Release behaviour of cryptomeria japonica pollen allergenic cry J 1 and cry J 2 in rainwater containing air pollutants

Abstract

Japanese cedar (Cryptomeria japonica) pollinosis is the most popular pollinosis in Japan. In recent years, it was reported that the most Cryptomeria japonica pollen allergenic species were scattered as fi ne particles in the urban atmosphere. It is thought that allergenic fi ne particles are responsible for inducing asthma by breaking into lower respiratory tract; this phenomenon was observed in fi eld investigations during sunny days after rainfall. Hence, it is considered that the release of fi ne allergenic species derived from pollen grains may be induced during rainfall events. For this reason, we investigated the releasing behaviour of Cryptomeria japonica pollen allergenic species in rainwater containing air pollutants, through rainwater sampling and laboratory experiments. The pollen grain counts, pollen burst ratios, ionic concentrations and pH in each rainwater sample were measured, when rainwater samples were separately collected in Saitama City, a suburban area north of Tokyo metropolis. Additionally, three simulated rainwater (SR) samples were prepared to investigate the releasing behaviour of pollen allergenic species. In the samplings, the most pollen grains were trapped into initial rainwater (IR). Moreover, burst pollen grains were observed in many rainwater samples. Burst ratio of pollen grains were positively correlated with pH and ionic concentrations in rainwater. Therefore, it was thought that pollen grains were washed out by IR containing air pollutants. On the other hand, for the laboratory experiments, the elution of allergenic Cry j 1 and Cry j 2 was observed when pollen grains were exposed to different SR samples. A time-dependent increase of Cry j 1 was observed, but the elution of Cry j 2 was not observed from pollen grains exposed to SR samples. In particular, the elution of Cry j 1 increased by contact with SR samples under conditions of Asian dust events. The results demonstrated that the burst of pollen grains is associated with the production of fi ne particles containing pollen allergenic species, and that the release of allergenic species was induced by rainwater containing air pollutants.

Estimation of pollen counts from light scattering intensity when sampling multiple pollen taxa – Establishment of Automated Multi-taxa Pollen Counting Estimation System (AME System)

“…The KH-3000-01 is a widely used automatic pollen counting system (e.g. Wang et al 2014;Takahashi et al 2001;Miki et al 2017Miki et al , 2019Kawashima et al 2007Kawashima et al , 2017Matsuda and Kawashima 2018). A laser irradiates particles that pass through the sampling system and the forward and side scattering signals from each particle are recorded.…”

Automatic pollen recognition with the Rapid-E particle counter: the first-level procedure, experience and next steps

“…It can also be used for informing people about the current pollen concentration in the air. Finally, real-time data are needed for short-term pollen forecasts with statistical and atmospheric dispersion models (Sofiev et al, 2013(Sofiev et al, , 2015(Sofiev et al, , 2017Prank et al, 2016;Ritenberga et al, 2016;Zink et al, 2017).…”

Automatic pollen recognition with the Rapid-E particle counter: the first-level procedure, experience and next steps

“…This makes it particularly difficult for the monitors to satisfy the needs of allergic people and allergologistsunlike many other regions. Thus, Cryptomeria japonica is the species that has been identified in the automated pollen identification system more than 10 years ago by Kawashima et al (2007) and is still the main pollen type recognised by that system (Kawashima et al, 2007;Wang et al, 2013;Wang et al, 2014;Takahashi et al, 2018). However, it seems to be more or less sufficient for that region.…”