The use of leaded paints in an urban neighborhood in Quito, Ecuador: A case study

Lead has been used in paints since ancient times, posing significant public health and environmental risks. In 2012, a maximum permissible concentration of 600 ppm of Pb in paints was adopted in Ecuador, however since 2024 a new maximum limit of 90 ppm was stablished, with an implementation period of 30 months. In this regard, the present study aimed to present for the first time a preliminary screening related to the presence of Pb in paints used in exterior walls, public spaces, and streets in a densely populated area in Quito-Ecuador, analyzing 171 painted spots in situ through a portable X- Ray Fluorescence (pXRF) analyzer. Pb content was compared to the former and latest maximum threshold limits. Results varied from < LOD (5 ppm) to 45,216 ppm in painted spots with different colors and paint uses, in which 40.4% of samples exceeded the 600 ppm limit. Regarding colors and paint use, yellow, orange, green, and two samples of red, and road marking and metallic paint presented the highest Pb values. This preliminary study shows that regulation for the use of lead-based pigments in paints in Ecuador continues to face significant regulatory and enforcement challenges, exposing populations to harmful Pb levels.