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Polycyclic aromatic hydrocarbons (PAHs) constitute a large class of organic compounds that are composed of two or more fused aromatic rings. They are primarily formed by incomplete combustion or pyrolysis of organic matter and during various industrial processes. PAHs generally occur in complex mixtures which may consist of hundreds of compounds (Abou-Arab et., al 2002). Humans can be exposed to various chemicals including ubiquitous polycyclic aromatic hydrocarbons (PAHs) mostly through food consumption and/or inhalation (Andrea Polachova et. al. , 2020). The human absorption of PAHs follows different routes. While for non-smokers, the major route of exposure is through the combustion of food, for smokers the contribution from smoking may be significant. Food can be contaminated from environmental sources that are present in the air, soil, or water, by industrial food processing methods (e.g heating, drying, and smoking) and by home food preparation (e.g grilling and roasting). The Scientific Committee on food SCF (2005) reported that 15 priority PAHs out of the 33 PAHs which were considered in their assessment showed clear evidence of mutagenicity/genotoxicity in somatic cells in experimental animals in vivo and with the exception of benzo(ghi)perylene also showed clear carcinogenic effects in various types of bioassays in experimental animals. Teratogenicity is caused in pregnant women and their developing fetuses are particularly susceptible populations to environmental contaminants because alterations in hormone physiology during gestation can have adverse consequences on the health of the pregnancy (Amber L. Cathey et al ., 2020). This, SCF (2005) conclusively reported that these compounds may be regarded as potentially genotoxic and carcinogenic to humans and thus represent a priority group in the assessment of the risk of long-term adverse health effects following intake of PAHs.

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Evolving resistant microbial strains have posed a great challenge on antibacterial chemotherapy in recent times. Search for novel antimicrobial agents has therefore remained a highly prospective area of research, especially those of plant origin. To this end, Prosopis africana pod used in West Africa in traditional medicine was evaluated for phytochemical constituents using standard procedures. Antibacterial activity was determined using the disc diffusion method of National Committee for Clinical Laboratory Standards. Discs were impregnated with 0.10 and 0.20 mg/ml of the aqueous and ethanolic extracts. Test organisms were wild strains of Streptococcus pyogenes, Staphylococcus aureus, Salmonella typhi, Proteus mirabilis and Escherichia coli sourced from a medical hospital's microbiology laboratory. 0.20 mg/ml ethanolic fraction exhibited highest activity against E. coli and S. aureus with mean zone of inhibition of 18.2 and 17.6 mm respectively. The 0.20 mg/ml aqueous fraction was more active against S. aureus (16.40 mm) and P. mirabilis (14.80 mm). The least zone of inhibition was 10.10 mm. Phytochemical screening of the extracts showed the presence of terpenoids, saponnins, glycosides, alkaloids and tannins, to which the observed antibacterial activity could be attributed. The extracts are potent in vitro antibacterial preparations. With this prospect, this can be employed as starting material for the development of a novel antimicrobial agent.

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