ingestion and dermal contact (Health Protection Agency, 2006a).
This paper describes a specific incident involving the petroleum product JP-8 as a consequence of a spillage at a refinery in Pembrokeshire, Wales, UK. It highlights the multi-disciplinary, multi-agency response to the incident, together with the public health risk assessment undertaken and the subsequent communication of risk to members of the public potentially exposed. The multidisciplinary/ agency public health response model that has been developed in Wales for providing advice and support on the acute and chronic public health implications of such chemical incidents is described.
On Tuesday 2 August 2005 a leak was reported from a fuel storage tank facility at Sem Logistics Milford Haven Limited, Llanstadwell. This resulted in the spillage of approximately 600 tonnes of JP-8. JP-8 migrated through ground water in highly-fissured rock, migrating northeastward to contaminate a nearby stream, the beach which it flowed through and emerging at a cliff outfall at nearby Milford Haven. In addition, there were sightings of hydrocarbon films on residential lawns and ponds in the small village of Hazelbeach; the movement of the plume in an easterly direction is depicted by Figure 1.0.
Air quality sampling for kerosene as total petroleum hydrocarbons (TPHs) by photo-ionisation detector (PID), undertaken by the local authority adjacent to the stream, gave readings of approximately 150,000μgm-3, while 3- 4m away concentrations were <10,000μgm-3 and street concentrations were recorded as being 2-3000μgm-3. Migration into the sewerage system resulted in a large number of homes being affected by odour. Several homes in the village had elevated indoor concentrations of kerosene measured as TPHs, with reported levels as high as 200,000μgm-3 in one home, where the property had been extended over a manhole cover. Occupants were offered alternative accommodation.
The sampling of mains water by the utility company (Dwr Cymru/Welsh Water) and subsequent analysis by gaschromatography- mass spectroscopy did not detect elevated concentrations of total petroleum hydrocarbons or kerosene, whereas sampling by the local authority for total petroleum hydrocarbons (TPH) using infra-red spectroscopy identified levels ranging from 17-55μgl-1 at four properties sampled from 1-3 September. One resident complained of a foul odour and an oily film on the surface of tea made from the household public drinking water supply. A water bowser was supplied to the house in question, but no kerosene was detected. There were no recorded abstraction points for private water supplies. Over the course of the following few weeks, several residents complained of symptoms including nausea, vomiting, headache and dizziness. All symptomatic patients were offered a referral to a clinical toxicologist for assessment. Three patients were assessed, but further clinical effects were not apparent and the patients were subsequently discharged.
A suite of public health measures were put in place, following the convening of a multi-agency incident management team, by the local health board following advice received from the National Public Health Service for Wales (NPHS) and the Chemical Hazards and Poisons Division (CHaPD) of the Health Protection Agency. Accordingly, affected residents were advised to open windows and ventilate the properties in question and were temporarily re-housed. All local public water supplies were located to ascertain potential contamination. Coupled to this, reports of odours were investigated, as kerosene may migrate via groundwater underneath houses, thereby exposing occupants to vapour. Under such circumstances, indoor air monitoring and water sampling was undertaken. If the indoor levels exceeded 10,000μgm-3, temporary rehousing of residents was considered and re-occupation was not considered until levels fell to <1,000μgm-3, although one household was extremely eager to return to the property and did so when levels fell below 100,000μgm-3 – see later for an explanation of how these figures were arrived at.
Public notices were posted and letters written to all residents informing them of the need to stay away from contaminated areas, including the local beach and stream, not to consume local cockles, the need to wash and peel locally grown produce and to inform the local authority of persistent odours. This approach was supplemented by direct meetings with the public, initially on a weekly basis, and included representation from local public health staff. A member of staff from the local authority provided a consistent on the ground presence, both monitoring ambient air levels and responding to questions of individuals.
Further public health advice was sought by also convening a multi-disciplinary, multi-agency public health advisory group (HAG), with representatives from Welsh Assembly Government, The Wales Centre for Health, The Environment Agency, Pembrokeshire County Council, Local Health Boards, HPA, NPHS, Petroplus Ltd and The Health and Safety Executive. This advice was fed into the local incident management team (Figure 2.0).
It was concluded that the incident had been appropriately managed and that environmental monitoring should continue to determine the extent of kerosene contamination of air, water and soil, but that epidemiological follow-up was inappropriate on the basis of the initial population exposure assessment.
Environmental decontamination was carried out together with the deployment of in-stream interceptors, the placement of oil absorbent booms and pads and the pumping out of contaminated water.
Chemical incidents involving petroleum hydrocarbons are not uncommon. Public health surveillance data collated over a five year period from 1999 indicates that there were 240 reported incidents in the UK as the consequence of spillages, leaks, fires and explosions (Health Protection Agency, 2005).
The potential public health significance of such incidents is graphically illustrated by the incident at Buncefield, Hertfordshire, UK in December 2005, where catastrophic failure resulted in the largest post-war explosion in Western Europe. The incident resulted in a dense black plume consisting of products of combustion, soot and particulates approximately 10km across and dispersed in a south-easterly and southwesterly direction and resulting in multi-agency, multidisciplinary emergency response (Health Protection Agency, 2006b).
Spillage of petroleum hydrocarbons at sea has also been reported and with consequent public health implications. In 1993, the Braer oil spill in Shetland in 1993 resulted in exposed individuals having significantly higher rates of headache, sore throat and itchy eyes compared to controls (Campbell et al., 1993, 1994).
Similarly, the spillage of 72,000 tonnes of crude oil in 1996, from the Sea Empress in Milford Sound, Pembrokeshire, Wales resulted in significantly greater self-reporting of physical and psychological symptoms in communities residing in the vicinity of the incident (Lyons et al., 1999).
In the current incident, widespread contamination of a local stream, pooling of kerosene on lawns and gardens and contamination of ambient and indoor air were all noted. Therefore, incidents involving petroleum hydrocarbons may contaminate all environmental media and have a significant public health impact. Such contamination of environmental media has major potential implications for public health, with human receptors being potentially exposed through inhalation of contaminated air, ingestion of contaminated water and crops and through dermal contact (Ritchie et al., 2003). This is borne out by the findings of the present incident, in which contamination of a local stream, pooling of kerosene on lawns and gardens and contamination of ambient and indoor air were all noted.
The toxicology of environmental petroleum hydrocarbons is complex as these substances are present in the environment as complex mixtures, containing many hundreds of individual compounds, each with its own toxicological properties (IARC, 1989b; ATSDR, 1998). The symptoms of nausea, vomiting, headaches and dizziness reported following the Petroplus incident are consistent with exposure to petroleum hydrocarbons. Accordingly, ingestion of hydrocarbon mixtures are recognised as inducing coughing, nausea, vomiting and diarrhoea, while inhalation is associated with headache, dizziness, drowsiness and inco-ordination (Health Protection Agency, 2006); higher concentrations are recognised as inducing cardiac arrhythmias, convulsions and coma (ATSDR,1998).
In the described incident, elevated concentrations of TPHs were measured in both indoor and outdoor air. Interpretation of the public health implications of the air quality, however, is problematical, as there are no derived environmental standards for kerosenes. Rather, occupational standards based on a 10-hour weighted exposure have been derived, with a value of 100mgm-3 (NIOSH, 2005). Therefore, for the purposes of deriving a working exposure level for community exposure and thus public health, this standard was arbitrarily divided by an uncertainty factor of 100, thereby providing an ‘environmental standard’ of 1000ugm-3. This is consistent with the reference concentration (RfC) value of 1000ugm-3 derived for total petroleum hydrocarbons, defined as “the level of continuous inhalation exposure that is likely to be without appreciable risk of deleterious effects during a lifetime”, (TPHCWG, 1997). Therefore, a measured indoor level of 10,000ugm-3 was considered a hazard to health and occupants were offered alternative accommodation; mass evacuation was not considered necessary or appropriate.
Water contamination was a potential issue: Local authority data obtained by infra-red spectroscopy suggested that groundwater was contamination with kerosene while gas chromatography-mass spectroscopy (GC-MS) analysis undertaken by the water company could not corroborate this. This apparent anomaly may be explained by the fact that the two methods use different principles of measurement – GC-MS is widely regarded as being both sensitive and specific, whereas IR does not allow hydrocarbon banding or identification of petroleum hydrocarbon fractions and may suffer from poor accuracy and precision (TPHCWG, 1998). GC-MS is therefore the industry standard method, endorsed by the Water Research Council and the Standing Committee of Analysts (SCA). Even if it is assumed that the IR measured values of up to 55μgl-1 are accurate and precise, the taste/odour threshold for hydrocarbons in drinking water is 10μgl-1 and the toxicity threshold between 300-900μgl-1. Therefore, the water would at worst have been unpalatable, but unlikely to cause illhealth (TPHCWG, 1997).
The multi-agency response
The addressing of the individual but related components of environmental chemistry, toxicology, environmental distribution, environmental monitoring, public health and clinical implications, together with environmental impact, necessitated a multi-agency and multi-disciplinary response. This formed the basis for local, regional and national collaboration and co-ordination, resulting in an holistic and integrated response, as part of the local, regional and national emergency planning partnership. This partnership also provided the foundation for subsequent community risk communication.
The public health axis of local, regional and national structures worked closely with other agencies and organisations, (including the company involved), the professional clean-up company, the local authority, the Environment Agency, the Health and Safety Executive, Welsh Water, the Food Standards Agency and the Community Council to ensure that environmental aspects of the incident, such as contamination, sampling and clean up, was complimentary to the public health implications and requirements.
Within Wales, such collaborative working between organisations involved in public health is well established as part of integrated emergency planning, preparedness, response and recovery. It has been further strengthened by the establishment of Chemicals in Wales Network, with partners including the local health boards, NPHS, HPA and Food Standards Agency signing an informal contractual agreement (‘compact’). The compact provides the basis for the convening of a health advisory group (HAG). The HAG does not convene during the acute phase of the incident, but rather provides a forum for expert integrated debate regarding contentious and difficult issues pertaining to environmental chemicals. It therefore assesses incident management, addressing positive and negative aspects and subsequently disseminates lessons learnt. It also provides a forum for the identification of significant gaps in knowledge in the field, thereby providing a platform for tailored research and development. This in turn may influence policy through scientific innovation. Collectively, the HAG therefore may improve the protection of public health in Wales in relation to chemical events, by adding value to the work of the individual partner organisations (Welsh Assembly Government).
In accordance with the compact arrangements, a HAG was convened for this incident and considered the multiagency response, provided further guidance on complex issues which had been raised locally and access to further sources of advice including academia. It endorsed the risk assessment approach undertaken, which was consistent with recognised methodology (Department for Business Enterprise and Regulatory Reform (BERR), formerly Department of the Environment, Transport and the Regions) (2000)) and concluded that environmental sampling should continue. However, although it was recognised that undertaking epidemiological studies in small geographical areas is technically feasible (Elliott et al., 1997), it was concluded that there were likely to be major limitations associated with studies of small populations and the subsequent meaningful interpretation of results. The limitations of seeking to undertake meaningful studies in relation to environmental hazards associated with small populations has been highlighted by the Committee on the Medical Aspects of Air Pollution (COMEAP), which has advised health bodies investigating the health effects of local industry that “single site studies of the effects of air pollutants on health are unlikely to have sufficient statistical power to confirm or refute assertions of effects and there is a significant risk that the results of such investigations will be impossible to interpret” (Department of Health, 1998).
The multi-disciplinary approach used here reinforces the importance of integrated emergency planning and preparedness and subsequent response and recovery, and is consistent with established models of practice in this field. (WHO/IPCS, 1999). The incident further illustrates the complex toxicological properties of common chemicals and the difficulties of risk assessing the likely public health consequences. Such incidents are undoubtedly multi-disciplinary, underlining the necessity for harmonised and integrated communication and collaboration.
Chemical incidents involving total petroleum hydrocarbons are relatively common and may result in widespread environmental contamination.
The chemistry of total petroleum hydrocarbons is complex owing to the presence of numerous constituents and additives,
The potential contamination of air, water, land and crops, coupled with the recognised toxicity of petroleum hydrocarbons may have a significant impact upon community health.
Public health risk assessment requires an understanding of environmental chemistry and toxicology, environmental persistence, distribution and fete, environmental monitoring as well as clinical toxicology. Therefore, a multidisciplinary/ agency approach is required. This is best addressed through integrated emergency planning and developing robust and clear channels of communication.
Risk communication is an essential component of the response and should be commenced as soon as possible following declaration of an incident in an open and transparent manner.
The authors would like to gratefully acknowledge the contribution of Pembrokeshire County Council, without whom this paper would not have been possible. In addition, the authors are very grateful to Professor David Williams of the Department of Chemistry, Cardiff University, Cardiff, Wales, UK, for his constructive comments.
Campbell D, Cox D, Crum J, Foster K, Christie P andBrewster D (1993). Initial Effects of the grounding of the tanker Braer on health in Shetland, BMJ Vol. 307(6914), pp1251-1255.
Campbell D, Cox D, Crum J, Foster K and Riley A (1994). Later effects of grounding of tanker Braer on health in Scotland. BMJ, Vol. 309 (6957), pp 773-774.
Department for Business Enterprise and Regulatory Reform
(BERR) (formerly Department of the Environment, Transport and the Regions) (2000). ‘Guidelines for Environmental Risk Assessment and Management’, Available online at: www.defra.gov.uk/environment/risk/eramguide/03.htm
Department of Health. Committee on the Medical Affects of Air Pollution (1998). Quantification of the effects of air pollution on health in the United Kingdom. London: The Stationery Office.
Elliott P, Cuzick J, English D and Stern R (1997). Geographical and environmental epidemiology: Methods for small area studies. Oxford University Press (Oxford).
Health Protection Agency (HPA) (2005) ‘Health Protection in the 21st Century – Understanding the burden of disease; preparing for the future.’ [accessed 18/02/09]
International Agency for Research on Cancer (IARC) (1989a). Occupational exposures in petroleum refining: Crude oil and major petroleum fuels. Monographs Eval. Carcinogen. Risk Chem. Hum., Vol. 45, pp 203–218.
International Agency for Research on Cancer (IARC) (1989b). Monographs on the evaluation of carcinogenic risks to humans. Occupational exposures in petroleum refining, crude oil and major petroleum fuels, Vol 45 World Health Organisation Lyon, France.
Lyons R A, Temple J M, Evans D, Fone D L and Palmer S R (1999). Acute health effects of the Sea Empress oil spill. Journal of Epidemiology & Community Health, Vol. 53, pp 306-10.
Ritchie G D, Still K R, Rossi J, Bekkedal M Y-V, Bobb, A J, Arfsten, D P (2003). Biological and health effects of exposure to kerosene-based jet fuels and performance additives. J. Toxicol and Environ Health (B): Critical Reviews, Vol 6(4), pp 357–451.
The National Institute for National Safety and Occupational Health
(NIOSH) (2005). ‘Pocket Guide to Chemical Hazards’ (CDC, USA). Available online at: www.cdc.gov/niosh/npg/
Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) (1997). Volume 4: Development of fraction specific reference doses (Rfds) and reference concentrations (RfCs) for total petroleum hydrocarbons (TPH). Prepared by Edwards D et al., Massachusetts, USA: Amherst Scientific
World Health Organisation (1999). Public Health and Chemical Incidents: Guidance for National and Regional Policy Makers in the Public/Environmental Health Roles. Inter-Organisation Programme for the Sound Management of Chemicals IOMC, WHO.
Download this article as a PDF.