Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Endotoxins in house dust pose a significant risk for asthma

02.12.2005


Exposure to household endotoxin levels poses a significant risk for asthma, according to the first nationwide sampling of house dust.



The study appears in the first issue for December 2005 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

Endotoxins are toxic substances associated with the outer membrane of certain gram-negative bacteria. These molecules are bound to the bacterial cell wall and are released when the bacterium ruptures or disintegrates. According to the authors, inhalation exposure to endotoxins is common in homes. Indoor sources include: dust, pets, humidifiers, pests, and outdoor air.


Past studies have shown that exposure can cause lung inflammation.

Peter S. Thorne, Ph.D., of the Environmental Health Sciences Research Center at the University of Iowa, Iowa City, and five associates, evaluated 2,456 residents in 831 homes selected to represent the demographic characteristics of the U.S. population. The investigators took 2,552 house dust samples from five locations within the homes, including bedroom floors, bedding, family room floors, sofa surfaces, and kitchen floors.

"This study clearly demonstrates significant relationships between household endotoxin and diagnosed asthma, recent asthma symptoms, current use of asthma medications, and wheezing," said Dr. Thorne. "No effect was observed of allergy status on the relationship between endotoxin and asthma outcomes. This suggests that current endotoxin exposure may have little impact on allergy status and that airway inflammation is the most significant effect of endotoxin exposure in a cross-section of the population."

The authors found the strongest relationship between asthma, asthma medications, and wheezing came from endotoxin levels in bedroom floor and bedding dust. However, the effects were observed only in adults and not in children.

Moreover, the investigators also noted that the endotoxin concentrations were highest in kitchen and living room floor dust, and lowest for bedding (including mattress and pillow).

"The mean concentration of endotoxin in the kitchen floor dust was 2.3-fold higher than bedroom floor dust and 4.3-fold higher than bedding dust," said Dr. Thorne.

Two field workers visited each household and took answers from residents to detailed questionnaires, conducted a home inspection, and vacuumed dust into an in-line filter.

The study yielded an 11.3 percent prevalence rate for diagnosed asthma among the homes surveyed. This figure compared favorably with the 11.1 percent prevalence rate of diagnosed asthma associated with the 2002 National Health Interview Survey.

The authors also noted that their national survey demonstrated that U.S. household endotoxin exposure levels were higher than those in Europe.

Suzy Martin | EurekAlert!
Further information:
http://www.thoracic.org

More articles from Health and Medicine:

nachricht Study tracks inner workings of the brain with new biosensor
16.08.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>