Occupational exposure to zoonotic agents among agricultural workers in Lombardy Region, northern Italy.

OBJECTIVES: This study was conducted in Northern Italy with the aim of defining the risk of agricultural workers' contact with biological agents through the determination of serum antibodies against selected zoonotic agents. Immunity against tetanus was also investigated. METHODS: Two groups of agricultural workers consisting of 153 animal breeders (exposed) and 46 non- breeders (controls) were included in the study. In a first group of 103 workers (89 exposed and 14 controls) the serum concentrations of antibodies against Hepatitis E Virus (HEV) were measured, whereas in the second group of 96 workers (64 exposed and 32 controls) the serum concentrations of antibodies against Leptospira spp., Coxiella burnetii, Borrelia burgdorferi, Brucella spp. and Salmonella spp. were addressed. Imunization against tretanus was also studied in this group. RESULTS: Animal breeders showed higher rates of IgG antibodies against Coxiella burnetii (50% vs. 31.2%), and Leptospira spp. (59.4% vs. 43.7%). Results of logistic regression analysis revealed that breeder workers showed a tendency to have higher prevalence of positivity for antibodies to Leptospira spp.and Coxiella burnetii than non-breeders (ORs ~ 3). Only one exposed subject showed antibodies against hepatitis E (none in controls), but when tested with another commercially available kit the percentage of anti HEV IgG positive subjects increased to 22.3% in the exposed, while none of the controls showed positive. None of the subjects showed antibodies against Salmonella spp. and Brucella spp. Italians and other European workers have better protection against tetanus (91%) compared to non-EU workers (81%). CONCLUSIONS: The higher frequency of the presence of serum antibodies to zoonotic agents (e.g. Leptospira spp. and Coxiella burnetii) in animal breeders suggests that they are more exposed to biological agents than workers not involved in animal breeding activities. The risk of contact with HEV deserves further studies because the adoption of different assays can result in significantly different results. The promotion of immunization of agricultural workers might be a priority, in particular for migrants.

Emerging zoonoses: the "one health approach".

Zoonoses represent a public health risk recently pointed out by the spreading of previously unknown human infectious diseases emerging from animal reservoirs such as severe acute respiratory syndrome and avian influenza caused by H5N1-virus. These outbreaks have shown that animal breeding activities can pose a significant public health risk. Until now, the risk of zoonoses has probably been underestimated, particularly in occupational settings. The emergence or re-emergence of bacterial (Mycobacterium bovis and Brucella spp) or viral (hepatitis E virus) infections shows that zoonoses should be considered as emerging risks in agricultural and animal breeding and should be addressed by specific preventive interventions. Close cooperation and interaction between veterinarians, occupational health physicians and public health operators is necessary, for a worldwide strategy to expand interdisciplinary collaborations and communications in all aspects of health care for humans, animals and the environment. This is what the One Health Approach was intended to be.

Immune changes in animal breeders: a pilot study conducted in northern Italy.

OBJECTIVE: Farming is associated with exposure to a wide variety of risk factors including organic dusts, endotoxins, allergens and other chemicals. The ability of some of these agents to interact with the immune system is demonstrated in the presented study which was undertaken to evaluate the relationship between pig and cow breeding, and the immune system early changes. Particular attention is paid to selected serum cytokines. METHODS: Sixty four animal breeders (36 cattle and 28 pig breeders) were selected as the exposed group, and 32 rural workers not engaged in animal breeding were utilised as the controls. Personal data were collected through a questionnaire, and selected serum parameters measured, including cytokines IL-6, IL-8, IL-10, IFNγ and TNFα, immunoglobulins and proteins, and total and differential white blood cell counts. RESULTS: The study stresses the significant increase of TNF-α, IL-8, and IL-10 in animal breeders, with the highest values in pig breeders, and a slight but statistically significant increase in albumin and total serum proteins. CONCLUSIONS: The findings of the presented study suggest a condition of immune system activation in animal breeders, with the highest levels observed in pig breeders. These changes may be attributable to exposure to organic dusts, endotoxins, or to the different biological agents present in the rural environment. The prognostic significance of these findings, however, remains unclear, but the observed changes might be indicative of a risk of developing respiratory toxic and allergic diseases, which need to be further investigated.

Farmers' exposure to herbicides in North Italy: assessment under real-life conditions in small-size rice and corn farms.

Although rice and corn are two main cash crops in Lombardy (North Italy) and their cultivation involves several thousands of farmers, risk assessment of pesticide exposure is rarely done, especially in small and medium sized enterprises. With the use of pads for environmental monitoring (OECD protocol), of pre- and post-exposure 24h urine collection for biological monitoring and of hand wash for hands' exposure, we measured the exposure of 28 agricultural workers to propanil and terbuthylazine in real-life working conditions. In propanil applicators, median daily exposure on the clothes was 73.5µmol per worker, while the exposure on the skin was 22.4µmol. For terbuthylazine, these exposures were 37.2µmol and 0.86µmol per worker, respectively. Median excretion of the propanil metabolite (3,4-dichloroaniline) after exposure was 84nmol in 24h urine, and 13nmol for the metabolite of terbuthylazine. Risk assessment performed by comparing to the AOELs of the applied active ingredients with an estimated internal dose, obtained based on the measured levels of skin and hand exposure and the percentage of dermal absorption of the active ingredients considered showed that 4 propanil workers, and no terbuthylazine workers, were overexposed. Our study helps define and confirm relationships between different exposure determinants, which can be used in the development of tools for risk assessment of exposure to pesticides in small and medium sized enterprises.

Integration of biological monitoring, environmental monitoring and computational modelling into the interpretation of pesticide exposure data: introduction to a proposed approach.

Open field, variability of climatic and working conditions, and the use of complex mixtures of pesticides makes biological and environmental monitoring in agriculture, and therefore risk assessment and management, very complicated. A need of pointing out alternative risk assessment approaches, not necessarily based on measures, but simple, user-friendly and reliable, feasible also in the less advanced situations and in particular in small size enterprises, arises. This aim can be reached through a combination of environmental monitoring, biological monitoring and computational modelling. We have used this combination of methods for the creation of "exposure and risk profiles" to be applied in specific exposure scenarios, and we have tested this approach on a sample of Italian rice and maize herbicide applicators. We have given specific "toxicity scores" to the different products used and we have identified, for each of the major working phases, that is mixing and loading, spraying, maintenance and cleaning of equipment, the main variables affecting exposure and inserted them into a simple algorithm, able to produce "exposure indices". Based on the combination of toxicity indices and exposure indices it is possible to obtain semiquantitative estimates of the risk levels experienced by the workers in the exposure scenarios considered. Results of operator exposure data collected under real-life conditions can be used to validate and refine the algorithms; moreover, the AOEL derived from pre-marketing studies can be combined to estimate tentative biological exposure limits for pesticides, useful to perform individual risk assessment based on technical surveys and on simple biological monitoring. A proof of principle example of this approach is the subject of this article.

Occupational health and safety in agriculture: situation and priorities at the beginning of the third millennium.

Agriculture is a human activity, which includes a number of different tasks and occupies a huge number of people worldwide. Estimates of World Bank for 2003 suggest that 51% of globalpopulation lives in rural areas. ILO estimates that 1.3 billion of workers are engaged in agriculture, and they represent almost a half of the total number of economically active subjects (2,838,897,404). In developed countries, agriculture workers are only a small fraction of the whole work force (up to 9% according to ILO data), while in developing countries, especially in Asia, agriculture workers represent up to the 60% of the total work force. Most agriculture workers reside in Asia, in the Pacific (74%) and in Africa (16%). ILO estimates suggest that half of fatal occupational injuries in the world are attributable to agriculture. This means that around 170,000 agriculture workers die every year as a consequence of occupational injuries. Using the same estimate, half of the fatal accidents could be linked to agricultural activities (more than 130 million). Comparing this estimate with the 6.328.217 people injured in war in 2002 or with the 20-50 million injured victims of road accidents, one has a much clearer picture about the importance of preventing agricultural injuries. In a complicated situation such as occupational health and safety problems in agriculture, it is not so easy to select priorities clearly. But "legalization" of agriculture workers could be a key to solving all the other problems. Actual data on fatal and non-fatal occupational injuries in agriculture show that occupational health and safety issues are among the top priorities for that discipline.