China
Africa
Explore chapters and articles related to this topic
Evaluation of Food and Food Contaminants
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
Several chemicals commonly encountered in the environment have been associated with altered endocrine function in animals and humans, and exposure to some endocrine-disrupting chemicals may result in adverse effects on reproduction, fetal/child development, metabolism, neurologic function, and other vital processes.530 Recent attention to the potential risks that environmental chemicals may pose to reproductive and developmental health has also been driven by reports of temporal downward trends in semen quality481,531 and male testosterone levels532,533; increased rates of development anomalies of the reproductive tract, specifically hypospadias and cryptorchidism534; and increased rates of testicular cancer.535–537 Public and scientific concern also stems from recent reports of inexplicable increases in the rates of thyroid cancer,538,539 congenital hypothyroidism,540 and neurologic development disorders such as autism.541 Not only do these studies report temporal trends, but many also describe wide geographic variability in these measures and trends, which provides further evidence that environmental factors may play a role.
Feasibility of Advanced Water Purification Processes
Published in Frank R. Spellman, Land Subsidence Mitigation, 2017
Data on semen quality collected systematically from reports published worldwide indicate clearly that sperm density declined appreciably from 1938 to 1990, although we cannot conclude whether or not this decline is continuing today. Concomitantly, the incidence of some genitourinary abnormalities including testicular cancer and possibly also maldescent (faulty descent of the testicle into the scrotum) and hypo- spadias (abnormally placed urinary meatus) has increased. Such remarkable changes in semen quality and the occurrence of genitourinary abnormalities over a relatively short period are probably due more to environmental rather than genetic factors. Some common prenatal influences could be responsible both for the decline in sperm density and for the increase in cancer of the testis, hypospadias, and cryptorchidism (one or both testicles fail to move to scrotum). Whether estrogens or compounds with estrogen-like activity or other environmental or endogenous factors damage testicular function remains to be determined (Carlson et al., 1992). Even though we do not know what we do not know about endocrine disruptors, it is known that the normal func- tions of all organ systems are regulated by endocrine factors, and small disturbances in endocrine function, especially during certain stages of the life cycle such as devel- opment, pregnancy, and lactation, can lead to profound and lasting effects. The criti- cal issue is whether sufficiently high levels of endocrine-disrupting chemicals exist in the ambient environment to exert adverse health effects on the general population.
Scope of the Problem
Published in Jason W. Birkett, John N. Lester, Endocrine Disrupters in Wastewater and Sludge Treatment Processes, 2002
One of the main reasons for concern is the possible effect EDCs may have on human health. Endocrine disrupting chemicals are now being linked as potentially responsible for various human health problems, so should we be concerned? Environmental chemicals with endocrine activity are thought to be responsible for the decrease in the quality and quantity of human sperm during the past 40 years. A study by Carlsen et al. 63 examined sperm quality over the last 50 years from 61 studies and found that there was a decrease in sperm quality and quantity over this period. However, according to Handelsman,62 this meta analysis is marred by numerous flaws that invalidate its claims. Major defects include severe heterogeneity of component studies, rendering them unsuitable for aggregation, and defective analysis of data which showed no significant changes over time. Therefore, the data did not support the claim of falling sperm counts or any deterioration in male health. The question of whether sperm quality has actually declined is likely to remain unanswered until valid, representative, population-based studies of human sperm output can be produced. Other human health effects include increases in testicular and prostate cancer,64,65,161 cryptorchidism (undescended testes),65 hypospadias (penis malformation),65,162 and female breast cancer.163 However, none of these effects has been shown to have a definite cause–effect relationship with EDCs.
Per- and polyfluoroalkyl substances and male reproductive health: a systematic review of the epidemiological evidence
Published in Journal of Toxicology and Environmental Health, Part B, 2020
Kajsa Ugelvig Petersen, Josefine Rahbæk Larsen, Laura Deen, Esben Meulengracht Flachs, Katia Keglberg Hærvig, Sidsel Dan Hull, Jens Peter Ellekilde Bonde, Sandra Søgaard Tøttenborg
Selected characteristics of all 26 studies included in our qualitative analysis of associations between exposure to PFAS and male reproductive health are shown in Table 1. Nineteen studies were cross-sectional, 4 were case-control studies, and 3 were cohort studies. Twelve studies were conducted in Europe (including Greenland), 8 in the United States of America, and 6 in Asia. The included study populations were exposed either occupationally (Barry, Winquist, and Steenland 2013; Costa, Sartori, and Consonni 2009; Olsen et al. 1998; Sakr et al. 2007) or through other environmental sources. Most investigators reported measures of association for semen quality (n = 13) and/or reproductive hormones (n = 17). Only few contributed information on cryptorchidism, hypospadias, and testicular cancer (Tables 2–4).
Maternal bisphenol A exposure disrupts spermatogenesis in adult rat offspring
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Patricia De Campos, Isabela M. Oliveira, Janaina Sena de Souza, Rodrigo Rodrigues Da Conceição, Gisele Giannocco, Maria I Chiamolera, Magnus R.Dias-Da Silva, Marco A. Romano, Renata Marino Romano
The incidence of male reproductive disorders, such as cryptorchidism, hypospadias, testicular cancer, and low sperm count, has progressively increased, and these conditions may arise during fetal development (Kortenkamp 2017). The perinatal period is a sensitive and vulnerable window of time during development that includes a crucial period involving hypothalamic sexual differentiation, during which imbalances in sexual hormones may exert an impact on fertility in adulthood (Bellingham et al. 2016). These abnormalities in the male reproductive tract may be related to the increased presence of natural and synthetic chemicals in the environment, known as endocrine-disrupting chemicals (EDCs) (Ena et al. 2018; Guo et al. 2017; Main et al. 2010; Sifakis et al. 2017; Yoon et al. 2014). Endocrine-disrupting chemicals produce toxicity at low doses in specific tissues that are not traditionally observed with other drugs because of the complex dynamics of hormone receptor occupation and saturation (Schug et al. 2011; Welshons et al. 2003). Therefore, EDC may interfere with the functionality of the endocrine system, producing alterations in development, behavior, and reproduction in both humans and animals (Kortenkamp 2017).
Windows of sensitivity to toxic chemicals in the development of reproductive effects: an analysis of ATSDR’s toxicological profile database
Published in International Journal of Environmental Health Research, 2018
Melanie C Buser, Henry G Abadin, John L Irwin, Hana R Pohl
Chemically induced effects on the development of the male reproductive system were studied in 34 total studies following exposure to 13 different chemicals (Figure 4). The majority of the studies utilized the rat as the model organism (n = 28). The main effect noted in these studies related to alterations in testicular development, as well as hypospadias and cryptorchidism. Sixteen studies exposed animals during gestation only, and half of these studies utilized single-day exposures; 11 studies observed effects in animals exposed during gestation through lactation, with a few extending into adulthood. Single-day exposures on any of GD6 (Kuriyama et al. 2005), GD8 (Gray and Ostby 1995), GD15 (Mably et al. 1992; Bjerke and Peterson 1994; Bjerke et al. 1994; Ohsako et al. 2002), or GD18 (Ohsako et al. 2002) impaired proper development of the male reproductive system. The most common single-day exposure was on GD15 with four studies exposing animals on this day, suggesting that this represents a sensitive window for chemical exposure. Furthermore, all but seven of the other studies had exposure periods that included GD15, thus providing additional support that GD15 may represent a sensitive window for developmental effects in the reproductive system following chemical exposure.