The First Total Diet Study (TDS) in Sub-Saharan Africa

Certain persistent organic pollutants (POPs) are governed by the Stockholm Convention. Through their diets, humans are chronically exposed to these chemical substances, which have a range of toxicological effects and health impacts across populations.

Such exposure can be characterised by total diet studies (TDS) that clarify both their occurrence data and the eating habits of study populations. Contamination levels for six categories of POPs (dioxins, PCBs, organochlorine pesticides, brominated and chlorinated flame-retardants, perfluoroalkylated substances) were identified in foodstuffs as prepared and eaten in sub-Saharan Africa. Four countries were included in the study, i.e. Benin, Cameroon, Mali, Nigeria.

Three points stood out in the results:

• the contamination levels in this TDS were equivalent to or less than those reported in previous European and Asian TDS, for all the POP categories tested,
• the highest concentrations of POPs were found in the most lipophilic samples, particularly fish,
• smoking was shown to be a possible source of contamination of fish by pollutants such as dioxins and PAH (Ingenbleek et al., 2019). The burning materials used may be the main cause of the POPs identified in those foodstuffs.

Improving the fish smoking process is a possible risk-management option for reducing dietary exposure to POPs in the study populations. This TDS also looked at other categories of chemical substances such as pesticides, mycotoxins or even trace metals.

Partners: this work was the result of cooperation between LABERCA (INRAE Angers-Nantes), the United Nations' Food and Agricultural Organization (FAO), World Health Organization (WHO), INOVALYS, the Cameroon Pasteur Centre (CDC), and various national coordination institutions in the African nations involved, i.e.  ABBSA (Benin), ANSSA (Mali), NAFDAC (Nigeria), LCSSA (Cotonou, Benin), and LTA (Mali).

Donors: the project was supported by the STDF (Bank Standard and Trade Development Facility) STDF/ PG/303 programme.

Related publications:

• Vaccher, V., Ingenbleek, L., Adegboye, A., Hossou, S. E., Kone, A. Z., Oyedel, A. D., Kisito, C., Dembele, Y. K., Hu, R. W., Malak, I. A., Cariou, R., Venisseau, A., Veyrand, B., Marchand, P., Eyangoh, S., Verger, P., Dervilly-Pinel, G., Leblanc, J. C., & Le Bizec, B. (2020). Levels of persistent organic pollutants (POPs) in foods from the first regional Sub-Saharan Africa Total Diet Study. Environment International, 135.
  http://doi.org/10.1016/j.envint.2019.105413
• L. Ingenbleek, B. Veyrand, A. Adegboye, S.E. Hossou, A.Z. Koné, A.D. Oyedele, C.S.K.J. Kisito, Y. Koreissi Dembélé, S. Eyangoh, P. Verger, J.C. Leblanc, S. Durand, A. Venisseau, P. Marchand, B. Le Bizec. Polycyclic aromatic hydrocarbons in foods from the first regional total diet study in Sub-Saharan Africa: contamination profile and occurrence data. Food Control, 103 (2019), pp. 133-144, https://doi.org/10.1016/j.foodcont.2019.04.006

To find out more about the STDF programme (Total Diet Study for Sub-Saharan Africa): https://www.standardsfacility.org/PG-303

Previous publication (2019) - Polycyclic Aromatic Hydrocarbon (PAH) exposure

PAHs in food in Sub-Saharan Africa mainly come from smoked fish and cooking oil.

Among the polycyclic aromatic hydrocarbons (PAH), 13 are recognised as possibly damaging to DNA, thereby causing genetic changes. They are genotoxic and carcinogenic. The dietary exposure of the populations of Benin, Cameroon, Mali and Nigeria is not currently known. A multicentre total diet study was initiated to describe PAH levels and profiles in a representative sample of the foodstuffs eaten in those four Sub-Saharan countries.

 

 

 

PAH levels exceeded compliance thresholds (European regulations) in 100% of smoked fish and 50% of cooking oils. On average, the sum of the four PAH indicators (benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, and chrysene) in the food tested accounted for 77% of the 13 genotoxic and carcinogenic PAHs. An atypical contamination profile, with a high cyclopenta[cd]pyrene level, could be explained by the interaction between pyrene and silica in the dust, given non-optimal hygiene conditions during food smoking and drying.

 

These data will be used as part of a broader study with a wide spectrum of chemical contaminants, designed to assess the chemical risks related to a typical diet in Sub-Saharan Africa. The conclusions of this activity, which includes preparation of a doctoral thesis under the supervision of UMR LABERCA, will provide information to risk managers with a view to improving food safety in the countries involved.

Partners: FAO (Food and Agriculture Organization), WHO (World Health Organization), INRA-Oniris LABERCA unit, Cameroon Pasteur Centre, NAFDAC (National Agency for Food and Drug Administration and Control, Nigeria), ABSSA (Beninese Food Safety Agency), Mali's Health Ministry.
This article is part of the thesis work of Luc Ingenbleek, a doctoral student at LABERCA and was defended on 28 June 2019 in Nantes.

Funding: Bank Standard and Trade Development Facility¹.
¹ The STDF was set up by the FAO, OIE (World Organisation for Animal Health), World Bank, WHO and WTO.

Related publication: Luc Ingenbleek, Bruno Veyrand, Abimbola Adegboye, Sètondji Epiphane Hossou, Abdoulaye Zié Koné, Awoyinka Dada Oyedele, Chabi Sika K.J. Kisito, Yara Koreissi Dembélé, Sara Eyangoh, Philippe Verger, Jean-Charles Leblanc, Sophie Durand, Anaïs Venisseau, Philippe Marchand, Bruno Le Bizec, Polycyclic aromatic hydrocarbons in foods from the first regional total diet study in Sub-Saharan Africa: contamination profile and occurrence data, Food Control, Volume 103, 2019, Pages 133-144, ISSN 0956-7135, https://doi.org/10.1016/j.foodcont.2019.04.006.