Association Between Blood Nanoplastic Exposure and Reproductive Hormone Levels in Healthy Young Adults: A Cross-Sectional Study

Abstract

Background: Nanoparticles constitute one of the most serious pollutants in the environment because of their prevalence and endocrine-disrupting nature. Various experimental researches had proposed that nanoparticles could affect reproductive health via inducing oxidative stress, causing inflammation, and interfering with the synthesis and signaling of hormones. There is little data on the relationship between the exposure to nanoparticles and reproductive hormones levels in humans. Objective of this study is to analyze the relationship between the exposure to nanopartic and serum levels of progesterone and testosterone.Methods: Cross-sectional research was carried out in Baghdad, Iraq, from November 2025 to March 2026. It involved 67 healthy volunteers, comprising 35 women and 32 men aged between 18 and 35 years. Blood samples were obtained and tested under identical conditions for serum progesterone and testosterone content, as well as the quantity of nanoplastic particles in the blood. Data analysis was performed, with statistical significance established at p < 0.05. Results: However, no statistically significant association was found between nanoparticle exposure and absolute levels of progesterone and testosterone. Likewise, no statistically significant difference was found among the means of hormone levels between the exposure groups. On the other hand, all abnormal hormone levels fell under the medium and high exposure groups. There is a statistically significant association between the highest exposure group and abnormal testosterone levels but there is no statistically significant association with abnormal progesterone levels.Conclusion: In this study, no relation was found between exposure to plastic nanoparticles and alteration in the level of blood progesterone and testosterone. Nevertheless, there were instances of irregular hormone level in people who have been exposed moderately and heavily to plastic nanoparticles. This could mean that plastic nanoparticles have the possibility of being an early agent of endocrine disruption. Future studies on this topic should be conducted to confirm the findings.