Old Mattresses May Cause Asthma

[sharon sanders]

Old mattresses may cause asthma
20 November 2007



<!--Shado Debug: Getting From RenderCache qPageContainerItem--> Research suggests children who sleep on old mattresses during the first year of life are more at risk of developing breathing disorders such as asthma.
A study by The University of Auckland showed that wheezing at ages 3.5 and 7 years was more common in children who slept on a used mattress in the first year of life. Children who were treated with antibiotics or spent time at daycare in the first year of life also showed signs of breathing problems at 7 years old.
The study assessed 871 New Zealand children of European descent at birth and ages 12 months, 3.5 years and 7 years. Any incidents of wheezing or whistling in the chest over the year prior to the assessments were noted, and parents were asked to provide details of lifestyle, including pet ownership, breastfeeding, smoking by members of the household, use of bedding, such as mattresses, quilts and pillows, day care attendance and health and development.
The study found that 24% of children suffered from wheezing at 3.5 years and 18% at 7 years. The main factors associated with children with breathing problems were maternal smoking during pregnancy, being in daycare, antibiotic use, the presence of a dog and sleeping on a used cot mattress in the first year of life.
"Environmental factors are known to have an effect on allergic diseases, such as asthma, particularly in children," says Professor Ed Mitchell of the Faculty of Medical and Health Sciences. "This study has shown that some factors thought to affect children?s breathing, such as use of pillows, do not have a great effect but others, such as maternal smoking, antibiotics, daycare attendance and used mattresses, do. The observation that used cot mattresses are associated with asthma at 7 is particularly intriguing, and may be related to higher levels of house dust mite, endotoxin or other germs in the mattress."
The results of the study are published in the online edition of Clinical and Experimental Allergy. The research was initially funded by the Health Research Council of New Zealand, with additional support from Hawkes Bay Medical Research Foundation, Child Health Research Foundation, Becroft Foundation and the Auckland Medical Research Foundation. Assessment studies were conducted at the Starship Children?s Research Centre.



http://www.auckland.ac.nz/uoa/about/news/articles/2007/11/asthma_mattress.cfm

 

[sharon sanders]

PLoS - Indoor Air Quality & Airborne Contagions

PLoS - Indoor Air Quality & Airborne Contagions

Indoor Air Quality is a concern, particularly in institutional settings. Not all areas can accommodate natural ventilation.




Natural Ventilation for the Prevention of Airborne Contagion

<!-- end title area --> <!-- start authors --> A. Roderick Escombe^1,^2,³^*, Clarissa C. Oeser³, Robert H. Gilman^3,⁴, Marcos Navincopa⁵, Eduardo Ticona⁵, William Pan⁴, Carlos Martínez⁵, Jesus Chacaltana⁶, Richard Rodríguez⁷, David A. J. Moore^1,^2,³, Jon S. Friedland^1,², Carlton A. Evans^1,^2,^3,⁴
<!-- end authors --> <!-- start affiliations --> 1 Department of Infectious Diseases & Immunity, Imperial College London, London, United Kingdom, 2 Wellcome Trust Centre for Clinical Tropical Medicine, Imperial College London, London, United Kingdom, 3 Asociación Benéfica PRISMA, Lima, Perú, 4 Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America, 5 Hospital Nacional Dos de Mayo, Lima, Perú, 6 Hospital Nacional Daniel Carrión, Lima, Perú, 7 Hospital de Apoyo Maria Auxiliadora, Lima, Perú
<!-- end affiliations --><!-- start: abstract --> Background
Institutional transmission of airborne infections such as tuberculosis (TB) is an important public health problem, especially in resource-limited settings where protective measures such as negative-pressure isolation rooms are difficult to implement. Natural ventilation may offer a low-cost alternative. Our objective was to investigate the rates, determinants, and effects of natural ventilation in health care settings.
Methods and Findings
The study was carried out in eight hospitals in Lima, Peru; five were hospitals of “old-fashioned” design built pre-1950, and three of “modern” design, built 1970–1990. In these hospitals 70 naturally ventilated clinical rooms where infectious patients are likely to be encountered were studied. These included respiratory isolation rooms, TB wards, respiratory wards, general medical wards, outpatient consulting rooms, waiting rooms, and emergency departments. These rooms were compared with 12 mechanically ventilated negative-pressure respiratory isolation rooms built post-2000. Ventilation was measured using a carbon dioxide tracer gas technique in 368 experiments. Architectural and environmental variables were measured. For each experiment, infection risk was estimated for TB exposure using the Wells-Riley model of airborne infection. We found that opening windows and doors provided median ventilation of 28 air changes/hour (ACH), more than double that of mechanically ventilated negative-pressure rooms ventilated at the 12 ACH recommended for high-risk areas, and 18 times that with windows and doors closed (p < 0.001). Facilities built more than 50 years ago, characterised by large windows and high ceilings, had greater ventilation than modern naturally ventilated rooms (40 versus 17 ACH; p < 0.001). Even within the lowest quartile of wind speeds, natural ventilation exceeded mechanical (p < 0.001). The Wells-Riley airborne infection model predicted that in mechanically ventilated rooms 39% of susceptible individuals would become infected following 24 h of exposure to untreated TB patients of infectiousness characterised in a well-documented outbreak. This infection rate compared with 33% in modern and 11% in pre-1950 naturally ventilated facilities with windows and doors open.
Conclusions
Opening windows and doors maximises natural ventilation so that the risk of airborne contagion is much lower than with costly, maintenance-requiring mechanical ventilation systems. Old-fashioned clinical areas with high ceilings and large windows provide greatest protection. Natural ventilation costs little and is maintenance free, and is particularly suited to limited-resource settings and tropical climates, where the burden of TB and institutional TB transmission is highest. In settings where respiratory isolation is difficult and climate permits, windows and doors should be opened to reduce the risk of airborne contagion.

<!-- end abstract --> <!-- start footnote section -->Funding: ARE was initially funded by the Sir Halley Stewart Trust, United Kingdom. ARE, DAJM, CAE, JSF, and RHG are funded by the Wellcome Trust, UK; and ARE, DAJM, and CAE have Wellcome Trust Clinical Tropical Medicine Research Fellowships. RHG is supported by USAID award #HRN-5986-A-00-6006-00, GHS-A-00-03-00019–00, and Global Research Activity Cooperative Agreement, National Institutes of Health/National Institute of Allergy and Infectious Diseases (T35A107646). These funding agencies had no involvement in the conduct or publication of this research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.



http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0040068