Distribution and Enrichment of Heavy Metals in Fine-Grained

Overview

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Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

• Lead reaches up to ~2 wt.% in the finest e-waste fraction (<0.15 mm).
suitable for further metallurgical processing (18,19). Other approaches include oxidative
distinguish light and heavy fractions. The light fraction represented approximately 13 % of
the total mass, while the heavy fraction accounted for about 87 %. The heavy fraction was
ensured stable separation conditions. The sample (total mass 2 kg) was subjected to the
accounted for approximately 77% of the total mass (Figure 3). Together with the 1–0.5 mm
fraction, nearly 90% of the total mass was distributed within the particle size range of
Dv (10) = 14.8 µm and Dv (90) = 184 µm, respectively, indicating that 80% of the particles fall
e-waste fraction, approximately 6–7 vol.% of particles were smaller than 10 µm (PM10)
and about 2 vol.% were smaller than 2.5 µm (PM2.5). In comparison, the fine dust frac-
from repeated measurements are summarized in Table 1 and reported in ppm and wt.%.
Table 1. Content of selected elements in separated fractions of e-waste.
2 wt.% in fractions below 0.25 mm, corresponding to several ten-fold (up to ~70-fold)
approximately 349 ppm in fraction 5 to 636 ppm in fraction 6, while selenium concentrations
below 0.5 mm, where its content reached values of several thousand ppm. This behaviour
hazardous metals, as shown in Table 1. It contains significant amounts of chromium, nickel,
approximately 14–15 vol.% PM10 and about 3.5 vol.% PM2.5, confirming the potential

Methods (brief)

while only a limited fraction is formally collected and recycled, resulting in considerable
of heavy metals in airborne dust and biological samples of workers involved in e-waste
Biomonitoring studies have also reported increased levels of metals in biological samples
increasing volumes of formally collected e-waste place growing demands on downstream
ensured stable separation conditions. The sample (total mass 2 kg) was subjected to the
From each obtained size fraction, representative samples weighing approximately
50 g were collected for chemical composition analysis. Samples of the crushed e-waste
as well as the individual size fractions were placed into dedicated sample cups covered
equipped with a dedicated holder for the analysis of small and loose samples. The obtained
together with the collected fine dust, was determined using a laser diffraction particle size
dispersion unit. Prior to measurement, the samples were carefully homogenized to ensure
size class relative to the total mass of the sieved sample. The finer fractions below 0.5 mm
crushing, handling, and separation of the e-waste material was collected and analysed
sizes below 0.15 mm, as well as to the fine dust fraction collected during material processing
diffraction: fraction < 0.15 mm and collected fine dust. Solid lines represent differential volume
e-waste sample, as determined by energy-dispersive X-ray fluorescence (ED-XRF) analysis.
and Sn in the collected fine dust. In comparison with fraction 6 (<0.15 mm), the fine dust
whereas Hg was not detected in any analysed sample.

Implications

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Verification notes

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Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and 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.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised