Assessment of Children’s Metal Exposure via Hand Wipe,

Overview

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Key numbers

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each digestion batch also contained 10% reagent blank sample and parallel sample to
The relative standard deviations in parallel measurements were lower than 5%. The
recovery rates of elements ranged from 93% to 110%. The limits of detection (LOD) for all
metals ranged from 2.0 to 20 µg·kg−1 (the details are presented in Table S1).
(mg·day−1 ); f is daily time proportion (%); Csoil is the metal concentration in soil (mg·kg−1 );
factor (%). Details of the parameter values are shown in Table S2.
pathway were presented in Table S3. Hazard index (HI) was calculated to characterize the
dermal contact pathway are presented in Table S3. Risk lower than 10−4 was considered to
wipes, with a median value of 0.8 µg·m−2 . Compared with the results from the limited
Table 1. Descriptive statistics of the amounts of metals in hand wipe samples per unit area.
men’s rank correlation coefficients (Table 2). Most metals showed positive and significant
correlations with each other (p < 0.05). Some metals showed strong correlations (R ranges:
moderately correlated with each other (R ranges: 0.29–0.49), such as Cd and Cr (R = 0.29)
Table 2. Spearmen’s rank correlations between metals in hand wipes.
factors which might be associated with metal levels in hand wipes (Table 3). It was found
of children’s play areas (classified into bare soil and hard ground surface; n = 28 and
Table 3. Analysis of the influencing factors on metal levels in hand wipes (μg∙m−2)
Table 3. Analysis of theninfluencing ·m ). Cd −2
approximately 90% of soil particles on hands were smaller than 100 µm. In addition, the
questionnaires (Table 4). Due to the low dermal absorption factor of metals, the exposure
pathway, accounting for nearly 99% of the total exposure.
Table 4. The estimated exposure dose to metals in hand wipes through hand-to-mouth contact and
The median combined HI of the target metals was within the acceptable level (Table S4),
was the dominant risk source, accounting for 74% to 99% of the total risk. The risk decreased
The median combined HI of the target metals was within the acceptable level (Table S4),
was the dominant risk source, accounting for 74% to 99% of the total risk. The risk de‐
The total cancer risk was 4.0 × 10−4 (Table S5), indicating the potential health threat to
The total cancer risk was 4.0 × 10−4 (Table S5), indicating the potential health threat
accountingfor for89%
nearly half of the total variance, followed by body weight. In addition, the contribution of 23.1% of
to that in exposure dose (Tables S6–S9). Remarkably, the cancer risk deriving from Cr
that in exposure dose (Tables S6–S9). Remarkably, the cancer risk deriving from Cr expo‐ flame retardant exposure
between metal levels in the external environment and blood were explored (Table S10).
population (56). The average Pb level was 3.2 µg·dL−1 , with 89 % children’s levels lower
between metal levels in the external environment and blood were explored (Table S10).
limits for different metals in the study; Table S2 The value of parameters in exposure assessment
via different sampling and evaluation strategies; Table S3 Summary of toxicity factors used for risk
assessment; Table S4 The non-carcinogenic risk form exposure to metals in hand wipes through hand
to mouth contact and dermal absorption pathway; Table S5 The cancer risk form exposure to metals
in hand wipes through hand to mouth contact and dermal absorption pathway; Table S6 The non-
pathway; Table S7 The cancer risk form exposure to metals in outdoor soil through ingestion and
dermal absorption pathway; Table S8 The non-carcinogenic risk form exposure to metals in indoor

Methods (brief)

exposure samples (hand wipe, outdoor soil and indoor dust), blood samples and child-specific
exposure factors were simultaneously collected for 60 children aged 3 to 12 years from an area of
samples collected from a single location of an exposed participant, such as soil from the
environments. In addition, different sample-sieving strategies were applied. For instance,
inconsistence in sample-sieving methods might facilitate the bias in assessment results and
In comparison with traditional soil and dust samples, hand wipes, an emerging matrix,
correlations with those in biological samples (22,23). It was found that hand-dermal
that soil was the key exposure pathway for the local children. The blood sample, hand
children spent most of their time were collected simultaneously for each child in September
2.2. Sample Collection
Hand wipe collection: Hand wipe samples were collected using gauze pads
in an ultra-clean laboratory, each pad was weighed to get a pre-sample weight. One
post-sample weight. Thus, the amount of dust adhering to each child’s hands could be
obtained by the weight difference of the pre- and post-samples. The weighed pad was
Outdoor soil collection: Soil samples were collected from the outside place where
of soil (0–2 cm) from an area of 100 cm2 . All soil samples were sieved through a 0.25 mm
Indoor dust collection: Indoor dust samples were collected from the floors of children’s
living place using a dust-free brush. Each sample consisted of 4 to 5 sub-samples mixed

Implications

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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