Migration of some toxic metals from crayons and water colors

Photoluminescence Sensing of Soluble Lead in Children's Crayons Using Perovskite Nanocrystal In Situ Growth on an Aluminum Hydroxide Layer

In this study, a fluorescence sensing approach for lead ion (Pb²⁺) was developed using in situ growth of methylamine lead bromine (MAPbBr₃) perovskite on an aluminum hydroxide (Al(OH)₃) thin layer. The Al(OH)₃ thin layer could be obtained on a glass slide by liquid phase deposition and is of a large specific surface area and insoluble in water. After sulfhydryl functionalization, the Al(OH)₃ thin layer reveals effective adsorption and excellent enrichment ability to Pb²⁺ and is additionally used as the substrate for the in situ growth of lead halogen perovskite. The fluorescence sensing of Pb²⁺ could be realized by the fluorescence intensity of lead halogen perovskite on the Al(OH)₃ layer. The linear relationship between the fluorescence intensity and the concentration of Pb²⁺ was found in the range from 80 to 1500 mg/kg. The detection limit of Pb²⁺ is found to be 40 mg/kg, which is lower than the maximum permission of lead residue in student products (90 mg/kg) stipulated by the National Standard of the People's Republic of China (GB21027-2020). After being grinded and pre-treated, soluble lead in watercolor paint and crayon samples can be extracted by the sulfhydryl functionalization Al(OH)₃ layer, then lead halogen perovskite can be generated in situ on the layer to achieve the fluorescence sensing for the determination of soluble lead in the samples.

A pediatric health risk assessment of children's toys imported from China into Nigeria

Trade liberalization led to the flooding of the Nigerian markets with ''made in China'' children's toys. Information about metal contamination in toys is vital to ensure the safety of children's product. This is a pediatric health risk assessment of three toxic metals (Pb, Cd and As) in children toys purchased from Nigerian market. Thirty cheap ''made in China'' toys were purchased from stores in Port Harcourt, Nigeria. Three toxic metals (Pb, Cd and As) in the thirty toys samples were determined by absorption spectrophotometry. Pb, Cd and As were present in all the toys at levels below the limits set by EU. The oral and dermal exposure risk assessment showed no significant non-carcinogenic and carcinogen health risks of public health concern. Some ''made in China'' toys imported into Nigeria may not add to the body burden of these metals in children.

Toxic metals in children's toys and jewelry: coupling bioaccessibility with risk assessment

A total of 45 children's toys and jewelry were tested for total and bioaccessible metal concentrations. Total As, Cd, Sb, Cr, Ni, and Pb concentrations were 0.22-19, 0.01-139, 0.1-189, 0.06-846, 0.14-2894 and 0.08-860,000 mg kg(-1). Metallic products had the highest concentrations, with 3-7 out of 13 samples exceeding the European Union safety limit for Cd, Pb, Cr, or Ni. However, assessment based on hazard index >1 and bioaccessible metal showed different trends. Under saliva mobilization or gastric ingestion, 11 out of 45 samples showed HI >1 for As, Cd, Sb, Cr, or Ni. Pb with the highest total concentration showed HI <1 for all samples while Ni showed the most hazard with HI up to 113. Our data suggest the importance of using bioaccessibility to evaluate health hazard of metals in children's toys and jewelry, and besides Pb and Cd, As, Ni, Cr, and Sb in children's products also deserve attention.

Children's exposure to harmful elements in toys and low-cost jewelry: characterizing risks and developing a comprehensive approach

Contamination problem in jewelry and toys and children's exposure possibility have been previously demonstrated. For this study, risk from oral exposure has been characterized for highly contaminated metallic toys and jewelry ((MJ), n=16) considering three scenarios. Total and bioaccessible concentrations of Cd, Cu, Ni, and Pb were high in selected MJ. First scenario (ingestion of parts or pieces) caused unacceptable risk for eight items for Cd, Ni, and/or Pb (hazard index (HI)>1, up to 75, 5.8, and 43, respectively). HI for ingestion of scraped-off material scenario was always <1. Finally, saliva mobilization scenario caused HI>1 in three samples (two for Cd, one for Ni). Risk characterization identified different potentially hazardous items compared to United States, Canadian, and European Union approaches. A comprehensive approach was also developed to deal with complexity and drawbacks caused by various toy/jewelry definitions, test methods, exposure scenarios, and elements considered in different regulatory approaches. It includes bioaccessible limits for eight priority elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Sb). Research is recommended on metals bioaccessibility determination in toys/jewelry, in vitro bioaccessibility test development, estimation of material ingestion rates and frequency, presence of hexavalent Cr and organic Sn, and assessment of prolonged exposure to MJ.

Assessment of toxic metals and phthalates in children's toys and clays

Toxic metals and phthalates are introduced in the manufacturing of plastic toys and modeling clays. In Lebanon, inexpensive plastic toys and modeling clays (sold in dollar stores) are affordable and popular, and there is no legislation to monitor or regulate such toys. This study aimed to assess the quality of inexpensive plastic toys and modeling clays imported in Lebanon. Metal concentrations in toys, namely, zinc [not detectable (ND) to 3,708 μg/g], copper (ND to 140), chromium (ND to 75 μg/g), tin (ND to 39 μg/g), and cadmium (Cd) (ND to 20 μg/g), were lower than the European Union (EU) Directive limits, whereas lead (ND to 258 μg/g) in 10% of samples and antimony (Sb) (ND to 195 μg/g) in 5% of samples were greater than the EU limits. In modeling clays, most of the metals were lower than the EU Directive limits except for Cd and arsenic (As). Cd was detected in 83% of samples, with a mean level of 9.1 μg/g, which is far greater than the EU Directive limit (1.9 μg/g). The As mean level of 4.5 μg/g was greater than the EU limit (4.0 μg/g) and was detected in 9% of samples. Phthalic acid esters (PAEs) were found in 60% of children's toys and 77% of modeling clays. Phthalic acid butyl ester had the highest-level PAE encountered and was ≤59.1 % in one type of clay. However, among children's toys, di(4-octyl) ester terephthalic acid was the highest encountered phthalate at a concentration of 25.7%. The community survey indicated that 82% of households purchase their toys from inexpensive shops and that only 17% of parents were aware of the health hazard of such toys. Consequently, an intervention plan was proposed for the provision of safe toys to children.

Contamination by ten harmful elements in toys and children's jewelry bought on the North American market

Toys and children's jewelry may contain metals to which children can be orally exposed. The objectives of this research were (1) to determine total concentrations (TC's) of As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sb, and Se in toys and jewelry (n = 72) bought on the North American market and compare TC's to regulatory limits, and (2) to estimate oral metal bioavailability in selected items (n = 4) via bioaccessibility testing. For metallic toys and children's jewelry (n = 24) 20 items had TC's exceeding migratable concentration limits (European Union). Seven of seventeen jewelry items did not comply with TC limits in U.S. and Canadian regulations. Samples included articles with very high Cd (37% [w/w]), Pb (65%), and Cu (71%) concentrations. For plastic toys (n = 18), toys with paint or coating (n = 12), and brittle or pliable toys (n = 18), TC's were below the EU migration limits (except in one toy for each category). Bioaccessibility tests showed that a tested jewelry item strongly leached Pb (gastric: 698 μg, intestinal: 705 μg) and some Cd (1.38 and 1.42 μg). Especially in metallic toys and jewelry, contamination by Pb and Cd, and to a lesser extent by Cu, Ni, As, and Sb, still poses an acute problem in North America.

Heavy metals in toys and low-cost jewelry: critical review of U.S. and Canadian legislations and recommendations for testing

High metal contamination in toys and low-cost jewelry is a widespread problem, and metals can become bioavailable, especially via oral pathway due to common child-specific behaviors of mouthing and pica. In this review, the U.S., Canadian, and European Union (EU) legislations on metals in toys and jewelry are evaluated. A literature review on content, bioavailability, children's exposure, and testing of metals in toys and low-cost jewelry is provided. A list of priority metals is presented, and research needs and legislative recommendations are addressed. While the U.S. and Canadian legislations put emphasis on lead exposure prevention, other toxic elements like arsenic and cadmium in toy materials are not regulated except in paint and coatings. The EU legislation is more comprehensive in terms of contaminants and scientific approach. Current toy testing procedures do not fully consider metal bioavailability. In vitro bioaccessibility tests developed and validated for toys and corresponding metal bioaccessibility data in different toy matrices are lacking. The U.S. and Canadian legislations should put more emphasis on metal bioavailability and on other metals in addition to lead. A two-step management approach with mandatory testing of toys for total metal concentrations followed by voluntary bioaccessibility testing could be implemented.