Initial effects ofthe grounding ofthe tanker Braer

Objective-To determine if the oil spillage from the tanker Braer had any immediate health effects on the exposed resident population. Design-Cohort study with a comparison against controls, exposure status being assigned on the basis ofgeographical location. Setting-Rural Shetland. Subjects-All those resident on or after 5 January 1993 (day 0) within 4 5 km of the site of tanker's grounding. Controls matched for sex and age were drawn from a general practice list 95 km distant. Outcome measures-Demographic details; smoking and alcohol consumption; perception of health and reported presence or absence of specific symptoms; peak expiratory flow; results of haematology, liver and renal function tests, and blood and urine toxicology. Results-Of subjects contacted, 420 (66%) exposed people and 92 (68%) controls were studied; 56 non-attenders were surveyed. Principal health effects arose on days 1 and 2 and were headache, throat irritation, and itchy eyes. No significant differences between those exposed and controls were found for any of the biological markers. Toxicological studies did not show any exposures that are known to affect human health. Conclusions-The study confirmed the anecdotal reports of certain acute symptoms. No evidence of pulmonary, haematological, renal, or hepatic damage was detected at the population level. Toxicological samples from exposed people did not find levels known to affect human health. Further studies are required to ascertain whether there have been any long term effects on the population. Environmental Health (Scotland) Unit, Ruchill Hospital, Glasgow G209NB D Campbell, consultant in public health medicine Shetland Health Board, Lerwick, Shetland ZEI ORB D Cox, director ofpublic health J Crum, research associate Grampian Health Board, Aberdeen AB9 1RE K Foster, senior registrar Common Services Agency for Scottish Health Service, Edinburgh EH5 3SQ P Christie, senior registrar D Brewster, senior registrar Correspondence to: Dr Campbell. BMJ 1993;307:1251-5 Introduction On 5 January 1993 the tanker MV Braer on passage from Norway to Quebec ran aground on Garth's Ness, a rocky headland on the south west of Shetland.' Over the next six days it leaked its cargo of 85 000 tonnes of Norwegian Gullfaks crude oil, the maximum discharge occurring as the ship broke up on 11 January. Concems were expressed as to the immediate and long term health effects on the exposed population, public anxiety being exacerbated by statements from individuals and organisations. There were anecdotal reports of acute toxic symptoms, mainly of shortlived types related to exposure.2 The volatile nature of the oil and the extreme weather conditions resulted in it being blown over the land to the north and east of the vessel, exposing soil, crops, buildings, animals, and humans to hydrocarbons as vapour, droplets, and oil-water emulsions. Dispersants were sprayed and fell over land as well as sea.3 Some of the constituents of the oil were known to be potentially carcinogenic.4 Environmental exposure to crude oil and its components may occur by ingestion, inhalation, or dermal absorption. The release from the Braer would have generated aerosols from wind and wave action and vapours by evaporation. Most of the aerosol would have settled on surfaces or been filtered by the nose and mouth, only a small proportion of droplets being in the respirable range. Shetland Islands Council's detailed environmental sampling started on 10 January, estimating vapour, particulates, and settled and precipitated material (measuring hydrocarbons of lengths C3 to C16). Hydrocarbon concentrations were measured in the public raw drinking water and in soil and vegetable samples. The highest estimated airbome hydrocarbon concentration (6-33 ppm) occurred on 11 January, the day the tanker broke up, at the dwelling nearest the wreck, with a corresponding benzene concentration of 0 074 ppm. On 10 January the concentrations at the same site were 0-264 ppm and 0-023 ppm and on 12 January, 0-066 ppm and 0-018 ppm (P Leinster and N E Thomson, report to environmental services department, Shetland Islands Council). Epidemiological investigations of major oil spillages have been undertaken infrequently and have focused on workers involved in cleanup operations rather than exposed residents, and performed only at later stages in the incidents.56 Studies on hydrocarbon hazards have concentrated on occupational rather than residential exposures, emphasising chronic rather than acute exposures.7 This study was designed to determine the immediate effects of the oil spillage on the health of the Shetland population with the objectives of collecting baseline information from and performing biological measurements on a group of residents potentially exposed to the spillage. This project did not offer "health checks," which are a clinical matter between individuals and their general medical or occupational health practitioner.8 Approval was granted by Shetland Health Board's research ethics committee; data collection started on 13 January and was completed on 21 January 1993.