Exposure to Phthalates

FIGURE 7.6 Intake of DEHP by source for an adult. Ingestion with food is by far the most important mechanism of exposure. Source Reproduced with permission from Shea (2003). 

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Chronic Toxicity. The effects of repeated oral exposure to phthalates for periods ranging from a few days to 2 years have been studied in a number of animal species including rats, mice, hamsters, guinea pigs, ferrets, and dogs (37). 

In Franco et al. [15] it is concluded that the characterization models, like EUSES and ACC-human, underestimate human exposure to phthalate esters because they consider only a few key pathways. It is not known whether the more relevant pathways for phthalate esters are taken into account in the Usetox model ... 

Franco A, Prevedouros K, Alii R, Cousins IT (2007) Comparison and analysis of different approaches for estimating the human exposure to phthalate esters. Environ Int 33(3) 283—291... 

To evaluate human exposure to phthalates and their substitutes, the main approaches investigate either the levels of chemicals in matrices relevant for human exposure (indoor air, dust, food and packages, etc.) or the levels of parent and metabolite compounds in human samples (serum, urine, or breast milk). An overview of phthalate and nonphthalate plasticizers together with their metabolites commonly reported in literature is presented in Table 5. The half-lives for the most of these compounds are already established and therefore, by evaluating the levels of their metabolites in human urine, the levels of their parent compounds may be... 

Adibi JJ, Perera EP, Jedrychowski W, Camann DE, Barr D, Jacek R, Whyatt RB (2003) Prenatal exposures to phthalates among women in New York City and Krakow, Poland. Environ Health Perspect 111 1719-1722... 

Duty SM, Singh NP, Silva MJ, Barr DB, Brock JW, Ryan L, Herrick RE, Christiani DC, Hauser R (2003) The relationship between environmental exposures to phthalates and DNA damage in human sperm using the neutral comet assay. Environ Health Perspect 111 1164-1169... 

Duty SM, Calafat AM, Silva MJ, Brock JW, Ryan L, Chen Z, Overstreet J, Hauser R (2004) The relationship between environmental exposure to phthalates and computer-aided sperm analysis motion parameters. J Androl 25 293-302... 

Hauser R, Duty S, Godfrey-Bailey L, Calafat AM (2004) Medications as a source of human exposure to phthalates. Environ Health Perspect 112 751-753... 

Foster PM (2006) Disruption of reproductive development in male rat offspring following in utero exposure to phthalate esters. Int J Androl 29 140-147... 

David RM (2000) Exposure to phthalate esters. Environ Health Perspect 108 A440... 

Barr DB, Silva MJ, Kato K, Reidy JA, Malek NA, Hurtz D, Sadowski M, Needham LL, Calafat AM (2003) Assessing human exposure to phthalates using monoesters and then-oxidized metabolites as biomarkers. Environ Health Perspect 111 1148-1151... 

Weuve J, Sanchez BN, Calafat AM, Schettler T, Green RA, Hu H, HauserR (2006) Exposure to phthalates in neonatal intensive care unit infants urinary concentrations of monoesters and oxidative metabolites. Environ Health Perspect 114 1424—1431... 

If an analytic method lacks sufficient specificity, chemical interferences will result in an erroneously high reported concentration. If a measured chemical is introduced as an artifactual contaminant during sample collection or analysis, reported concentrations will also be overestimated. For example, credibly estimating human exposure to phthalates was hindered by the difficulties involved in avoiding specimen contamination with these ubiquitous chemicals the problem was resolved by focus on the much less prevalent metabolic product, the phthalate half-ester (Silva et al. 2004). Alternatively, a chemical measured as a marker of exogenous exposure may be identical with a chemical formed by an unrelated endogenous metabolic pathway. In each of those cases, a rigorous laboratory-method validation should detect the problem before data are reported. More subtly, the measured biomarker of exposure may be chemically identical with a dietary... 

Koo H and Lee B (2004) Estimated exposure to phthalates in cosmetics and risk assessment. Journal of Toxicology and Environmental Health A 67(23-24) 1901-1914. 

There are concerns regarding potential adverse health effects due to exposure to phthalates. particularly reproductive and developmental health effects. 

Schettler T. Human exposure to phthalates via consumer products. Int JAndrol 2006 29(1) 134-9. 

Because of its widespread use, relatively large amounts of these compounds are released into the environment and some of them enter the food chain. They have become ubiquitous in the environment.The most commonly used phthalates have been included in the list of priority pollutants in several countries. These are dimethyl- (DMP), diethyl- (DEP), di- -butyl- (DnBP), butylbenzyl- (BBP), bis(2-ethyUiexyl)- (DEHP), and di- -octyl (DnOP) phthalates. The United States Environmental Protection Agency (US EPA) has established a maximum admissible concentration (MAC) in water of 6 /rg/1 for DEHP." " In recent years, considerable attention has been paid to human exposure to phthalates because of the suspicion of its carcinogenic and estrogenic properties. " " ... 

The most common phthalate plasticisers are di-2-ethyl hexyl phthalate (DEHP), di-isodecyl phthalate (DIDP), and di-isononyl phthalate (DINP). Phthalate use has been controversial for years becanse of its snspected health hazards, especially in the case of DEEIP. In both wildlife and laboratory animals, phthalates have been linked to a range of reproductive health effects, with claims that most of them can function as an endocrine disrupting chemical (EDC), and also as cancer-causing agents (specifically in the liver and kidneys). Snch negative effects that phthalates are suspected to have on health have been attribnted to short ester chains (< C9). In fact, phthalates are already distributed worldwide in the environment. Some phthalates are even found in deep-sea jellyfish 1,000 meters below the surface of the North Atlantic Ocean. A number of studies have shown that most people are probably contaminated by substantial quantities of these chemicals, and yet for hnmans, no safe level of exposure to phthalates has been determined. There are also claims about the leaching of certain phthalate plasticisers from biomedical plastics (e.g., intravenous tubes) and hence directly into the patients bloodstream. In one snch stndy, it was shown that about 60% of the DEHP/DOP had migrated to the patient, while almost all of the bis (2-ethylhexyl) adipate (DOA) has been retained in the tnbe [28]. 

In the same year, in a US government journal, it was claimed for the first time that exposure to phthalates in the womb can affect sexual development in male infants, by suppressing male sexual hormones [41]. 

In some cases occupational exposures to phthalates have been associated with adverse health effects. A case-control study among a population of Danish workers employed in PVC production for 5 years or greater demonstrated a significant increase in the risk of multiple myeloma.Phthalate mixtures containing BBP have been associated with respiratory or neurological effects and cancer,increased incidence of menstrual disorders, and spontaneous abortions. " A stutfy of college students with no known exposure to phthalates found a ne tive correlation between DBP concentration and sperm density or total number of sperm. - However, this study did not consider con-founders nor did it provide ample evidence for a causal relationship of sperm characteristics to DBP levels. There were no human health data available for DEHP, DIDP, DINP, DnHP, norDnOP. 

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