PLASTIC-ASSOCIATED CHEMICALS AND THEIR IMPACTS ON HUMAN HEALTH

Abstract

Plastics, along with the numerous chemicals embedded inside them, are essential to contemporary existence but present considerable hazards to human health. Numerous plastic-associated compounds (PACs), including bisphenols, phthalates, and flame retardants, are recognized as endocrine disruptors and metabolic toxicants; however, alternative alternatives have not been adequately investigated. Extensive and continual human exposure to PACs via air, food, water, and consumer products necessitates immediate examination of their health implications. This study investigated the relationship between internal exposure to prevalent PACs and metabolic, cardiovascular, inflammatory, and endocrine health outcomes in adults, focusing on less-explored exposure pathways and cumulative effects. A cross-sectional biomonitoring study was conducted at University of Southern Punjab, Multan, on 300 individuals aged 20–65 years. Urinary bisphenols (BPA and BPS) and phthalate metabolites (MnBP, MiBP, MEHHP, and MEOHP) were measured by LC–MS/MS. The primary endpoint was insulin resistance (HOMA-IR), while secondary outcomes included lipid levels, inflammatory markers (CRP), blood pressure, and thyroid function (TSH and free T4). Multivariable linear regression models were adjusted for age, sex, BMI, and smoking status. The detection rates for BPA, BPS, MnBP, MiBP, and DEHP metabolites were over 90%. Elevated urine ∑DEHP concentrations were correlated with heightened insulin resistance (β = +0.42, 95% CI: 0.18–0.66, p = 0.001), elevated triglycerides (+5.8 mg/dL), LDL cholesterol (+2.5 Â mg/dL), greater CRP (+0.21 mg/L), and increased blood pressure. BPA levels exhibited an inverse correlation with TSH (β = −0.08 µIU/mL, p = 0.008) and a positive correlation with free T4 (+0.03 ng/dL, p = 0.014). These associations remained consistent throughout the sensitivity analysis. The results indicate quantifiable exposure to various PACs in humans, with consistent correlations across metabolic, cardiovascular, inflammatory, and endocrine domains. These findings underscore the significance of biomonitoring in risk assessment and advocate for revised regulatory frameworks that consider cumulative exposure, at-risk groups, and novel replacements.