Occupational exposure to pesticides : challenges for research, evaluation and prevention

The mission of the Working Group on "Agricultural workers and pesticides", set up by ANSES in 2012, is to identify and characterise the situations in which people working on French farms (family labour, permanent and part-time employees, outside workers, etc.) are exposed to pesticides. The WG brings to bear expertise from a wide range of disciplines (agronomy, economics, epidemiology, ergonomics, exposure assessment, history, metrology, sociology and toxicology). The term "Pesticides" is understood in the broad sense as covered by several regulations (plant protection products, biocides, certain veterinary medicines for external use), which means that a given compound may be found in each of these three types of product. Several sources of information were analysed: scientific literature, grey literature, statistical data, and various information systems which might contain data on exposure (for example Phyt'attitude), etc. The results of a systematic review of the available scientific literature on exposure situations in France were widely disseminated. This was then followed by a public announcement inviting further contributions in February 2014. The results show that there is little documentation about the exposure to pesticides of persons working in agriculture in France, and that the existing information is difficult to access. Fewer than a hundred articles were identified across all disciplines, for all production situations, without limit of time. The few studies available are not enough to enable a description and analysis – and, a fortiori, a ranking – of exposure situations for all agricultural workers. Although there is some, though still insufficient, information available for certain sectors and certain tasks (viticulture, arable crops, etc.), this mainly relates to the tasks required when treating the crops (preparation and application of the plant-protection products) and tells us little about situations of "indirect" exposure during post-application tasks. Some sectors of activity do not appear at all and/or have not been the subject of investigations identified in the scientific literature (livestock-keeping, arboriculture, horticulture/market gardening, seed storage, crop packaging workshops, subcontracting, etc.). Furthermore, some work situations have not or have only slightly been taken into account when characterising exposure (re-entry tasks, contact with treated plants or animals, etc.). It has to be admitted that available information in this area is minimal. For the study to be complete, the examination of the publicly-available scientific data should be supplemented by a description and an assessment of the procedures followed and the data used to assess exposure during the administrative approval process for plant protection, biocidal and veterinary products in France. However this kind of information is often confidential and difficult to get, which has limited the extent of the analysis. To address this deficit of information, other paths were explored based on two case studies, one on re-entry tasks in orchards and another on external anti-parasite treatments used in sheep farming. An in-depth analysis of the foreign literature on these two case studies highlights a set of issues which are not being considered by scientific and institutional debate in France. It also raises questions about the limits on extrapolating from foreign literature to situations in France. Interviews with different specialists as a part of this study revealed that the different sets of regulations governing the use of pesticides are often drawn up without due consideration of actual practice. For example, they ignore the issue of cumulative exposure resulting from the use of multiple products for one or more farm productions, and at different times of life, for people working on farms. More generally, the regulations governing the use of pesticides (on plant protection products, veterinary medicines, biocides, personal protective equipment, etc.), and which aim to assess and advise on the dangers and how to protect against them, are extremely complex and difficult to grasp for all the actors concerned, including even the most specialised experts. It is very difficult to find and summarise the available information, to access the source data, and to transform such heterogeneous information, which is sometimes incomplete and contradictory, into operational recommendations for practical use. Given the lack of a regular advisory body for consulting all those working in agriculture on the risks related to exposure to the whole range of pesticides, and given the lack of a shared knowledge platform, the responsibility for gathering and summarizing this complex information is transferred to the people who work on farms.