Heavy Metals Concentration In Body Creams Commonly Used In Delta State Tertiary Institutions And Their Implications For Human Health

Overview

This paper quantifies ten heavy metals (lead, cadmium, cobalt, total arsenic, manganese, silver, zinc, nickel, chromium, total mercury) in 20 brand-coded body cream/lotion samples purchased from college business centres at two Nigerian Colleges of Education in Delta State — Warri (COEW; n=10, codes CWBCA–CWBCJ) and Mosogar (COEM; n=10, codes CMBCA–CMBCJ). Quantification used flame atomic absorption spectrophotometry (Buck AAS model 210 VGP) after aqua regia (HNO₃:HClO₄ 3:1) hot-plate digestion. Silver and mercury were below the reporting limit of 0.001 ppm in every sample at both sites. Of the remaining eight metals, manganese and zinc carried the highest concentrations (Mn maximum 1.104 mg/kg at COEM; Zn maximum 0.701 mg/kg at COEW), followed by nickel and chromium at COEW (Ni up to 0.295 mg/kg; Cr up to 0.201 mg/kg) and cobalt and lead at COEM (Co up to 0.362 mg/kg; Pb up to 0.155 mg/kg). The authors note all measured values stay within their cited regulatory references (WHO/Health Canada/FDA Pb cosmetic limit 10 ppm; FDA color-additive Pb limit 20 ppm) but argue long-term bioaccumulation and accidental ingestion via hand-to-mouth transfer warrant regulatory attention.

Key numbers

Sample basis (n=20 across two sites): 10 samples per site, sample code → row mapping given by authors as CWBCA→CWBCJ (COEW, Table 1, p. 29) and CMBCA→CMBCJ (COEM, Table 2, p. 29). All concentrations in mg/kg (the paper interchangeably uses “mg/kg” in tables and “ppm” in narrative; these are equivalent for solid cosmetic matrices at the densities reported).

Site 1 — College of Education Warri (COEW); Table 1, p. 29; per-sample values in mg/kg:

Sample	Ag	tAs	Cd	Co	Cr	tHg	Mn	Ni	Pb	Zn
CWBCA	<0.001	0.011	0.004	0.009	0.068	<0.001	0.586	0.062	0.103	0.113
CWBCB	<0.001	0.015	0.014	0.002	0.145	<0.001	0.959	0.102	0.034	0.322
CWBCC	<0.001	0.008	0.015	0.044	0.172	<0.001	0.063	0.292	0.083	0.325
CWBCD	<0.001	0.003	0.009	0.109	0.201	<0.001	0.909	0.160	0.010	0.701
CWBCE	<0.001	0.011	0.044	0.061	0.019	<0.001	0.917	0.016	0.136	0.284
CWBCF	<0.001	0.007	0.005	0.008	0.175	<0.001	0.024	0.155	0.065	0.335
CWBCG	<0.001	0.017	0.019	0.065	0.159	<0.001	0.067	0.285	0.135	0.625
CWBCH	<0.001	0.004	0.043	0.044	0.175	<0.001	0.019	0.295	0.055	0.125
CWBCI	<0.001	0.011	0.044	0.107	0.067	<0.001	0.097	0.165	0.135	0.115
CWBCJ	<0.001	0.014	0.009	0.005	0.045	<0.001	0.072	0.291	0.035	0.225

COEW marginal ranges (Table 1 native values): Ag all <0.001; tAs 0.003–0.017; Cd 0.004–0.044; Co 0.002–0.109; Cr 0.019–0.201; tHg all <0.001; Mn 0.019–0.959; Ni 0.016–0.295; Pb 0.010–0.136; Zn 0.113–0.701.

Site 2 — College of Education Mosogar (COEM); Table 2, p. 29; per-sample values in mg/kg:

Sample	Ag	tAs	Cd	Co	Cr	tHg	Mn	Ni	Pb	Zn
CMBCA	<0.001	0.042	0.015	0.059	0.063	<0.001	<0.001	0.078	0.123	0.235
CMBCB	<0.001	0.001	0.008	0.095	0.001	<0.001	0.089	0.044	0.047	0.327
CMBCC	<0.001	0.043	0.016	0.001	0.043	<0.001	<0.001	0.074	0.083	0.325
CMBCD	<0.001	<0.001	0.027	0.008	<0.001	<0.001	<0.001	0.058	0.015	0.636
CMBCE	<0.001	<0.001	0.015	0.059	<0.001	<0.001	1.104	0.058	0.155	0.358
CMBCF	<0.001	<0.001	0.027	0.095	<0.001	<0.001	0.161	0.083	0.105	0.375
CMBCG	<0.001	0.002	0.025	0.001	0.055	<0.001	0.075	0.075	0.055	0.656
CMBCH	<0.001	0.001	0.015	0.008	<0.001	<0.001	1.005	0.045	0.037	0.322
CMBCI	<0.001	<0.001	0.025	<0.001	0.005	<0.001	0.159	0.044	0.025	0.225
CMBCJ	<0.001	<0.001	0.007	0.362	0.015	<0.001	<0.002	0.043	0.075	0.355

COEM marginal ranges (Table 2 native values): Ag all <0.001; tAs <0.001–0.043; Cd 0.007–0.027; Co <0.001–0.362; Cr <0.001–0.063; tHg all <0.001; Mn <0.001–1.104; Ni 0.043–0.083; Pb 0.015–0.155; Zn 0.225–0.656.

Pooled-site marginal ranges (abstract, p. 24, both sites combined): Ag <0.001 ppm (all); tHg <0.001 ppm (all); tAs <0.001–0.063 ppm; Cd 0.004–0.044 ppm; Co <0.001–0.362 ppm; Cr <0.001–0.201 ppm; Mn <0.001–1.104 ppm; Ni 0.016–0.291 ppm; Pb 0.010–0.136 ppm; Zn 0.113–0.700 ppm. (The abstract’s tAs upper bound 0.063 and Ni upper bound 0.291 ppm do not match the per-sample tables — tables show tAs max 0.043 and Ni max 0.295. See Verification notes.)

Authors’ reported concentration ordering by site:

COEW: Mn > Zn > Ni > Cr > Pb > Co > Cd > tAs (Ag = tHg < 0.001 in all samples).
COEM: Mn > Zn > Co > Pb > Ni > Cr > tAs > Cd (Ag = tHg < 0.001 in all samples).

Authors’ cited reference limits (Discussion, pp. 27, 30): WHO permissible Pb cosmetic limit 10 ppm; alternative cited limit 0.1 mg/L (Singh et al., 2019); US FDA maximum permissible Pb 10 ppm in cosmetic Good Manufacturing Practices and 20 ppm in colour additives; Health Canada Pb cosmetic limit 10 ppm; EU prohibits Pb and its salts in cosmetics outright (Regulation EC 1223/2009); a 3 ppm As threshold for skin-lightening creams (cited from Sukender et al. 2012 and Alqadami et al. 2017). All measured per-sample values fall below the 10 ppm Pb reference and the 3 ppm As reference cited.

Methods (brief)

Sampling: 20 brand-coded body cream/lotion products purchased anonymously from four shops (two per institution) at College of Education Warri (Lat. 5°54359’E, Long. 5°74238’N) and College of Education Mosogar (Lat. 5°87731’E, Long. 5°73292’N), Delta State, Nigeria. Five samples per shop. Codes were assigned to conceal brand identities. Product type span (toning, petroleum jelly, coloured jelly, bleaching/skin-lightening creams, “and many others”) is reported only in aggregate; per-sample type is not disclosed (p. 28).

Digestion: 1.0 g sample + 5.0 mL aqua regia (concentrated HNO₃:HClO₄, 3:1 v/v); hot-plate at 90 °C for 2–3 h to near-dryness; add another 3.0 mL of the same acid mixture; heat 2–3 h to complete digestion. Cool, add 5.0 mL deionised water, shake to homogenise, filter through Whatman No. 41, dilute to 25 mL in a standard volumetric flask. Refrigerate digestate prior to analysis. (p. 28, citing Chauhan et al. 2010 for the digestion procedure.)

Quantification: Atomic absorption spectrophotometry on a Buck AAS model 210 VGP (p. 28). The paper does not separately report flame vs graphite-furnace AAS mode; the Buck 210 VGP is a flame-AAS configuration unless explicitly fitted with a furnace accessory, and no furnace accessory is mentioned. No reference materials, recovery percentages, blanks, LODs, LOQs, or QC scheme are reported. The paper reports a single concentration per sample without indicating replicate analyses or uncertainty.

Speciation: Total metals only. The paper reports “arsenic (As)” and “mercury (Hg)” without species separation; this page therefore records tAs and tHg. Chromium is total (no Cr-VI speciation reported).

Reporting limit: 0.001 ppm for both Ag and Hg, expressed as the “<0.001” floor in both tables; the same floor applies to several tAs, Co, Cr, and Mn values at COEM.

Limitations the paper itself states: none beyond the general call for regulatory attention. Limitations apparent to the reader (recorded here, not by the authors): no LOD/LOQ values for the eight non-floor metals, no blanks or recovery data reported, no replicate-sample structure, no breakdown of concentrations by product type (toning vs petroleum jelly vs jelly cream vs bleaching cream), and unresolved narrative/abstract discrepancies against the per-sample tables (see Verification notes).

Implications

Certification (HMTc): Contributes Nigerian adult body-cream/lotion category-level occurrence data for ten metals to the Cat 13 Row 4 Body/hand leave-on skin care evidence base. Concentrations measured (Pb up to 0.155 mg/kg, Cd up to 0.044 mg/kg, tAs up to 0.043 mg/kg, Ni up to 0.295 mg/kg, Cr up to 0.201 mg/kg) sit well below the WHO/FDA/Health Canada 10 ppm Pb cosmetic limit and below the 3 ppm As skin-lightening-cream reference the authors cite. No threshold values are proposed by this source page.

Courses: Limited utility as a methods case study because the paper does not report LOD/LOQ, blanks, recovery, replicates, or QC scheme. Useful as a regional-supply-chain awareness teaching example (informal market, Nigerian tertiary institutions, code-anonymised brand sampling) and as a worked example of why methods-section completeness matters for downstream pooling decisions.

App: Not directly applicable. The paper measures adult body-cream/lotion products, which are outside the consumer-app scope (focussed on children’s foods and personal care).

Microbiome: Not addressed.

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