Over recent decades there has been a dramatic increase in the production of industrial and agricultural chemicals and heavy metals, and this has coincided with widespread reports of breeding problems in wild animals. Fertility also appears to be declining among humans and there has also been a rise in reproductive defects observed in newborn babies.
Until now, most studies have looked at a short-lived exposure to high doses of single compounds, and have usually done so in mice and rats. Dr. Fowler and his colleagues decided to study the effect of long-term, low-level exposure to a cocktail of chemicals and heavy metals in an animal which has a long pregnancy, therefore better replicating the situation in the human.
“Our ‘real life’ model exposed developing sheep fetuses by pasturing their mothers on fields fertilised with either inorganic fertiliser, the control group, or, in the case of the treatment group, with digested human sewage sludge, before and during pregnancy”, said Dr. Fowler.
“ We examined the ovaries from the fetuses at day 110 of gestation, the equivalent of week 27 in a human pregnancy, and found that the ovaries from the fetuses where the mother was grazing the sewage sludge fields contained fewer eggs and also a number of protein abnormalities. These differences could have implications for problems such as cancer in later life.”
The scientists hope that their Wellcome Trust-funded study will help to pinpoint the stages of pregnancy at which the developing fetus is most sensitive to disruption and also to measure the degree to which fertility is affected in the offspring after puberty, following their exposure as fetuses to environmental concentrations of a mixture of pollutants. “Switching some mothers from sewage sludge fertilised to control pastures before conception will tell us whether maternal exposure either before or during pregnancy does most damage to the offspring”, said Dr. Fowler. “The sheep model is quite novel, with relatively little research in the area currently being performed in this way. One of the collaborators in the project, Professor Richard Sharpe from the MRC Human Reproductive Sciences Unit in Edinburgh, UK, has already found reduced testosterone and testis cell numbers in the male fetus exposed to sewage sludge at day 110 of gestation.
The group has applied for further funding to look more closely at the implications of the sheep findings for humans, for instance by comparing quantities of chemicals in the human fetus with those seen in sheep, and investigating whether changes induced in the sheep fetus could be a problem for the developing human. They also intend to look at the mechanisms by which exposure to environmental chemicals can cause defects in reproductive development in order to determine what might be done to reduce risks for the human fetus.
There is still considerable debate around the level of importance of environmental chemicals in cancer, obesity, infertility and other complex diseases which have multiple causes. “We hope our research will help in the drive for evidence-based policy making on this issue”, said Dr Fowler. “If we can definitely establish that environmental chemicals are important in triggering these diseases, then we might be able to produce better treatments, but it would also be important to devise legislation to begin reducing the levels of such chemicals. We would then look to work with chemical and agricultural industries to find safer chemicals by improving how they assess fetal development effects. If such measures helped to reduce the rates of cancer, obesity and infertility, there would be considerable benefits in terms of the costs of healthcare.”
Mary Rice | EurekAlert!
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses