According to the study, bedding and sheets made of synthetic fibers
double the risk of asthma in children by age 7 while sheets with
natural fibers appear to reduce the risk of wheezing. The research
involved 863 children who participated in an infant survey in 1988
and an asthma study in Tasmania, Australia, in 1995, seven years
later. Outcomes measured included recent and frequent wheezing.
The results showed that composite, or synthetic, infant bedding
used was associated with recent wheezing and the wheezing effects
increased the more dust mite-rich bedding was used. Those infants
sleeping in synthetic bedding had an increased number of house
dust mite-rich bedding. Effects were further enhanced by home environmental
factors of bedroom heating, recent bedroom painting, and absence
of bedroom carpeting. When any 2 or more of these environmental
factors were present, a strong relationship to wheezing was evident.