Reproductive and Developmental Toxicity of Phthalates

The purposes of this review are to (1) evaluate human and experimental evidence for adverse effects on reproduction and development in humans, produced by exposure to phthalates, and (2) identify knowledge gaps as for future studies. The widespread use of phthalates in consumer products leads to ubiquitous and constant exposure of humans to these chemicals. Phthalates were postulated to produce endocrine-disrupting effects in rodents, where fetal exposure to these compounds was found to induce developmental and reproductive toxicity. The adverse effects observed in rodent models raised concerns as to whether exposure to phthalates represents a potential health risk to humans. At present, di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), and butyl benzyl phthalate (BBP) have been demonstrated to produce reproductive and developmental toxicity; thus, this review focuses on these chemicals. For the general population, DEHP exposure is predominantly via food. The average concentrations of phthalates are highest in children and decrease with age. At present, DEHP exposures in the general population appear to be close to the tolerable daily intake (TDI), suggesting that at least some individuals exceed the TDI. In addition, specific high-risk groups exist with internal levels that are several orders of magnitude above average. Urinary metabolites used as biomarkers for the internal levels provide additional means to determine more specifically phthalate exposure levels in both general and high-risk populations. However, exposure data are not consistent and there are indications that secondary metabolites may be more accurate indicators of the internal exposure compared to primary metabolites. The present human toxicity data are not sufficient for evaluating the occurrence of reproductive effects following phthalate exposure in humans, based on existing relevant animal data. This is especially the case for data on female reproductive toxicity, which are scarce. Therefore, future research needs to focus on developmental and reproductive endpoints in humans. It should be noted that phthalates occur in mixtures but most toxicological information is based on single compounds. Thus, it is concluded that it is important to improve the knowledge of toxic interactions among the different chemicals and to develop measures for combined exposure to various groups of phthalate

HENVINET. Evaluation questionnaire - causal chain for phthalates.

The HENVINET consortium has developed a questionnaire to identify knowledge gaps in the state of the art in scientific knowledge. Literature reviews covered all elements that compose the causal chain of the different environmental health issues from emissions to exposures, to effects and to health impacts. Ultimately, the aim is to discuss the implications of these for policy and research. In this evaluation we focus on the cause¿effect relationship between phthalates in the environment and endocrine disruption in humans. The questionnaire consists of two separate parts. In Part A, you will be asked to comments on the completeness and structure of a diagram illustrating our current understanding of the cause¿effect relationship. In Part B, you will be asked to express your level of confidence in the scientists¿ ability to predict the magnitude of a variety of effects of phthalates in the environment

Dioxins, PCBs, chlorinated pesticides and brominated flame retardants in free-range chicken eggs from peri-urban areas in Arusha, Tanzania: Levels and implications for human health

The environment in the northern part of Tanzania is influenced by rapid population growth, and increased urbanization. Urban agriculture is common and of economic value for low income families. In Arusha, many households sell eggs from free-ranging backyard chicken. In 2011, 159 eggs from different households in five different locations in Arusha were collected, homogenized, pooled into 28 composite samples and analyzed for a wide selection of POPs. Levels of POPs varied widely within and between the locations. The levels of dieldrin and σDDT ranged between 2 and 98,791 and 2 and 324 ng/g lipid weight (lw), respectively. EU MRLs of 0.02 mg/kg dieldrin for eggs were exceeded in 4/28 samples. PCBs, HCHs, chlordanes, toxaphenes and endosulfanes were found at lower frequency and levels. Brominated flame retardants (BFRs), e.g polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD) and 1,2-bis(2,4,6-tribromphenoxy)ethane (BTBPE) were present in 100%, 60% and 46% of the composite samples, respectively. Octa-and deca-BDEs were the dominating PBDEs and BDE 209 levels ranged between <. LOQ (limit of quantification) - 312 ng/g lw. Dioxins were measured using the DR-LUC bio-assay and found in levels of <. LOQ - 20 pg bio-TEQs/g lw. Four samples (13%) exceeded the maximum level of 5 pg/g total WHO-TEQs for hen eggs set by the Commission Regulation (EU) No 1259/2011. The daily/weekly intake was calculated and risk was characterized for all compounds comparing with available toxicity reference values (TRVs) such as the provisional tolerable intake (PTDI) or Reference Doses (RfDs). In one sample dieldrin exceeded the PTDI (100 ng/kg bw/day). Correlation was found between bio-TEQs and lipid adjusted levels of σPBDEs, suggesting similar sources. Open fires in backyards may be one of the sources for contamination of eggs with BFRs and dioxins