The U-M School of Public Health study also reported suggestive findings consistent with a previously reported link between a chemical called bisphenol-A and thyroid hormone levels. BPA is best known for its use in certain plastic water bottles and in the linings of canned foods.
Researchers used publicly available data from the U.S. National Health and Nutrition Examination Survey to compare urine metabolites and serum thyroid measures from 1,346 adults and 329 adolescents. Generally speaking, greater concentrations of urinary phthalate metabolites and BPA were associated with greater impacts on serum thyroid measures, said John Meeker, assistant professor at U-M SPH and lead study author.
Specifically, researchers found an inverse relationship between urinary markers of exposure and thyroid hormone levels, meaning as urinary metabolite concentrations increased, serum levels of certain thyroid hormone levels decreased.
Phthalates and BPA are chemical compounds that appear in solvents, plasticizers and common household products. These latest results were consistent with findings from previous smaller studies by Meeker and others that suggested the relationship.
The current study showed the strongest relationship between thyroid disruption and DEHP, a phthalate commonly used as a plasticizer. Research has shown that the primary exposure to DEHP is through diet. Urine samples in the highest 20 percent of exposure to DEHP were associated with as much as a 10 percent decrease in certain thyroid hormones compared to urine samples at the lowest 20 percent of exposure.
"This seems like a subtle difference," Meeker said, "but if you think about the entire population being exposed at this level you'd see many more thyroid related effects in people."
Researchers looked at another phthalate called DBP but overall, didn't find a significant relationship between exposure and thyroid measures. DBP is also a plasticizer, and is also used in solvents and personal care products.
Thyroid hormones play an important role in many body functions, from reproduction to metabolism and energy balance.
While the study focused primarily on adults, these findings underscore the need for more research on adults, pregnant women, and children, Meeker said, because fetal and child development may be particularly vulnerable to disruptions in thyroid hormone levels associated with exposure to environmental chemicals.
Meeker pointed out that the study had limitations. Since urine and serum samples were collected at a single point in time, researchers couldn't conclude a cause-and-effect relationship; it would be better to follow people over time and collect several samples, especially since these chemicals metabolize quickly and one snapshot may not represent the true chemical exposure.
The group has several ongoing studies on the potential impacts of phthalate and BPA exposure on pregnancy outcomes and child development.
The paper appears on the recent edition of the journal Environmental Health Perspectives.
The University of Michigan School of Public Health has been promoting health and preventing disease since 1941, and is ranked among the top public health schools in the nation. Whether making new discoveries in the lab or researching and educating in the field, our faculty, students, and alumni are deployed around the globe to promote and protect our health http://www.sph.umich.edu/
Laura Bailey | EurekAlert!
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering