By Mark Mayah
The 34th Inaugural Lecture of the Covenant University, Ota was marked by a compelling presentation from Prof Akan Williams of the Department of Chemistry, who emphasized the urgent need to sensitize the Public on the health hazards associated with aflatoxin contamination.
Prof Williams highlighted that
research conducted by a Chemist on various food items ranging from poultry products, fruits, fishes, rice, water and other edible items have posed a challenge to regulatory authorities to rise up to their responsibilities to check, control and discourage unhealthy practices in food production and manufacturing.
He said, the research findings showed that feed millers fortify their feeds with antibiotics, mainly sulfonamides, in varying quantities without declaring the same, compromising the security of poultry birds and human consumers.
These and many more were revealed by Akan B. Williams, a Distinguished Professor of Chemistry, Department of Chemistry, College of Science and Technology, Covenant University, OTA, Nigeria.
In his inaugural lecture titled: “The Burdens Of Pollution And Imperatives For Environmental Clean-up”, marking the 34th in the series delivered at the University chapel at the weekend, Professor Akan Williams declared, “The Nigerian environment is largely unclean, its uncleanliness mainly caused by man, who is expected to clean and protect the environment. It is imperative for the government to ensure compliance with required environmental protection regulations.
He charged the National Environmental Standards and Regulations Enforcement Agency (NESREA), State Ministries of Environment and the relevant offices at the local government areas should be made to perform their oversight duties.
Research Findings
He said, “Results from our study suggest that feed millers surreptitiously fortify their feeds with antibiotics without declaring the same, thus exposing poultry chickens to sub-therapeutic dosages of the drugs.
“Also, many farmers do not observe the cessation period before poultry birds treated with antibiotics are sold to consumers, exposing them to hazardous antibiotic residues.
“Our findings indicated elevated levels of antibiotic residues in tissues of locally produced and illegally imported poultry meat samples.”
2. Oyedeji et al. (2021) describes the initial study on the simultaneous determination of multiclass antibiotic residues in imported and local frozen poultry specimens, including turkey gizzard and muscle tissues, and chicken muscle tissues, commonly consumed in Ogun State, Nigeria. For the determination of six antibiotic residues, including fluoroquinolones, sulfonamides, and macrolides, a solid-phase extraction method was used, followed by extract analysis using high-performance liquid chromatography-diode array detection (HPLC-DAD). Enrofloxacin, sulfadimethoxine, sulfamerazine, and tylosin showed high concentration levels in the frozen poultry beyond acceptable maximum residue limits (MRLs).
According to the research findings, “The six drugs considered in this study were present at higher concentrations in domestic chicken tissues than the permissible level. This suggests that farmers do not observe the cessation period before poultry birds previously treated with antibiotics are sold to consumers, thus exposing them to potentially hazardous antibiotic residues.”
3. Determination of Levels of Trace Metals in Fruit Juices, Beverages and Vegetables
Williams et al. (2009) determined trace metal levels in selected fruit juices and carbonated beverages purchased in Lagos, Nigeria, using an atomic absorption spectrophotometer. Fruit juices analysed were grape, pineapple, apple, orange, lemon juices and their brand names were used.
Some carbonated drinks were also evaluated for metal levels. Trace metals investigated were Cr, Cu, Pb, Mn. Ni, Zn, Sn, Fe, Cd and Co.
Trace metal contents of fruit juices were found to be more than the metallic contents of carbonated beverages.
However, the metal levels of selected fruit juices and carbonated beverages were within permissible levels except for Mn in pineapple juice and Pb in lemon juice.
Determination and Assessment of Mycotoxin Burdens in Edible Grains
As Fungal contamination of seeds remains a major problem of food safety in tropical Africa, local farmers and traders follow unscientific and defective storage conditions to preserve commodities in order to guarantee steady availability of some perishable farm produce.
According to the researchers, the commodities are exposed to fungal activities and production of mycotoxins such as ochratoxins and aflatoxins, leading to health and economic concerns.
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Twenty-five different brands of rice from Lagos markets were sampled and assessed for ochratoxin A (OTA) contamination using High Performance Liquid Chromatography (HPLC) (Avejuyo et al 2008).
Samples were homogenised, the extracts cleaned-up and pre-concentrated prior to HPLC analysis.
The result indicated that the OTA level in pic rice was non-detectable. Twenty-four of the twenty-five brands of rice analysed contained trace levels of OTA, the content of which ranged from 0.01 ng g in Miss Lily parboiled rice to a maximum concentration of 2.18 ng gin Rice King. The mean concentration was 0.34 ng g’ The low levels of contamination suggested that consumption of rice available in Lagos markets was relatively safe, as they were within acceptable limits.
“We also determined the levels of ochratoxin A in local rice, imported rice,
sorghum, com and nillet from Ota market (Kazeem et al., 2019). Ochratoxm A was only detected in trace quantities in corn and imported rice with values of 0.12 ng gand 0.14 ng g, respectively, and were within the stipulated regulatory limits.
Levels of aflatoxin in maize, sorghum, millet, wheat and rice obtained from Lagos and Ota markets have been reported (Oloyede et al., 20161 Aflatoxin determination was carried out using a high-performance liquid chromatograph coupled with a diode array detector (HPLC-DAD), The concentrations of aflatoxins in the grains obtained from Mile 12 market, Lagos, ranged between 34.3 µg/kg and 300.1 pg/kg, while the concentrations in the grains obtained from Dada market, Ota, ranged between 42.3 µg/kg and 1245 µg/kg.
The levels of total aflatoxins were generally higher in the grams sampled from the Lagos market. These values exceeded the maximum limits of 10 µg/kg set by regulatory bodies in Nigeria, thus posing a great health risk for consumers.
Determination of Levels of polychlorinated biphenyls in Water and sediment samples of Ogun River
The samples collected from three locations in the study area showed concentration of PCBs in surface and bottom water from the locations were higher than the Critical Micelle Concentration (CMC) values of 2000 ng/L. (2 ppb) peculiar to USEPA and British Columbia. It was also higher than the Critical Coagulation Concentration (CCC) value of 14 ng/L (0.014 ppb) indicating acute toxicity for users.
“Surface and bottom sediments from the three locations also showed higher values than the stipulated standard from USEPA, PCB-206 was present in very high and harmful concentrations in all the locations and is capable of causing adverse health effects to users and toxicity to aquatic life.”
Recommendations
Professor Akan Williams advocated for the creation of awareness on aflatoxin in order to sensitise people to the health hazards associated with us contamination.
Also, there is a need to promote proper practices of grain production and storage to prevent its contamination and reduce exposure
He advocated that self-regulation by farmers in the poultry industry should be discouraged and urged relevant authorities to take steps to reduce and control the use of antibiotics to protect public health.
“An improvement is required in the surveillance capabilities of key monitoring agencies to curb the excessive use of antibiotics.
” An enlightenment campaign is required to educate feed producers and farmers on the dangers inherent in the inclusion of antibiotics in their products.
“The porousness of our transnational borders is a concern and should be checked by our Customs Service.
“There is a need to sensitise the public on the health hazards associated with aflatoxin contamination, apart from promoting good practices in grain production and storage to prevent its contamination.
While the levels of POPs in water, sediments and biota were within acceptable limits in some of our research findings, they were above the acceptable limits in a few cases, with the consequential effects on the health of humans. Hence, the monitoring of the environment by Environmentalists should be a continuous endeavour.
Speaking on the need to fortify Nigeria’s coastal vulnerability and the need for the protection of sensitive and vulnerable areas, Akan Williams called on the Nigeria Maritime Administration and Safety Agency (NIMASA), Lagos to conclude conclude on the documentation for the establishment of Particularly Sensitive Sea Area (PSSA) in Nigeria by the International Maritime Organisation (IMO).
