Socioeconomic disparities in hygiene behaviors and their association with urinary metal levels in Chinese preschoolers

The relationship between personal hygiene and the risk of communicable diseases is well established, with socioeconomic status recognized as a significant factor in this context. Given that infectious diseases, environmental pollutants, and metals share pathways of entry into the human body, this study sought to investigate the correlation between hygiene practices and urinary metal levels in preschool-aged children. A cross-sectional analysis involving 1,477 preschoolers was conducted where urinary concentrations of 23 metals were determined using inductively coupled plasma mass spectrometry. Information about hygiene practices and socioeconomic status was collected from the children's guardians. The results of regression analyses revealed a significant association between improved hygiene practices and lower urinary levels of chromium, iron, and antimony (all <i>p</i> < 0.05), as well as with high household per capita monthly income. Compared to children from low-income families, children from high-income families had better hygiene behaviors (all <i>p</i> < 0.05). In low-income families, children with good hygiene behaviors had lower urinary chromium, iron, and antimony levels (all <i>p</i> < 0.05). Mediation analysis further suggested that bathing and hygiene practices could explain about 7.56% to 28.24% of the effects of urinary chromium, iron, and antimony levels related to household per capita monthly income (all <i>p</i> < 0.05). These findings emphasized that good hygiene behaviors might be a feasible way to reduce heavy metal exposure among children.