RISK ASSESSMENT OF THE EXPOSURE OF SENEGALESE CONSUMERS TO PESTICIDE RESIDUES IN ARTISANALLY PROCESSED SARDINELLA AURITA AND SARDINELLA MADERENSIS PRODUCTS

in a . are Pesticides are used to combat mainly This study assessed the sanitary quality of processed sardinella and the risk to consumers exposed to residues of these pesticides. Twenty-five samples of smoked-dried sardinella ( ketiakh ) were taken from various points along the Senegalese coast. Residues (nature and concentrations) were determined by the PRIMORIS laboratory (Belgium) by combining two multi-residue methods (148 active substances were tested in GC-MS/MS). The results showed the presence of chlorpyrifos, cypermethrin and fenitrothion, at concentrations ranging from 0.011 to 0.310 mg/kg for chlorpyrifos. The risk of exposure to these three insecticides was evaluated by calculating the predicted short-term intake (PSTI) for a 70 kg adult and a 20 kg child during a meal prepared according to a traditional recipe, then compared to the respective acute reference dose and acceptable daily intake values. The calculation of PSTI indicated values reaching 10,000% of the toxicological reference values. The results of the study therefore indicate that the consumption of artisan-processed S. aurita and S. maderensis along the Senegalese coast may present a major toxicological risk for both young and adult consumers.


ISSN: 2320-5407
Int. J. Adv. Res. 8(04), 323-332 325 Each sample consisted of three fish (full sardinella) taken at random from a hazardously selected processor in a group called GIE (Economic Interest Grouping). The ketiakh was prepared from Sardinella aurita and/or Sardinella maderensis, braised or smoked, headed, gutted, scaled and sprinkled with salt or not and then dried (photos 1, and 2). Each sample was wrapped immediately with aluminium foil and kept in a sealed plastic bag in a cool place until it was sent to Belgium for residue analysis. 326 residues (screening of 148 active substances, including organophosphorus and pyrethroid insecticides) in high fat matrices (vegetable oils, coconut, cocoa, meat, fish, milk, etc). After sub-sampling followed by grinding, the samples were submitted to apolar extraction followed by column purification, gas chromatographic analysis and residue identification by GC-MS/MS. The limit of quantification (LOQ) for each of the 148 substances was 0.01 mg/kg. It should be noted that there is no minimum residue limit (MRL) for dried fish.

Assessment of risk from predicted short-term intake (PSTI):
Consumer exposure can theoretically be calculated from the estimated consumption (in g/day) and the observed residue concentration (in mg/kg) relative to the mean body weight (in kg) (WHO, 1997). However, it is preferable to estimate the intake of a given pesticide residue during a meal (or a day) by referring to the predicted short term intake (PSTI) calculation methods currently in use in the European Union. To characterize the risk, the PSTI values are compared with the toxicological reference values for each substance: the acute reference dose (ARfD), which is the most relevant; and the acceptable daily intake (ADI), which should be considered with caution in cases of acute exposure. The formula adopted for calculation of the PSTI (mg/kg) is the following (AFSCA, 2014; Schiffers, 2011): Where: U = unit (food unit weight) in kg; OR = observed residue, in mg/kg (or ppm); V = variability factor = 0; 5 or 7 (chosen according to U); t = processing factor (1 if unknown); bw = body weight of the group in question The unit weight (U) of smoked-dried sardinella (ketiakh) and the percentile of the large consumers LP97.  Results:-

Results of residue analyses of the samples of ketiakh taken:
The results of the analysis provided by the PRIMORIS laboratory (Belgium) of the 25 samples of smoked-dried Sardinella aurita and Sardinella maderensis (ketiakh) from sites in the regions of Dakar, Thies and Saint-Louis: are presented in table 3. Residues of chlorpyrifos (organophosphorus) and cypermethrin (pyrethroid) were found to be above the LOQ in the samples from Dakar and Thies. Fenitrothion (organophosphorus) was found in only one of the samples from Thies (tables 2 and 3). Residues in all five samples from the Saint-Louis region were below the LOQ of 0.01 mg/kg (table 2).
< LOQ = the result is below the quantification limit of the method

Discussion:-
The determination of pesticide residues, apart from the direct evaluation of the residue study, is an integral part of the risk assessment process, making explicit the continued likelihood of exposure and ensuring that accepted daily intakes are not exceeded (Abhauer, 1990;Blasco et al., 2005). Following the initial study of Mbaye et al. (2012), which indicated the presence of some of the most hazardous pesticide residues (parathion, pirimiphos-methyl, chlorpyrifos, lindane, permethrin and dieldrin) in ketiakh from the sites of Mbalene, Khelcome and Kayar, the search for pesticide residues was extended to other sites, the number of samples was multiplied by ten, and the number of active substances searched for was increased. For this study, sampling was carried out over the entire coastline, with sites in the regions of Saint-Louis, Dakar and Thies. The analytical methods used made it possible to search for 148 residues in each sample.
The residue concentrations measured are high, and confirm the results of the study by Mbaye et al. (2013) at the Mbalene and Khelcome sites. The presence of two organophosphorus insecticides and a pyrethroid is of concern in light of the toxicity of these compounds to the nervous system. Measured values of chlorpyrifos, cypermethrin and fenitrothion in samples of ketiakh from the Dakar and Thies regions (tables 2 and 3) indicate that pesticides are applied to processed products without any measurement, when insects proliferate, insecticide powder is mixed with the rock salt applied. Processors use any pesticide that vendors advertise as Kaata. For example, parathion, pirimiphos-methyl, chlorpyrifos, permethrin and even dieldrin have been detected and quantified previously. In the region of Saint-Louis, the site of Guet Ndar, the residue values were below the LOQ of the method for the 148 molecules analyzed. Given the sensitivity of the analytical methods used, this probably means that these processors did not use pesticides. On some occasions, the PSTI values obtained for adults and children were 10,000% higher than the ARfD or ADI values (tables 4 and 5). These results indicate that adult consumers of these processed products, and especially the much more vulnerable juvenile consumers, are at high risk of acute and chronic intoxication ( (table 3). For chlorpyrifos, the estimation of PSTI for adults of 70 kg and children of 20 kg gave values exceeding the ADI and ARfD of chlorpyrifos by 100% in almost all samples (tables 4 and 5). Therefore, in terms of exposure, these samples of ketiakh constitute both a chronic and acute intoxication risk for adult and especially juvenile consumers, as the toxicological risk is considered unacceptable for the consumer if the PSTI is higher than the toxicological reference value (COLEACP/PIP, 2010). These toxicological risks constitute a real public health concern because chlorpyrifos can cause long-term neurotoxic and endocrine-disrupting effects (Baldi et al., 2011;PPDB, 2019); can affect the development of the central nervous system (Slothkin et al., 2006); and is also known to affect endocrine secretion (Wilson, 1998). Chlorpyrifos is highly toxic when ingested in children, and some studies indicate an association between chlorpyrifos metabolites and learning disabilities (autism) in children (Ondine et al., 2019;PPDB, 2019;Whyatt et al., 2003). This is why representatives of EU member states voted to ban chlorpyrifos and chlorpyrifosmethyl in December 2019 (Actu-Envi, 2020).

Cases of cypermethrin and fenitrothion:
Cypermethrin was quantified in two samples from Dakar and Thies; it should be noted that these two samples also contained chlorpyrifos. With respect to the calculation of the PSTI 70 and PSTI 20 , the comparison with the ADI and ARfD of cypermethrin resulted in percentages of less than 100% (tables 4 and 5), suggesting that these samples of ketiakh did not pose a risk to adult and child consumers. However, because these two samples from Dakar and Thies each contained both an organophosphorus and a pyrethroid, consumers would experience a "cocktail effect" of these Fenitrothion, on the other hand, was detected and quantified in only one sample from Thies, where the PSTI calculated and compared to the ADI and ARfD of the latter, gave only percentages below 100% for both adult and child consumers. Therefore fenitrothion represents neither a chronic nor an acute risk for the exposure of consumers of ketiakh (adults and children) from these sites as the PSTI values were all below the ADI and ARfD values.

Conclusion:-
The presence of pesticide residues in foodstuffs is a serious public health problem and gives rise to legitimate consumer concern. As the use of plant protection products on processed fish products is neither usual nor recommended practice, there are no MRLs for these commodities. However, it must be noted that this dangerous and illegal practice has spread in Senegal and continues to this day because these products are easily accessible to processors. Unaware of the adverse health consequences for consumers, processors indiscriminately use neurotoxic substances (chlorpyrifos, cypermethrin and fenitrothion), which can cause immediate intoxication after consumption of the dish. In the longer term, repeated exposure to these substances can also cause, especially in children, many pathologies such as cancer of hormone-dependent organs (breast, prostate, testicles, ovaries or thyroid), but also disorders of the reproductive organs (infertility) and brain development disorders, as they are known to act as endocrine disruptors. It is therefore strongly recommended that the Senegalese authorities raise awareness among the population, both processors and consumers, of the risks associated with pesticide use in ketiakh production, and seek alternative solutions to protect fishery products against attacks by Dermestes.