Household dust 'a potpourri of toxins'

Washington, March 7 : Everyday household dust is a blend of harmful substances including lead and arsenic, a new study has revealed.

A 2009 study from the University of Arizona, appearing in Environmental Science and Technology, says most of the floor dust is actually tracked in from the outside and may contain potentially harmful substances.

The scientists first derived a formula to calculate the amount of outdoor soil and airborne particles that gets mixed with indoor dust.

Thereafter, using their mathematical model they found that around 60 percent of floor dust comes from soil stuck on shoes. And if one's house is near a contaminated Superfund site or industrial plant, this dirt could be a potpourri of toxins.

"Although we've conducted a small pilot project to collect our own data to validate the model presented in this study, the next step would be to conduct a larger study where we'd collect data from several households," Discovery News quoted Paloma Beamer, an environmental scientist at the University of Arizona, as saying.

Beamer went on: "Ideally, we'd also like to see if participants could collect their own samples."

Gary Holub, a spokesperson for Health Canada, which is conducting the Canadian House Dust Study, a separate, ongoing, four-year project, pointed out that indoor material also adds to indoor dusts' metal content.

Holub said: "In addition to the outdoor sources listed in the University of Arizona study model, we've observed that indoor sources also contribute significantly to metal content of indoor dust.

"But the relative contributions of outdoor and indoor sources are highly variable."

Both Holub and Beamer believe kids are more at risk from indoor dust.

Holub said: "Indoor dust can be swallowed by young children through normal hand-to-mouth activities, and in that way, they can become exposed to any chemicals which are in the dust."

According to the University of Arizona study, the amount of lead particles in floor dust is a key determinant of children's blood-lead levels.

The Arizona study also spelt out simple measures to prevent dust from settling indoors.

Beamer said: "You could consider leaving your shoes outside the door, and you can vacuum with a HEPA vacuum, especially ones equipped with a dirt detector.

"You can wet dust rather than dry dust, and you should also change your air conditioning filters regularly."

--ANI