Deranged hembiosynthetic pathway in gasoline dispensers in Nigeria: Implications for risk of myeloproliferative disorders and chemoprevention

Abstract

Objectives: There is increasing exposure to petrochemicals, including benzene, particularly in the low and medium-income countries. Benzene is a component of many petrochemicals and a ubiquitous environmental pollutant. Phenol is one of its principal metabolites and serves as a biomarker of exposure to benzene. The mechanism of its toxicity is incompletely elucidated. Benzene’s interaction with key micronutrients; copper (Cu), iron (Fe), and zinc (Zn) in the haemopoietic system has only been poorly explored, particularly in the developing countries where their status is variable and uncertain, with attendant intense exposure to petrochemicals. Material and Methods: Two groups of 50 gasoline dispensers (GDs) and 50 non-occupationally exposed participants were selected from Oye Local Government Area, Nigeria. The duration of occupational exposure was 2–10 years. Serum levels of Cu, Fe, and Zn were determined using flame atomic absorption spectrophotometry while heme and phenol were determined by standard spectrophotometry. Results: Phenol was significantly higher in GDs (P = 0.000), compared to controls (P < 0.05). The micronutrients, Cu, Fe, and Zn were all significantly decreased in GDs compared to controls (P = 0.000 in all cases). Phenol and Fe demonstrated significant inverse correlation (r = −0.557, P = 0.00), while heme and Zn also exhibited inverse correlation respectively to phenol (r = −0.38, P = 0.01; r = −0.37, P = 0.01). Conclusion: These data suggest intense perturbation of the haemopoietic system in GDs; likely from altered xenobiotic metabolism requiring heme in cytochrome P450; cell cycle dysregulation, where Zn is pivotal, p53 suppression also dependent on Zn and oxidative stress all converging in haemopoietic dysregulation. Importantly, depression of these micronutrients implies potentiation of myelotoxicity and risk of myeloproliferation, probably arising from alterations in transcription, differentiation errors, genome instability, and derangement in cell signal transduction moderated by Zn; accentuating risk of myeloproliferation; suggesting a role for these micronutrients in chemoprevention. Understanding these events may be important in risk assessment, policy formulation, regulatory measures and chemoprevention in GDs and the general population.

Birth Weight and Third-trimester Maternal Vitamins A, C, and E Levels

“…Vitamins A and E are both fat-soluble with overlapping roles from embryonic to fetal development [31][32][33], yet not one but both were depleted at the third trimester. Furthermore, that these results should be of concern are several factors and deleterious situations that cut across age groups already mitigating against the health and well-being of individuals in the different communities where the participants were recruited [34][35][36][37].…”

Exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) at Nigeria's petrol stations: a review of current status, challenges and future directions

“…In 2018, there were 29,197 petrol stations in Nigeria (2). This proliferation is attributed to the country's increasing population, urbanization, industrialization, auto-mobilization, and energy use (3,4). The daily petrol consumption in Nigeria is about 93 million liters (5).…”