Chapter 13 - Di(2-ethylhexyl)phthalate in the Ocean

Abstract

Di(2-ethylhexyl)phthalate (DEHP), also called bis(2-ethylhexyl)phthalate or 1,2- benzenedicarboxylic acid bis(2-ethylhexyl) ester, is a synthetic diester of o-phthalic acid (1,2-benzenedicarboxylic acid). Although phthalic acid and a few dialkyl esters may be natural products, DEHP is not known to be a synthetic or diagenic product of any organism. DEHP was introduced commercially in 1949 and production has increased steadily since then. Consumption in Western Europe alone was 400,000 to 500,000 metric tons in the late 1990s. Large amounts of DEHP also are released to the environment during incomplete incineration of plastics or by leaching directly into water. Because of the large amounts manufactured and its facile release to the environment, DEHP has become a ubiquitous trace contaminant in the environment. The estimated annual flux of DEHP to the Gulf of Mexico in 1977 was approximately 230 metric tons; 49 tons from riverine inputs, 25 tons from ocean dumping, and 76 to 161 tons from aerial deposition. Ocean dumping in the western Gulf of Mexico was banned in the 1980s, eliminating this source of DEHP. Because phthalates are so widely distributed in the environment and because they have a high affinity for adsorption to surfaces, they are very difficult to be analyzed at trace levels in environmental samples. Therefore, in reviewing the data on the distribution of DEHP in the ocean and its bioaccumulation by and toxicity to marine organisms, it is important to recognize that much of the data may provide anomalously high measures of DEHP concentrations in the natural environment.