The study explored possible reproductive and endocrine effects of short-term (5 days) oral exposure to anatase TiO₂ nanoparticles (0, 1, 2 mg/kg body weight per day) in rat. Nanoparticles were characterised by scanning electron microscopy (SEM) and transmission electron microscopy, and their presence in spleen, a target organ for bioaccumulation, was investigated by single-particle inductively coupled plasma mass spectrometry and SEM/energy-dispersive X-ray. Analyses included serum hormone levels (testosterone, 17-β-estradiol and triiodothyronine) and histopathology of thyroid, adrenals, ovary, uterus, testis and spleen. Increased total Ti tissue levels were found in spleen and ovaries. Sex-related histological alterations were observed at both dose levels in thyroid, adrenal medulla, adrenal cortex (females) and ovarian granulosa, without general toxicity. Altered thyroid function was indicated by reduced T3 (males). Testosterone levels increased in high-dose males and decreased in females. In the spleen of treated animals TiO₂ aggregates and increased white pulp (high-dose females) were detected, even though Ti tissue levels remained low reflecting the low doses and the short exposure time. Our findings prompt to comprehensively assess endocrine and reproductive effects in the safety evaluation of nanomaterials.

The potential hazardous effects that estrogen- and androgen-like chemicals may have both on wildlife and human health have attracted much attention from the scientific community. Endocrine disruptors (EDCs) are chemicals that have the capacity to interfere with normal signalling systems. EDCs may mimic, block or modulate the synthesis, release, transport, metabolism and binding or elimination of natural hormones. Even though potential EDCs may be present in the environment at only very low levels, they may still cause harmful effects, especially when several different compounds act on one target. EDCs include persistent pollutants, agrochemicals and widespread industrial compounds. Not all EDCs are man-made compounds; many plants produce substances (phytoestrogens) that can have different endocrine effects either adverse or beneficial in certain circumstances. Natural substances such as sex hormones from urban or farm wastes can become concentrated in industrial, agricultural and urban areas; thus, such wastes may be considered potential ‘EDCs’ for humans and/or wildlife. Much attention has focussed on changing trends in male reproductive parameters in relation to EDC exposure; however, studies on the female reproductive system have been less comprehensive. We have focussed this article on four major aspects of female reproductive health: fertility and fecundability, endometriosis, precocious puberty and breast and endometrial cancer.

There is significant evidence that continuous and prolonged exposure to several endocrine disrupting chemicals (EDC) is a risk factor for reduced fertility and fecundity in women. There is also evidence that ED exposure has trans-generational effects. In this systematic review, we evaluate the evidence for an association between EDC exposure and women's reproductive health. Studies were found by searching the PubMed database for articles published up to 2010. Associations between ED exposure and women's reproductive health reported in the PubMed database are summarized and classified as fertility and fecundity, pregnancy outcomes, transgenerational exposure and effects. Epidemiological studies on EDCs are not always consistent, in part due to limitations imposed by practical constraints. In order to make progress in this field, we recommend taking advantage of biomonitoring and biobanks, including the development of appropriate biomarkers, and taking into greater consideration modulating factors such as genetic polymorphisms and dietary habits. Further human studies are warranted with particular focus on impaired fertility/fecundity associated with currently widespread ED (e.g. bisphenol A, phthalates and polybrominated flame retardants). A detailed appraisal of compounds specifically related to adverse reproductive outcomes is very important for prevention and risk-communication strategies. Besides research needs, the current evidence is sufficient to prompt precautionary actions to protect women's reproductive health.

Organophosphorus insecticides, as Chlorpyrifos (CPF), are widely used in agriculture and against household pests; these compounds receive an increasing consideration as potential endocrine disrupters. The aim of the present study was to examine the potential short- and long-term effects of CPF on thyroid and adrenal glands in CD1 mice following exposure at dose levels not inducing brain acetyl cholinesterase (AchE) inhibition, during gestational and/or postnatal vulnerable phases. Pregnant dams were treated with 0, 3, 6 mg/kg bw/day of CPF on gestational days 15–18. After delivery, pups were treated subcutaneously on postnatal days (PND) 11–14 with: 0, 1, 3 mg/kg bw/day of CPF. Serum thyroxin (T4), thyroid and adrenals histology and histomorphometry were evaluated in dams and in F1 mice. In dams at 6 mg/kg, decreased T4 levels and increased cell height in thyroid were observed, and adrenal histology showed a slightly increased vacuolization in the X-zone. In the F1, short-term morphological modifications (reduced follicular size at PND 2) and long-term morphological (increased necrotic follicular cells) and biochemical alterations (reduced serum T4 levels) were found at PND 150 with an apparent higher vulnerability of males. For the first time these results indicate that CPF exposure at dose levels not inducing brain AchE inhibition causes thyroid alterations in dams and in F1 CD1 mice. Thyroid may be a sensitive target to CPF developmental exposure possibly leading to long-term effects on thyroid function. Because thyroid plays a pivotal role in mammalian development, these findings can be relevant to humans.