Analysis of Hazardous Elements in Children Toys: Multi-Elemental Determination by Chromatography and Spectrometry Methods

An investigation into the present levels of contamination in children's toys and jewelry in different countries: a systematic review

Contamination by heavy metals and toxic elements in children's toys and jewelry is an ongoing challenge in different countries. These contaminants can enter the children's body via oral, dermal, and respiratory routes, leading to adverse health effects. This study aimed to investigate the present levels of contamination in children's toys and jewelry in 15 countries, including UK, Saudi Arabia, Cambodia, China, Kosovo, Nigeria, North American, Kazakhstan, UAE, Pakistan, Iraq, Israel, West Bank/Palestine, Czech Republic, and Turkey. In this review, the legislation and recommendation of the United States (U.S.), the Bureau of Indian Standards (BIS), Turkish Standards Institute (TSE), Canada, and the European Union (E.U.) on toxic elements in toys and jewelry are introduced. Plastic or metallic toys and children's jewelry still have the most severe toxic elements pollution and the existence of lead (Pb), nickel (Ni), cadmium (Cd), arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), selenium (Se), barium (Ba), Zinc (Zn), cobalt (Co), manganese (Mn), bisphenol A, phthalates, parabens, azo dyes, and flame retardants has been regarded as an ongoing challenge in these articles. Finally, this review offers benchmarking of the concentrations of toxic elements in all types of children's toys and jewelry in different nations.

Short-term exposure to multiple metals mixture and mitochondrial DNA copy number among children: A panel study

BACKGROUND

Little is known regarding the individual and overall associations of short-term co-exposure to metals mixture with mitochondrial DNA copy number (mtDNAcn) among healthy children.

METHODS

We conducted a panel study across three seasons among 144 children aged 4 to 12 years in Guangzhou. For each season, we collected the first-morning urine for four consecutive days and fasting blood on the 4th day to detect 23 urinary metals and blood leukocyte mtDNAcn, respectively. Linear mixed-effect (LME) models and multiple informant models were used to examine the relations of individual metals with mtDNAcn over different lag days, and the least absolute shrinkage and selection operator (LASSO) regression was applied to determine the most important metal. We further employed weighted quantile sum (WQS) regression to investigate the overall association of metals mixture with mtDNAcn.

RESULTS

Nickel (Ni), manganese (Mn) and antimony (Sb) were independently associated with mtDNAcn in a linear dose-response manner. Each 1-fold increase in Ni at lag 0 day, Mn and Sb at lag 2 day was associated with respective decrements of 8.74 %, 6.93 % and 3.98 % in mtDNAcn in multi-metal LME models. LASSO regression also selected Ni, Mn and Sb as the most significant metals at the corresponding lag day. WQS regression showed overall inverse associations between metals mixture and mtDNAcn both at lag 0 and lag 2 day, with mtDNAcn decreased by 2.75 % and 3.14 % in response to a quartile increase in the WQS index. Additionally, the associations of Ni and Mn with decreased mtDNAcn were stronger among children younger than 7 years, girls and those having less vegetables and fruit intake.

CONCLUSION

We found an overall association between metals mixture and decreased mtDNAcn among healthy children, in which Ni, Mn and Sb were the major contributors. Younger children, girls and those with less vegetables and fruit intake were more susceptible.

Metals as toxicants in event-based expedited production of children's jewelry

Globally, the hazardous substance in children's goods is of great concern. Toxic chemicals are potentially harmful to the health and growth of infants and children. Lead (Pb) and cadmium (Cd)-contaminated children's jewelry is widely encountered in many countries. This study aims to determine the concentration of metal toxicants (Pb, Cd, Ni, Cu, Zn, Co, and Fe) in event-based (Independence Day festival) children's jewelry, considering time-limited and fast production products that may compromise the quality and safety parameters during manufacturing. The determinations are for the time-constraint industrial production of children's jewelry in the context of the toxic substances in a variety of base materials used. This is the first time event-based children's jewelry has been monitored and critically assessed for metal contamination. Forty-two samples, including metallic, wooden, textile, rubber, plastic, and paint-coated plastic children's jewelry, were tested. Seventy-four percent of samples detected Pb and Cd in quantifiable amounts. Ni in 71%, Cu in 67%, Co in 43%, and Zn and Fe were detected in 100% samples with quantifiable amounts. Twenty-two ID-CJ samples exceeded the US regulatory limit for Pb and four samples for Cd. However, twenty-nine samples for Pb, eleven for Cd, five for Co, and one for Cu exceeded the EU regulatory limit. The highest concentration of Pb was found in paint-coated plastic jewelry, and the highest Cd was found in metallic jewelry. These results suggest that the potential hazards of event-based children's jewelry deserve the attention of government agencies seeking to limit children's exposure to toxic chemicals. Intergovernmental organizations and individual countries regulate chemicals in consumer products, but a coordinated international approach is lacking. Some continents and countries still lack in regulations for children's products, especially jewelry, and toys.

On the Determination of Cr(VI) in Cr(III)-Rich Particulates: From the Failure of Official Methods to the Development of an Alternative Protocol

The goals of this work are the evaluation of the performances of official methods in the challenging determination of Cr(VI) in Cr(III)-rich particulate matter, and the development of a novel and robust analytical protocol for this issue. A liquid chromatography inductively coupled plasma mass spectrometry apparatus (LC-ICP-MS), together with an isotope-enriched spike addition technique, was used to allow the study of Cr(III)/Cr(VI) interconversions during the extraction step. An original separation strategy based on Cr(OH)₃ head-column stacking was developed to tolerate high concentrations of Cr(III) (up to 10 mg/kg, with a Cr(VI) limit of detection of 0.51 µg/kg) without the need of any sample pretreatment. After observing, the official extraction protocols always yield false positive values in the challenging situation of particulate matter of leather industries (where huge amounts of Cr(III) are present), a new extraction strategy was developed. The novel procedure involves a 48-h extraction at room temperature using a pH-8 phosphate buffer, which demonstrated that no Cr(III)/Cr(VI) interconversions occur during this phase. To get rid of any possible interference caused by co-extracted substances, the measurement of the redox potential, together with the addition of a Fe(II)/Fe(III) redox buffer was performed to fix chromium speciation during the overall analytical protocol.

Contamination of potentially toxic metals in children's toys marketed in Iran

Chemical exposure of heavy metals in children is of particular concern. However, using heavy metal-contaminated toys can threaten the life and well-being of children. Therefore, quality control of toys for avoiding children exposure to potentially toxic metals is important. The investigation of potentially toxic metals (arsenic, barium, antimony, cadmium, chromium, mercury, lead, selenium) in toys was performed in present study. A total number of 150 popular cheap priced plastic toy samples were purchased from the eight metropolitan and most visited provinces in Iran and analyzed by atomic absorption spectrophotometer for arsenic, barium, antimony cadmium, chromium, mercury, lead, and selenium. As results showed As, Ba, Cd, Cr, Hg, Pb, Sb, and Se respectively were in the range of 0-0.9 mg/kg, 0.3-5 mg/kg, 0-3.1 mg/kg, 0.04-4.8 mg/kg, 0-0.03 mg/kg, 0.22-11.7 mg/kg, 0-1.2 mg/kg, and 0.03-1.1 mg/kg. Cadmium was higher than the European standard in Kurdistan province. The highest amount of mercury was also observed in Tehran. The highest amount of lead, selenium, and antimony was detected in Qom province. The results showed that all the toxic elements in the collected toys were within the permissible limit. Furthermore, market monitoring is needed to control toys safety on a large scale in metropolitan cities like Qom province.

Contamination by hazardous elements in low-priced children's plastic toys bought on the local markets of Karachi, Pakistan

Children's plastic toys may contain toxic metals to which infants and young children can be orally exposed and may pose acute or chronic adverse health effects. This research aims to evaluate the total metal concentrations (TMCs) of Pb, Cd, Cr, Ni, Zn, Cu, and Mn in children's plastic toys bought in the local markets of Karachi, Pakistan, and compare TMCs to different toy safety regulatory limits. A total of 44 children's plastic toys sourced in the Karachi local markets were analyzed by an atomic absorption spectrophotometer for contamination of hazardous elements. Toy samples were divided into two groups: plastic toys (DCT) and plastic toys with paints or coatings (DPCT). For plastic toys, 83% (19) of samples had TMCs that exceeded European Union (EU) toy safety regulation limits for Pb, and 65% (15) of samples that exceeded for Cd. For plastic toys with paints or coating, 43% (9) of samples had TMCs that exceeded EU migration limits for Pb and 24% (5) for Cd. More than 20 samples exceeded the United States Consumer Product Safety Commission (US CPSC), Canadian, and Bureau of Indian Standards (BIS) toy safety regulation limits. In toy samples (n = 44), very high TMCs of Pb (64%), Cd (45%), Cr (5%), and Ni (2%) were observed. Zn, Cu, and Mn TMCs existed but were below the regulation limits. The contamination levels of Pb, Cd, Cr, and Ni and smaller extent of Zn, Cu, and Mn still pose health issues in children and may cause serious problems in their health.

One-minute highly selective Cr(VI) determination at ultra-trace levels: An ICP-MS method based on the on-line trapping of Cr(III)

An analytical method derived from the coupling of frontal chromatography (FC) with Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) is proposed for the fast determination of Cr(VI) ultra-traces. The insertion of a short, homemade column filled with a strong cationic exchange resin in the flow-path of a commercial ICP-MS allows on-line trapping of cationic Cr(III) and elution of anionic Cr(VI). As a result, only the Cr(VI) front reaches the detector. This separation mechanism enables the highly selective quantification of Cr(VI) ultra-traces (LOD = 0.026 µg/kg - defined as 3 s of 10 replicated measurements of a 0.050 µg/kg solution) over a wide linearity range (tested up to 1024 µg/kg), even in the presence of Cr(III) concentration as high as 50 mg/kg. Key advantages of the proposed method are the extremely short analysis time (one minute), together with the simplicity and cost-effectiveness of the modifications applied over a commercial ICP-MS instrumental configuration. No time- or chemical-consuming pretreatments are needed: it is only necessary to acidify the sample prior Cr(VI) determination, as normally performed for common ICP-MS analysis. The applicability of the method was demonstrated over mineral water samples and toy migration solutions.

Speciation of Chromium in Alkaline Soil Extracts by an Ion-Pair Reversed Phase HPLC-ICP MS Method

The aim of this work was to study by a hyphenated HPLC-ICP MS technique the chromium species released during alkaline extraction of various soils collected from a contaminated area of an old tannery. An ultrasound-assisted extraction procedure using 0.1 mol L⁻¹ Na₂CO₃ solution was developed for the release of chromium species from the soil. The chromium species in the soil extracts were separated on a C₈ column using EDTA and TBAH solution as a mobile phase. The use of an ICP-QQQ MS spectrometer in tandem mass configuration (MS/MS) combined with an octopole reaction system (ORS³) pressurized with helium allows one to eliminate spectral interferences during Cr determination in the soil extracts. The detection limit of the procedure was 0.08 µg L⁻¹ for Cr(III) and 0.09 µg L⁻¹ for Cr(VI) species. The trueness of the IP RP HPLC-ICP MS method was proved by an analysis of CRM 041 and CRM 060. The advantage of the proposed method is the analysis of soil extracts without their preliminary neutralization, which limits the losses of Cr(VI) due to the reduction process. The analysed soils mainly contained chromium in immobile forms (94.6–98.5% of the total Cr content). In all alkaline soil extracts mostly the Cr(VI) form was found, but in the extract of organic soils Cr(III) was also present. This arose from the reduction of Cr(VI) species by organic matter (humic acids) and Fe(II). The amount of formed Cr(III) species was dependent on the type of soil (content of organic matter, Mn and Fe) and its moistness. For the first time, the presence of neutral and non-polar chromium fractions in the soil extracts was also demonstrated. It was found that reliable speciation analysis results could be obtained for mineral soils.