Endocrine disruptors and abnormalities of pubertal development

Sustainability, substance-flow management, and time, Part II: Temporal impact assessment (TIA) for substance-flow management

High-quality food and general good health are fundamental needs that have to be satisfied if society is to attain a high standard of living. Accordingly, a great deal of effort is expended in order to guarantee a high quality of food and ensure healthy living conditions. Among other things, these efforts entail massive substance flows. Significant substance flows are connected with the production and consumption of food and can be regarded from an economic, social, or environmental point of view. Substance flows are a part of both nature and the anthroposphere. This study demonstrates that food production at present is not linked to societal issues of production and sustainability; rather, it shows that a systematic approach and an analysis of issues and measures to be taken are required. This interconnectedness can be described as a timescape, in analogy to a landscape. For proper orientation in a landscape, a map is helpful, especially in combination with a compass. In the same way, we need a temporal orientation. Time scales serve as a compass to give orientation. A complete temporal analysis that includes all relevant temporalities provides the information that is encoded in a map. What has to be learned and exercised is the reading of such temporal maps. One method of doing this is temporal impact analysis (TIA). Temporal impact analysis brings issues that are not normally focused on into the foreground. It allows a better understanding of the implications of certain substance flows and the measures necessary for their management, and it provides an opportunity to develop a more sustainable management of substance flows.

The influence of endocrine disruptors on pubertal timing

PURPOSE OF REVIEW

Overview of the effects of endocrine disruptors on pubertal timing.

RECENT FINDINGS

Epidemiologic studies in humans support animal data demonstrating that exposures to endocrine-disrupting compounds have pronounced effects on pubertal timing and that the timing of endocrine-disrupting compound exposure and the specific agent causes different outcomes. Recent studies confirm subtle effects of lead, dioxins, and phytoestrogens on delaying onset of puberty and demonstrate an association of phthalates and polychlorinated biphenyls with earlier breast development and menarche, respectively. These studies, however, are complicated by mixed exposures of compounds which individually may have opposing actions on the reproductive axis.

SUMMARY

Animal and human data confirm perturbations in pubertal onset with exposures to endocrine-disrupting compounds.

Delayed initiation of breast development in girls with higher prenatal dioxin exposure; a longitudinal cohort study

OBJECTIVES

While many studies have assessed the health impacts of PCDD/Fs and PCBs on animals and humans, long-term consequences for especially adolescents, have not (yet) been well documented. This is certainly also true for the effects of PBDE exposure. As part of a longitudinal cohort study, now well into its second decade, effects of perinatal and current PCDD/F exposure, as well as current dl-PCB and PBDE exposures, on puberty, were assessed.

STUDY DESIGN

Prenatal, lactational and current PCDD/F, dl-PCB and PBDE concentrations were determined using GC-MS. Pubertal development and growth were assessed by means of physical examination and the Tanner scale. 33 Children (born between 1986 and 1991) consented to the current follow-up study. Outcomes were evaluated using linear regression or the non parametric Spearman's correlation coefficient.

RESULTS

A delay in initiation of breast development was found in girls (n = 18) with higher prenatal (p = 0.023) and lactational PCDD/F exposure (p = 0.048). The males revealed a negative trend with age at first ejaculation. For other endpoints on puberty and growth (pubic hair, axillary hair, genital stage, length, BMI, testicular volume, menarche) no significant relation was found with any of the measured compounds.

DISCUSSION AND CONCLUSION

A relation between prenatal PCDD/F exposure and later initiation of breast development was seen. A Belgian study found a delay in breast development with higher current serum concentrations of dioxin-like compounds. The initiation of puberty is a complex process and it is yet not clear how dioxin-like compounds precisely affect this process prenatally. Further follow-up into adulthood is warranted, in order to detect the possibility of developing malignancies and fertility problems.

Persistent, bioaccumulative and toxic substances in fish: human health considerations

Fish are important dietary items that provide essential nutrients. Fish however, bioaccumulate monomethyl mercury (MMHg) and organo-halogenated pollutants (OHP) that are persistent bioaccumulative and toxic substances (PBTS). Unlike man-made OHP, MMHg is mainly of natural origin but background concentrations of aquatic systems are determined by the environmental Hg-methylating potential. Industrial activities can modulate environmental discharges and fish bioaccumulation of PBTS. Fish and seafood consumption are associated with human body load of PBTS, but farming practices that utilize fishmeal increase the terrestrial food chain resulting in farm-animal accumulation of PBTS. These substances are neurotoxic and endocrine active that can impact humans and wild life, but chemical characteristics of MMHg and OHP modulate interactions with animal tissues. MMHg is protein reactive with a faster metabolism (months) than OHP that are stored and slowly (years) metabolized in fat tissues. Except for brain-Hg, neither Hg nor OHP in tissues are markers of toxic effects; however, deficits in neurobehavioral test-scores of children have been shown in some fish-eating populations. These deficits are transient and within normal range, and are not prodromes of neurological diseases. Although population studies show that consumption of fish at current levels of contamination do not explain neurological disorders, endocrine activity remains controversial. Understanding risk of hazard caused by fish-PBTS consumption requires a wide range of expertise. We discuss chemical, toxic, metabolic, and ecological characteristics associated with PBTS in fish. There are proven health outcome derived from fish consumption, while risk of exposure to avoidable PBTS is a chance that can be minimized by societal actions.