Ragweed infestation in southern Germany poses allergy threat

Bavaria is battling the spread of ragweed, a plant indigenous to North America that causes particularly severe symptoms in allergy sufferers.

Ragweed infestation in southern Germany poses allergy threat
Ragweed. Photo: DPA

“During our investigations in 2019, we found 45 new large areas of ragweed growth, bringing the total number of large areas identified to 509,” Bavarian health minister Melanie Huml (CSU) confirmed on Monday when inspecting a ragweed population in the district of Roth. 

The number of unreported cases is expected to be significantly higher.

READ ALSO: Pollen at 'unusually high levels' amid early spring in Germany

The pollen of ragweed can cause allergic reactions such as hay fever, conjunctivitis and allergic asthma in humans, even in small quantities. 

Roth is one of the most badly affected districts in Bavaria. Thirty-four large areas with more than 100 plants each have been discovered there since 2007.

Originally native to the USA, the plant has been spreading in Bavaria since the 1990s.

“The pollen of the North American ragweed, which is about to bloom, can cause severe allergic reactions in humans. That is why our aim is to stop the spread of the plant in Bavaria as much as is possible”, Huml said. 

The southern state is investing €90,000 in monitoring the weed. Some success as been had in slowing down the uncontrolled spread of the plant.

“But as our monitoring shows, the numbers are still rising. We are therefore working on a more comprehensive strategy,” said Huml.

Experts say that ragweed pollen has an allergy potential five times higher than grass pollen. About 80 percent of all pollen allergy sufferers also react to ragweed.

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Denmark’s pollen season underway earlier than expected

One of Denmark’s main pollen plagues, birch pollen, has arrived two weeks earlier than normal.

Denmark's pollen season underway earlier than expected
File photo: Bax Lindhardt/Ritzau Scanpix

Although the birch pollen season does not usually begin until mid-April, pollen counters began registering the grains during last weekend, when weather was unusually warm for the time of year.

The early start to the pollen season is linked to a mild spring and a sudden increase in temperature, according to Astma-Allergi Danmark, which issued a press statement after the weekend’s pollen counts.

The count reached as high as 31 in the west of the country by the end of last weekend, but was as low as 3 in Copenhagen.

“It’s still difficult to predict how the season will take shape, but if the weather continues with sun and warm temperatures, we can expect high pollen counts. We have already had record-high amounts of alder and hazel this spring,” Andrea-Pil Holm, a biologist who is responsible for the pollen counts, said in a press statement.

“On the other hand, cold weather and rain could set pollen levels back a bit,” Holm added.

Although weather patterns have since brought cooler air back to the country, forecasts currently suggest that warmer days could return next week.

Birch pollen is one of the worst culprits for people with pollen allergies.

An analysis has found that over half of the around one million people in Denmark who have pollen allergies are affected by it.

Pollen counts indicate the amount of pollen in the air at a given moment: in the case of birch, the level is low if the measurement is under 30; moderate if between 30 and 100, and high when over 100.

The country’s highest ever birch pollen counts were recorded on April 21st, 2014, with 4,696 in Copenhagen and 2,526 in Viborg.

Despite these relatively large values, a count of 100 is considered high because that is enough to provoke a reaction in all allergy sufferers.

READ ALSO: Weather news from Denmark