|Fig. 1: Nigerian Map Highlighting Delta State, one of the major oil producing State, located in the Niger Delta region of Nigeria. (Source: (Wikimedia Commons)|
Nigeria is the largest oil producer in Africa and the eleventh largest producer of crude oil in the world.  Since the initial discovery of oil in commercial quantity in 1956 in the River Niger Delta basin of Nigeria, oil has overtaken agriculture as the dominant source of revenue in the nation (Fig. 1). In 1958, Shell D'arcy, the pioneer oil company in Nigeria, started commercial production of oil at a rate of 5100 barrels per day. This quantity doubled in the following year, and 20 years later in January 1979, the rate of crude oil production reached a peak of over 2 million barrels of crude oil a day. Oil revenue supports the Nigerian economy to the extent of providing 90% of foreign exchange earnings and 85% of total government revenue.  Additionally, the increased press coverage of localized disturbances has caused an increased public and professional concern about health and about the environmental hazards that seem to accompany the wealth obtained from petroleum. Like other oil-producing countries, Nigeria experiences some significant problems of pollution, but each country, invariably, presents some unique conditions under which oil and petrochemical pollution occurs and how such pollutions may be prevented, treated, or controlled.
Prospecting and extraction of oil occur in over 50% of the Niger Delta region, resulting in a cornucopia of access roads, pipelines, wells, gas flaring, dredged spoils and flow stations that are often located near homes, schools, farms, and within communities.  Oil spills are common throughout the region, as a consequence of pipeline corrosion, poor maintenance of infrastructure, spills or leaks at the well heads, human error, theft of oil and intentional vandalism.  A report by Jernelov estimated that the total spillage into the Niger Delta was between 9 and 13 million barrels over 50 years - roughly 1.5 million tons per year, equivalent to one Exxon-Valdez spill annually for half a century.  The collective impacts of these pervasive massive spills on the environment and local inhabitants are worsened by seasonal floods which transfer the oil pollution to farmlands and occupied areas.  Currently, hundreds of thousands of people who live in the Niger delta region are being exposed to oil contamination near their homes, farm lands, fishing grounds and in their drinking water and foods but the consequences of such exposure on their health are unknown. 
A study by Nriagu et al. documents the health risks associated with oil pollution in the Niger Delta.  There is a high level of worry, annoyance and intolerance associated with oil production and refinery in the Niger Delta areas of Nigeria. Emotional distress can induce dysregulation of multiple interrelated physiological systems including the cardiovascular, endocrinological and immunological systems and hence are risk factors for a wide range of pathological diseases; the high burden of disease symptoms found in this study is tremendous.  As example, people with type II diabetes mellitus, a rapidly rising issue in Nigeria, are twice as likely to suffer from depression compared to the general population, which in turn can lead to greater difficulty with self-care.  People with emotional distress are more likely to smoke cigarettes as others; they showed show that 17% of the participants smoked regularly and this rate may be rising.  Patients who are depressed have higher risk of having a heart attack compared to the general population.  Of particular significance in Nigeria is the fact that annoyance and intolerance are considered to be risk factors for aggression through loss of self-control.  People who show heightened aggressive cognition, physiological arousal, and anger tended to make hostile attributions about others behavior (polluters in the Niger Delta for instance), which heightens the tendency towards aggression.  The cause-effect relationship between exposure to oil pollution and high level of violence in the Niger Delta as well as the hostility towards oil producing companies is an intriguing question for further research. The results of this study make a strong case for national attention to be paid to what the study has shown to be a silent epidemic of psychological problems in communities of the Niger Delta area. 
© Opemipo Akerele. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 O. Odeyemi and O. A. Ogunseitan, "Petroleum Industry and Its Pollution Potential in Nigeria," Oil Petrochem. Pollut. 2, 223 (1985).
 J. Nriagu et al., "Health Risks Associated With Oil Pollution in the Niger Delta, Nigeria," Int. J. Environ. Res. Public Health 13, 346 (2016).
 A. Jernelv, "The Threats From Oil Spills: Now, Rhen, and in the Future," Ambio 39, 353 (2010).