No comprehensive study is known to have been carried out into the health impacts of gas flaring on communities in the Delta, including the level of pollutants in the food chain. However, communities firmly believe that the flaring is damaging their health, reducing crop production and damaging their homes. While other factors may be at play, the lack of attention paid to this crucial issue, means that villagers' questions and fears are unanswered. Conviction that oil production is such a damaging force fuels community anger against oil companies.
Even in the absence of such a study, however, it is clear that flaring harms people, cattle and the environment. In this section, we describe how this happens.
Flaring emits a cocktail of toxic substances
Flaring of AG from oil production facilities is like setting a match to an enormous container of lighter fluid. They are so hot that nothing will grow next to them.
Emissions resulting from the combustion of AG in this open, uncontrolled manner will be a mix of smoke, more precisely referred to as particulate matter; combustion by-products, including sulfur dioxide, nitrogen dioxides and carcinogenic substances, such as benz[a]pyrene and dioxin; and unburned fuel components, including benzene, toluene, xylene, and hydrogen sulfide. The Canadian Public Health Association has noted over 250 identified toxins.[ 65 ]
Environmental and health agencies have published excellent reviews of how exposure to these pollutants impact human health. According to the United States Environmental Protection Agency (U.S. EPA):
"Many scientific studies have linked breathing particulate matter to a series of significant health problems, including: aggravated asthma, increases in respiratory symptoms like coughing and difficult or painful breathing, chronic bronchitis, decreased lung function, and premature death." [ 66 ]
Also, according to the U.S. EPA:
"It has been clearly established and accepted that exposure to benzene and its metabolites causes acute nonlymphocytic leukemia and a variety of other blood-related disorders in humans." [ 67 ]
Flaring is likely causing premature deaths and cases of leukemia
It is possible to estimate the extent to which emissions from gas flares are causing health effects among citizens of the Niger Delta. To simplify our analysis, we focus only on citizens of Bayelsa State and their exposure to two pollutants: particulate matter and benzene.
The human health effects of exposure to pollutant emissions from gas flares will be localized to the vicinity of such flares. Therefore, it is important to estimate how much gas each flow station in the Delta flares. Recent data show that the Kolo Creek and Obama flow stations in Bayelsa State flare, on average, approximately 800,000 m3/day of gas.[ 68 ] It is reasonable to assume that this is representative of the average quantity of gas flared per flow station in Bayelsa State. Seventeen on-shore flow stations in Bayelsa State have been identified.[ 69 ] If each flow station flares an average of 800,000 m3/day, then this would account for 13,700,000 m3/day, which is consistent with recent data about AG production and flaring from on-shore sources in the Western Sector of the oil producing region of the Niger Delta.[ 70 ]
It is possible to estimate the impact on ambient air quality of typical 800,000 m3/day flare by examining data obtained by Canadian researchers who measured pollutant emissions of sweet gas flares in Alberta, Canada. Their data showed that: 1) A small flare (8,600 m3/day) would elevate particulate matter levels by 0.23 micrograms/m3 (ug/m3) at a distance of 1,325 meters from such flare; 2) This same flare would elevate benzene levels by 0.025 ug/m3 at a distance of 5,000 meters from such flare.[ 71 ] Pollutant emissions are directly proportional to the size of a sweet gas flare. Hence, based on the Canadian data, an 800,000 m3/day sweet gas flare would elevate ambient air levels of particulate matter by 21 ug/m3 at a distance of 1,325 meters from such flare, and would elevate ambient levels of benzene by 2.3 ug/m3.
A substantial number of persons will be exposed to these emissions. Recent data show that the population density of Bayelsa State is roughly 250 persons per square kilometer (km2).[ 72 ] Assuming there are 17 on-shore flow stations in Bayelsa State, it is reasonable to assume that, at this population density, 35,000 persons live within 1,325 meters of a flow station, and that 333,000 persons live within 5,000 meters of a flow station.
From this information, it is possible to gauge the extent of human exposure.
According to the World Bank, human exposure to particulate matter causes the following increased rates of adverse health effects:
Assuming, conservatively, that 40% of the population of Bayelsa State are children[ 74 ] and that 5% of the population are asthma sufferers, particulate matter emissions from gas flaring at the 17 on-shore flow stations in Bayelsa State would likely cause, each year, at least:
According to the U.S. EPA., human exposure to 1.0 ug/m3 of benzene represents an elevated 1:100,000 lifetime risk of cancer.[ 75 ]
On the same conservative assumptions, benzene emissions from gas flaring at the 17 on-shore flow stations in Bayelsa State would likely cause:
On the basis of current information, the above estimates are the minimum extent of the human toll that gas flaring can reasonably be expected to cause in the Bayelsa State. For the following reasons, it is reasonable to assume that the actual human toll is considerably higher, perhaps by several orders of magnitude:
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Flaring causes acid rain
Delta residents have long complained about how their corrugated roofs have been corroded by the composition of the rain that falls as a result of flaring. The primary causes of acid rain are emissions of sulphur dioxide (SO2) and nitrogen oxides (NOx), which combine with atmospheric moisture to form sulfuric acid and nitric acid, respectively. The graphic on the right from the U.S. EPA website shows how acid rain forms.
Acid rain acidifies lakes and streams and damages vegetation. In addition, acid rain accelerates the decay of building materials and paints. Prior to falling to the earth, SO2 and NOx gases and their particulate matter derivatives, sulfates and nitrates, contribute to visibility degradation and harm public health.[ 76 ] In the Delta, an oily hue is often observed on collected rain water.
A recent scientific study links gas flare emissions to the corrosion of infrastructure in the Niger Delta. In this study, a researcher from the Institute of Oceanography, University of Calabar, showed that rain water samples at Ekpene Obo town of Esit Eket local government area, situated close to gas flares in Akwa Ibom State, contained high levels of acidity resulting in corrosion of corrugated roofs. According to the study:
"an acidic rain of pH 5.4 was measured in a sample from Eket. A comparison of this direct rainfall with the corresponding roof rainfall showed a marked drop in chloride content from 1,050 mg/l in the direct rainwater to 28.4 mg/l in the roof rainwater. This drop is attributed to the reaction between HCl in rain and zinc in roofing material. A similar trend was also found in sulfate concentration, which was attributed to the reaction between H2SO4 in rainwater and the protective ZNO layer of zinc plated iron roofs. These reactions are responsible for the accelerated rusting of roofing materials in oil producing communities of Southern Nigeria. The main source of these acids in rainwater at Eket, is the Mobil Producing gas flaring operations at nearby onshore and offshore locations. During the wet season, flare gases are carried inland throughout Eket and environs by South West Trade Winds leading to persistent acidic rain in these communities with attendant infrastructural damages." [ 77 ]
The observation that gas flaring in the Niger Delta is causing acid rain is also backed by the U.S government's Energy Information Administration, which states:
"The continued process of gas flaring has not only meant that a potential energy source - and source of revenue - has gone up in smoke, but it is also a major contributor to air pollution and acid rain." [ 78 ]
Other reasons aside, the toxic emissions which local communities in the Delta face daily from gas flares are a sufficient justification in themselves for ending the practice.
[ 65 ] "There have been over 250 identified toxins released from flaring including carcinogens such as benzopyrene, benzene, carbon di-sulphide (CS2), carbonyl sulphide (COS) and toluene; metals such as mercury, arsenic and chromium; sour gas with H2S and SO2; nitrogen oxides (NOx); carbon dioxide (CO2); and methane (CH4) which contributes to the greenhouse gases." Canadian Public Health Association, Background to 2000 Resolution No. 3, available here.
[ 66 ] See http://www.epa.gov/air/urbanair/pm/hlth1.html.
[ 67 ] U.S. EPA (1997) "Carcinogenic Effects of Benzene: An Update." Available here: http://www.epa.gov/NCEA/pdfs/benzene.pdf.
[ 68 ] Ishisone, M. (2004) "Gas Flaring in the Niger Delta: the Potential Benefits of its Reduction on the Local Economy and Environment." Available here: http://ist-socrates.berkeley.edu/~es196/projects/2004final/Ishone.pdf.
[ 69 ] Nembe Creek, Nembe Creek North, Creek North, Nombe Creek East, Nembe Creek West, Kolo Creek, Etelebou, Non River, Diebu Creek, Opukushi North, Tunn, Beniseide, Brass Oil Terminal, Obama, Tebidoba, Ogoinbiri, Clough Creek.
[ 70 ] UNDP/World Bank Energy Sector Management Assistance Programme (ESMAP)'s Strategic Gas Plan for Nigeria, February 2004, Appendix 3, Table A.3.3.
[ 71 ] Strosher, M. (November 1996) "Investigations of Flare Gas Emissions in Alberta." Available here: http://www.eub.gov.ab.ca/bbs/documents/reports/StrosherInvestigationOfFlareGasEmissions-1996.pdf.
[ 72 ] Onokerhoraye, A.G. (June 1999) "Access and Utilization of Modern Health Care Facilities in the Petroleum-producing Region of Nigeria: The Case of Bayelsa State." Available here: http://www.hsph.harvard.edu/takemi/rp162.pdf.
[ 73 ] World Bank (1997) "Vehicular Air Pollution: Experiences from Seven Latin American Urban Centers," World Bank Technical Paper No. 373, p. 34.
[ 74 ] According to the CIA World Factbook, 43.4% of Nigeria's population is aged 0-14 years (male 29,985,427; female 29,637,684). Available here: http://www.cia.gov/cia/publications/factbook/geos/ni.html#Intro.
[ 75 ] See: http://www.epa.gov/iris/subst/0276.htm.
[ 76 ] See U.S. EPA: http://www.epa.gov/airmarkets/acidrain/effects/index.html.
[ 77 ] Akpan, E.R. (2003) "Acidic precipitation and infrastructural deterioration in oil producing communities of Akwa Ibom State: a case study of Eket, South Eastern Nigeria," Global Journal of Environmental Sciences, 2(1):47-52. Abstract available here: http://www.ajol.info/viewarticle.php?jid=11&id=6024&layout=abstract.
[ 78 ] Also available here: http://www.eia.doe.gov/emeu/cabs/nigenv.pdf.
Executive Summary | Introduction | Section 2 | Section 3 | Section 4 | Section 5 | Section 6 | Section 7 | Section 8 | Section 9 | Conclusions