Worker exposure to pesticide residues on cut flowers and on horticultural products | Exposition des travailleurs aux résidus de pesticides sur les fleurs coupées et sur les produits horticoles

Persons who, during their professional tasks, come in contact with pesticide residues are exposed by various routes, with possible negative effects on their health. The aim of the thesis is to evaluate the exposure risks of two categories of workers indirectly exposed to pesticide residues (parent compounds and metabolites): Belgian florists and Tunisian market gardeners. As a first step, the exposure of Belgian florists to pesticide residues present on cut flowers was studied. A survey of florists reveals that, despite a fairly long work period, they do not protect themselves enough from contact with residues. The analysis of residues on cut flowers most sold in Belgium has shown that they are highly contaminated, with 107 residues of different pesticides were detected on 90 samples. By wearing cotton gloves by florists, it has been established that 111 residues of different pesticides could be transferred from the flowers to the hands. In the worst case, the estimated systemic exposure of florists to four active substances exceeds (at maximum concentrations) the acceptable threshold values (AOEL). The bio-monitoring approach conducted with Belgian florists and a reference group led to the conclusion that the florists' urine is significantly more contaminated and that a linear relationship exists between dermal exposure to residues and urinary excretion. The same methodological approach, except biomonitoring, was used to assess the exposure of Tunisian market garden workers to pesticide residues. The survey reveals that the majority of workers doesn't generally protect themselves during the re-entry tasks despite an extended daily working time. The wearing of cotton gloves, combined with the sampling and analysis of residues on the handled horticultural products, demonstrated that chili pepper and tomato samples are contaminated by pesticide residues, with 7 exceedances of EU MRL. A total of 57 and 63 pesticide residues were detected on gloves worn by workers during harvesting in tomato and chili pepper greenhouses, respectively. The systemic exposure of workers harvesting tomatoes and chili peppers exceeds (at maximum concentrations) their AOEL values, for 9 and 15 pesticides, respectively. The study has thus demonstrated that Belgian florists and Tunisian workers are exposed during their usual tasks to significantly high amounts of pesticide residues whose toxicological properties suggest that they could have on long-term negative effects on health.