PARENT SESSION

PM04 Phthalate Esters: Fate and Effects
Exhibit Hall
8:00 AM - Monday

(PM027) Distribution of phthalate di-esters and mono-esters in a marine food web: field and laboratory studies.

Webster, G¹, Mackintosh, C¹, Ikonomou, M², Gobas, F¹, ¹ Simon Fraser University, Burnaby, BC, Canada² Institute for Ocean Sciences, Sidney, BC, Canada

ABSTRACT- Di-alkyl phthalate esters (DPEs) are high production volume chemicals used in a broad range of consumer and industrial products. DPEs are widely distributed in the environment and have been detected in organisms from an urban marine food web up to the low ppm (g/g lipid) level. DPEs are readily hydrolyzed to mono-alkyl phthalate esters (MPEs) in the digestive tract and tissues of many organisms, which prevents the biomagnification of parent DPEs within the food web. The distribution of MPE metabolites within the food web has not yet been characterized, partly due to a lack of analytical methods to extract MPEs from complex biological tissues. MPEs are not expected to biomagnify because they are likely to be further oxidized, glucuronidated and excreted in many species. However, their presence in wild biota is of particular interest since two MPEs, MBP and MEHP, have been linked to reproductive and other toxic effects in exposed organisms. Laboratory studies indicate that molar concentrations of several MPEs and DPEs are approximately equal in fish tissues at steady state, suggesting that total DPE + MPE body burdens in wild fish may be twice as high as expected from DPE measurements alone. Field data to test this hypothesis do not currently exist. This study examines the distribution of MPEs in a wide range of species from False Creek, an urban marine inlet in Vancouver BC Canada, using a recently developed method to extract MPEs from biological tissues. MPE concentrations are compared to previously determined DPE concentrations within the same food web. Congener ′fingerprints′ and MPE:DPE concentration ratios in individual species are compared to those from recent laboratory studies in Staghorn sculpin, and interpreted in terms of total phthalate exposure in wild fish.

Key words: mono-ester, phthalate ester, food web, aquatic