Many young men have a low sperm count and more and more boys are born with malformed sexual organs. A little less than five per cent of all Danish boys are, for example, born with hypospadias, where the opening of the urethra is on the underside of the penis. Substances disturbing the hormonal balance during the foetal development have long been suspected of being one of the causes of such birth defects.
"Several animal tests have shown that endocrine-disrupting chemicals, which have an effect on the male sex hormone testosterone, can result in such malformations in young male rats. In vitro testing and short-term animal testing have also suggested that concurrent exposure to several chemical substances can result in endocrine-disrupting effects even if exposure to each individual substance does not show any effect. We are now able to document that this is actually the case," says Ulla Hass, senior scientist at the National Food Institute, Technical University of Denmark.Significant cocktail effects
The three chemicals were administered in doses which are harmless individually. Concurrent exposure to the three substances did, however, show significant cocktail effects. The male rats did, among other things, develop female characteristics in the form of retained nipples and severely malformed external sexual organs. Sixty per cent of the male rats were, for example, born with hypospadias.Underestimated risk
"Our studies show that concurrent exposure to several endocrine-disrupting substances in small doses can increase the frequency of malformations such as hypospadias even though the doses are harmless individually. It is therefore not sufficient to establish reference values only by looking at one substance at a time," concludes Sofie Christiansen, PhD student at the National Food Institute, Technical University of Denmark.
"In order not to underestimate the risk of chemicals to humans, it is important to include the possible concurrent exposure of two or more chemicals in the risk assessment. To establish an adequate protection level for consumers, potential cocktail effects should be taken into account, and thus the way a chemical may interact with other chemicals," adds Ulla Hass.
Ulla Hass | alfa
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine