Allergy sufferers may find the summer heat more stifling as ragweed comes into bloom in more areas of France.
Ragweed (ambroisie in French) is a North American plant with distinctive yellow flowers that has been spreading its highly allergenic spores throughout Europe for the past century. It can reach up to three feet in height, and propagates along riverbanks and in farmland.
In France, more than 90% of departments are concerned by the spread of ragweed, with consequences for agriculture as well as for allergy sufferers. The Rhone and Loire valleys and the regions of Bourgogne, Rhone-Alpes and Auvergne are particularly impacted.
See here the spread of ragweed (latest information 2017):
Ragweed releases its spores during the months of August and September. While the plant itself is odourless, the spores are extremely allergenic, with 10 spores per square metre enough to provoke a reaction, which can include:
· Swollen eyes
· Asthmatic reactions
Up to 3.5 million people in France may suffer from reactions to pollen, states the French health authority ANSES. These are best managed by over the counter treatments, such as anti-histamines, decongestants and nasal sprays. For people with unmanageable reactions to the spores, current advice is to stay indoors.
If you see individual ragweed plants, Anses advises to rip them up, preferably before the flowers can bloom. However, where the weed is present in significant numbers, it recommends flagging it on the dedicated Stop Ambroisie website or by calling 09 72 37 68 88.
It is best to destroy the plant in June before it can develop and propagate.
Efforts to curb the spread of ragweed in Europe have been hampered by the regularly long, hot summers, which have seen the plant spread as far north as Scotland.
It has been suggested that the accidental introduction of the American Ragweed leaf beetle into Europe, which feeds on the weed, could help curb the spread, however it is not yet present in France.