TL: HUMAN HEALTH IMPACTS OF OIL SO: Greenpeace International (GP) DT: Unknown Keywords: energy oil health chemicals toxics / GREENPEACE OIL BRIEFING - 7 (GP) HUMAN HEALTH IMPACTS OF OIL Crude oil contains thousands of different chemical compounds which vary depending on the source of the oil. The most abundant compounds are hydrocarbons (50-98% of the total composition). Sulphur, nitrogen and oxygen are important minor constituents. Variable concentrations of trace metals are also present and may include vanadium, nickel, copper and iron. Light crude, the cargo of the Braer, contains a higher proportion of volatile aromatic hydrocarbons than heavy crude, the cargo of the Exxon Valdez. Some of the hydrocarbons present in crude oil are known to be highly toxic. For many other compounds present there is little or no toxicological data available. Following an oil spill such as the Braer incident, the temperature, weather conditions and the unique composition of the oil will determine the type of exposure to local communities. The volatile single ring aromatic hydrocarbons including benzene, toluene and xylene are among the most important constituents in terms of exposure. These compounds are more water soluble and have greater bioavailability than do possibly more toxic but less soluble crude oil constituents. Inhalation of these vapours may have been responsible for a wide range of symptoms such as sickness, headaches and sore throats suffered by people in the south of Shetland. Benzene may enter the body via the respiratory tract, gastrointestinal tract or skin (in workers exposed to benzene 20-40% of the total dose is via skin absorption). It causes irritation to skin, eyes and the upper respiratory tract. Further exposure leads to depression, headaches, dizziness and nausea. It is carcinogenic to humans and there is no known safe threshold.1 Studies of workers exposed to benzene over a period of years have found an increased incidence of leukaemia.2 In pregnant women aromatic compounds such as benzene are concentrated in the foetal blood supply. However no abnormalities have been documented in the babies of mothers exposed to low levels of benzene. Toluene is readily absorbed through the respiratory tract but absorption through the skin is believed to be minimal. Its solvent like odour is perceptible at low concentrations of 1mg/m3. Its main effects are on the central nervous system. The lowest observed effect level is around 375 mg/m3 (100 ppm).1 Effects range from fatigue, headache, throat and eye irritation to lack of co-ordination, mental confusion and muscular weakness. After effects include insomnia. Xylene irritates the eyes, nose, throat and respiratory tract at exposures of 110-460 ppm.3 It causes nervous system effects similar to those seen with toluene. Chemical pneumonitis, and kidney and liver impairment have also been recorded at high doses. Significant inhalation of crude oil can cause chemical pneumonitis and chemical pheumonia4 and poses a hazard to salvage teams. There is no precedent for the health effects of the fine mist of light crude il and vapours thrown off the seas from the Braer. It is assumed that at low levels the risk would be minor for most people. However, people with pre-existing chest disease such as asthma and chronic bronchitis may experience respiratory symptoms. It is not known whether exposure to light crude oil can induce asthma but fractions of crude such as kerosene may do so. Kuwaiti patients with lung disease reported an increase in symptoms from exposure to air pollution from oil fires in the aftermath of the Gulf war. They reported more cough, wheeze and breathlessness and black sputum.5 The Kuwaitis were exposed to high levels of smoke and gaseous pollutants cause by oil combustion and so cannot be directly compared with the Shetland population. Several workers from the Exxon Valdez clean up operation subsequently suffered multi system disease believed to be due to the combination of heavy crude oil and toxic clean up agents.6 Symptoms included respiratory distress, palpitations, joint and muscle pain and one death was reported. Polynuclear (polycyclic) aromatic hydrocarbons (PAH's) are also present in rude oil. There are several hundred PAH's, the best know being benzo(a) pyrene (BaP). PAH's may cause skin and lung cancer and because of their carcinogenicity no safe level can be recommended. PAH's tend to concentrate in weathered oil and may be of significant long term concern for human health.7 People living in affected areas should limit exposure to crude oil and crude il mists. Faced with a similar situation staff at California's Air Resources Board would evacuate children living in the affected locality.8 People involved in clean up operations should wear protective clothing which is impervious to crude oil and crude oil vapours. Where there is a risk of inhaling vapours or oil mists protective masks should be worn. Produce (meat, fish, milk, vegetables,) tainted with hydrocarbons usually as an unpleasant taste. To prevent further contamination through the food chain animals should be prevented from grazing on contaminated land.9 Psychiatric problems have often been recorded following technological and natural disasters. People living in Alaskan communities directly affected by the Exxon Valdez oil spill in 1989 reported an increase in depression one year after the incident.10 (1) World Health Organisation, Air Quality Guidelines for Europe, 1987. (2)Klaassen C D, Amdur M O, and Doull J 1986, Casarett + Doull's Toxicology -he Basic Science of Poisons, 3rd Ed, Macmillan New York. (3)Evaluation of the health effects from exposure to gasoline and gasoline vapour. Aug 1989. North East States for Co-ordinated air use Management. (4)EPA, Marine Safety Data Sheet, Crude Oil, 1987. (5)Green M, British Lung Foundation. (pers comm) (6)Boston Sunday Globe, May 10, 1992 (7)Rall, D. P. Science 1989, 245 (4917): 463 (8)Holmes. J, Director of Research, California Air Resources Board (pers comm) (9)Hay A, (pers comm) (10)Ethnic differences in stress, coping, and depressive symptoms after the Exxon Valdez oil spill, Palinkas L A et al, J Nerv Ment Dis 180: 287-295, 1992. =end=