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Introduction The risk for a beekeeper to become allergic to bee venom is higher than the general population. The possibility that they develop an allergy is greater when rarely bite with 2/3 month interval. On the contrary, when bites are simultaneous or tight over time the probability of allergy decreases. Beekeepers who receive more than 200 stings do not develop venom allergy. In general, subjects developing a reaction limited to the skin have 70% possibility of a spontaneous recovery. On the contrary, people haveing a systemic reaction tends to show the same or greater reaction when restung. Discussion Work suitability of bee allergic beekeepers, which had a systemic reaction is a relevant problem for occupational doctors. They should be prescribed appropriate DPI and provided of auto-injectable adrenaline as emergency treatment, sure that they received the necessary training. Furthermore, it is desirable that every allergic subject receives a desensitising treatment, as it is efficacious in 95% of patients. The treatment will last for 5 years, except for subjects with high basal tryptase who should be treated for a life-time, as the risk of anaphylaxis reappears after the discontinuation of an already effective immunotherapy. The cardiac involvement during anaphylaxis is very frequent with the picture of Kounis Syndrome (KS), characterised by infarction induced by the effects on coronaries of mast cell chemical mediators. In particular, histamine, usually vasodilator agent, can induce vasoconstriction subjects with coronary endothelial lesions. In this situation, the coronary spasm worsens the perfusion of a tachy heart, already with increased blood demand, with a potentially life-threatening ischemia. Furthermore, in a subject developing a KS the administration of adrenaline should be carefully evaluated as adrenaline, having vasoconstriction effects, can worsen the myocardial ischemia. Conclusions It is our opinion that work suitability cannot be granted to beekeepers who developed KS with.

Aim of the session To discuss occupational allergies in basic mechanisms, testing and newer clinical topics 1Dr. A. Fourie, 2Dr. L. Wengenroth, 3Dr. E. Kuroda, 4Dr. M. Di Gioacchino 1National Institute for Occupational Health, National Health Laboratory Services, Johannesburg, South Africa 2Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Munich, Germany 3Laboratory of Adjuvant Innovation, Centre for Vaccine and Adjuvant Research (CVAR), National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan 4Unit of Immunotoxicology and Allergy, CeSI-MET, G. d’Annunzio University, Chieti, Italy

Introduction TiO2-NPs are the most produced nanomaterial as UV filters. They are considered as nontoxic at the exposure levels of the occupational environments; nevertheless, potentially dangerous organic molecules can be formed due to photocatalysis. Mesoprous silica (SiO2) nanoparticles (MSN) incorporating Ti-nano were produced to improve their properties. We studied whether human lymphocytes/monocytes can be the target of a toxic action of all these NPs. Methods Activated/quiescent huPBMCs were exposed ex-vivo to: TiO2-NPs (21 nm); MSN (100 nm); TiO2-MSN (4.4 nm TiO2 into MSN pores). They were characterised for: cell viability/apoptosis by MTT and Annexin-V; ROS by DCFH oxidation; nuclear morphology by fluorescence microscopy; cytokines by ELISA. Results The viability of activated lymphocytes exposed to the highest doses all NPs was significantly reduced. All NPs induced apoptosis, but only TiO2-NPs induced ROS. IL-2, IL-17, IFN-g were downmodulated by all; MSNs were associated with increased IL-1β and IL-4 secretion; TiO2-NPs induced IL-10, TNF-α and IL-23. Conclusion Different patterns of cytokine in response to the three different NPs tested: they are all immunosuppressive, but only TiO2-MSN seem to act as pro-inflammatory and pro-allergic agents. The presence of TiO2 in MSN appear to influence the effects of these larger NPs, possibly related to its pro-oxidative and pro-apoptotic effect.

Introduction Exposition to asbestos may cause adverse health effects, but a clear relationship between mineralogy and texture of fibres versus toxicity is still lacking. Toxicological studies can be properly interpreted and compared only if quantitative features of fibres are determined. Methods Amphibole fibres were characterised by XRPD, FTIR, SEM-EDS and EMP-WDS. Fibres deposited from solutions of 0.1, 1, 10, 25, 50, 75 and 100 mg/L were counted using SEM images. The single vs agglomerated fibres was assessed. The viability of human lymphocytes exposed to the fibres was investigated by MTT test. Results Only crystals with definite stoichiometry are present. At 0.1 and 1 mg/L the fibres are well separated, whereas between 1 and 10 mg/L they start to agglomerate. In vitro tests performed on fibres deposited at the same concentrations show that the cytotoxic effect rate decreases for asbestos concentration >10 mg/L. Conclusions Considering that the mineralogy is constant, the decreasing rate of toxicity suggests that the hazardous potential must be attributed mainly to the single fibres, while the agglomerated fibres, whose amount increases strongly for increasing total fibres play a minor role.

Introduction The inflammatory effects of organic sub-10nm particles generated and emitted from a diesel engine fueled with a biodiesel and a commercial diesel oil are analysed in this paper. Diesel combustion is the major sources of ultrafine particles (UFP) in the environment, particularly in urbanised areas. In the last years, there is an increasing use of biomass-derived fuels because they are a renewable source of energy that may mitigate climate change through the reduction of net CO2 with respect to conventional fossil fuels. Although there is a general agreement on biofuels ability to reduce conventional pollutants, new and potentially harmful pollutants can be formed during biofuel combustion. In particular, the emission of sub-10nm particles is strongly increased with respect to that of larger soot particles. Methods Organic sub-10nm particles are separated from larger sizes particulate matter by collection in water suspension for toxicological and inflammatory tests. After exposure to sub-10nm particles, the effects on proliferation, apoptosis and secretion of cytokines, chemokines and growth factors networks production is analysed in immortalised non-tumorigenic human dermal keratinocyte cell line (HaCaT) and human alveolar epithelial-like cells (A549). Results Nanoparticles exert different cytotoxic effects in the two cell lines, suggesting that the dermal way of exposure is more sensitive than the inhalant way. These differences are most evident in the secretion of pro-inflammatory, angiogenic and proliferative cytokines and chemokines whose expression is more finely modulated in HaCaT cells compared to A-549 cells. Conclusion Considering the size of these particles, it is important to promote the culture of prevention also for the dermal way in particularly exposed workers.

Aim of the session To discuss immunotoxicological alterations caused by occupational and envuironmental substances 1Dr. Y. Nishimura, 2Dr. Q. Niu, 3Dr. P. Pedata, 4Dr. T. Otsuki 1Department of Hygiene, Kawasaki Medical School, Kurashiki, Japan 2School of Public Health, Shanxi Medical University, Taiyuan, China 3Seconda Universita degli Studi di Napoli, DMS-SIMLL, Naples, Italy 4Department of Hygiene, Kawasaki Medical School, Kurashiki, Japan