Single mild blast exposure can cause brain injuries similar to Alzheimer’s disease

Sep. 24, 2013 — A new study published in the September issue of the Journal of Alzheimer's Disease reports that even a single mild explosion can cause changes in the brain that have similarities to those found in diseases like Alzheimer's disease and chronic traumatic encephalopathy.

Flying debris or getting thrown against other objects are not the only things that make explosions so dangerous. The primary shock waves that emanate from explosions also can kill a person if they are intense enough. However, most blast survivors experience less powerful shock waves that cause less severe immediate symptoms, such as temporary disorientation or headaches, but on the surface leave victims apparently unscathed. Scientists are especially concerned when these mild blast exposures happen repeatedly--likening them to the repetitive hits endured by boxers and other athletes.

"Some of the big questions in mild traumatic brain injury are about a molecule called tau" said Dr. David Cook of VA Puget Sound Health Care System and University of Washington. "In many brain diseases, tau gets chemically modified to create something called 'phospho-tau'. Phospho-tau is important because it is the starting building block of 'tau tangles', which can build up over time and damage brain cells."

The Seattle team used a rodent laboratory model to study brain changes caused by mild blast exposure. Dr. Cook noted, "We were a bit surprised to find that after only a single mild blast, phospho-tau remained elevated for at least a month."

"Tau pathology is part of end-stage TBI," said Dr. Iboja Cernak of the University of Alberta, Canada and a co-author on this report, "so, it is very interesting to discover that persistent phospho-tau increases also appear to be part of earlier phases of blast-induced neurotrauma."

These new findings raise the possibility that early-intervention with tau-based treatments may someday prove valuable in treating blast-induced neurotrauma.

View the original article here

Car Ventilation Settings May Reduce Exposure to Pollution

FRIDAY, Sept. 13 (HealthDay News) -- Your car ventilation settings have a major effect on the levels of exposure to particulate pollution while driving, according to a new study.

Particulate pollution is the black, sooty smoke produced by diesel engines and coal-fired power plants.

In this study, researchers from the University of Southern California (USC) measured in-vehicle particulate pollution exposure in a wide range of car types and operating conditions.

"Short of driving less, putting your ventilation to 'recirculate' is the best way to reduce exposure to all types of vehicle-related particulate pollution," study senior author Scott Fruin, an assistant professor of preventive medicine at USC, said in a university news release.

"Otherwise, an hour-long commute to work or school can double your daily exposure to traffic-related particulate air pollutants," he added.

Compared to ventilation settings that bring in outside air, the "recirculate" setting reduced in-vehicle pollution from 80 percent of on-road levels to 20 percent for small-particle pollution and from 70 percent to 30 percent for larger particles, the researchers found.

The windows of the cars were always kept closed for the study. Keeping windows open while driving quickly raises inside pollutant concentrations to the same levels as on-road levels, the researchers said.

They also found that particulate pollution levels are lower in newer cars, at slower speeds and when driving on arterial roads instead of freeways. Pollution levels are five to 10 times higher on highways than in other locations, according to the researchers.

Leaving the windows closed over 30-minute or longer drives with several passengers raised carbon dioxide levels in the cars, Neelakshi Hudda, a research associate in the environmental health department at USC's Keck School of Medicine, said in the news release.

"Some people are sensitive to high [carbon dioxide] concentrations," Hudda said. "To prevent this, outside air should be pulled in every 10 or 15 minutes for a minute or two, especially if there are two or more people in the vehicle."

The study was published online recently in the journal Environmental Science & Technology.

More information

The U.S. Environmental Protection Agency has more about particulate pollution.

Copyright c 2013?HealthDay. All rights reserved.

View the original article here

Education May Protect Brain From Exposure to Solvents

AppId is over the quota
AppId is over the quota

TUESDAY, May 29 (HealthDay News) -- People with less than a high school education who work with solvents may have problems with their thinking skills later in life, according to a study of people in France.

In the study, researchers from Harvard University noted that people with more education did not experience the same types of issues with their thinking, or so-called "cognitive," skills, even if they had the same amount of exposure to these chemicals.

"People with more education may have a greater cognitive reserve that acts like a buffer, allowing the brain to maintain its ability to function in spite of damage," study author Lisa Berkman, of Harvard University in Cambridge, Mass., said in news release from the American Academy of Neurology. "This may be because education helps build up a dense network of connections among brain cells."

In conducting the study, the investigators followed more than 4,100 people who worked at the French national gas and electric company. While working at the company, the participants were exposed to four types of solvents: chlorinated solvents, petroleum solvents, benzene and non-benzene aromatic solvents.

The researchers assessed the workers' lifetime exposure to these solvents and tested their thinking skills when they were an average of 59 years old. By this time, 91 percent of the study participants were retired.

Most of those studied worked at the company for their entire career and 58 percent had less than a high school education. Of those without a high school diploma, the study revealed 32 percent had problems with their thinking skills. In contrast, only 16 percent of those with more education had similar thinking problems, the findings showed.

The study, published in the May 29 issue of Neurology, also found that high levels of exposure to chlorinated and petroleum solvents was associated with 14 percent greater risk for thinking problems among the less-educated workers, compared to their peers with no exposure.

Moreover, the less-educated workers with a high level of exposure to benzene were 24 percent more likely to have problems with their thinking skills, and those with significant exposure to non-benzene aromatic solvents were 36 percent more likely to have such problems.

"These findings suggest that efforts to improve quality and quantity of education early in life could help protect people's cognitive abilities later in life," Berkman said. "Investment in education could serve as a broad shield against both known and unknown exposures across the lifetime. This is especially important given that some evidence shows that federal levels of permissible exposure for some solvents may be insufficient to protect workers against the health consequences of exposure."

While the study uncovered an association between education level, solvent exposure and thinking skills, it did not prove a cause-and-effect relationship.

More information

The U.S. Department of Labor has more about the health effects of exposure to solvents.

Copyright c 2012?HealthDay. All rights reserved.