Identifying dietary and daily product-use patterns explaining joint variation in multiple urinary phthalate metabolites via sparse reduced-rank regression.

BACKGROUND

Phthalates are synthetic plasticizers widely used in consumer and industrial products, resulting in widespread human exposure and potential adverse reproductive, neurodevelopmental, and metabolic effects. However, the relative contributions of diverse lifestyle-related sources to the overall phthalate burden remain unclear. In this study, we aimed to identify dietary and daily product use factors most prominently associated with joint variations in urinary phthalate metabolite mixtures in a nationally representative sample of Korean adults.

METHODS

We analyzed data from 3,760 adults from the Korean National Environmental Health Survey Cycle 4 (2018-2020). Information on dietary consumption, food-contact material use, and consumer product use was collected through questionnaires, and urinary concentrations of eight phthalate metabolites [mono-methyl phthalate, mono-ethyl phthalate, mono-n-butyl phthalate, mono-benzyl phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, and mono-(3-carboxypropyl) phthalate] were measured. Sparse reduced-rank regression was used to identify latent patterns of dietary consumption, food-contact material use, and consumer product use jointly associated with the eight metabolite levels after covariates adjustment, and analyses were repeated by sex.

RESULTS

A single latent pattern was identified, in which all phthalate metabolites showed positive loadings (+0.10 to +0.46). Mineral spring water (+0.08), grains (+0.08), tap water (+0.06), and beverages in plastic pouches (+0.08) exhibited the largest loadings in the same direction as the phthalate metabolites. In sex-stratified analyses, drinking water and grain consumption among men and the use of beverages in plastic pouches and makeup products among women showed prominent loadings in the same direction as the eight metabolites.

CONCLUSION

Consumption of mineral spring water, tap water, grains, and beverages in plastic pouches were major dietary and daily product use factors associated with higher urinary phthalate metabolite mixtures in Korean adults. Given that current Korean regulations cover a limited subset of phthalates at levels less stringent than international standards, expanding regulatory frameworks for drinking water and food-contact materials and adopting precautionary lifestyle measures are warranted, along with prospective studies to clarify source-specific causal pathways.