Toxicity of phthalates

Fetal or infant exposure to phthalates was shown to be associated with reproductive or developmental health outcomes in males (e.g., correlation with shortened anogenital distance (Swan, 2006) or prematnre breast development (Colon et al., 2000)). Positive associations between phthalate metabolites in urine and symptoms of ADHD (Kim et al., 2009) as well as phthalate exposure and asthma or allergy (Bomehag et al., 2004) among school-age children have been reported. 

The major health impacts of phthalates supported by recent studies and showing an association significant at p 0.05 were summarized by Meeker et al. (2009b) as well as by Wargo (2008) and are shown in Table 7.7. A detailed discussion of the adverse impacts or mechanisms of endocrine disruption are beyond the scope of this chapter. Several excellent reviews (Committee on the Health Risks of Phthalates, National Research Council, 2001 Versar, Inc. and Syracuse Research Corporation, 2010) discuss the various biological impacts of exposure to phthalate. 

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The majority of studies on the acute and chronic toxicity of phthalates to aquatic organisms show no toxic effects at concentrations 200—1000 times the water solubiUty. However, there are some studies iadicatiag higher toxicity which are beheved to be due to the flotation and entrapment effects outlined above. 

Sediment Toxicity. Because of their low solubiUty ia water and lipophilic nature, phthalates tend to be found ia sediments. Unfortunately httle work has previously been carried out on the toxicity of phthalates to sediment dwelling organisms. Eor this reason ECPI has commissioned some sediment toxicity studies designed to measure the effect of DEHP and DIDP ia a natural river sediment on the emergence of the larvae of the midge, Chironomus riparius. 

The chemical industry uses esters for a variety of purposes. Ethyl acetate, for instance, is a commonly used solvent, and dialkyl phthalates are used as plasticizers to keep polymers from becoming brittle. You may be aware that there is current concern about possible toxicity of phthalates at high concentrations, although a recent assessment by the U.S. Food and Drug Administration found the risk to be minimal for most people, with the possible exception of male infants. 

Environmental aspects of PVC are examined on the basis of the findings of a number of studies carried out in Europe and the USA into recycling and waste disposal and the toxicity of phthalate plasticisers used in PVC toys and medical equipment. 

Dillingham EO, Autian J. 1973. Teratogenicity, mutagenicity, and cellular toxicity of phthalate esters. Environ Health Perspect 81-89. 

Shea, K.M. (2003). Pediatric exposure and potential toxicity of phthalate plasticizers, American Academy of Pediatrics, Technical Report, Pediatrics, 111, 6, 1467-1474. 

Martino-Andrade AJ, Chahoud I (2010) Reproductive toxicity of phthalate esters. Mol Nutr Food Res 54 148-157... 

Krauskopf LG Studies on the toxicity of phthalates via ingestion. Environ Health Per-spea 3 61-72, 1973... 

Gray, T.J.B. Gangolli, S.D. (1986) Aspects of the testicular toxicity of phthalate esters. 

The acute toxicity of phthalates is very low, exhibiting symptoms of somnolence and dyspnea in test animals only at high doses. Some of these substances are listed as U.S. EPA priority pollutants. 

Gray TJ, Rowland IR, Foster PM, et al. 1982. Species differences in the testicular toxicity of phthalate esters. Toxicol Lett 11 141-147. 

Parkerton, T. F. and Konkel, W. J., Application of quantitative structure-activity relationships for assessing the aquatic toxicity of phthalate esters, Ecotoxicol. Environ. Saf., 45, 61-78, 2000. 

The acnte toxicity of phthalate esters is very low. High doses may, however, pro-dnce somnolence, weight loss, dyspnea, and cyanosis. Animals administered large doses manifested weak developmental toxicity. Carcinogenicity was not observed in animal studies. The pure liquids are mild irritants to skin. The toxicity of some of these esters of commercial importance and listed as priority pollutants is discussed in brief in the following sections. It may be noted that phthalate esters are relatively harmless and are among the least toxic organic industrial products. 

The established use of flexible PVC in the manufacture of medical devices is increasingly threatened by doubts about the toxicity of phthalate plasticisers normally used in the PVC compounds concerned. For many years BIP Vinyls Limited have been working to develop alternative flexible PVC compounds using plasticiser systems which are more acceptable than standard phthalates. 

Phthalates are a group of chemicals most commonly used to soften PVC (the plastic polyvinyl chloride). In the textile industry they are used in artificial leather, rubber and PVC and in some dyes. There are substantial concerns about the toxicity of phthalates such as DEHP (Bis (2-ethylhexyl) phthalate), which is reprotoxic in mammals, as it can interfere with development of the testes in early life. The phthalates DEHP and DBP (Dibutyl phthalate) are classed as toxic to reproduction in Europe and their use is restricted. Under EU REACH legislation, the phthalates DEHP, BBP (Benzyl butyl phthalate) and DBP are due to be banned by 2015. 

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