Phthalate metabolites in harbor porpoises (Phocoena phocoena) from Norwegian coastal waters

May Britt Rian,Kristine Vike-Jonas,Susana Villa Gonzalez,Tomasz Maciej Ciesielski,Vishwesh Venkatraman,Ulf Lindstrøm,Bjørn Munro Jenssen,Alexandros G Asimakopoulos

doi:10.1016/j.envint.2020.105525

Abstract

The exposure of marine mammals to phthalates has received considerable attention due to the ubiquitous occurrence of these pollutants in the marine environment and their potential adverse health effects. The occurrence of phthalate metabolites is well established in human populations, but data is scarce for marine mammals. In this study, concentrations of 17 phthalate metabolites were determined in liver samples collected from one hundred (n = 100) by-caught harbor porpoises (Phocoena phocoena) along the coast of Norway. Overall, thirteen phthalate metabolites were detected in the samples. Monoethyl phthalate (mEP), mono-iso-butyl phthalate (mIBP), mono-n-butyl phthalate (mBP) and phthalic acid (PA) were the most abundant metabolites, accounting for detection rates ≥ 85%. The highest median concentrations were found for mIBP (30.6 ng/g wet weight [w.w.]) and mBP (25.2 ng/g w.w.) followed by PA (7.75 ng/g w.w.) and mEP (5.67 ng/g w.w.). The sum of the median phthalate metabolites concentrations that were found in the majority of samples (detection rates > 50%) indicated that concentrations were lower for porpoises collected along the coastal area of Bodø (Nordland), Lebesby (Finnmark) and Varangerfjord (as compared to other coastal areas); these areas are among the least populated coastal areas but also the most distant (>700 km) from offshore active oil and gas fields. The monomethyl phthalate metabolite (mMP) was detected in 69% of the samples, and to our knowledge, alongside with PA, this is the first report of their occurrence in marine mammals. PA, as the non-specific marker of phthalate exposures, showed a statistically significant negative association with the body mass and length of the harbor porpoises. Among the phthalate metabolites, statistically significant positive associations were found between mBP and mIBP, mMP and mEP, PA and mEP, mIBP and mono(2-ethyl-5-oxohexyl) phthalate (mEOHP), mIBP and mono(2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), mBP and mEHHP, mono-n-nonyl phthalate (mNP) and PA, and between monobenzyl phthalate (mBzP) and mNP. To our knowledge, this is the first study on the biomonitoring of 17 phthalate metabolites in harbor porpoises.

Highlights

Phthalates have received considerable public and scientific attention due to their widespread occurrence in the environment and their associations to adverse health effects in organisms (AMAP, 2017; Casarett et al, 2013; Fourgous et al, 2016; Oehlmann et al, 2009)
The mMP concentrations were ~1.5-fold higher in the liver than those determined in both muscle and blubber
The isomers, mBP and mIBP, were found in similar concentrations in muscle and liver, but in the blubber, mBP was not detected and mIBP was determined in trace concentrations. mHxP and PA were determined in trace concentrations in all three matrices, the concentration of the latter, being the most polar metabolite from the phthalate metabolites class, was found in higher (~2-fold) concentrations in the muscle than the blubber

Summary

Introduction

Phthalates have received considerable public and scientific attention due to their widespread occurrence in the environment and their associations to adverse health effects (e.g., reproductive impairment) in organisms (AMAP, 2017; Casarett et al, 2013; Fourgous et al, 2016; Oehlmann et al, 2009). Phthalates are not chemically bound to the plastic product matrix, and demonstrate a high leaching potential to abiotic and biotic environmental compartments (AMAP, 2017; Fourgous et al, 2016; Hu et al, 2016; Vorkamp et al, 2004).

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Results

Conclusion