Microbial Consortia as Plant Biostimulants: Definition, Concept, Categories, and Regulation.

peer reviewedMicrobial consortia include cellulolytic bacteria, fungi, yeasts, and microbial-based biofilms which can be found in, or constituents of, food products, soils, wastewater, etc. flourishing in nature. The characterization, design, and management of these consortia are feasible, and their application in diverse fields, such as agriculture, is under research. During the last decades, considerable attention has been paid to microbial consortia as plant bio stimulants. They are an ecological alternative for sustainable agriculture and a win-win strategy to grow valuable plants without releasing fertilizers and/or pesticides into the environment. Plant biostimulants are natural preparations, of a diverse class of substances and/or micro-organisms, which positively affect plant growth conditions, stimulate natural processes, improve yield and chemical composition, and increase tolerance to biotic and abiotic stress. The purpose of this chapter is to provide an up-to-date overview of microbial consortia used as plant biostimulants. Aiming to describe the emerging definitions of plant bio stimulants, their concept, the functional categories, and their potential application as a significant tool for modern eco-friend agriculture. The chapter focuses also on reporting the regulatory framework and the current market situation of plant bio stimulants, as well as their advances in research

Worker exposure to pesticide residues on cut flowers and on horticultural products

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

Potential demal exposure of florists to fungicide residues on flowers and risk assessment

Flowers are susceptible to many pests and diseases. Therefore, they can be sprayed several times during their growth considering that no MRL are set for flow-ers. High levels of pesticide residues potentially expose daily the florists who han-dle cut flowers and possibly could endanger their health. A study was carried out to evaluate the risk for florists exposed to fungicide residues during normal profes-sional tasks. Cotton gloves were distributed to 20 florists (two pairs to each florist) and worn during two consecutive half days during normal professional tasks (from min 2 hours to max 3 hours/day) to measure their potential dermal exposure (PDE). Samples were analyzed with a multi-residue (QuEChERS) method validated by a laboratory accredited for pesticide residues and with a combination of gas and liquid chromatography tandem mass spectrometry. It appears from the results that a total of 54 fungicides with different toxicity classes were detected on cotton gloves. An average of 15.53 mg/kg fungicide residues per glove sample was meas-ured. Six of 54 are suspected of causing cancer after prolonged or repeated expo-sure. Boscalid was both the active substance for which the highest maximum and average concentrations (26.21 and 3.47 mg/kg, respectively). Famoxadone had the most critical PDE (156% AOEL for the maximum concentration). As a consequence, this study leads to conclude that Belgian florists, who worked for several years and handled a large number of flowers contaminated by high concentrations of pesti-cide residues, are exposed daily with a potential effect on their health. This sug-gests that safety standards should be set for residue levels on cut flowers

Risk Assessment of Florists Exposed to Pesticide Residues through Handling of Flowers and Preparing Bouquets

Abstract: 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

Pesticide Residues on Three Cut Flower Species and Potential Exposure of Florists in Belgium

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

PESTICIDE USE AND RISK PERCEPTIONS FOR HUMAN HEALTH AND THE ENVIRONMENT: A CASE STUDY OF ALGERIAN FARMERS

peer reviewedIn Algeria, market gardeners consider the use of pesticides as necessary to manage pests, diseases and weeds during cultivation under greenhouses, in an effort to reduce or eliminate yield losses and maintain a high level of productivity. Despite their popularity and extensive use, pesticides may pose a significant threat to human health and the environment. The purpose of this study is to evaluate market gardeners’ practices and attitudes with regard to pesticide use and to assess the impact of pesticides on human health and the environment. A survey was carried out in Ain Naga (East Ziban) and Doucen (Ziban West). 96 vegetable farmers randomly selected were interviewed from October 2016 to December 2017. The survey revealed that a total of 143 pesticide products were used by farmers surveyed, representing 70 different active substances. According to CLP classification, the majority of active substances have an acute and/or chronic effects for human health and could cause great harm for ecosystems and target and non-target organisms. According to the WHO classification, four actives substances are considered as highly (WHO class Ib) and one extremely (WHO class Ia) hazardous. However, exposure is particularly critical for abamectin (WHO class Ib), since it is the most commonly used by the majority of farmers (79%). Over 60% of the farmers use pesticides lack knowledge and risk perceptions. More than 50% of the farmers presented safety issues when spraying pesticides. While 72% of the farmers encountered at least one symptom of severe poisoning due to pesticide use. Market gardeners are highly exposed to a wide range of pesticides, with a potential effect on their health