US EPA

5353243 

Journal Article 

Supplemental Data 

Uptake and metabolism of phthalate esters by edible plants [Supplemental material] 

Sun, J; Wu, X; Gan, JJ 

2015 

1 

Environmental Science & Technology
ISSN: 0013-936X
EISSN: 1520-5851 

49 

14 

English 

is a supplement to 5555815 Uptake and metabolism of phthalate esters by edible plants

Phthalate esters (PAEs) are large-volume chemicals and are found ubiquitously in soil as a result of widespread plasticulture and waste disposal. Food plants such as vegetables may take up and accumulate PAEs from soil, posing potential human health risks through dietary intake. In this study we carried out a cultivation study using lettuce, strawberry and carrot plants to evaluate plant uptake, translocation and metabolism of di-n-butyl phthalate (DnBP) and di-(2-ethylhexyl) phthalate (DEHP) and their primary metabolites mono-butyl phthalate (MnBP) and mono-butyl phthalate (MnBP). All four compounds were detected in the plant tissues, with the bioconcentration factors (BCFs) ranging from 0.16 ± 0.01 to 4.78 ± 0.59. However, the test compounds were poorly translocated from roots to leaves, with translocation factor below 1. Further, PAEs were readily transformed to their monoesters following uptake. Incubation of PAEs and MPEs in carrot cells showed that DnBP was hydrolyzed more rapidly than DEHP, while the monoesters were transformed more quickly than their parent precursors. Human exposure calculated using the whole plant data showed exposures well below the reference doses for individual PAEs. However, given the extensive metabolism of PAEs to monoesters in both whole plants and plant cells, metabolites such as MPEs should be considered when assessing human exposure via dietary intake of food produced from PAE-contaminated soils.