Gul 2022 - hazardous elements in low-priced Karachi plastic toys

Gul and colleagues measured total metal concentrations of Pb, Cd, Ni, Zn, total Cr, Cu, and Mn in 44 low-priced children’s plastic toys purchased from local markets in Karachi, Pakistan. The raw file is the Research Square version 1 preprint, which states that a version of record was published in Environmental Science and Pollution Research with DOI 10.1007/s11356-022-19362-0. The routeable evidence is finished-toy total metal concentration in mg/kg for plastic toy substrate materials and plastic toys with paint or coatings; the paper compares those total concentrations with EU, U.S. CPSC, Canadian, and BIS toy limits but does not report a migration or bioaccessibility assay.

Key numbers

• Sample frame: 44 low-priced toys purchased from Karachi local markets, stalls, mall stores, bargain stores, roadside vendors, and retail toy shops. The study targeted plastic toys designed for children around 3-5 years old and mostly demanded by low-income groups.
• Groups: children’s plastic toys (DCT, n = 23) and children’s plastic toys with paint or coating (DPCT, n = 21).
• Analytes: Pb, Cd, Ni, Zn, total Cr, Cu, and Mn as total metal concentrations (TMCs) in mg/kg.
• EU scraped-off toy material comparison limits copied from Table 1: Pb 23 mg/kg, Cd 17 mg/kg, Ni 930 mg/kg, Cr 460 mg/kg, Zn 46,000 mg/kg, Mn 15,000 mg/kg, and Cu 7700 mg/kg.
• Overall Table 4 summary for all 44 toys: average Pb 292.68 mg/kg, Cd 63.24 mg/kg, Cr 244 mg/kg, Zn 239.06 mg/kg, Cu 136.67 mg/kg, Ni 362 mg/kg, and Mn 779.25 mg/kg.
• Overall Table 4 ranges for all 44 toys: Pb 0.62-1190 mg/kg, Cd 0.34-459.01 mg/kg, Cr 90-560 mg/kg, Zn 20-1036.48 mg/kg, Cu 3.07-821.35 mg/kg, Ni 110-3000 mg/kg, and Mn 0.96-3240 mg/kg.
• Overall EU-limit exceedance counts from Table 4: Pb 64% (28), Cd 45% (20), Cr 5% (2), and Ni 2% (1). Zn, Cu, and Mn are shown as not exceeding the listed EU limits.
• Overall U.S. CPSC and BIS exceedance counts from Table 4: Pb 30% (13), Cd 16% (7), and Cr 45% (20).
• Overall Canadian exceedance count from Table 4: Pb 30% (13); the table shows no Cd exceedance under the Canadian comparison.
• DCT group averages from Table 5a: Pb 205.3391 mg/kg, Cd 85.64783 mg/kg, Ni 225.9217 mg/kg, Cr 153.1739 mg/kg, Zn 220.9304 mg/kg, Mn 894.7826 mg/kg, and Cu 135.6652 mg/kg.
• DCT EU-limit exceedance counts: Pb 83% (19), Cd 65% (15), Ni 4% (1), and Cr 9% (2).
• DPCT group averages from Table 5b: Pb 263.3952 mg/kg, Cd 17.86667 mg/kg, Ni 98.33333 mg/kg, Cr 65.61905 mg/kg, Zn 259.7524 mg/kg, Mn 541.9048 mg/kg, and Cu 118.5619 mg/kg.
• DPCT EU-limit exceedance counts: Pb 43% (9) and Cd 24% (5); Ni, Cr, Zn, Cu, and Mn are shown as not exceeding the EU limits in DPCT.
• Highest values named in the Results: Pb 1191 mg/kg in DPCT14 and 1111 mg/kg in DCT07; Cd 459 mg/kg in DCT11 and 426.1 mg/kg in DCT13; Cr 561 mg/kg in DCT03 and 479 mg/kg in DCT07; Ni 3000.1 mg/kg in DCT08.

Table 2 DCT sample values

Concentrations are copied as mg/kg; ND is the source table’s non-detect notation.

Table 3 DPCT sample values

Concentrations are copied as mg/kg; ND is the source table’s non-detect notation.

Methods (brief)

The authors purchased 44 low-priced toys from Karachi markets and grouped them into DCT and DPCT sets. Toy bodies were cut into small pieces; some samples were crushed or ground, and different parts and colors from the same toy were combined into one composite sample per toy. Two preparation approaches were used: dry ashing for some toys followed by digestion with high-purity HNO3 (65%) and H2O2 (30%), and direct acid treatment to remove paint/coating for coated samples. Standards, blanks, and digests were analyzed at Global Environmental Lab Karachi using an Atomic Absorption Spectrophotometer (AAS-Thermo Scientific Series Model iCE 3000).

Implications

Certification (HMTc): This source supports Pakistan-market occurrence context for low-priced plastic toys, with separate DCT substrate and DPCT paint/coating tables. It should not be pooled with migration-test datasets without preserving the total-content basis and Pakistan market frame.

Courses: The paper is a compact example of why total metal concentration, migration limits, and chromium speciation must be separated. The chromium measurements are total Cr by AAS, not Cr(VI).

App: If toy-material context is surfaced, this source can say that the Karachi low-priced-toy sample found Pb and Cd exceedances in both unpainted plastic toys and painted/coated plastic toys, with lower-frequency Cr and Ni exceedances in the total sample set.

Wiki pages this source may touch

• toys-substrate-materials
• toys-painted
• lead
• cadmium
• nickel
• zinc
• chromium
• copper
• manganese

Verification notes

• PDF text was extracted with pdftotext -layout to /tmp/ingest.txt; the title page, abstract, methods, Tables 1-5, Results/Discussion, and Conclusion were checked against this page.
• Identity checks before creation: Research Square DOI 10.21203/rs.3.rs-1001076/v1, version-of-record DOI 10.1007/s11356-022-19362-0, exact title, raw handle MFK_cat21-18-research-square-rs1001076, raw SHA-256 44d418f1cec4b56f81947b914acf3a844fbfa9eea435c8f870257f47dda73ae7, and candidate cite keys gul2022-karachi-plastic-toys-metals / gul2021-karachi-plastic-toys-metals were searched in wiki/sources/ and data/evidence/; no existing source page was found.
• Version note: the local raw PDF is the Research Square version 1 preprint and carries DOI 10.21203/rs.3.rs-1001076/v1; its first page states that a version of record was published in Environmental Science and Pollution Research on March 7, 2022 at DOI 10.1007/s11356-022-19362-0. Frontmatter uses the version-of-record DOI for deduplication but the numbers on this page are extracted from the local preprint PDF.
• Units: all toy sample concentrations are copied as mg/kg; no conversion was performed. Table 1 regulatory comparison limits are copied as mg/kg except the source’s U.S. CPSC Cd entry shown as 200ug.
• Speciation: Cr is total chromium measured by AAS. The page does not substitute Cr(VI) for total Cr. Pb, Cd, Ni, Zn, Cu, and Mn are reported as total elemental concentrations.
• Brand firewall: no consumer brand names are attached to contamination values. Sample descriptions such as Painted car 4, Lion, and Crocodile are de-identified product-form/sample descriptors from the source table and are preserved for provenance.
• Product slug note: DCT values route to toys-substrate-materials; DPCT values route to toys-painted. There is no separate matrix slug for non-food toy material, so matrices is intentionally empty.
• Source-internal anomalies preserved: Table 4 reports Pb maximum 1190 mg/kg, while Table 3 and the Results text list DPCT14 Pb as 1191 mg/kg; Table 4 reports Cd maximum 459.01 mg/kg, while Table 2 lists DCT11 Cd as 459; Table 3 lists DPCT14 Cd as 09. These are copied as the source renders them rather than normalized.
• Evidence tier: B because the version of record is peer-reviewed and the study reports sample-level values and methods, but the local extracted PDF is the preprint version and the sample frame is a small local market survey.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.