Abstract
Phthalates are chemical additives to common consumer goods including cleaning products, cosmetics, personal care products, and plastic. Because they are not chemically bound to these products and are widely used, the potential for environmental contamination is significant. Phthalates and their metabolites have been associated with endocrine disruption and reproductive impairment, among other adverse health effects, in laboratory animals and human epidemiologic studies. Common bottlenose dolphins (Tursiops truncatus) are vulnerable to environmental pollutants due to their apex position in the food chain, long life spans, and habitat overlap with developed coastal areas. The objective of this study was to quantify phthalate metabolite concentrations in urine collected from bottlenose dolphins in Sarasota Bay, Florida, during May 2016 (n = 7) and May 2017 (n = 10). Screening of nine phthalate monoester metabolites in bottlenose dolphin urine was performed by liquid chromatography tandem mass spectrometry using methods adapted from those used for analyzing human samples. At least one phthalate metabolite was detected in 71% of the dolphins sampled across both years, with the highest concentrations detected for monoethyl phthalate (MEP; GM = 5.4 ng/ml; 95%CI: 1.3-22.0 ng/ml) and mono-(2-ethylhexyl) phthalate (MEHP; GM = 1.9 ng/ml; 95%CI: 1.1-3.2 ng/ml). These data demonstrate exposure to two of the most commonly used phthalates in commercial manufacturing, diethyl phthalate (DEP) and di-2-ethylhexyl phthalate (DEHP). This study establishes methods for urinary detection of phthalate metabolites in marine mammals and provides baseline data to address a significant and growing, yet poorly understood, health threat to marine wildlife.