Food Packaging and Bisphenol A and Bis(2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention

TLDR

Bisphenol A and bis(2‑ethylhexyl) phthalate are widely used in food‑packaging plastics and have been linked to endocrine disruption in animals and some human studies. This study aimed to quantify how much food packaging contributes to overall exposure by measuring urinary BPA and DEHP metabolites before, during, and after a three‑day fresh‑foods dietary intervention. Twenty participants from five families followed their usual diet, then a three‑day period of fresh foods without canned or plastic packaging, while evening urine samples were collected over eight days and analyzed using mixed‑effects models and Wilcoxon signed‑rank tests. Urinary BPA and DEHP metabolite levels fell markedly during the intervention, with geometric‑mean BPA decreasing 66 % (3.7 → 1.2 ng/mL) and DEHP metabolites 53–56 % (57 → 25 ng/mL), and maximum concentrations dropping 76 % for BPA and 93–96 % for DEHP.

Abstract

Background: Bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) are high-production-volume chemicals used in plastics and resins for food packaging. They have been associated with endocrine disruption in animals and in some human studies. Human exposure sources have been estimated, but the relative contribution of dietary exposure to total intake has not been studied empirically.Objectives: To evaluate the contribution of food packaging to exposure, we measured urinary BPA and phthalate metabolites before, during, and after a "fresh foods" dietary intervention.Methods: We selected 20 participants in five families based on self-reported use of canned and packaged foods. Participants ate their usual diet, followed by 3 days of "fresh foods" that were not canned or packaged in plastic, and then returned to their usual diet. We collected evening urine samples over 8 days in January 2010 and composited them into preintervention, during intervention, and postintervention samples. We used mixed-effects models for repeated measures and Wilcoxon signed-rank tests to assess change in urinary levels across time.Results: Urine levels of BPA and DEHP metabolites decreased significantly during the fresh foods intervention [e.g., BPA geometric mean (GM), 3.7 ng/mL preintervention vs. 1.2 ng/mL during intervention; mono-(2-ethyl-5-hydroxy hexyl) phthalate GM, 57 ng/mL vs. 25 ng/mL]. The intervention reduced GM concentrations of BPA by 66% and DEHP metabolites by 53–56%. Maxima were reduced by 76% for BPA and 93–96% for DEHP metabolites.Conclusions: BPA and DEHP exposures were substantially reduced when participants' diets were restricted to food with limited packaging.