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Ragweed pollen

High cost of pollen allergy

Munich, 09/26/2012

The plant known in North America as ragweed, a potent source of allergens, is on the march in Europe. A recent study involving LMU researchers has estimated that the continuing spread of the weed could result in annual costs of up to 1 billion euros.


In Germany, the high season for hay fever normally falls in the period from March to July, when most tree and grass species are in flower. However, for many sufferers, the season has been getting longer in recent years. The plant responsible for exacerbating their distress is Ambrosia artemisiifolia, known as ragweed in its native North America. It arrived in Europe in the 19th century and has spread rapidly in recent decades, flowering between August and October. Ragweed pollen is highly allergenic, and can induce serious reactions in susceptible individuals.

It is estimated that, in Germany, one-fifth of the population is subject to episodes of hay fever, although it is not yet clear what proportion of these react to contact with ragweed pollen. In Hungary, many regions of the countryside are blanketed with the plant, and up to half of all hay-fever patients there may have been sensitized to its pollen. If the plant continues to spread in Germany, it is expected that up to 10% of the population could be directly affected.

Assessing the costs of ragweed allergies
“The potential outlay caused by an increase in the incidence of ragweed allergies must be set in relation to what it would cost to control the spread of the plant,” says environmental economist Dr. Wanda Born, who led the effort to quantify these costs at the Helmholtz Center for Environmental Research (UFZ) in Leipzig, but has since moved to another institution. As part of the new study, a random sample of patients attending LMU’s Allergy Center, who were allergic to pollen and were known to be sensitized to ragweed, were interviewed.

All had been referred to the clinic for treatment of an allergic syndrome. The majority of those interviewed reported that allergic reactions forced them to consult their family doctor five times a year, on average. In addition, one-third of the patients stated that the condition required them to spend approximately five days in hospital each year, and one-fifth of these required two weeks of sick leave annually. This not only represents a considerable drain on the health insurance system, it is also costly for patients, who spend up to 200 euros per year on things like pollen filters.

Adverse effects on quality of life
“The negative effect on the patients’ quality of life can be gauged from the fact that more than one-third of them would be willing to contribute to the cost of arresting the dispersal of ragweed,” says LMU allergologist Professor Franziska Ruëff. This is understandable when one considers that, during the pollen season, 50% of sufferers find even mild physical activity fatiguing. However, a reliable estimate of the cost of measures to prevent the plant from spreading further would require extensive investigation of its present distribution and rate of expansion.

Extrapolating from the data currently available, one can anticipate that the cost of treating pollen allergies is likely to rise by 10 to 20%, a figure that is equivalent to an increase of between 1300 and 2100 euros per patient per year. “It is nearly impossible to relate the cost of treatment to allergies caused by one specific allergen,” says UFZ researcher Oliver Gebhardt. “Nevertheless, the study indicates how much worse the problem could get – given that ragweed flowers so late and that its spread will be further facilitated by climate change.”  (Umweltmed Forsch Prax 17 (2) 201280) UFZ/suwe

The study was carried out with the support of the Federal Ministry of Education and Research, as part of the project “INVASION: Evolutionary, Ecological and Social Consequences of Biological Invasions”.

Professor Franziska Ruëff
Allergy Center, LMU
Phone: +49 89 - 5160-6010

Dr. Wanda Born
Email: und
Telefon: +49 160 -977 88 326

Oliver Gebhardt
Helmholtz-Zentrum für Umweltforschung (UFZ), Leipzig
Telefon: +49 341-235-1477


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