P-095 Abstract: Ambrosia artemisiifolia L., Asteraceae (short, annual, common ragweed), is an annual plant that originates from North-America. When in flower it produces great quantities of highly allergenic pollen and later of seeds. This pollen is the reason why French allergists were the first to alert authorities in 1978. These observations were registered about a century after botanists first identified ragweed in Europe in the 1860s and about forty years after farmers first observed it in the Lyon area in the 1930s. Ragweed has begun spreading through Europe and in France near Lyon only in the 1960s. Ragweed takes hold when ground cover is absent, on building sites, along communication routes, in numerous crops. Its destruction is difficult and expensive. The aim of this abstract is to alert European Community as in spite of numerous publications, there is no European policy and regulation about ragweed. Around Lyon, in exposed populations, prevalence of pollinosis (medical examination) was 3% in 1988, 5.4% in 1990, 3% in 1993 (phone inquiry). Since 1996 (medical examination), 6 to 20% of population is affected in the polluted areas (6%: 100 000 persons in the Rhône department). This pollinosis is lasting for up to two months, with about 50% of asthma and/or tracheitis. Moreover ragweed-induced-pollinosis does not always occur in atopic families. So, nobody knows if sufferer's children will become allergic. Cost. In the Rhône-Alpes Region (2005), 70% of the costs of the medical treatment (except asthma) of ragweed-induced pollinosis was 1.2 million Euros (50% of all costs incurring by pollinosis). Pollen counts. Around Lyon, the number of weeks exceeding the T5, pathological risk period for the patient, is 6–11, exceeding the T100, disability risk period, is 0–6. Remote sensing. In 2003 a study showed that at least 4% of the studied area (60km/60km) was occupied by ragweed. A new kind of spread has recently been observed. Ragweed is often found under bird cages: ragweed seeds are supplied together with sunflower in birdseed. In France local authorities have been in charge of the problem since 1994. Some methods of eradication are dangerous for workers pull out great quantities of ragweed, some workers fall ill within 48 hours. Moreover, they are likely to suffer from ragweed-induced pollinosis in later years. Local regulations are imposed but are difficult to apply. To impose in France and Europe a global and safe strategy for the prevention and control of ragweed would be important.