Khaoula Toumi

Khaoula Toumi


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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KTKhaoula Toumi
Khaoula Toumi
CVChristiane Vleminckx
Christiane Vleminckx
JLJoris Van Loco
Joris Van Loco
BSBruno Schiffers
Bruno Schiffers
In order to assess the prevalence of pesticide contamination and the risk of florists’ exposure when handling cut flowers, sampling and analysis of 90 bouquets of the most commonly sold cut flowers in Belgium (50 bouquets of roses; 20 of gerberas, and 20 of chrysanthemums) were carried out. The bouquets were collected from 50 florists located in the seven largest cities of Belgium (Antwerp, Brussels, Charleroi, Ghent, Leuven, Liege, and Namur) and from five supermarkets located in the different regions. To have a better understanding of the route of exposure and professional practices a questionnaire was also addressed to a group of 25 florists who volunteered to take part in the survey. All florists were interviewed individually when collecting the questionnaire. The residual pesticide deposit values on cut flowers were determined in an accredited laboratory using a multi-residue (QuEChERS Quick Easy Cheap Effective Rugged Safe) method and a combination of gas chromatography (GC) and liquid chormatograhphy (LC) analysis. A total of 107 active substances were detected from all samples; i.e., an average of about 10 active substances per bouquet. The most severely contaminated bouquet accumulated a total concentration of residues up to 97 mg/kg. Results show that roses are the most contaminated cut flowers; with an average of 14 substances detected per sample and a total concentration per rose sample of 26 mg/kg. Some active substances present an acute toxicity (acephate, methiocarb, monocrotophos, methomyl, deltamethrin, etc.) and exposure can generate a direct effect on the nervous system of florists. Nevertheless, fungicides (dodemorph, propamocarb, and procymidone) were the most frequently detected in samples and had the highest maximum concentrations out of all the active substances analysed. Dodemorph was the most frequently detected substance with the highest maximum concentration (41.9 mg/kg) measured in the rose samples. It appears from the survey that, despite being exposed to high deposits of residues, florists usually do not protect themselves from contact with residues even if they spend several hours handling cut flowers and preparing bouquets (from 2 to 6 h/day, depending on the time of year and/or selling periods) daily. Bad habits (eating, drinking, or smoking at work) and absence of personal protective equipment of most florists also increase the risk of contact with pesticide residues.

KTKhaoula Toumi
Khaoula Toumi
LJLaure Joly
Laure Joly
CVChristiane Vleminckx
Christiane Vleminckx
BSBruno Schiffers
Bruno Schiffers
Flowers are frequently treated with pesticides and, as a result, florists handling daily a large number of flowers can be exposed to pesticide residues. A study was conducted among twenty volunteer florists located in Namur Province and in the Brussels Capital Region of Belgium in order to assess their potential dermal exposure to dislodgeable pesticide residues transferred from flowers to hands. Two pairs of cotton gloves were worn during two consecutive half days while handling flowers and preparing bouquets (from min 2 h to max 3 h/day). The residual pesticide deposits on the glove samples were extracted with a multi-residue Quick Easy Cheap Effective Rugged Safe (QuEChERS) method and analyzed by a combination of gas and liquid chromatography tandem mass spectrometry (GC-MS/MS and LC-MS/MS) by an accredited laboratory. A total of 111 active substances (mainly insecticides and fungicides) were detected, with an average of 37 active substances per sample and a total concentration per glove sample of 22.22 mg/kg. Several predictive levels of contamination were considered to assess the risk. The potential dermal exposures (PDE) of florists were estimated at the average, for different percentiles, and at the maximum concentration of residues in samples. At the PDE P90 and at the PDEMAX (or worst case) values, three and five active substances respectively exceed the Acceptable Operator Exposure Level (AOEL), indicating risk situations. For the systemic exposure (SE), one active substance (clofentezine) exceeds the AOEL at the P90 predictive level. In the worst case, SEMAX (at the maximum concentrations), four active substances (clofentezine, famoxadone, methiocarb, and pyridaben) exceed their respective AOEL values. Among the 14 most frequently detected active substances, two have SEMAX values exceeding the AOEL. Exposure could be particularly critical for clofentezine with an SEMAX value four times higher than the AOEL (393%). The exposure of florists appeared to be an example of a unique professional situation in which workers are exposed regularly to both a very high number of toxic chemicals and rather high concentration levels. Therefore the priority should be to raise the level of awareness among the florists who must change their habits and practices if they want to minimize their exposure.