Effect of air pollution on age at menarche in polish females, born 1993-1998.

The aim of the study was to analyse the association between the degree of air pollution (suspended particulate matter, sulphur dioxide, benzopyrene levels) in the location of residence during childhood and adolescence and the age at menarche. The research was carried out in the period from 2015 to 2018 in Poland. Anthropometric measurements were performed, and questionnaire data were collected from 1,257 women, aged 19-25 years. The average levels of subjects' exposure to analysed air pollutants, i.e., particulate matter, sulphur dioxide, nitric oxide and benzene during childhood-adolescence was assessed from the data acquired by the Polish Chief Inspectorate for Environmental Protection. Negative relationships between age at menarche and suspended particulate matter as well as nitrogen levels were found. A similar trend was observed in an analysis of the relationship between age at menarche and the complex air pollution index. The tendency for age at menarche to decrease together with worsening air quality was also visible after adjusted for socioeconomic status. Girls exposed to high suspended particulate matter levels were characterised by higher risk of early age at menarche. High levels of air pollution are related to younger age at menarche and the risk of the menstruation onset below 11 years.