Ist. Chimica Agraria ed Ambientale

Summer School 2006

Pesticide and Environment

Fourth Edition of the Summer School "Pesticide and Environment" organised the 11th June to 15th June 2006. Hotel Marina Beach Orosei (Nuoro, Sardinia, Italy)

The beginning of the 2006 Edition of the GRIFA Summer School was represented by an introducing presentation from Prof. Marco Trevisan and Ettore Capri, that showed what GRIFA is, what the aims of this summer school are and also the program of the school with all the lessons and the relators.
After this introduction, the first presentation named “Health effects and risk assessment of pesticides – Regulatory and innovative aspects” by Emanuela Testai of the Ist. Sup. Sanità (Italia) was showed. She introduced very quickly some general and regulatory aspects concerning pesticides and something about the toxicological risk assessment. A very important section concerned the presence of uncertainty factors in the toxicological tests and the estrapolation to humans. In the second part of the presentation, she focused her attention on the pesticides transformation pathways and pesticides metabolites, with some interesting examples.
The second presentation named “Risk assessment for pesticides” by William Roelofs, risk analyst from Central Science Lab (UK). At the beginning, he spoke about the generic aspects of effect of pesticides on ecosystems. Then he focused on Risk end points (especially TER). The main aim of this presentation was to compare the deterministic risk assessment and the probabilistic risk assessment.
At the end he showed 2 examples (one for an aquatic ecosystem and one for a terrestrial ecosystem), useful for the pratical session of the afternoon, where the students had to some exercises of first tier aquatic acute assessment.
The third presentation of the first day regarded “Theory of degradation kinetics” by Sabine Beulke from Central Science Lab (UK). Basic aspect and section of the FOCUS work were illustrated. These theoric aspects were very well supported with a practical session, where the students had to use the Model Maker Software to do some exercises.

The second day of the Pesticide Symposium – summer 2006- was opened by professor Daniele Daffonchio, University of Milan, who spoke about “microbial pesticides for control of insects and other plant pests”. He showed the advantage and disadvantage of using biological pesticide respect to the use of chemical pesticide. The use of microbial pesticides is a new trend that aims at the insect biocontrol, for example by using safe microbial pesticide Bacillus Thuringensis or microbial symbiosis Wolbachia Pipientis.
The characteristics, activities (insecticidal, anti-fungal and anti-bacterial) and problems concerning the use of the Bacillus Thuringensis (resistance and potential virulence) were explained in detail. He briefly spoke about Bacillus Cereus and Bacillus Anthracis, whose are considered with Bacillus Thuringensis one species with substantial differences in the plasmid genes. The second part of the presentation was focused on symbiotic bacteria Wolbachia pipientis and C. Cardinium, which stay in the cytoplasm of host cells with a mutual symbiosis (Nematodes) or reproductive parasitism (Arthropods). It was proposed the exploit of the main Wolbachia characteristic, e.g. the cytoplasmic incompatibility (CI) between female and male in arthropods, to control the insect population. A very promising Wolbachia strain is “pop corn”, which has shown to be highly pathogenic in fruit flies, but it expresses the pathogenetic trait only in old insects.
The other symbiotic bacterium described was Cardinium. It is localized into the phloem and is transmitted by insect S. Titanus, the vector of Flavecenza Dorata in Vitis Vinifera. It was explained the characterization of the microflora associated with S. Titanus, showing in detail several techniques used for this work, , for example LH-PCR, DGGE, TEM, nested PCR. These results open a new prospective for the biological control of S. Titanus and for the symbiontic control of Flavescenza Dorata.
The second speaker, professor Sacchi, University of Milan, focused his speech on the chemical control of plant growth and development. After a short introduction on the phytohormone biochemistry and the differences between mammalian and plant hormones, he explained in detail the structure and mode of action of the main plant hormones (auxins, gibberellins, citokinines, abscissic acid, ethylene, brassinosteroids, jasmonates, sialicilic acid and poliamines), and how alteration of the hormone concentration can induce a phenotype plant modification. The last part of this oral presentation was focused on the chemical genetic approach to study the function of a gene product (protein) by using exogenous ligands to alter the function of the protein within the complex cellular context.
The third speaker of the day, Doctor Fontana, Monsanto Europe (Italy), explained the biotechnology regulations in Europe, in particular the use of GMOs in food production chain. Despite the clear advantages of the biotechnology and in particular the genetical modified microorganisms (GMOs), a widespread public concern about the possible impact on human health and the environment has raised. The EU has been legislating on GMOs since the early 1990s. This rule and regulation cover the use, traceability and labelling of GMOs on products and feeds containing GMOs, and are designed to protect the health of both citizens and environment. It has been presented the European Directives on the contained use of GMOs, on the release of GMOs into the environment, and the European Directives that regulate research and industrial work activities involving GMOs. The last part of the oral presentation was focused on the principles of the Genetically Modified Food and Feed regulation, on the traceability and labelling of GMOs approved for the use in food products, and on the transboundary movements of genetically modified organisms. It was explained the rules of the co-existence between transgenic crops and traditional or organic crops and the important role of EFSA (European Food Safety Authority) in the European Union risk assessment regarding food and feed safety.
During the third day of Grifa Summer school 2006 several topics were dealt from the novel analytic techniques to determine pesticide residues in the food, to the function of P 450 cytocrome, to the ecologic risk assessment.

The third day. Professor Valverde presented an exhaustive lecture about the Analytical Methodologies, Quality and Assurance Control strategies to apply to Control Pesticide Residues. He stressed the concept of food safety: “foods without toxic substance at levels which can be harmful to the consumer health”; underlining the importance to evaluate the risks benefits to pesticide uses. Starting from the residues definitions he presented the QuEChERS method, a Quick, Easy, Cheap, Effective, Rugged, Safe multi residue techniques and its intra laboratory validation across the worlds. He underlined also the importance to choice the proper detector (GC_MS, LC-MS MS, LC/TOF-MS) especially to detect the new generation pesticide residues. He spoke about strategies, certifications, guidelines to follow to assure the quality of pesticide residues labs, a key stone in the official monitoring programs of pesticide residues in food.
Doctor Pierluigi Caboni gave an interesting lecture about the P450 cytochrome family and their activity in the metabolism of drugs in general and in particular of pesticides. He presented a deep biochemical overview of this important class of enzymes, starting form biochemical cycle, through cellular and bacterial locations, classification, structural crystallization , catalytic site, so far ending to explain the activity and their rules. He showed techniques to isolate P450s from tissues and the application of these techniques to carry on studies about clinical drugs, pesticides, spectral interactions (substrate or inhibitor), different rate of metabolism even in the same organism. He underlined the importance of in vitro system to study the pesticide metabolism, and to understand how the pesticide and their metabolites could interact activating or inhibiting the several iso-forms of cytochromes and cell enzymes. In this way he showed with enthusiasm the results of his research carried on across the States and Sardinia to the young researchers, participants of GRIFA School.
Doctor Matthias Liess’s lecture dealt about his long experience on aquatic ecotoxicology. He did a proof and careful analysis of the current standard registration strategies to assess the ecological risk of pesticide and/ or xenobiotics in the environmental. He showed the advantages and limitations to use artificial ecosystems, a reduction of them (Mesocosms) and the probabilistic risk assessment. He showed which are the parameter (exposure, delay effect, population regulation, predator prey relationship, environmental stressor, recovery ) and which not to consider to obtain a more realistic estimation of risk, linking effects from the laboratory to the field. He enriched his lecture with the results derived from his work experiences around the world ( Antarctica, EU, Australia). He introduced the SPEAR concept; to reduce the site-specific variation of community descriptors due to environmental factors, species were classified and grouped according to their vulnerability to pesticides. He presented a validate model using the SPEAR concept to estimate the effect of pesticide in small streams coping with the EU diversity and limited data availability.

Proceedings will be soon available at www.grifa.org quaderno, num. 25

Annalisa Merli
Elena Ottico
Rossella Riccio

Notes
[1] Istitute member
[2] External author