How chronic exposure to tiny levels of carbon monoxide damages hearing in young ears

June 03, 2005

FINDINGS: UCLA scientists have discovered how chronic exposure to low levels of carbon monoxide (CO) damages the inner ear of young rats, resulting in permanent hearing loss. At the Ca/OSHA's exposure limit of 0.0025 percent -- or 25 parts per million CO in the air -- the gas creates oxidative stress, a condition that damages the cochlear cells, leading to impairment of the auditory nerves.

CONTEXT: Tobacco smoke, gas heaters, stoves and ovens all emit CO, which can rise to high concentrations in poorly ventilated homes. Infants and children are particularly vulnerable to CO exposure because they spend a great deal of time in the home. No policies exist to regulate CO in the home. Many commercial home monitors sound an alarm only 20 minutes after CO concentrations reaches 70 parts per million -- nearly three times the 25 parts per million limit set by Cal/OSHA.

IMPACT: This is the first time that inhaled CO has been linked to oxidative stress, a known risk factor in many disorders, including Alzheimer's, Parkinson's, multiple sclerosis, Lou Gherig's disease and cardiovascular disease. Tobacco smoke, which contains CO, aggravates many of these diseases. The UCLA findings highlight the need for policy makers to reexamine the regulation of car exhaust, tobacco smoke, smog, and heating and cooking appliances.

AUTHORS: John Edmond, Ph.D., professor of biological chemistry; Ivan Lopez, Ph.D., assistant professor of head and neck surgery; and Douglas Webber, Ph.D., postdoctoral fellow; at the David Geffen School of Medicine at UCLA, are available for interviews.

JOURNAL: The research appears in the June 1 issue of the Journal of Neuroscience Research.

FUNDING: The University of California's Tobacco-related Disease Research Program and the Stein-Oppenheimer Foundation.
-end-


University of California - Los Angeles

Related Tobacco Articles from Brightsurf:

UC studies tobacco use, cancer connection
Researchers at the University of Cincinnati have identified new clues into ways tobacco use impacts patients with kidney cancer.

'Best' hospitals should be required to deliver tobacco treatment
A UCLA-led report published today in the Journal of the American Medical Association Internal Medicine exposes what the authors call a weakness in the high-profile 'Best Hospitals Honor Roll' published annually by US News and World Report.

Small shops, heavy advertisers less likely to ID for tobacco
'Our findings suggest that certain types of stores -- tobacco shops, convenience stores and those with a lot of tobacco advertising -- are more likely to sell tobacco to a young person without checking his or her ID.'

Youth smoking and vaping: What does it mean for tobacco control
New research from PIRE/PRC features analysis of in-depth, qualitative interviews with young vapers in California between 15 and 25.

Truth telling about tobacco and nicotine
In 'Truth Telling about Tobacco and Nicotine,' PRC researchers explain that, although there is agreement among researchers about evidence that vaping can be less harmful than combustible cigarettes, the tobacco control community remains divided about how to communicate -- or even whether to communicate -- information about the relative risks of tobacco and nicotine products.

A 'joint' problem: Investigating marijuana and tobacco co-use
A survey of marijuana and tobacco co-users by Medical University of South Carolina investigators found that co-users with high degree of interrelatedness between their use of the two substances had greater tobacco dependence and smoked more cigarettes per day.

How genes affect tobacco and alcohol use
A new study gives insight into the complexity of genetic and environmental factors that compel some of us to drink and smoke more than others.

Tobacco use linked with higher use of opioids and sedatives
Tobacco is a known risk factor for the misuse of prescription opioids.

Changes in flavored tobacco product use among youth tobacco users
Self-reportedĀ use of flavored tobacco products by middle and high school students decreased from 2014 to 2016 but climbed back up in 2017 in an analysis of national survey data.

Heated tobacco product claims by tobacco industry scrutinized by UCSF researchers
Claims by the tobacco industry that heated tobacco products (HTPs) are safer than conventional cigarettes are not supported by the industry's own data and are likely to be misunderstood by consumers, according to research published in a special issue of Tobacco Control.

Read More: Tobacco News and Tobacco Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.