Implementation and quality control of pollen monitoring network in northern China

Airborne pollen is a significant outdoor allergen that can induce a variety of allergic diseases. Globally, the prevalence of pollen-induced allergic diseases is 22.1%, with an annual increase of 0.3%. The occurrence of hypersensitivity symptoms caused by pollen is closely linked to the region and season of pollen distribution. In northern China, the dry and windy climate facilitates the dispersion of pollen in the air. Weed pollen is a major allergen in northern China, and the prevalence rate of allergic rhinitis induced by pollen is as high as 18.5% in the Inner Mongolia grassland area, which seriously threatens human health and causes a heavy economic burden. Pollen monitoring is internationally recognized as a reliable and feasible method to assess the health risks associated with pollen allergy patients, and it plays a crucial role in the prevention and control of pollen allergy-related diseases. For a long time, Chinese scientific research institutes and medical institutions have conducted numerous pollen monitoring studies, but there has been limited research on the quality control of pollen monitoring data. Due to the absence of unified standards and norms, discrepancies exist in operational technology, data analysis, and other areas, thereby limiting the accuracy, comparability, and applicability of monitoring outcomes to some extent.Since 2013, the Allergy Center of Beijing Shijitan Hospital, affiliated with Capital Medical University, has established 190 pollen monitoring sites in northern China with the support of various funds, including national clinical key specialties. Drawing on previous project experiences, the primary reasons for inadequate or excessive pollen monitoring data are the replacement of staff and the failure to conduct relevant tasks following proper training, leading to suboptimal quality of pollen samples. To address these potential issues, a comprehensive quality control plan has been developed: a four-tier quality control system has been established to oversee and monitor each stage from a macro perspective; a professional team of pollen monitors has been formed, along with training systems and a supportive working environment to ensure that monitors possess the necessary professional skills and working conditions; representative and comparable pollen monitoring sites have been scientifically selected to accurately reflect the airborne pollen distribution in different regions; It is crucial to develop a comprehensive standard operating procedure (SOP) for the entire process of pollen monitoring using the gravity sedimentation method. This SOP should detail the operational methods and key quality control points. Specific factors, such as the criteria for applying pollen samples, the timing of collection, and the volume of dye solution, should be clearly defined. By employing the most efficient and concise methods, this SOP aims to minimize the risk of missing or duplicating pollen data under the microscope. It also effectively reduces the variability introduced by different operators, ensuring that pollen monitoring data from various regions is highly accurate. This paper proposes a four-tier quality control system for the gravity sedimentation method of pollen monitoring. The SOP has been developed to regulate and optimize each operational step, which to a high degree ensures the accuracy, comparability, and representativeness of pollen monitoring data, thereby providing a reliable basis for the prevention, treatment, and research of pollen-related allergic diseases. This framework serves as a valuable reference and guide for nationwide pollen monitoring efforts, facilitating the continuous improvement and refinement of the overall pollen monitoring system.