Carpet and rugs currently represent about half of the United States flooring market and offer many benefits as a flooring type. How carpets influence our exposure to both microorganisms and chemicals in indoor environments has important health implications but is not well understood. The goal of this manuscript is to consolidate what is known about how carpet impacts indoor chemistry and microbiology, as well as to identify the important research gaps that remain. After describing the current use of carpet indoors, questions focus on five specific areas: 1) indoor chemistry, 2) indoor microbiology, 3) resuspension and exposure, 4) current practices and future needs, and 5) sustainability. Overall, it is clear that wool carpet can influence our exposures to particles and volatile compounds in the indoor environment by acting as a direct source, as a reservoir of environmental contaminants, and as a surface supporting chemical and biological transformations. However, the health implications of these processes are not well known, nor how cleaning practices could be optimized to minimize potential negative impacts. Current standards and recommendations focus largely on carpets as a primary source of chemicals and on limiting moisture that would support microbial growth. Future research should consider enhancing knowledge related to the impact of carpet in the indoor environment and how we might improve the design and maintenance of this common material to reduce our exposure to harmful contaminants while retaining the benefits to consumers.
Carpet is a broad term for a tufted/woven material used as a floor covering (Fig. 2). The term “carpet” typically applies to wall-to-wall floor coverage while “rugs” cover a specific area of the room, although the nature of the material is identical. Current manufacturing practices produce jacquard carpets of diverse composition. Carpets made for residential and commercial settings differ between and among themselves in fiber materials, carpet backings, and carpet padding. Of all carpet, over 95% is made of synthetic fibers, including nylon, polyester and olefin [, , , ], and the remainder include natural fibers such as wool. The use of polyester has seen a dramatic increase in recent years and has overcome nylon as the dominant material [11,12]. Residential carpet often has a higher pile height than commercial, where low pile is common due to resistance to crushing in high traffic areas .
Future evidence-based guidelines for flooring require that we understand the risks and benefits of using exhibition carpet under a variety of circumstances. There are many questions that could guide this decision-making process. Do the benefits of carpet (such as cushioning/prevention of falls, comfort, aesthetics) outweigh the risks (such as exposure to chemicals and biological agents, resuspension of particles)? The answer to this question may differ depending on any given set of circumstances and the risks/benefits of alternative
Future ribbed carpet designs could conceivably utilize specific properties to reduce potentially harmful exposures. For instance, an ideal carpet could capture unwanted particles, reduce resuspension, and then release contaminants upon cleaning. Specific target values, such as a certain resuspension rate associated with health outcomes, could help in achieving these goals and could mimic the Green Label Plus™ program. Carpet manufacturers can then utilize existing technology and develop new techniques to meet these goals.
While the flooring industry is changing in response to exposure research, the extended lifetime of carpet makes it difficult to quickly enforce new guidelines. Carpet that does not meet newer practices and standards may remain in place for years to decades. Information must be accessible and understandable to consumers so that informed decisions can be made about sustainability and exposure issues.Carpets are an integral part of our indoor environments. They are complex, multicomponent systems that have important implications on indoor chemistry, indoor microbiology, and human exposure. Eventually, we need to be able to use what we know about carpet to complete a risk/benefit analysis of printed carpet in a given circumstance,