Activities of crude oil refining disrupt natural ecosystems which expose residents to environmental pollution, and consequently pose threat to their health and wellness. This study was aimed to analyze serum trace elements levels, oxidative status, and biochemical indices in the residents of an oil host community (Ugbegungun) in Delta State, Nigeria. A total of 100 subjects were recruited for this study which comprised 50 individuals from Ugbegungun and 50 individuals from Okada, a non-oil host community. Serum levels of lead (Pb), zinc (Zn), and cadmium (Cd) were evaluated using Atomic Absorption Spectrophotometer. Alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphate (ALP) activities, and urea and creatinine were all evaluated with a commercially available enzymatic kit. The oxidative and antioxidative activities in the serum were estimated using the semi-automated spectrophotometric procedure. Enzyme-linked immunoassay was used to assess tumor necrotic factor-alpha (TNF-?) and 8-hydroxy-2-deoxyguanosine (8-OHdG). The results showed that serum levels of Pb, Cd, urea, creatinine, ALT, AST, ALP, malondialdehyde, TNF-?, and 8OHdG were significantly higher (p<0.05) in female and male residents of Ugbegungun when compared with the female and male residents of the non-oil host community. The activities of superoxide dismutase, catalase, glutathione reductase, and total antioxidant capacity were significantly lower (p<0.05) in both female and male residents of Ugbegungun when compared with the residents of non-oil host community. In conclusion, the residents of an oil host community in Nigeria may be at high risk of kidney and liver toxicity through oxidative stress induction associated probably with heavy metal accumulation in the system.

CHAPTER ONE: INTRODUCTION

1.1       Background of the study

Environmental degradation is a major challenge in the oil host communities and this may affect the health of the residents in the area (Pfeiffer et al., 2010). Petroleum-derived environmental pollution contaminants constitute one of the most prevalent sources of environmental degradation (Kautz and Topp, 2000). The hydrocarbon molecules that make up crude oil and petroleum products are highly toxic to many organisms, including humans in large concentrations (Trench et al., 2001). Petroleum also contains trace amounts of sulfur and nitrogen compounds, which are dangerous by themselves and produce secondary poisonous chemicals (Trench et al., 2001). Petroleum can permanently contaminate large areas of soil, underground water, and sea water, making them economically useless as well as dangerous to human health (Trench et al., 2001; Chiara et al., 2009).
Refining petroleum creates air pollution which releases toxins into the atmosphere that are dangerous for human and ecosystem health. Effects of petroleum pollution on human health may vary depending on the concentration and duration of exposure (ATSDR, 2000). Inhaling petroleum vapors causes nervous system effects, liver tumors, and respiratory irritation, very high exposure may cause coma and death (Kponee et al., 2015; Walsh et al., 2016). A study carried out in the Niger Delta region of Nigeria, reported a very high frequency of neurological, haematological, and irritation symptoms in residents from an oil host community (Kponee et al., 2015). Some studies reported fatigue, headaches, respiratory and eye irritation, and a high risk of spontaneous abortion among cleanup workers of Oil spillage (Sabastian et al., 2001; 2002).
Trace elements such as nickel, lead, cadmium, and vanadium are also present in petroleum (Wang et al., 2005; Li et al., 2008; Zhao et al., 2010; Wang et al., 2012). Humans are exposed to these trace elements through ingestion, inhalation, food, and dermal contact (Cook et al., 2005). The adverse effects of trace elements on humans have long been documented by Jarup et al., 2003; Bernard et al., 2008; Kim et al., 2015; Rahimzadeh et al., 2017. An epidemiological research study reported an association between petroleum pollution and the number of cancers, cardiovascular and respiratory diseases (Pope et al., 2002). In another study carried out in the Peruvian Amazon, a significantly high level of serum lead level among indigenous children and adults living close to an oil extraction site was established (Anticona et al., 2011; 2012).
The environmental degradation in the oil host community is a major concern in Nigeria, which affects the everyday life of the residents. Thus, this study will bridge a gap and provide background information for further study, and provide a relationship between trace elements and alteration in the physiological process. This study will also offer possible roles of trace elements in related diseases which might lead to proper management, prevention, and effective policies control in the oil host communities in Nigeria.

1.2       Aim of the Study

This study was aimed to analyze serum trace elements levels, oxidative status, and biochemical indices in the residents of an oil host community (Ugbegungun) in Delta State, Nigeria.
 

1.3       Objectives of the study

The specific objectives of this study are:

1. To estimate the serum trace elements level of an oil host community residents in Delta State, Nigeria.
2. To evaluate the serum biochemical indices of an oil host community residents in Delta State, Nigeria.
3. To determine the serum oxidative markers of an oil host community residents in Delta State, Nigeria.