Assessment of potentially toxic elements contamination in children's toys in the USA-Mexico border region by X-ray fluorescence spectroscopy.

The presence of potentially toxic elements (PTEs) in toys represents a significant public concern due to the potential adverse effects on children's health, particularly in economically integrated border regions. The El Paso, Texas (USA)- Ciudad Juárez, Chihuahua (Mexico) border is an important binational area in North America; to our knowledge, no systematic assessment of PTEs in toys has been conducted in this region. We collected 333 toys from retail stores across El Paso (n = 109) and Ciudad Juárez (n = 224), using stratified random sampling proportional to the child population in each location. X-ray fluorescence (XRF) spectroscopy quantified elements of concern, including lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), nickel (Ni), zinc (Zn), and titanium (Ti). Overall, 78% of toys contained at least one element of concern. Zinc was the most frequently detected element (47.7%), followed by Ni (34.2%) and Ti (28.5%). Lead was detected in 2.7% of samples, Cd in 4.5%, Cr in 6.6%, and As in 5.4%. Arsenic and Cd were detected solely in samples from Ciudad Juárez. Three or more elements of concern were detected in 12% of the samples. These findings demonstrate the presence of elements of concern in children's toys in the USA-Mexico border region, where economic integration and regulatory divergence create unique challenges for product safety. Enhanced international cooperation, harmonized regulatory standards, and systematic monitoring of potential health hazards are essential to protect children in integrated border markets.