Health Impact of Gas Flares on Igwuruta / Umuechem Communities in Rivers State

This paper examined the relationship between human exposure to toxicological factors in the environment arising from gas flares and the development of various human health related conditions. The impact of environmental factors was investigated at four stations set up concentrically around Agbada II flow station, for a period of nine months (May, 2007 – January, 2008) and sampling was performed manually across the four stations on an hourly basis. The analytical program was done in line with WMO recommendations. Parameters investigated include particulates and gases. Mean particulate concentrations in rainy season across all sites ranged from 0.4 ± 0.4μg/m in June to 25 ± 5.4μg/m in May. Concentration levels of particulates were excessive in the months of December and January, exceeding allowable regulatory limits for TSP, PM10 and PM7 across all stations. Mean concentration levels of gases in both wet and dry seasons were within allowable regulatory limits. Analysis of medical records showed a greater frequency of disease types such as Asthma, Cough, breathing difficulty, eye/skin irritation in (Igwuruta/Umuechem), the study area with a long history of gas flaring compared to Ayama with no flaring history. These subset of diseases accounted for 22.4% and 5.9% (a 4 to 1 ratio) of all cases reported at the respective health centers. The high level of particulates in the dry season constitutes a greater short-term exposure risk to residents and workers with the particular risk of respiratory irritation, itching/eye irritation and cough being endemic in the area surrounding the flare. @ JASEM Oil and gas activities include drilling, refining and transportation of the finished product to consumers. During these activities, wastes either in solid, liquid or gaseous form are generated or discharged into the environment. Among the generated waste is flared gas. According to Egbuna, (1987), Natural gas is a mixture of hydrocarbons (containing mainly methane, ethane, propane and buthane, as well as, sometimes, their stable chemical derivatives such as ethylene, butylenes, etc.) occurring in a gaseous state at room temperature and pressure, and also containing other trace gaseous 'impurities' and noncombustibles (Egbuna, 1987). Stewart et al (1998) defined flaring as a combustion controlled process of volatile organic compounds (VOCs) in which the gases are piped to a remote, usually elevated location and burned in an open flame in the open air using a specially designed burner tip, auxiliary fuel and steam or air to promote mixing for gas destruction. In recent times, there has been reported cases of physiological effects recorded in areas with intense gas flaring and these effects include birth defects which occur during the reproductive cycle of women in their first trimester of pregnancy. Other effects are disturbance in the wake-sleep rhythm which is also associated with nervous problems and low ability to thrive among individuals found in similar area where gas flaring activities are taking place. This view is supported by the findings of Pope and Dockery (1996). In a related study, Calabrese and Kenyon (1991) reported cases of respiratory problems, skin/eye irritation, cancer and other ailments associated with exposure to gas flares in western Canada, (Calabrese and Kenyon, 1991). Godson, et al. (2005), discovered that compounds such as Sulphur oxides (SOx), carbon monoxide (CO), photochemical oxidants, Nitrogen oxides (NOx) and a number of other harmful compounds are contained in flared gases, these are believed to be associated with environmental pollution (Godson, et al, 1995). Researchers have associated skin disorders and respiratory tract infections with exposure to high concentrations of atmospheric pollutants such as carbon monoxide (CO), Sulphur-dioxide (SO2) and suspended particles, (Abbey et al, 1993; Wieslander et al, 1994; and Hall et al, 1995). According to James, (2001) Naphthalene is a hemolytic agent, destroying the membrane of the red blood cell with the liberation of hemoglobin, and an irritant of the eyes that may cause cataracts. The report pointed out that initial symptoms include eye irritation, headache, confusion, excitement, malaise, profuse sweating, nausea, vomiting, abdominal pain and irritation of the bladder. These few studies cited above have aroused interest in this field since communities in the Niger Delta share similar experiences. This paper examines these problems in detail on a small scale by assessing the nature and effects of gas flares in terms of health and the environment in two communities around Agbada II flow station (Igwuruta and Umuechem). It is hoped that this paper would serve as a reference for Government and oil firms in delineating the health and environmental implications of gas flaring in the Niger Delta region when formulating policies or initiating actions that would be beneficial to those living within such vicinity. OBJECTIVES OF THE STUDY The objective of this paper is to examine the relationship between human exposure to toxicological factors in the environment arising from gas flares and the development of various human health related conditions, and identify various mitigation measures feasible where a correlation is established. The above objective is achieved through examination of changes in body Health Impact of Gas Flares on Igwuruta / Umuechem Communities in Rivers State * Corresponding author: Gobo, A. E. 28 functions occurring among individuals exposed to gas flares and examining health facilities available or in use to determine health problems associated with flared gases. STUDY AREA DESCRIPTION Agbada II flow station belonging to SPDC Nigeria limited is located between Eneka and Igwuruta communities in lkwerre Local Government Area of Rivers State. Geographically the facility is located on longitude 7° 0 – 7 10E and latitude 4 31 – 4 40N in Rivers State of Nigeria (Gobo et al, 2006). The facility is bounded on the north by lgwuruta town, on the south by Eneka town, on the east by EnekaIgwuruta road and on the west by air Airport road. The facilityhas three different flare points consisting of two vertical and one horizontal flarepoints. Accessibility to the site is through a tarred road from the Eneka axis or Igwuruta Airport road. The facility is well fenced with an entrance gate in front and surrounded by farm lands. MATERIALS AND METHODS EPIDEMIOLOGICAL SURVEY: This paper looks into the impact of flared gases on human health using Igwuruta/Umuechem communities as a case study. The study covered the period May 2007 to January 2008. A mobile clinic was run to provide the researcher with current information on the epidemiological background of the inhabitants of the area under survey. Five hundred questionnaires requesting health information were distributed to inhabitants/workers in Igwuruta/Umuechem communities. In addition, four years medical records from the primary health care centre in Igwuruta were compared to that of Ayama in Abua/Odual local government area of Rivers State with no history of gas flaring. AIR QUALITY: Three stations and one control area were defined. The four study sites were arranged concentrically about the flare points. • Area I Upwind • Area II Midpoint • Area III Downwind • Area IV Control FIELD SAMPLING Particulate matter and gases were collected at sites in Igwuruta. The samplers were approximately 200m from the main roads to minimize the contributions of re-suspended soil dust from nearby streets. Sampling was performed during a 9 month period (May 2007January 2008). Sample readings were taken at 3 different sites at approximately 1 hourly interval. PARTICULATES: PM10, PM7, PM2.5, PM1 and TSP were collected using an Aerocet 5319800 Rev for the measurement of respirable particulate matter and TSP. The machine provides a fast indication of particulate mass concentration per cubic feet sampled air for the most commonly tested particle size fractions. GASES CARBON MONOXIDE (CO): A MultiRae PLUS Carbon Monoxide Gas monitor model PGM 7840 was used for the detection of Carbon monoxide. The range of detection is between 0-1000 ppm with alarm set at 50 and 150 ppm. Measurements were done by holding the sensor to a height of about two meters in the direction of the prevailing wind and readings recorded at stability. Sulphur oxides (SOx): A MultiRae PLUS Sulphur Oxides Gas monitor model PGM 7840 with an electrochemical sensor was used for the detection of SOx The range of detection is between 020 ppm with a resolution of 0.1 ppm. The alarm set points (low/high) were at 2 and 10 ppm. Measurements were done by holding the sensor to a height of about two meters in the direction of the prevailing wind and readings recorded at stability. NITROGEN DIOXIDES (NO2): A MultiRae PLUS Nitrogen Oxides Gas Monitor model PGM7840 with an electrochemical sensor was used for the detection of NOx. The range of detection is between 020 ppm with a resolution of 0.1 ppm. The alarm set points (low/ high) were 1 and 10 ppm. Measurements were done by holding the sensor to a height of about two meters in the direction of the prevailing wind and readings recorded at stability. HYDROGEN SULPHIDE (H2S): MultiRae PLUS Hydrogen Sulphide Gas Monitor model PGM 7840 was used for the detection or H2S. The range of detection is between 020 ppm with alarm set at 10 and 30 ppm. Measurements were done by holding the sensor to a height of about two meters in the direction of the prevailing wind and readings recorded at stability. VOLATILE ORGANIC COMPOUNDS (VOCs): A MultiRae PLUS (PGM-50). A programmable Multi Gas monitor with an electrochemical sensor was used for the detection of volatile organic compounds. The equipment detects gas via a plug in catalytic head and has a detection range of 1010004ig VOCS Measurements were done by holding the sensor to a height of about two meters the direction of the prevailing wind and readings recorded at stability. The limit of detection is 0.01% volatile organic compounds. METHODS FOR ANALYSIS OF AIR QUALITY DATA Simple descriptive analysis involving mean, standard deviation and variance were used. A correlation analysis using ANOVA was carried out in order to ascertain the level of association between various chemical parameters. The student Health Impact of Gas Flares on Igwuruta / Umuechem Communities in Rivers State * Corresponding author: Gobo, A. E. 29 ttest was used to ascertain the statistical significance of the difference between means. The level of significance was taken as p < 0.01. Graphs as well as tables were used to present data in a manner that could be easily understood. RESULTS AND DISCUSSION t-TEST ANALYSIS: PARTICULATES Table 1: t-test analysis of TSP at 99% Table 1 above is a summary of the results of t-Test analyses on TSP in dry/wet seasons at downwind station. The data indicates that variance arising from differences in stations was strongly significant [tstat (12.32) > tcrit (6.96) 0.01]. Similarly t-Test results 0f PM10 and PM7 indicates significant variance [tstat (7.17) > tcrit (6.96) 0.01] and PM7 [tstat (66.65) > tcrit (6.96) 0.01]. GASES VOLATILE ORGANIC COMPOUNDS (VOCs): Table 2 below is a summary of the results of t-Test analyses on VOCs in dry/wet seasons across the stations. The data indicates that variance arising from differences in stations was not significant [tstat (0.21) < tcrit (2.62) 0.01]. Similarly t –Test result for CO, NO2, and H2S were insignificant. Table 2: t-test analysis of VOC at 99% t-Test: Two-Sample Assuming Equal Variances for VOC at 99% of dry & wet seasons at downwind Dry mths Wet mths Mean 6.64 5.94 Variance 48.34 39.36 Observations 8.00 8.00 Pooled Variance 43.85 Hypothesized Mean Difference 0.00 Df 14.00 t Stat 0.21 P(T<=t) one-tail 0.42 t Critical one-tail 2.62 P(T<=t) two-tail 0.84 t Critical two-tail 2.98 PARTICULATES AND GASES CORRELATION Table 3: Correlation Analysis of all Parameters Investigated using ANOVA SO2 NO2 CO TSP PM10 PM7 PM2.5 PM1 SO2 1.00 NO2 0.79 1.00 CO 0.73 0.35 1.00 TSP 0.98 0.66 0.79 1.00 PM10 0.99 0.74 0.76 0.99 1.00 PM7 0.99 0.70 0.78 0.99 0.99 1 PM2.5 0.98 0.89 0.68 0.92 0.96 0.95 1 PM1 0.96 0.67 0.88 0.98 0.98 0.98 0.93 1 t-Test: Two-Sample Assuming Equal Variances for TSPat 99% Of dry & wet months at Downwind station Dry season Wet season Mean 517.35 27 Variance 3144.25 24.5 Observations 2 2 Pooled Variance 1584.37 Hypothesized Mean Difference 490.35