Dusting: Why it's Not Just for Sitcom Mother-in-Laws with White Gloves

Air quality is not something the average person thinks about on a daily basis. Unless you are plagued with allergies you probably never consider what you are breathing in your own home. Out of sight, out of mind, right? I can't see any particles in the air so it must be pretty clean, right? Dusting is just a matter of aesthetics, right? Dust gives a house that warm, fuzzy feeling, right?

....Wrong

Breathing in microscopic dust particles is one of the easiest way to boost chronic consumption of toxins without ever realizing it. If you live in the Northeast, odds are you are walled up in your house six months of the year breathing indoor air. While outdoor air also has its dangers depending on where you live, indoor air can also be dangerous when not tended to properly. Besides irritating respiratory passages and creating allergic reactions, dust can pose a risk for a wide range of  long-term health risks depending on which chemicals are present in the dust. One troubling aspect to exposure through house dust is that it tends to affect children the most. Children spend time closer to the ground and on carpets where dust accumulates. They also put things in their mouth frequently which increases the transfer of dust and other harmful toxins into their bodies. Since children are developing and changing more than adults, they are the most vulnerable to adverse effects from exposure to toxins as well.

I'm sure many have heard the statistic that dust is mostly comprised of dead skin cells and soil. But what about the rest of it? Well, a lot of things make up dust. Among the most troubling chemicals living in dust that will be discussed further are lead, PFCs, phthalates, and flame retardants.

Lead

The danger of dust as a route of exposure for heavy metals was first discovered in Australia in the early 1900's.  Lead paint and house dust were found to be two of the most robust methods of exposure to lead in young children (Gibson, 1904). While lead paint has been out of use since 1978, lead can still be found in house dust as it makes its way into the home through soil and air pollution. The EPA sets the acceptable limit of dust lead loading (concentration of lead per unit of area) as 40 μg/ft² (TSCA section 403). However, there is evidence that this level is not low enough to properly protect the public. An epidemiological review conducted by Lanphear et al. (1998) found that levels of lead loading between 5-10 μg/ft²  (many times less than the EPA's limit) still predicted blood lead concentrations in children, some of which were higher than the 10 μg/dL demarcation of "lead poisoning". 

Perfluoroalkyl Chemicals (PFCs)

PFCs are found in a wide range of industrial products, such as: floor polish, non-stick cookware, packaging, water repellents coatings for fabrics, tiles, and leather, and many more. The main concern with PFCs is that they tend to be very resistant to breakdown due to their strong carbon-flouride bond. This leads them to bio-accumulate and increase in concentration in tissues and in the environment. House dust is one route of administration besides the more prevalent route of oral administration. PFCs have been found in house dust in many countries and in human tissues (Kubwabo et al, 2005; Moriwaki, Takata, & Arawaka, 2003; Strynar & Lindstrom, 2008).These compounds also pass easily between mother and fetus both prenatally across the placental membrane and postnatally through breast milk (Fields, 2007). Breast-fed infants are exposed to as much as 200μg of PFCs a day (Karrman et al., 2007)!!  While the health risks associated with PFCs are still not completely known, research has suggested that exposure to PFCs lowers the efficacy of vaccinations and may have long-term immunotoxic effects (Grandjean et al., 2012).  For this reason, PFCs have been given more attention by the EPA and following future research they may be banned or regulated. Even if they are banned, they will be found in dust and human tissues for decades to come due to their long half-lives and resistance to degradation. 

Phthalates 

Phthalates are found in many products, primarily in plastics and PVC. They can also be found in vinyl flooring and some building materials, the amount of which correlate to the concentration of phthalates found in dust (Bornehag et al., 2005).  They are known endocrine disruptors and have been linked to breast cancer, reproductive birth defects in males, low birth weight, asthma, obesity, and behavioral abnormalities in children. Phthalates are not chemically bound to the plastics that they are found in, which allows them to leech off into the environment easily and more rapidly as the plastic ages. They are found in bodily tissues and their metabolites can be found in the urine of children and adults (Becker et al., 2012). 

Flame Retardants

Another class of harmful chemicals lurking in dust comes from substances that are supposed to protect us. Flame retardants are included in furniture, baby products, and mattresses. However, these chemicals have been linked with cancers, learning disorders, and infertility. Poly-brominated diphenyl ethers (PBDEs) is one class of flame retardants that were commonly used in the past and continue to be found in house dust and in human tissues. Organophosphates (OPs) are another class of flame retardants found in house dust. These compounds are endocrine disruptors and OP concentrations in house dust have been correlated with decreased semen quality and infertility in men (Meeker & Stapleton, 2010). One flame retardant, TBPH, has been used as a replacement for PBDEs. However, these replacements may not be any safer. A recent animal study has discovered that the metabolites from gestational exposure to this compound can potentially cause maternal thyroid and liver toxicity as well as testicular abnormalities in the fetus (Springer et al., 2012). 

Best Ways to Lower Your Exposure

While there is no way to ever completely reduce exposure to these toxins, there are steps that can be taken to limit it as much as possible. The best way to do this is by removing and inhibiting the accumulation of dust. Vacuuming frequently (at least twice a week) with a vacuum equipped with a HEPA filter is one of the easiest and most cost-effective ways to reduce exposure. Investing in a high quality air filter for your home is also a cost-effective option that will reduce the amount of dust and particulate matter circulating and settling. A more expensive option would be to replace carpets with hardwood or non-toxic flooring  (vinyl floors are a source of phthalates and PFCs can be found in the sealants used for tile!!). 

Maintaining and keeping filters updated is also imperative for effectively removing dust. The instructions for cleaning the filter in your vacuum cleaner provided by the manufacturer should be followed regularly. Disposable particulate respirators are a great (and relatively cheap) way to protect your air passages from irritation while cleaning filters or disturbing dust. 

Another way to limit your exposure is to reduce the sources of the chemicals. While it seems like a no-brainer, homes that have more sources of toxic chemicals have higher concentrations of those chemicals in house dust. This becomes particularly troubling when the chemicals are coming from flooring or building materials, which are not easily swapped out and occupy large surface areas in a home. Investigating which chemicals are in certain types of materials and products such as plastics, insulation, furniture, and mattresses and making an informed decision as a consumer can help limit yours and your family's exposure to potentially dangerous chemicals. 

References:

Becker, K., Seiwert, M., Angerer, J., Heger, W., Koch, H.M., Nagorka, R.... Ullrich, D. (2004). DEHP  metabolites in urine of children and DEHP in house dust. International Journal of Hygiene and Environmental Health, 207(5), 409-417.

Bornehag, C., Lundgren, B., Weschler, C.J., Sigsgaard, T., Hagerhed-Engman, L. & Sundell, J. (2005). Phthalates in indoor dust and their association with building characteristics. Environmental Health Perspectives, 113(10), 1399-1404. 

Fields, S. (2007). Mapping a course for PFCs: Transfer between mothers' milk and serum. Environmental Health Perspectives, 115(2).

Gibson, J. L. (1904). A plea for painted railings and painted rooms as the source of lead poisoning among Queensland children. Australia Medical Gazette 23, 149-153.

Grandjean, P., Anderson, E.W., Budtz-Jorgensen, E., Nielsen, F., Molbak, K., Weihe, P. & Heilmann, C. (2012). Serum vaccine antibody concentrations in children exposed to perfluorinated compounds. The Journal of the American Medical Association, 307(4), 391-397.

Karrman, A., Ericson, I., Bavel, B.V., Darnerud, P.O., Aune, M., Glynn, A....Lindstrom, G. (2007). Exposure of perfluorinated chemicals through lactation: Levels of matched human milk and serum and a temporal trend, 1996-2004, in Sweden. Environmental Health Perspectives, 115(2), 226-230. 

Kubwabo,C., Stewart,B., Zhu,J.P., Marro,L., (2005).Occurrence of perfluoro sulfonates and other perfluoro chemicals in dust from selected homes in the city of Ottawa, Canada. Journal of Environmental Monitoring, 7(11),1074–1078.

Lanphear, B.P, Matte, T.D., Rogers, J., Clickner, R.P., Dietz, B., Bornschein, R.L....Jacobs, D.E. (1998). The contribution of lead-contaminated house dust and residential soil to children's blood lead levels: A pooled analysis of 12 epidemiological studies. Environmental Research, 79, 51-68.

Moriwaki, H., Takata,Y., & Arakawa,R. (2003). Concentrations of Perfluoro Octane Sulfonate (PFOS) and Perfluoro Octanoic acid (PFOA) in vacuum cleaner dust collected in Japanese homes. Journal of Envirnonmental Monitoring, 5,753–757.

Springer, C., Dere, E., Hall, S.J., McDonnell, E.V., Roberts, S.C., Butt, C.M....Boekelheide, K. (2012). Rodent thyroid, liver, and fetal testis toxicity of the monoester metabolite of Bis-(2-ethylhexyl) tetrabromophthallate (TBPH), a novel brominated flame retardant present in indoor dust. Environmental Health Perspectives.

Stapleton, H.M., Eagle, S., Sjodin, A. & Webster, T.F. (2012). Serum PBDEs in a North Carolina toddler cohort: associations with hand wipes, house dust, and socioeconomic variables. Environmental Health Perspectives.

Stryner, M.J. & Lindstrom, A.B. (2008). Perfluorinated compounds in house dust from Ohio and North Carolina, USA. Environmental Science Technology, 42, 3751-3756.

http://epa.gov/superfund/lead/products/dust_sampling_guidance_final.pdf
http://www.epa.gov/opptintr/existingchemicals/pubs/actionplans/pfcs.html
http://www.epa.gov/lead/hazard.html

More Information and Useful Links:

http://www.epa.gov/airquality/particlepollution/health.html

http://www.healthybuilding.net/press/carpet.html

http://www.hss.doe.gov/nuclearsafety/qa/hepa/index.html

http://www.northernsafety.com/Top-Products/Disposable-Respirators