Dziubanek et al. 2025 - Upper Silesia child recreational-soil metals

Dziubanek and colleagues measured Cd, Pb, and Zn in 77 surface-soil samples from playgrounds, sports fields, gyms, parks, and other child recreation areas in three postindustrial districts of Upper Silesia, Poland. The source is primary environmental-health evidence for non-dietary child exposure to contaminated soil and dust. It is not food, ingredient, or consumer-product occurrence evidence.

Key numbers

Soil sampling frame

The study collected 77 topsoil samples from places where children spend time: 51 playground samples, 15 sports-field/gym samples, and 11 samples from other recreational places such as squares, parks, and green areas. Samples came from Katowice-Szopienice (KT), Swietochlowice-Lipiny (SW), and Piekary Slaskie-Brzeziny (PS).

The authors compared results with Polish soil-contamination reference values of 2 mg Cd/kg dry matter, 200 mg Pb/kg dry matter, and 500 mg Zn/kg dry matter. They report that 65 of 77 samples (84.42%) exceeded the normative value for at least one of the three metals. Exceedances were 58 samples for Cd (75.32%), 46 for Pb (59.74%), and 44 for Zn (57.14%); 35 samples (45.45%) exceeded the values for all three metals.

Concentrations by recreational-area type

Table 6 reports soil concentrations as mg/kg dry matter:

All three area-type means exceeded the Polish comparison values for Cd and Zn. The Pb mean exceeded the 200 mg/kg comparison value in all three area types; the highest single Pb value was 4930.10 mg/kg in a playground sample.

Concentrations by city and area type

Table 7 reports additional city-by-area breakdowns. For playgrounds, the mean concentrations were:

For sports fields and gyms, the means were:

For other recreation areas, the means were:

Across all sample types within each city, the means were Cd 8.67, Pb 450.83, and Zn 877.30 mg/kg in Katowice-Szopienice; Cd 5.77, Pb 223.45, and Zn 920.21 mg/kg in Swietochlowice-Lipiny; and Cd 10.22, Pb 463.63, and Zn 1380.37 mg/kg in Piekary Slaskie-Brzeziny.

The authors report no statistically significant differences across locations or recreational-area categories by Kruskal-Wallis testing (p > 0.05), attributing this partly to large within-category variability.

Non-dietary ingestion risk

The risk model used reference doses of 0.001 mg/kg/day for Cd, 0.0035 mg/kg/day for Pb, and 0.3 mg/kg/day for Zn. Three scenarios used the lowest, average, and highest measured soil concentrations.

For preschool children, the highest-concentration Pb ingestion scenario produced significant non-cancer risk. In the all-sample S3 scenario, Pb dose was 10.6024 ug/kg/day with HQ 3.0292. In Katowice-Szopienice specifically, the S3 Pb values were the same: 10.6024 ug/kg/day and HQ 3.0292. Piekary Slaskie-Brzeziny S3 Pb was 3.4280 ug/kg/day with HQ 0.9794, close to the threshold. Cd and Zn HQ values stayed below 1 in all preschool ingestion scenarios.

For younger school children aged 6 to <12 years, the all-sample S3 Pb ingestion scenario produced dose 4.6510 ug/kg/day and HQ 1.3289; the Katowice-Szopienice S3 Pb value was also HQ 1.3289. Piekary Slaskie-Brzeziny S3 Pb had HQ 0.4297, and Swietochlowice-Lipiny S3 Pb had HQ 0.2292. Cd and Zn HQ values remained below 1.

For older school children aged 12-15 years, no ingestion scenario reached HQ 1. The highest Pb HQ was 0.2480 in the S3 all-sample and Katowice-Szopienice calculations.

Combined hazard index and other exposure routes

The combined Cd+Pb+Zn hazard index (HI) was highest in the youngest children and declined with age. For preschool children, S3 all-location HI was 3.150 overall, 3.150 in Katowice-Szopienice, 0.608 in Swietochlowice-Lipiny, and 1.069 in Piekary Slaskie-Brzeziny. In the playground-only S3 calculation, HI was 3.120 overall, 3.112 in Katowice-Szopienice, 0.449 in Swietochlowice-Lipiny, and 0.894 in Piekary Slaskie-Brzeziny.

For younger school children, S3 all-location HI was 1.382 overall and 1.382 in Katowice-Szopienice. The playground-only S3 HI was 1.369 overall and 1.365 in Katowice-Szopienice. For older school children, the highest S3 HI was 0.2579 overall and in Katowice-Szopienice, below the non-cancer threshold.

Dermal exposure estimates were negligible relative to ingestion. Reported daily dermal-dose ranges were Cd 3.5e-10 to 6.3e-8 ug/kg/day in preschool children, Pb 1.15e-8 to 7.72e-6 ug/kg/day, and Zn 6.83e-11 to 7.43e-9 mg/kg/day. Inhalation exposure was higher than dermal but still much lower than ingestion; for preschool children, 2024 max inhalation estimates were Cd 2.563 ng/kg/day and Pb 0.045 ug/kg/day.

Methods (brief)

Each soil sample was made from several topsoil grabs to 0.25 m depth and prepared as an approximately 0.5 kg composite. Samples were dried at 105 degrees C, sieved to <2 mm, and microwave-mineralized from 0.5 g aliquots with nitric acid and hydrogen peroxide. Cd, Pb, and Zn were measured by ICP-OES. The method validation table reports LOQs of 0.15 mg/kg for Cd, 12.68 mg/kg for Pb, and 3.28 mg/kg for Zn; LODs were 0.06, 5.80, and 1.43 mg/kg, respectively. Certified reference material recovery was 87-99% for Cd, 92-118% for Pb, and 81-105% for Zn.

Average daily dose from ingestion used metal concentration, US EPA soil-ingestion factors, a 10^-6 kg/mg conversion factor, and age-specific body weight. Soil-ingestion rates were 40 mg/day for children aged 1 to <6 years, 30 mg/day for children aged 6 to <12 years, and 10 mg/day for children aged 12-15 years. Body weights were 18.6 kg, 31.8 kg, and 56.8 kg, respectively. Hazard quotients were calculated as ADD/RfD, and hazard index was calculated as HQPb + HQCd + HQZn. Dermal and inhalation calculations used US EPA exposure-factor parameters plus regional PM10 Cd and Pb monitoring data for 2023 and 2024.

Implications

Certification: Do not use this source in HMTc food, ingredient, or consumer-product occurrence pools. It measures contaminated recreational soil and modeled non-dietary child exposure, not products as sold or consumed.

App: Useful as environmental-background context for lead exposure, especially the hand-to-mouth soil/dust pathway in postindustrial communities. It supports separating dietary lead risk from non-dietary soil and dust risk when explaining cumulative child exposure.

Courses: Useful for teaching why sample matrix, exposure route, basis, and population assumptions matter. The same Pb concentration has different implications when it is soil mg/kg dry matter, a modeled daily intake, a hazard quotient, or a food occurrence value.

Wiki pages this source may touch

• cadmium
• lead
• zinc
• index
• icp-ms
• soil-to-plant-transfer

Verification notes

This page was built from the full PDF, including the abstract, sampling description, ICP-OES validation table, exposure equations, Tables 2-17, discussion, conclusions, supplementary-material note, and data-availability statement. Products and ingredients are intentionally empty because the source is an environmental child-exposure study. The paper repeatedly describes the third locality as Piekary Slaskie-Brzeziny, while the Table 7 footnote labels PS as Piekary Slaskie-Orzel Bialy; this page uses the abstract and methods locality name and treats the table-footnote wording as an internal location-label inconsistency.

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.