Statistical analyses and risk assessment of potentially toxic metals (PTMS) in children’s toys

Abstract

Chemical exposure of children, especially from toys, is an engineering concern. The concentration and availability of potentially toxic metals (PTM) in children's toys were determined to assess the risk that these metals pose to children. Samples of 25 toys imported from China to Nigeria were purchased. Ternary acid digestion, followed by Atomic Absorption Spectrophotometry, was used to determine the concentration of PTM in the sample. Simulations of the saline and stomach acid extraction conditions were performed to determine the concentrations of PTM that could leach out from the toys during children's mouthing behaviours (available PTM), including chewing, sucking and swallowing. The total concentrations of PTM in the toys ranged from 3.55-40.7, 3.21-38.2, 9.78-159, 3.55-11.2, and 36.1-106 mg/kg for Cd, Cr, Cu, and Pb, respectively. Availability studies showed concentrations ranging from 2.60-5.60 mg/kg for Pb, 0.53-2.03 mg/kg for Cd and 0.15-2.88 mg/kg for Ni after saline extraction, and the concentrations after stomach acid extractions ranged from 3.33-7.10 mg/kg, 1.15-3.15 mg/kg and 1.33-1.81 mg/kg for Pb, Cd and Ni, respectively. Statistical analysis showed a positive correlation between the total concentration of PTM and toys made from PVC materials. The risk assessment study showed that Cd posed the highest risk, with a hazard index (HI) as high as 4.50 for saline extraction. The study revealed that more precaution is needed during the manufacture of children's toys.

Toxic elements in children’s crayons and colored pencils: Bioaccessibility assessment

“…To assess the bioavailability of TEs in the samples, extraction was performed using artificial saliva, according to the procedure presented elsewhere. 31 The TEs concentrations in all aliquots were measured by ICP-OES. The obtained concentrations for the TEs, expressed as average, are presented in (Table II…”

“…Artificial saliva was prepared according to unified BARGE method. 31 Bioavailability tests were conducted under the controlled conditions of temperature and pH. Each sample (0.5 g) was mixed with 25 cm 3 artificial saliva and shaken for 30 min (200 rpm, 37±2 filtered 0.45 µm PTEF filter.…”

Estimation of Some Metals in Children’s Colorful Modeling Clay Sold in the Markets of Erbil City, Kurdistan Region, Iraq

“…Varying concentrations of Cd and Pb and other toxic elements were recorded in several unbranded Indian soft plastic toys (Kumar and Pastore, 2007), 20 toys and children's jewellery bought on the North American market (Guney and Zagury, 2013), thirty different soft plastic toys collected from the Ghanaian markets (Kudjoe Gati et al, 2014), and over 100 of the collected vintage plastic toys (Miller and Harris, 2015). These toxic metals were recently detected in several PVC and non-PVC plastic toys (Oyeyiola et al, 2017) 200 second-hand plastic toys sourced in the UK (Turner, 2018), and different toy samples in Poznań city (Poland) (Karaś and Frankowski, 2018) and six infant care plastic products sold in markets of Kalar City, Kurdistan Region, Iraq (Issa and Alshatteri, 2019). The Scientific Committee on Health and Environmental Risks (SCHER) mentioned that the average ingested daily intake toy materials are still appropriate as follows; 400 mg/d for liquid or sticky toy material, 100 mg/d for dry, brittle, powder-like or pliable toy material, and 8 mg/d for scraped-off toy material (EC, SCHER.…”

“…2014). Several methods for the assessment of bioavailability and Hazard Index (HI) with health risk characterization were recently recommended and applied to investigate metals health hazard exposure in various products of children's toys (Cui et al, 2015, Dahab et al, 2016, Guney et al, 2014, Guney and Zagury, 2014b, Oyeyiola et al, 2017. Last decades, scientists and physicians have extremely mentioned that no content of Cd or Pb metal in human blood is normal or considered harmless.…”

Design of the Bartlett and Hartley tests for homogeneity of variances under indeterminacy environment

“…Bartlett's test and Hartley's test under classical statistics have been widely for the testing of the equality of variances in a variety of fields, see for example [1][2][3][4][5][6][7]. More application of statistical tests can be seen in [8][9][10].…”