Impact of Intranasal Lead on Subjective Symptoms of Japanese Cedar Pollinosis: A Clinical Study in Fukui, Japan.

Abstract

Background: About 50% of Japanese population suffers from Japanese cedar pollinosis (JCP) which is the most common seasonal allergic rhinitis in Japan caused by exposure to cedar pollen. This high prevalence together with the reduced quality of life of the patients due to subjective symptoms underlines the importance of understanding how pollen exposure affects JCP. It is well known that Lead (Pb), a common air pollutant can cause and exacerbate symptoms of respiratory allergies. However, there is limited information on specific effects of Pb on JCP and the Pb content in the pollen. Objectives: To evaluate the effect of intranasal Pb exposure on subjective symptoms of JCP by detecting Pb levels on pollen and epithelial lining fluid (ELF) of JCP patients and control subjects in both preseason and pollen season in 2016 and 2017 at Fukui Hospital, Japan Methods: A follow-up clinical study was conducted during the preseason and pollen seasons. The study involved 44 patients with JCP and 57 control subjects. Basic information and subjective symptoms were recorded using a questionnaire. Pollen grains were collected and counted using a Durham sampler. ELF and pollen were analyzed for Pb levels using inductively coupled plasma mass spectrometry (ICP-MS). Data were analyzed using descriptive statistics, Chi-squared tests, ANOVA, t-test, Spearman rank correlation, and logistic regression. Results: Mean Pb concentration detected in Japanese cedar pollen was 375 µg/kg. During the pollen season, Pb levels in the ELF of patients were 40% higher than those in control subjects, no significant difference was observed in preseason. Furthermore, Pb levels in ELF showed a positive association with pollen counts from the 4 days prior to hospital visits and also with subjective symptoms. Conclusion: Increased intranasal Pb levels, partially derived from pollen, may affect symptoms in JCP patients during the pollen season.