Vol. 9(3), pp. 218-227, March 2015 DOI: 10.5897/AJEST2015.1867 Article Number: 018C04950850 African Journal of Environmental Science and ISSN 1996-0786 Copyright © 2015 Technology Author(s) retain the copyright of this article http://www.academicjournals.org/AJEST Full Length Research Paper Seasonal variation of meteorological factors on air parameters and the impact of gas flaring on air quality of some cities in Niger Delta (Ibeno and its environs) Asuoha, Adaku N.1 and Osu Charles I.2* 1Safety Health and Environmental Department, Mobil Producing Nigeria, Nigeria. 2Department of Pure and Industrial Chemistry, University of Port Harcourt, P.M.B 5323 Choba, Port Harcourt, Rivers State, Nigeria. Received 19 January, 2015, Accepted 29 January, 2015 The impacts of gas flaring on meteorological factors at Ibeno, Eket, Onna, Esit Eket and Umudike - Nigeria were investigated by measuring air quality parameters. The results show that the mean concentration of air parameters value were below Federal Environmental Protection Agency (FEPA) and United States Environmental Protection Agency (USEPA) National air quality standards with exception of carbon monoxide which exceeded the limit of 35 ppm in March at Ibeno. Concentration of air parameters at Umudike showed a similar trend to that of study locations at Eket, Ibeno, Esit Eket and - Onna. Air quality parameters (Cl , SPM and SO2) were found to have positive correlation with vapour pressure, humidity and rainfall values in the study areas. It was also established that a positive correlation exits between NO2, H2S, SO2, SPM, chloride, carbon monoxide and wind speed relative humidity, temperature and vapour pressure in the study locations. Chloride and nitrate also have a positive relationship with wind speed in some of the study locations. Key words: Air parameters, gas flaring, meteorological factors. INTRODUCTION The atmosphere is a complex dynamic natural gaseous holds the highest record (19.79%) of natural gas flaring system that is essential to support life on planet Earth. globally and is responsible for about 46% of Africa’s total Stratospheric ozone depletion due to air pollution has gas flared per tonne of oil produced. Until present, there long been recognized as a threat to human health as well are not less than 123 flaring sites in the region making as to the Earth's ecosystems. Indoor air pollution and Nigeria one of the highest emitter of green-house gases urban air quality are listed as two of the world worst in Africa (Tawari and Abowei, 2012). pollution problems in the 2008 Blacksmith Institute World's Air pollution is a mixture of solid particles and gases in Worst Polluted Places report (Anderson, 2005). Nigeria the air. Car emissions, chemicals from factories, dust and *Corresponding author. E-mail: [email protected]. Tel: +234 803 7783246. Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Adaku and Osu 219 pollen and mold spores may be suspended as particles. 07° 51' E, Esit Eket is located at latitude 04° 39' N and longitude Some air pollutants are poisonous. Inhaling them can 08° 03' E all in in Akwa Ibom State. This area experiences a tropical increase the chances of having health problems. People climate consisting of rainy season and dry season. Onshore south- westerly winds are experienced throughout the year, due to the with heart or lung disease, older adults and children are maritime location of the study area (Figure 1). Umudike in Abia at greater risk from air pollution. Air pollution has been State was chosen as the control location for this study. identified as one of the most critical environmental problems confronting the Nigeria. Traffic, industry and gas flaring are the major air pollution sources in the region (Tawari Sample collection and Abowei, 2012). More than two million premature Air parameters were sampled from March 2007 to November 2007 deaths each year can be attributed to the effects of urban with the months of March, April, October and November representing outdoor and indoor air pollution and these effects are dry season and May to September representing rainy season. The more prominent in developing countries (Mabahwi et al., sampling locations were labeled; Eket, Esit Eket, Ibenno, Onna and Umudike (control sample). 2014). Pollution of air has great influence on living organisms and man in particular. Alarming quantity of gases and smoke are discharged daily into the atmosphere. Globally, Determination of air quality parameters the pollutants which account for almost 98% of the total pollution are carbon monoxide 52%, sulphurdioxide 18%, Crowcon Gasman Monitors were used for the determination of the hydrocarbon 2%, particulates 10% and oxides of nitrogen, ambient concentration of air parameter in each location. It operates 6%. by gas diffusion through an air filter into the sensors which is fitted Hydrogen sulphide (H S) is emitted from a number of directly under the air filter. The concentration of air parameters is 2 then displayed on the output meter. The instrument is calibrated metallurgical, petroleum and petrochemical processes. before use and was moved from one site to the other between the Fugitive emission of hydrogen sulphide can occur from hours of 8 am to 12 pm. sour gas wells and certain petrochemical processes. It is a highly toxic gas due to its chemical asphixant charac- teristics. Despite its strong rotten egg odour, it is often Determination of meteorological factors difficult to detect at high concentrations due to rapid Meteorological data for the sampling location were collected in olfactory fatigue. Hydrogen sulphide is highly soluble in Umudike, Eket, Ibeno, Onna and Esit Eket from January, 2006 to water and can be easily oxidized to form sulphur dioxide July 2007 using standard meteorological instruments. (Aliyu et al., 2013). Sulphur emissions influence the level of acidification of soils and freshwater ecosystems (Aliyu et al., 2013), climate change (Aliyu et al., 2013) and have RESULTS AND DISCUSSION impacts on human health (Aliyu et al., 2013). SO2 is oxidized to SO3 in the atmospheric air by photolytic and Mean concentration of H2S ranges from 0.15 ± 0.05 - catalytic processes involving ozone, oxides of nitrogen 0.40±0.12 ppm, Eket; 0.15 ± 0.02 - 0.50 ± 0.03 ppm, Esit (NOx) and hydrocarbon (HC), giving rise to the formation eket; 0.15 ± 0.08 - 0.40 ± 0.12 ppm, Ibeno; 0.10 ± 0.02 - of photochemical smog. Under normal conditions of the 0.25 ± 0.11 ppm, Onna and 0.15±0.01 - 0.35 ± 0.10 ppm atmosphere, SO3 reacts with H2O vapour to produce in Umudike (Table 2). H2S were present in all the study droplets of H2SO4 aerosol which give rise to the so called locations at a lower quantity. This shows that there are ‘acid rain’ causing damage to vegetation and materials. If other contributory factors to emission of H2S such as the concentration of SO2 is higher along with other fumes from automobile exhaust and power generators. gaseous pollutants in the troposphere and continues to Results obtained was lower than results (with the range accumulate over time, the overall concentration can have from 0.18 - 0.76) obtained by Aliyu et al. (2013). a negative effect on health, vegetation and structures Mean concentration of NO2 ranges from 0.20±0.02 – (Abdul Raheem et al., 2009) 0.60±0.03 ppm, Eket; 0.10±0.01 - 0.60 ± 0.11 ppm, Esit This study investigate the impact of gas flaring on air Eket; 0.20±0.04 - 0.65±0.06 ppm, Ibeno; 0.23±0.01 - quality of some cities in Niger Delta, a case study of 0.50±0.14 ppm, Onna and 0.28±0.08 - 1.00±0.04 ppm in Ibeno and its environs in Akwa Ibom State and the Umudike (Table 1). NO2 is recorded in all study locations. seasonal variation of meteorological factors on air Higher concentration in Umudike may be due to the use parameters was also investigated. of fertilizer in agriculture while that of Ibeno, Eket, Onna and Esit Eket may be as a result of sea spray. Mean concentration of SO2 in the study locations MATERIALS AND METHODS shows the same trend of being higher during dry season and lower concentration during rainy season. This is due Study area to dilution effect of rain on the atmosphere. Its values ranges from 0.95 ± 0.06 – 2.00 ± 0.11 ppm, Eket; 1.00 ± Ibeno, Eket, Onna and Esit Eket as the main study area are located in the Niger Delta region of Nigeria. Ibeno is located at latitude 04° 0.10 - 3.00 ± 0.07 ppm, Ibeno; 0.95 ± 0.04 – 2.00 ±0.12 33' N and longitude 08° 00' E, Eket is located at latitude 04° 38' N ppm, Esit; 1.00 ± 0.02 – 2.00 ± 0.01 ppm, Onna and 1.10 and longitude 07° 56' E, Onna is located at 04° 37' N and longitude ± 0.11 – 2.40 ± 0.01 ppm, Umudike (Table 3). The results 220 Afr. J. Environ. Sci. Technol. Figure 1. MAP showing sampling locations in Akwa Ibom and Abia State. Table 1. Mean concentration ± standard deviation (ppm) of NO2 in the studied area. Period Eket Esit Eket Ibeno Onna Umudike March 0.40±0.01 0.40±0.06 0.40±0.11 0.45±0.12 0.30±0.01 April 0.40±0.02 0.35±0.09 0.30±0.09 0.40±0.04 0.40±0.11 May 0.30±0.04 0.30±0.03 0.30±0.07 0.30±0.08 0.30±0.06 June 0.20±0.02 0.10±0.01 0.20±0.04 0.25±0.02 0.28±0.08 July 0.25±0.02 0.10±0.01 0.20±0.04 0.23±0.01 0.30±0.02 August 0.40±0.01 0.20±0.02 0.60±0.01 0.30±0.05 0.55±0.01 October 0.60±0.03 0.50±0.08 0.65±0.06 0.50±0.14 1.00±0.04 November 0.60±0.03 0.60±0.11 0.60±0.10 0.40±0.11 0.80±0.02 obtained in the dry season (March, April, October and higher than range of 0.03 – 0.09 ppm reported in Kano November) were higher than that of rainy season (May to metropolis, Nigeria (Okunola et al., 2012) and range of August).