China's "Green Wall" Causes Waves of Allergies

A medical and ecological paradox is shaking northern China: in the fight against desertification, Chinese authorities have made extensive use of the Artemisia plant, a resistant and low-maintenance species. But this strategy, used for decades in afforestation programs, has led to an explosion of cases of seasonal allergic rhinitis, affecting thousands of residents of the country's semi-arid regions, informs EFE.

According to a recent study published in the Journal of Hazardous Materials, five volatile compounds present in Artemisia pollen have been identified as triggers of strong allergic reactions. The discovery belongs to a team of researchers from Jiaotong University in Xi'an and the Forestry Research Institute in Yulin.

• A plant between ecology and health risk

Although the Artemisia plant has been cultivated for its remarkable qualities - drought resistance, soil-fixing capacity and low cost - its massive presence in local ecosystems has led to the accumulation of pollen in the atmosphere, especially in the months of August and September. This period corresponds to the peak of the allergic rhinitis season, also known as "hay fever”. The city of Yulin, in northern Shaanxi province, has become an epicenter of this phenomenon, with a sharp increase in cases over the past five years. Since 2019, health authorities in the area have observed a clear link between exposure to Artemisia pollen and recurrent allergic symptoms, including excessive sneezing, nasal congestion, itchy eyes and breathing difficulties.

• An ecological success with side effects

The strategy to combat desertification by planting Artemisia has been one of China's most ambitious environmental initiatives. In 2024, Beijing announced the completion of a 3,000-kilometer "Great Green Wall” that completely encircles the Taklamakan Desert, the world's second-largest sand desert. This green ring, created over four decades, has significantly slowed the advance of shifting dunes and stabilized fragile ecosystems in the Xinjiang region. But as the vegetation has expanded, so have health problems-especially in the Inner Mongolia, Gansu, and Shaanxi regions. People in these regions have been struggling with recurring allergy symptoms every fall, right around the time the Artemisia is in bloom. The situation has prompted a reassessment of reforestation strategies, and the Yulin authorities have promised to diversify plant species in future projects.

• A regional effort to combat sandstorms

In parallel with domestic issues, China is working with Mongolia to combat sandstorms that affect the north of the country every spring. A bilateral center for combating desertification has been established, and exchanges of good practices in the field of ecology are becoming more frequent. In June 2023, during a visit to Inner Mongolia, President Xi Jinping called for "new ecological miracles,” urging authorities to strengthen the "green barrier” and avoid the risks associated with overgrazing, deforestation, and climate change.

• Between climate and health: the challenge of a balance

The case of Artemisia highlights the complexity of the fight against climate change in a vulnerable environment like northern China. While Artemisia has brought undeniable benefits in terms of soil conservation and slowing the advance of the Mu Us Desert, its impact on public health can no longer be ignored. Researchers warn that it is essential that reforestation policies take into account not only ecological resilience, but also the effects on the health of local populations. In an era of climate imbalances, simple solutions can have unexpected consequences.