Contribution of authorship
All authors approved the final manuscript. H.K. initiated the concept
and H. N. designed the study. T.M. and T.F. provided additional advice.
A.S., Y.O., and M.K. collected the data. H.K. analysed the data and
wrote the manuscript. A.K., S.Y, M.H., K.F., S.Y., K.H., and the Japan
Environment and Children’s Study group reviewed the manuscript and gave
critical advice.