Accumulation of di-2-ethylhexyl phthalate from polyvinyl chloride flooring into settled house dust and the effect on the bacterial community.

Samantha Velazquez,Chenyang Bi,Suzanne L Ishaq,Rich Corsi,Jeff Kline,Susie Nunez,Ying Xu

doi:10.7717/peerj.8147

Abstract

Di-2-ethylhexyl phthalate (DEHP) is a plasticizer used in consumer products and building materials, including polyvinyl chloride flooring material. DEHP adsorbs from material and leaches into soil, water, or dust and presents an exposure risk to building occupants by inhalation, ingestion, or absorption. A number of bacterial isolates are demonstrated to degrade DEHP in culture, but bacteria may be susceptible to it as well, thus this study examined the relation of DEHP to bacterial communities in dust. Polyvinyl chloride flooring was seeded with homogenized house dust and incubated for up to 14 days, and bacterial communities in dust were identified at days 1, 7, and 14 using the V3–V4 regions of the bacterial 16S rRNA gene. DEHP concentration in dust increased over time, as expected, and bacterial richness and Shannon diversity were negatively correlated with DEHP concentration. Some sequence variants of Bacillus, Corynebacterium jeddahense, Streptococcus, and Peptoniphilus were relatively more abundant at low concentrations of DEHP, while some Sphingomonas, Chryseobacterium, and a member of the Enterobacteriaceae family were relatively more abundant at higher concentrations. The built environment is known to host lower microbial diversity and biomass than natural environments, and DEHP or other chemicals indoors may contribute to this paucity.

Highlights

Di-2-ethylhexyl phthalate (DEHP), a known endocrine-disrupting chemical, is widely used in consumer goods and building materials, from where it is leached into dust, water, or soilHow to cite this article Velazquez S, Bi C, Kline J, Nunez S, Corsi R, Xu Y, Ishaq SL. 2019
Home dust was incubated on polyvinyl chloride flooring, from which the dust was seeded with di-2-ethylhexyl phthalate (DEHP) over 14 days, averaging 1,041 mg/g on day 1, 4,547 mg/g on day 7, and 10,066 mg/g on day 14 (Fig. S1)
Shannon diversity was not affected by Day or DEHP concentration (Fig. 1B; Mann–Whitney, p > 0.05)

Summary

Introduction

Di-2-ethylhexyl phthalate (DEHP), a known endocrine-disrupting chemical, is widely used in consumer goods and building materials, from where it is leached into dust, water, or soilHow to cite this article Velazquez S, Bi C, Kline J, Nunez S, Corsi R, Xu Y, Ishaq SL. 2019. Experimental control samples of dust in glass petri dishes, one per time point, were subjected to identical conditions without the inclusion of vinyl flooring, the homogenized house dust did contain some background DEHP (291 mg/g dust). DEHP was passively adsorbed from polyvinyl flooring and loaded into dust in the experimental samples.

Results

Conclusion