Residential washing machine efficacy in removing lead from clothing: A pilot study

Workers exposed to lead sometimes wear their work clothes home. It is possible that lead from contaminated work clothing can transfer to uncontaminated clothing, including children's items that may be in the same load, during laundering. This is concerning because lead is especially toxic for children. The purpose of this pilot study was to understand lead extraction from fabrics typically worn by workers, the amount of lead removed during normal laundering, and lead transfer to other fabrics during a laundry washing cycle. The study validated EPA analytical method 200.8 Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma-Mass Spectrometry to analyze lead in Dickies pant fabric (DPF), T-shirt material (TSM), and blue jeans material (BJM). Because this methodology of extracting lead from fabrics is novel, a priori definitions of accuracy and precision used were ± 40%. Researchers spiked two levels (9 µg and 9,000 µg) of lead nitrate and three levels (9 µg, 900 µg, and 9,000 µg) of lead carbonate on 9 cm² fabric swatches and extracted lead by microwave-assisted digestion. Across all spike levels, mean recoveries were within 60% and 140% recovery. All percent coefficient of variation values were less than 20% for lead nitrate, indicating that this method for lead nitrate was sufficiently accurate and precise. For lead carbonate, the method was neither accurate nor precise at the 9 and 900 µg levels but was sufficiently accurate and precise at the 9,000 µg level. Eighteen loads of fabric swatches were spiked with either lead form and laundered in a washing machine using a common laundry detergent. The mean amount of lead removed from laundered DPF and TSM was similar (97.4 and 95.9%) and significantly higher (p < 0.05) compared to laundered BJM (70.6%). The amount of lead carbonate removed (92.6%) was significantly higher (p < 0.05) than lead nitrate (83.4%). The levels of lead that transferred from spiked fabric to bedsheets included in the same washing load were less than 0.5 µg. It is important to follow public health recommendations, such as laundering work clothes separately.