Relationship Between Annual Airborne Pollen Levels And Occurrence Of Thyroid, Skin, Esophagus, Kidney And Ovary Cancers, And Leukemia, Multiple Myeloma And All Cancers: A Retrospective Study Based On The National Registry Database Of Cancer Incidence In Japan, 1975–2015
Akira Awaya and Yoshiyuki Kuroiwa
Background: In Japan, pollen counts increased between 1977 and 1987, including three peaks (1978-
1980, 1982, 1984-1986) coinciding with Kawasaki disease (KD) outbreaks. Epidemiological findings
have been gradually accumulated that KD and related specific intractable diseases and further cancers
may be correlated to pollen exposure (PE).
Methods and results: To elucidate the effects of PE on occurrence of thyroid, skin, esophagus, kidney
and ovary cancers, and leukemia, multiple myeloma and all cancers, we evaluated the annual onsets of
malignant tumors in relation to pollen counts using data from a national database.
Increased rates of these cancers were observed during pollen counts increasing period between 1977 and
1987. Significant correlations were observed between the annual number of newly registered patients
(nRPs) and the annual pollen levels (PL) measured with a lag of 2 years for skin and kidney cancers, 4
years for thyroid cancer, 6 years for skin, esophagus cancers, leukemia and multiple myeloma, 8 years
for thyroid cancer, and 2,3 and 6 years for all cancers. Peaks of number of thyroid cancer in 2013, 1990
and 1980 are discussed about as compared with other cancers regarding effect of radioactive pollutants
occurred from three nuclear plant accidents.
Conclusion: Data suggest newly that the cumulative effects of PE within 2,3,4,6,8 years prior to
diagnosis might possibly trigger incidence of eight cancers and malignant tumors.
