Home lead detection with color-changing wipes ^{CEFR B2}

Lead in the home poses a serious risk to children's health, yet standard professional inspections—typically using X-ray fluorescence (XRF) devices—are costly, often delayed, and sometimes performed only after a poisoning is confirmed. A new study in the Journal of Exposure Science & Environmental Epidemiology evaluated a quicker, lower-cost screening option that families could use themselves.

Researchers from the University of Washington School of Public Health and Boston University School of Public Health tested colorimetric wipes developed by the National Institute for Occupational Safety and Health. They collected 104 wipes from nine homes and seven vehicles belonging to Boston-based construction workers who live with children. The wipes change to light orange, orange, or red to indicate low, medium, or high lead. Compared with later laboratory analysis, the wipes correctly identified most contaminated and uncontaminated surfaces, showed a low rate of false negatives, and detected lead on nearly 60% of home surfaces and 71% of vehicles.

The wipes found lead on floors, shoes, laundry appliances, trunks, and painted surfaces such as windowsills. Kitchens had the highest lead levels in homes, while trunks had the highest levels in cars. Federal guidelines currently recommend colorimetric wipes only in occupational settings because residential data are limited. Jonathan Levy, chair and professor of environmental health at BUSPH, noted that "because colorimetric wipes are much less expensive than standard approaches for lead investigations in homes, they can be used more often and in more places," and that knowing which surfaces are elevated can allow targeted remediation.

The researchers could not determine how much contamination came from take-home exposures versus lead paint. Lead paint was banned for residential use in the US in the 1970s but is still common in older housing, and Boston has one of the oldest housing markets in the country. Diana Ceballos and M. Pilar Botana Martinez developed a training guide for home use. The team recommends expanding studies to more homes, including households without exposed workers, and comparing other commercial kits to inform regulatory approval. The study was funded by the US Department of Housing and Urban Development.