Quantification of lead in telephone cord: use of x-ray photoelectron spectroscopy technique

There have been historic concerns that lead has existed as a plasticizer in telephone lines, causing health hazards, especially for children, who frequently mouth, chew, and swallow non-food items. The acid environment of the mouth may leach lead from the surface into the saliva under non-destructive conditions. Thus, distinguishing the amount of lead in the surface versus the inside of the polyvinyl chloride (PVC) material covering the phone cord line is very important in assessing health hazards. Using X-ray Photoelectron Spectroscopy (XPS), we measured lead in the PVC covers of telephone cords that connect the handheld part of the phone to the base. Lead was detected in both the inner and outer surface of an older (approximately 12 years) cord (1.3 atomic percent in inner surface; 0.4 atomic percent in the outer surface). However, when we tested four popular brands of newer cords (currently available in the market), there was no detectable lead. This study demonstrates that XPS is a useful technique that can distinguish lead contents between surface versus inner core of plasticized telephone cords. Telephone cords and other plasticized materials that may leach lead should be screened to establish safety.