Wan et al. 2016 - Potentially toxic elements in Beijing settled dust

Wan and colleagues measured twelve potentially toxic elements in 62 settled-dust samples from the Beijing urban area and used those concentrations in a US EPA-style exposure model. This is primary environmental and health-risk evidence, not food, ingredient, cosmetic, or consumer-product occurrence evidence. Its main value for the index is context: dust ingestion as a child exposure pathway, total-element method notes, and the relative contribution of arsenic, lead, and antimony to non-cancer hazard in an urban dust setting.

Key numbers

All concentration values below are from Table 2 and are reported as mg/kg in the <63 micrometer settled-dust fraction.

The authors classify V, Cr, Mn, Co, Ni, and Ba as close to local natural-soil background, while Cu, Zn, As, Cd, Sb, and Pb are elevated and more strongly anthropogenic. Cadmium had the strongest enrichment signal: 67.7% of samples had local-soil enrichment factors between 20 and 40, classified by the paper as very high enrichment.

For the non-cancer health-risk model, the total hazard index was 1.8 for children and 0.25 for adults. The sample-level total HI range was 0.88-5.4 for children and 0.12-0.75 for adults; 89% of child sample-site HIs exceeded 1. The element HI order for children was As > Pb > Sb > Cr > Mn > Ba > V > Cu > Cd > Zn > Ni > Co, and As, Pb, and Sb together contributed 75% of the child total HI. Dust ingestion contributed 92% of the total child HQ and 84% of the total adult HQ. The highest cancer-risk estimate reported in the text was 3.8 x 10^-5 for As via dust ingestion, within the paper’s stated 10^-6 to 10^-4 regulatory range.

Methods (brief)

The study collected 62 settled-dust samples in spring 2015, mostly from outdoor surfaces of residential buildings in Beijing. Samples were sieved to <63 micrometers, dried at 105 degrees C for 8-12 hours, and hot-digested in concentrated nitric, perchloric, and hydrochloric acids. Co, Ni, Cu, As, Cd, Sb, and Pb were measured by Agilent 7700x ICP-MS; Al, V, Cr, Mn, Zn, and Ba were measured by Leeman Labs Profile ICP-AES. The paper reports blank and duplicate quality control, <5% relative standard deviation precision, and reference-material recoveries near 100% +/- 5%.

Implications

Certification: Do not admit this source into product or ingredient benchmark pools. The matrix is urban settled dust, the basis is total concentration in a fine dust fraction, and the arsenic value is total As rather than inorganic arsenic.

App: Use as health/exposure context for dust ingestion, child hazard-index calculations, urban-environment source apportionment, and metal-page background. It should not populate food, supplement, cosmetic, personal-care, toy, or ingredient concentration rows.

Courses: Useful for teaching environmental matrix fit, total-element versus species-specific analytes, enrichment factors, and how an exposure model can identify arsenic, lead, and antimony as dominant hazard contributors even when several other elements are measured.

Wiki pages this source may touch

• index
• index
• arsenic
• lead
• cadmium
• chromium
• nickel
• copper
• zinc
• manganese
• antimony
• barium
• vanadium
• cobalt

Verification notes

This page was built from the full PDF text, including Table 2, Table 4, and Appendix Table A1. The concentration table is primary analytical data for settled dust and is retained as context-only evidence because the matrix is not a product, food, ingredient, or consumer-goods material. The source reports arsenic as total As by digestion/ICP-MS; it does not provide inorganic arsenic speciation. No brand names or product labels are present.

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.