by Clare Coppa

Indoor air pollution is an important health consideration when spending long hours in enclosed buildings. Aspergillus, a common fungus found in dust, clings to hair and piggybacks on clothes. It becomes airborne through movement and is inhaled regularly without a problem, but is linked to allergic reactions or asthma in weakened individuals. In those with suppressed immune systems, such as AIDS or organ-transplant patients, inhalation can be deadly.

The subject was studied by ASTM members S. Kay Obendorf, Ph.D. and Betsy L. Dart, M.S., in “Retention of Aspergillus Niger Spores on Textiles” published in ASTM STP 1386, Performance of Protective Clothing: Issues and Priorities for the 21st Century (Vol. 7; 2000). Their results imply that increased regulation of textiles in hospital isolation units could save lives.

Fungal spores are carried into hospital isolation units by staff or visitors. “In excess of 90% of the cases where someone with immunosuppression would get a pulmonary infection, it would be fatal,” said Dart, a consultant for Arthur D. Little, Inc., Mass., who has an M.S. in Fiber Science from Cornell University, N.Y.
“It’s likely that Aspergillus is transmitted but overlooked, regardless of the HEPA-filtration and regular air-sampling in isolation rooms,” she said. “The problem is that by the nature of the airflow design in the room, particulates coming off clothing are diluted very quickly. In-room air sampling devices would probably indicate much lower contamination levels than would be found in the microenvironment that you’d be experiencing very close to the person with the soiled clothing.”

It is a hospital policy and facility issue, said Obendorf, an associate dean of research and facilities at Cornell and professor, Department of Textiles and Apparel. “It’s a management thing. It’s understanding the phenomena and managing that phenomena versus developing clothing that won’t hold spores.”

Less than seven percent of bone-marrow units restrict visitors’ interaction with patients, according to a national survey, and less than 25% require cover-gowns. Careful monitoring of hospital-laundered garments in units could remove the fungal spores, Obendorf said. “As you notice in the paper, laundering and dry-cleaning removed these spores very easily.”

In June, 1992, the immune system of Dart’s five-year old daughter Dalia was chemically suppressed to avoid rejection of a bone marrow transplant for leukemia. Tragically, by Aug. 3, the child died of pulmonary Aspergillosis. During the ordeal, Betsy noticed that handwashing was strictly enforced in her daughter’s hospital isolation unit, and toys and surfaces were carefully wiped, but that visitors’ clothes were not covered.

Dart explored the subject in her Masters of Science thesis, “Redispersion of Aspergillus Spores From Textiles Relative to Hospital Infection Control,” (Cornell University, Ithaca, N.Y.; Aug. 1998). The thesis became the basis for the Dart/ Obendorf study.

“For instance,” Dart explained, “if you were sitting in a rocking chair and you had your child in your lap and you moved your arm creating some friction and some air flow, you could have this local high-density pollution and it would never be picked up by the air sampling.”

“Clothing billows,” added Obendorf. “You’ve got the situation where it doesn’t take very many spores. And there’s no effective pharmacological treatment.”

Professor Thad Godish, Ph.D., author of Sick Buildings, and director of indoor air quality research at Ball State University, Ind., wrote on his Web site that Aspergillus is a health concern. Godish interestingly pointed out that the tenacious fungus is “believed to have been responsible for the deaths that have been ascribed to King Tut’s curse.” A concentrated inhalation of Aspergillus by raiders of the tomb may have caused their demise, the Canadian Medical Journal concurred. Although the sarcophagus was sealed in 1352 BC, fungal spores are capable of surviving for long periods outside a host. When opened Nov. 26, 1922, a black fungus was found in the interior.

“A. fumigatus commonly found growing in compost and not uncommonly found in building dust is of particular concern to immune-compromised individuals who it readily infects and causes a life-threatening disease of the lungs,” Godish also wrote. (Dart and Obendorf used the less pathogenic Aspergillus niger to avoid risk of exposure during their study.)

Having received enthusiastic feedback to the study, their next step is to share their research with hospital policy makers. “We’re trying to get the word out to get people not to overlook this route of cross-contamination,” Obendorf said. //

Copyright 2001, ASTM