For Ma Bo, a resident of Hohhot, the capital of Inner Mongolia, late July marks the beginning of another round of suffering.He has suffered from hay fever – an allergic condition triggered by inhaling pollen – for many years.
His symptoms have gradually worsened since 2018, progressing from sneezing and conjunctivitis to an allergic cough and, eventually, bronchial asthma.The artemisia plant, which is widely cultivated in northwestern China to contain wind and sand erosion, has been identified...