A good night’s rest may literally clear the mind. Using mice, researchers showed for the first time that the space between brain cells may increase during sleep, allowing the brain to flush out toxins that build up during waking hours. These results suggest a new role for sleep in health and disease. The study was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the NIH.
“Sleep changes the cellular structure of the brain. It appears to be a completely different state,” said Maiken Nedergaard, M.D., D.M.Sc., co-director of the Center for Translational Neuromedicine at the University of Rochester Medical Center in New York, and a leader of the study.
For centuries, scientists and philosophers have wondered why people sleep and how it affects the brain. Only recently have scientists shown that sleep is important for storing memories. In this study, Dr. Nedergaard and her colleagues unexpectedly found that sleep may be also be the period when the brain cleanses itself of toxic molecules.
Scientists watched dye flow through the glymphatic system, a brain “plumbing” system, of a mouse when it was asleep and then, later, when it was awake. More dye flowed into the brain during sleep. Results from this study suggest the brain may flush out toxic molecules associated with neurodegenerative disorders during sleep.
Their results, published in Science, show that during sleep a “plumbing” system, called the glymphatic system, may open, letting fluid flow rapidly through brain. Dr. Nedergaard’s lab recently discovered the glymphatic system helps control whether cerebrospinal fluid (CSF), a clear liquid surrounding the brain and spinal cord, flows through the brain.
“It’s as if Dr. Nedergaard and her colleagues have uncovered a network of hidden caves and these exciting results highlight the potential importance of the network in normal brain function,” said Roderick Corriveau, Ph.D., a program director at NINDS.
Initially the researchers studied the system by injecting dye into the CSF of mice and watching it flow through their brains while simultaneously monitoring electrical brain activity. The dye flowed rapidly when the mice were unconscious, either asleep or anesthetized. In contrast, the dye barely flowed when the same mice were awake.
“We were surprised by how little flow there was into the brain when the mice were awake,” said Dr. Nedergaard. “It suggested that the space between brain cells changed greatly between conscious and unconscious states.”
To test this idea, the researchers inserted electrodes into the brain to directly measure the space between brain cells. They found that the space inside the brains increased by 60% when the mice were asleep or anesthetized.
“These are some dramatic changes in extracellular space,” said Charles Nicholson, Ph.D., a professor at New York University’s Langone Medical Center and an expert in measuring the dynamics of brain fluid flow and how it influences nerve cell communication.
Certain brain cells, called glia, control flow through the glymphatic system by shrinking or swelling. Noradrenaline is an arousing hormone that is also known to control cell volume. Treating awake mice with drugs that block noradrenaline induced sleep and increased brain fluid flow and the space between cells, further supporting the link between the glymphatic system and sleep.
Previous studies suggest that toxic molecules involved in neurodegenerative disorders accumulate in the space between brain cells. In this study, the researchers tested whether the glymphatic system controls this by injecting mice with radiolabeled beta-amyloid, a protein associated with Alzheimer’s disease, and measuring how long it lasted in their brains when they were asleep or awake. Beta-amyloid disappeared faster in mice brains when the mice were asleep, suggesting sleep normally clears toxic molecules from the brain.
“These results may have broad implications for multiple neurological disorders,” said Jim Koenig, Ph.D., a program director at NINDS. “This means the cells regulating the glymphatic system may be new targets for treating a range of disorders.”
The results may also highlight the importance of sleep. “We need sleep. It cleans up the brain,” said Dr. Nedergaard.
GHS OSHA Hazard Communication Training PowerPoint Now Available in English and Spanish
With OSHA’s adoption of the Globally Harmonized System (GHS) for the classification and labeling of hazardous chemicals, virtually every chemical label, MSDS—now called Safety Data Sheet (SDS), and written hazard communication plan must be revised to meet the new standard.
By December 1, 2013, all employees at your site that work with, or are exposed to, hazardous chemicals must be trained to understand the new classification system, labels, warning statements, precautions, pictograms, and safety data sheets for chemicals at your worksite.
Environmental Resource Center is making available a PDF presentation or a customizable PowerPoint that you can use for on-site worker training. The training program, which is designed to cover your site’s GHS Hazard Communication training requirements, is in a format that is easy to understand.
Pricing and options:
Multiple PDF copies can be purchased for $99/copy (1–10); $79/copy (11–20); or $69/copy (21+).
Multiple copies can be purchased for $199/copy (1–10), $179/copy (11–20), or $169/copy (21+).
Additional Options*:
1. Customized PowerPoint: send us your written GHS hazard communication plan and 10–20 safety data sheets. We’ll create a custom training program for your site: $899
2. If you have not updated your hazard communication plan, let Environmental Resource Center update it for you: $799
3. Customized PowerPoint and hazard communication plan: $1600.
*Call 800-537-2372 for Spanish pricing
How to Implement OSHA’s Globally Harmonized Hazard Communication Standard (GHS)
OSHA has issued a final rule revising its Hazard Communication Standard, aligning it with the United Nations’ globally harmonized system (GHS) for the classification and labeling of hazardous chemicals. This means that virtually every product label, safety data sheet (formerly called “material safety data sheet” or MSDS), and written hazard communication plan must be revised to meet the new standard. Worker training must be updated so that workers can recognize and understand the symbols and pictograms on the new labels as well as the new hazard statements and precautions on SDSs.
Emergency Recall of Gas Cylinders
The DOT’s Pipeline and Hazardous Material Safety Administration issued an Emergency Recall Order pursuant to 49 U.S.C. 512 1(d) and 49 CFR I09.17(c) of fall cylinders manufactured by The Lite Cylinder Company, Inc., (Lite Cylinder) and marked as authorized under DOT-SP 14562 (and DOT-SP-13957 as authorized therein), OOT-SP 131 05; any cylinder requalified under H706; and any cylinders manufactured under M5729 (hereinafter referred to as affected packaging(s)). This order applies to any person who is in possession of an affected packaging subject to this order.
PHMSA determined that the cylinders constitute or are causing an imminent hazard to public safety. If you possesses these cylinders, DOT recommends that you:
1. Take proper safeguards in identifying and handling the affected packagings identified in this Order
2. Use the instruction and information provided by Lite Cylinder for the safe handling and discharge of hazardous material and for the return shipment of cylinders. This information will guide Cylinder Owners to use only qualified persons, trained in handling cylinders in accordance with Federal regulations, and to safely discharge, purge, and remove the valve from, the cylinder.
3. Return the purged and empty cylinders to the manufacturer at the following address: The Lite Cylinder Company, 139 Southeast Parkway Court, Franklin, TN 37064
Atlanta Environmental, Transportation, and Safety Training
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Cal/OSHA Issues Notice of Proposed Emergency Regulatory Action for Process Safety Management (PSM) Program Assessment
California’s Department of Industrial Relations’ Division of Occupational Safety and Health (Cal/OSHA) is proposing to adopt emergency regulations to implement a methodology for determining and collecting an annual assessment to fund Cal/OSHA’s Process Safety Management Program. The emergency regulations propose to adopt Article 12.5 of Subchapter 2, of Title 8, California Code of regulations, sections 344.76, 344.77, and 344.79.
Government Code section 11346.1(a)(2) requires that, at least five working days prior to submission of the proposed emergency action to the Office of Administrative Law (OAL), the adopting agency provide a notice of the proposed emergency action to every person who has filed a request for notice of regulations action with the agency. After submission of the proposed emergency regulations to the Office of Administrative Law, OAL shall allow interested persons five calendar days to submit comments on the proposed emergency regulations as set forth in Government Code section 11349.6. Upon filing, OAL will have 10 calendar days within which to review and make a decision on the proposed emergency rule. If approved, OAL will file the regulations with the Secretary of State, and the emergency regulations will become effective for one hundred and eighty (180) days. Within the 180-day effective period, Cal/OSHA will proceed with a regular rulemaking action, including a public comment period. The emergency regulations will remain in effect during this rulemaking action.
California Adopts Reference Exposure Levels for Caprolactam
Reference Exposure Levels are airborne concentrations of a chemical that are not anticipated to result in adverse non-cancer health effects for specified exposure durations in the general population, including sensitive subpopulations.
OEHHA is required to develop guidelines for conducting health risk assessments under the Air Toxics Hot Spots Program (Health and Safety Code Section 44360(b)(2)). In response to this statutory requirement, OEHHA has developed RELs for caprolactam. These were developed using the most recent "Air Toxics Hot Spots Program Technical Support Document for the Derivation of Noncancer Reference Exposure Levels," released by OEHHA in 2008. This method allows for the estimation of acute, 8-hour, and chronic RELs for use in Air Toxics Hot Spots program risk assessments.
A draft of the caprolactam RELs was released on May 21, 2010, to solicit public comment, and was discussed at public workshops in Oakland and Diamond Bar, CA, during the subsequent 45-day public review period. The document was revised to reflect public comments, and peer reviewed by the State's Scientific Review Panel on Toxic Air Contaminants (SRP). The document was reviewed and approved by the SRP in 2011.
The REL values are:
- Acute REL (for a 1-hour exposure): 50 µg/m3 (11 ppb)
- 8-Hour REL (for repeated 8-hour exposures): 7 ?g/m3 (1.4 ppb)
- Chronic REL (for long-term exposures): 2.2 ?g/m3 (0.5 ppb)
New Oregon OSHA Rule on Cranes and Derrick Safety
This rulemaking is to keep Oregon OSHA in harmony with recent changes to federal OSHA’s standards.
Oregon OSHA amended 29 CFR 1926.800 Underground Construction, in Division 3/S; 1926.856 Removal of walls, floors, and material with equipment, in Division 3/T; and 1926.858 Removal of steel construction, also in Division 3/T, with changes as published in the April 23, 2013 Federal Register. With this rulemaking, Federal OSHA has clarified text in the demolition standard and applies the cranes and derricks standard to underground construction work and demolition work.
Oregon OSHA repealed 437-003-0080 Wind Velocity Device. This rule was inadvertently left in the former Division 3/DD. Subdivision DD was removed in Oregon earlier this year with rulemaking from the August 17, 2012 Federal Register. The substance of 437-003-0080 is addressed now in Cranes and Derricks in Construction, subdivision CC.
Oregon OSHA made the amendments from the April 23, 2013, Federal Register in construction, Division 3/S and 3/T.
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