Heavy metals in local and imported cosmetics in Ghana and their health risk assessment

Abstract

: This study aimed to determine the levels of heavy metal(loid)s in local and imported cosmetics purchased from the Kejetia market and to conduct their health risk assessment. Seven (7) metal(loid)s (Pb, Cd, As, Fe, Ni, Cr, and Hg) were analyzed in twenty-one (21) cosmetic samples. Atomic absorption spectroscopy (AAS) was used in this study. Some of the metal(loid)s in imported cosmetic samples were higher than those found in local cosmetic samples. However, there was no significant difference between the concentrations of the metal(loid)s in both local and imported cosmetic samples. The margin of safety (MoS) values for all the metal(loid)s in the cosmetics sample were below the WHO standard of 100. The HQ and HI values for almost all the metal(loid)s in the cosmetic samples were greater than their permissible limit of 1, suggesting that there may be health risks associated with using cosmetic samples for the sensitive sub-population. On the other hand, carcinogenic risk (CR) for Cr and As in local and imported cream and lotion were all higher than the tolerance levels. Moreover, from the results, the Pb, Cd, and Hg concentrations were higher than the acceptable permissible limits set by the various regulatory bodies. Cosmetic manufacturing industries are encouraged to adhere to the permissible limits set by regulators. We admonish the regulatory agencies to unforce regulations on permissible limits of heavy metals in cosmetics

Keywords:

• Hazards
• toxicity
• health
• regulatory
• margin of safety
• cosmetics products

PUBLIC INTEREST STATEMENT

This paper assessed the levels of heavy metals and metalloid in some cosmetic samples purchased from the market in Kumasi, Ghana. This is done to determine whether the amounts in the cosmetics can affect those who use the cosmetics that contain them. Heavy metals are toxic, persistent, does not break down and are harmful to humans even at low levels. They are stable and have the ability to impart colour. Therefore, they are employed in cosmetics. It was observed that the levels of these heavy metals in the cosmetics analysed were higher than their acceptable limits. The levels were also high that there is the potential for them to cause health hazards to sensitive people when they are used extensively over long periods. All cosmetics products irrespective of their country of manufacture are supposed to be used with care.

1. Introduction

The use of cosmetics has seen an upsurge in North America, Europe, Asia, and Africa. The global cosmetic industry was estimated to be worth $40 billion in 2012 (Owusu-Agyei et al., 2020) and the African cosmetics sector in the same year was worth an estimated $ 6.93 billion (West Africa Competitiveness Programme WACOMP, 2019). According to Ghana Food Drug Authority, a cosmetic is a substance or mixture of substances manufactured, sold, or represented for use in cleansing, improving, or changing the complexion, skin, hair, eyes, or teeth and involves perfumes and deodorant (Ghana Food and Drugs Authority, 2013). People who trade in cosmetics have grouped them into five classes and these include skincare, hair care, color (make-up), fragrances, and toiletries/others.

Heavy metal(loid)s are present in cosmetics and pose a major public health and environmental concern due to their potential to cause various health hazards (Ikehata et al., 2014). The toxic effects of these metals vary from acute to chronic depending on factors such as the route of exposure, metal type, and concentration in cosmetics (Tawila et al., 2019). Besides their important role in living organisms, heavy metal toxicity to humans and the environment has been a longstanding issue (Ikehata et al., 2014). The growing usage of cosmetics by diverse populations has led to increased public health concerns due to the presence of metal(loid)s such as Hg, Pb, Cd, and As in cosmetic formulations. The accumulation of these metals beyond the body’s detoxification capacity results in their retention in various organs and tissues, leading to harmful effects (Yahya et al., 2021). Despite the crucial function of the skin in shielding the body from exogenous contaminants, metal(loid)s present in cosmetics can traverse the skin due to direct application to the skin, leading to detrimental health impacts (Usman et al., 2021). For example, adverse reactions such as cancer, mutations, development problems, allergic reaction, and respiratory problems occur due to heavy metal contamination (Yahya et al., 2021). Some metals are utilized in the cosmetics industry as starting materials for manufacturing cosmetics, and these metals even at trace levels can stimulate adverse reactions in the body of humans (Nayak et al., 2021). For instance, chromium hydroxide (Cr (OH)₃) and lead acetate (Pb (C₂H₃O₂)₂) are used as coloring agents to produce lipstick and eye shadow. Besides, heavy metals found in cosmetics may be discharged into the final product by metallic devices during the manufacturing process or through metallic containers used to package these cosmetics products (Zakaria & Ho, 2015).

The Ghanaian cosmetic and personal care products industry tends to become the number one leading sector which will contribute significantly to the Ghanaian economy in the coming years (West Africa Competitiveness Programme (West Africa Competitiveness Programme WACOMP, 2019). Among the preeminent indigenous cosmetic brands in the Ghanaian market, there are noteworthy contenders such as Cocoa Care, Cocoa Expect, Kakam, Habiba, and Hudu. Notwithstanding, the findings of a research inquiry conducted by Nkansah et al. on foreign lipsticks have demonstrated that the lipstick samples under scrutiny were sourced from an array of nations such as India, the United States, China, South Korea, South Africa, and Malaysia (Nkansah et al., 2018). While locally-manufactured cosmetics and personal care items are available in the Ghanaian markets, the majority of Ghanaian consumers exhibit a clear preference for imported cosmetics on the grounds of perceiving local products as inferior in quality. In Ghana, there is very little attention given to exposure to metals due to cosmetic usage among the Ghanaian population, as compared to metals exposure via sources such as water, food, and soil.

A health risk assessment represents a suitable approach for evaluating the detrimental effects of different pollutants on both human health and the environment (Yahya et al., 2021). Worldwide, two primary methods are utilized for assessing the risk of chemical contaminants, namely the quantitative model and the uncertainty model, such as the Monte Carlo method (Karimian et al., 2021). The latter model is typically employed in circumstances that entail risk uncertainty and is thus commonly used by most researchers to perform health risk assessments. For example, Zheng et al. employed the Monte Carlo method to assess the risk linked to heavy metals such as Cu, Pb, As, Cd, and Cr in Chongqing hotpot seasoning (Zheng et al., 2020). In the present investigation, we utilized the Monte Carlo method to estimate the health risk of metal(loid)s in cosmetics.

Herein, the primary objective of this study was to ascertain the concentrations of the metal(loid)s, namely Hg, As, Pb, Cd, Cr, Fe, and Ni, in both domestic and imported cosmetic products, and to undertake a health risk assessment of these metal(loid)s in the cosmetics. Additionally, the investigation aimed to contrast the heavy metal(loid) levels with international regulatory guidelines. The findings of the health risk assessment provide a solid scientific rationale for the necessity of implementing regulations and guidelines for the production of cosmetics.

2. Methods and materials

2.1. Study area

Kumasi, the administrative and economic center of the Ashanti region in Ghana, is an important urban area situated between latitudes 6.350 N and 6.400 S and longitudes 1.300 W and 1.350 E. It is located approximately 270 km north of Accra, the capital of Ghana, and 120 km southeast of Sunyani, the capital of the Bono region. The city is home to the famed Kumasi central market, also known as Kejetia (Figure 1), which serves as a significant trading hub for Ghana and beyond. As one of the largest open-air markets in West Africa, Kejetia is situated at the heart of Kumasi, bordering the Kumasi cultural center to the north and the Komfo Anokye teaching hospital to the northwest. The southern boundary of the Kejetia market, situated in the heart of Kumasi and adjacent to the commercial center of Adum, forms a bustling hub of economic activity. Boasting over 10,000 stores and stalls, the market offers a vast array of goods, ranging from foodstuff and footwear to kente fabric and cosmetics. However, cosmetics sold at Kejetia are either imported from other countries or locally manufactured.

Figure 1. A map of Kejetia the study area.

2.2. Sampling and collection

A multistage sampling technique was employed. This sampling technique involves the use of two or more sampling methods to select a representative sample. The Kejetia market was divided into five parts and each part represents a cluster. The parts include southern, northern, eastern, western, and central. The shops in each cluster were numbered and the researcher selects randomly from the list of numbers which represent shops where the cosmetic products were purchased. The sampling was designed to ensure a maximum number of different brands of cosmetic products are included. In view of their daily usage and possible health risk, the cosmetics selected include body lotion, cream, eyeliner, and lipstick. A total of twenty-one (21) cosmetics were collected and transported to Ghana Atomic Energy Commission (GAEC) for analysis.

2.3. Reagents and standards

All reagents used in the experiment were of analytical grade. The reagents used including 65% HNO₃, and H₂O₂ were obtained from Spectrascan, Sweden. The standard stock solutions (1000 ppm) of all the metals were purchased from Spectrascan, Sweden. Deionized water was used in preparing all solutions.

2.4. Sample preparation

The wet digestion method was used since all the samples could not conveniently be processed by ash drying. As detailed by Amartey et al (Ackah et al., 2015). and Ackah et al (Marinovich et al., 2014), 0.5 grams of each sample were weighed into Teflon beakers and mixed with 7 mL of concentrated nitric acid (HNO₃) and 1 mL of hydrogen peroxide (H₂O₂) in a fume chamber. The samples were then placed on a microwave carousel, with the vessel cap tightly sealed using an appropriate screwing tool. After 21 minutes of microwave irradiation, the samples were allowed to cool at room temperature before being further diluted to a final volume of 50 mL using deionized water.

2.5. Quality control and assurance

The analysis in the study was subjected to quality assurance techniques to ensure accurate and reliable results. This included thorough cleaning and soaking of plastic and glassware in 5% HNO₃ solution for 24 hours before use, careful handling of samples to prevent contamination, and correction of instrument readings using reagent blank determinations. The instrument was calibrated after 10 runs, and a recovery study was conducted to validate the accuracy and precision of the analytical procedure using the spike recovery approach. The limit of detection (LOD) and limit of quantification (LOQ) were calculated using standard deviation of the blank solution.

2.6. Heavy metal analysis

The study utilized Atomic Absorption Spectroscopy (AAS Varian SpectrAA model 240FS, Tokyo, Japan) to analyze the concentrations of Pb, Ni, Cd, Cr, As, Hg, and Fe in cosmetic samples, with a cold vapor technique being used to measure Hg levels. Prior to analysis, standard metal solutions were created at different concentrations to obtain calibration curves. The metal concentrations in each sample were determined from the calibration curves, and the instrument displayed the results in milligrams per kilogram.

2.7. Statistical analysis

The data were analyzed using the statistical package for the social science (SPSS) VERSION 20. Descriptive statistical parameters such as mean and standard deviation (SD) were used to describe the heavy metal(loid) concentration in the cosmetic samples. Kruskal Wallis test was used to determine if there is a significant difference between the mean concentrations of heavy metal(loid)s in locally manufactured and imported cosmetics at a significance level of p < 0.05. Experiments were carried out in triplicate.

2.8. Health risk assessment

Health risks to humans as a result of exposure to heavy metals found in cosmetic products can be calculated as a Margin of Safety (MoS). MoS is the ratio of the No Observable Adverse Effect Level (NOAEL) to the Systemic Exposure Dosage (SED) as reported previously by Marinovich et al (Marinovich et al., 2014). Based on World Health Organization, the lowest amount of MoS is 100, and therefore if the MoS content is 100 or greater, it is considered safe.

MoS = NOAEL / SED (1)

The SED predicts the number of metals that enter the body via different pathways. The formula for calculating SED is given by the expression:

SED (mg/kg/d) = Cs x AA x SSA x F x RF x BF x 10⁻³ /BW (2)

Where Cs is the concentration of metal in the cosmetic sample (mg/kg), AA is the quantity of cosmetic product applied (g/cm²), SSA is the Surface area of skin onto which the product is applied (cm²), F shows the application frequency of a product/day, RF is the retention factor, BF is bio accessibility factor, 10⁻³, (mg/kg) is used as unit convertor, BW is the average body weight (70 kg) (Ghaderpoori et al., 2020). A level of exposure where no adverse effect is observed is called NOAEL and its value was calculated based on dermal reference dose (RfDs) as reported by Ghaderpoori et al (Ghaderpoori et al., 2020). The expression:

NOAEL = RfD × UF × MF (3)

Where UF is an uncertainty factor, MF is modifying factor, and defaults values for MF and UF are 1 and 100 respectively.

2.9. Non- carcinogenic risk

The hazard quotient, HQ (non-carcinogenic risk) of the different metals measured in the cosmetics can be computed. The HQ is the ratio of systemic exposure dose (SED) to the chronic reference dose (RfD) of the toxicant (mg/kg/d) as used by (Ghaderpoori et al., 2020).

Non- carcinogenic risk, HQ = SED/RfD (4)

If HQ ˂ 1, the exposed population is safe but if HQ ˃ 1, it is unsafe for humans.

The Hazard Index (HI) is the summation of HQ for all heavy metals under study. If HI ˂ 1, the exposed consumers are safe, if HI ˃ 1, it is considered not safe for human health (Liu et al., 2013).

HI = ∑ HQ (5)

2.10. Carcinogenic risk

The carcinogenic risk (CR) is normally determined for potential carcinogenic metals. CR is computed using the expression (Jan et al., 2015) described below

CR = SED × SF (6)

Where SF represents the cancer slope factor (mg/kg/d).

3. Results

3.1. Recovery studies

The results of the recovery study were within the acceptable range verifying the validity of the proposed method for analysis. The recoveries for the metal(loid)s as well as their LOD and LOQ are presented in Table 1.

Table 1. Results of recovery studies and LOD and LOQ

Metals	Un-spiked amount (mg/kg)	Amount added (mgkg)	Spiked amount (mg/kg)	Recovery %	LOD (mg/kg)	LOQ (mg/kg)
Pb	2.7 ± 0.02	8.0	10.5	74.28	0.16	0.539
Cd	1.5 ± 0.00	5.0	6.4	76.56	0.06	0.539
As	0.4 ± 0.01	4.0	4.3	113.95	0.029	0.097
Fe	0.3 ± 0.01	2.0	2.2	86.36	0.016	0.054
Ni	0.2 ± 0.00	1.0	1.1	81.81	0.001	0.050
Cr	0.2 ± 0.01	3.0	5.0	82.76	0.015	0.050
Hg	0.5 ± 0.02	2.0	2.3	78.26	0.07	0.054

3.2. Concentrations of heavy metals in cosmetics

In this study, we analyzed a total of twenty-one (21) cosmetic products for the presence of seven (7) different metal(loid)s. The mean concentrations of these metal(loid)s in the various cosmetic samples are depicted in Table 2.

Table 2. Mean concentrations (mg/kg) of heavy metals in cosmetics

Cosmetic	Pb	Cd	As	Fe	Ni	Cr	Hg
Local
Lotion	0.43 ± 0.51	0.88 ± 0.38	10.05 ± 0.29	1.50 ± 0.58	ND	0.41 ± 0.35	6.24 ± 0.20
Cream	1.57 ± 0.81	3.16 ± 2.05	1.25 ± 0.65	0.04 ± 0.00	0.00 ± 0.00	0.33 ± 0.21	8.25 ± 1.96
Eyeliner	1.22 ± 1.03	2.00 ± 1.77	9.23 ± 0.19	6.85 ± 2.54	0.00 ± 0.00	1.39 ± 0.37	0.26 ± 0.13
Lipstick	5.69 ± 3.85	2.49 ± 1.56	3.62 ± 1.98	9.87 ± 5.23	0.01 ± 0.00	7.26 ± 4.96	ND
Imported
Lotion	8.71 ± 5.17	5.55 ± 3.80	5.72 ± 0.99	7.11 ± 3.35	0.01 ± 0.00	7.68 ± 3.67	1.63 ± 0.76
Cream	6.19 ± 3.37	3.69 ± 1.90	3.38 ± 3.90	2.51 ± 2.43	0.02 ± 0.01	5.05 ± 1.83	5.03 ± 1.64
Eyeliner	9.05 ± 4.65	4.56 ± 2.31	4.92 ± 2.78	5.07 ± 3.50	0.00 ± 0.00	4.94 ± 0.88	1.84 ± 0.35
Lipstick	13.03 ± 2.00	9.58 ± 1.25	8.11 ± 0.99	12.98 ± 6.12	0.00 ± 0.00	5.56 ± 1.49	ND

3.3. Health risk assessment

Margin of safety (MoS)

The margin of safety index was computed to assess the risk of human contact with metal(loid)s impurities in cosmetic products. The margin of safety level for the heavy metals was estimated at 100% bioaccessibility and presented in Table 3.

Table 3. Margin of Safety for heavy metals using 100% bioaccessibility

Cosmetic	Pd	Cd	As	Fe	Ni	Cr	Hg
Local
Lotion	1.68	2.34 × 10^−5	6.17 × 10^−5	0.0048	-	0.00015	0.00094
Cream	0.46	0.00065	0.00049	1.81 × 10^−5	-	0.000188	0.00071
Eyeliner	1.04 × 10^−8	1.82 × 10^−7	1.19 × 10^−8	1.86 × 10^−7	-	7.86 × 10^−9	3.99 × 10^−8
Lipstick	1.31 × 10^−6	8.58 × 10^−7	1.77 × 10^−7	7.56 × 10^−7	4.26 × 10^−9	8.81 × 10^−7	-
Imported
Lotion	0.08	0.00039	0.0001	0.001	4.13 × 10^−6	0.0008	0.0036
Cream	0.12	0.00061	0.00018	0.0028	0.0002	0.0012	0.0011
Eyeliner	1.41 × 10^−7	7.84 × 10^−8	2.22 × 10^−8	2.52 × 10^−7	-	2.21 × 10^−7	5.64 × 10^−7
Lipstick	5.74 × 10^−5	2.23 × 10^−7	7.88 × 10^−8	5.74 × 10^−5	-	1.15 × 10^−6	-

3.4. Non-carcinogenic risks

The hazard quotient (HQ) was evaluated to quantify the non-carcinogenic risk posed by heavy metal(loid)s in cosmetic samples when assuming 100% bioaccessibility. The corresponding HQ values for the metal(loid)s are presented in Table 4.

Table 4. Hazard Quotient (HQ) of heavy metals in cosmetics using 100% bioaccessibility

Cosmetic	HQ values
	Pb	Cd	As	Fe	Ni	Cr	Hg
Local
Lotion	59.40	426	1620	2070	-	66.20	1060
Cream	217	153	2020	55.3	-	53.20	1400
Eyeliner	0.0095	0.055	0.84	0.54	-	0.013	0.0025
Lipstick	0.76	1.17	5.65	13.20	0.00023	1.14	-
Imported
Lotion	1210	2510	9230	9840	0.240	1240	277
Cream	856	1630	5450	3470	0.490	815	854
Eyeliner	0.07	0.130	0.450	0.397	-	0.045	0.0177

3.5. Carcinogenic Risks

The study estimated the carcinogenic risk at 100% bioaccessibility of two metals (Cr and As) in the cosmetic samples as shown in Tables 5 and 6.

Table 5. Carcinogenic risk of chromium for dermal exposure pathway for body cream and lotion samples (100% bioaccessibility)

Cosmetics	SEDDermal	Slope factor	Cancer Risk (CR)
Local: cream	3.19 × 10^−2	2.1	6.70 × 10^−2
Imported: cream	4.89 × 10^−1	2.1	1.03 × 10°
Local: lotion	3.97 × 10^−2	2.1	8.34 × 10^−2
Imported: lotion	7.44 × 10^−1	2.1	1.56 × 10°

Table 6. Carcinogenic risk of Arsenic for dermal exposure pathway for body cream and lotion samples (100% bioaccessibility)

Cosmetics	SEDDermal	Slope factor	Cancer Risk (CR)
Local: cream	1.21 × 10^−1	47.5	5.75 × 10°
Imported: cream	3.27 × 10^−1	47.5	1.55 × 10^1
Local: lotion	9.37 × 10^−1	47.5	4.62 × 10^1
Imported: lotion	5.54 × 10^−1	47.5	2.63 × 10^1

3.6. International regulatory bodies

The levels of Pb, Cd, and Hg were assessed against the regulatory thresholds established by the European Union, World Health Organization, and United States Food and Drug Administration, as illustrated in Figures 4–6.

4. Discussion

4.1. Concentration of heavy metals in cosmetics

Pb contamination poses a persistent threat to human health, as evidenced by several studies reporting high levels of Pb in various cosmetic brands (Ackah et al., 2015;Liu et al., 2013). Acute exposure to Pb can result in a range of adverse health effects, including loss of appetite, headache, fatigue, arthritis, hypertension, and abdominal pain (Alam et al., 2019). In pregnant women, exposure to elevated levels of Pb can increase the risk of preterm labor, miscarriage, spontaneous abortion, or low birth weight in newborns (Jan et al., 2015). Our study found that the concentration of Pb in local samples ranged from 0.43 ± 0.51 to 5.69 ± 3.85 mg/kg, while the concentration in imported samples ranged from 6.19 ± 3.37 to 13.03 ± 2.00 mg/kg (Table 2). Our study revealed that the imported lipstick sample had the highest concentration of Pb, while the local lotion sample exhibited the lowest concentration (Figure 2 (A)). Furthermore, the imported cosmetic products demonstrated higher levels of Pb compared to their locally produced counterparts. These findings highlight the urgent need for rigorous monitoring and regulation of cosmetic products to minimize the potential risks associated with Pb contamination. The local samples exhibited the following order of Pb concentration: lipstick ˃ cream ˃ eyeliner ˃ lotion, while the imported samples followed the order of lipstick ˃ eyeliner ˃ lotion ˃ cream. However, we observed no significant difference (p ˃0.05) in the means of local and imported cosmetics. Our study recorded lower levels of Pb concentration compared to that of (Marinovich et al., 2014). Conversely, Adepoju-Bello et al (Adepoju-Bello, 2012). reported much lower values for the level of Pb in lipstick and cream samples. These results are consistent with those of Ullah et al (Ullah et al., 2017), who also examined the concentration of Pb in lipstick and body cream. Our findings underscore the pressing need to establish and enforce strict regulations to monitor and mitigate the potential health risks associated with Pb contamination in cosmetics.

Figure 2. Heavy metal concentrations in cosmetic samples (A) Pb concentrations (mg/kg) in cosmetic samples (B) as concentrations (mg/kg) in cosmetic samples (C) Cd concentrations (mg/kg) in cosmetic samples (D) Fe concentrations (mg/kg) in cosmetic samples (E) Ni concentrations (mg/kg) in cosmetic samples (F) Cr concentrations (mg/kg) in cosmetic samples (G) Hg concentrations (mg/kg) in cosmetic samples.

The dermal application of cosmetics is one possible route of exposure to Cadmium (Cd), which can result in several deleterious effects, including cancer. Cd toxicity has been associated with cellular apoptosis, endocrine dysfunction, and DNA impairment. Our study revealed a range of Cd concentrations in local cosmetic samples of 0.88 ± 0.38–3.16 ± 2.05 mg/kg, while the imported cosmetic samples showed a range of 3.69 ± 1.90–9.58 ± 1.25 mg/kg (Table 2). The analysis of cosmetic samples in our study showed that the maximum and minimum concentrations of Cadmium (Cd) were detected in imported lipstick and local lotion samples, respectively (Figure 2b). Although the Cd concentration was higher in imported cosmetic samples than in the local counterparts, the means of the two groups were not significantly different. The order of Cd concentration in local samples was cream ˃ lipstick ˃ eyeliner ˃ lotion. Likewise, the order of Cd concentration in imported samples was lipstick ˃ lotion ˃ eyeliner ˃ cream. Notably, Yoeza and co-workers reported the range of Cd levels in cosmetics samples, such as lipstick, eyeliner, and foundation, as ND − 23.78 mg/kg (Yoeza et al., 2018). These findings were substantially higher than the results of our study, highlighting the necessity of continual monitoring and regulation of Cd levels in cosmetic products to safeguard public health. The findings of this research differ from the results of Rajagopal and co-workers, who were unable to detect any Cadmium (Cd) in their cosmetic samples (Rajagopal et al., 2015). On the other hand, our outcomes are consistent with the findings reported by Aminat et al (Aminat & Alem, 2019).

Arsenic exposure, resulting from the use of common products such as pesticides, herbicides, paints, wood preservatives, and cosmetics, presents a significant threat to human health. Arsenic exposure in humans has been shown to interfere with DNA repair processes, thereby increasing the risk of carcinogenesis (Arshad et al., 2020). The carcinogenic properties of inorganic arsenic, such as arsenite and arsenate, make them a threat to human health, with prolonged exposure resulting in cancer of the lungs, liver, bladder, and skin (Arshad et al., 2020). In Taiwan, prolonged exposure to inorganic arsenic via dermal contact has been linked to black foot disease, which is characterized by severe damage to blood vessels in the lower limbs (Rahil et al., 2019). The present study reveals that the concentration of As in the cosmetic products are 1.25 ± 0.65 mg/kg and 10.05 ± 0.29 mg/kg, representing minimum and maximum values respectively (Figure 2c). Interestingly, although the concentration of As was higher in local cosmetics than in imported cosmetics, there was no significant difference between their means according to Kruskal Wallis test. The order of As concentration in local cosmetics was lotion ˃ eyeliner ˃ lipstick ˃ cream while in imported cosmetics, it was lipstick ˃ lotion ˃ eyeliner ˃ cream. Notably, the As concentration in this study was lower than those reported by Nasirudeen and Ameachi (Nasirudeen & Amaechi, 2015), and Adejupo-Bello et al (Adepoju-Bello, 2012), but consistent with the results of Nancy et al (Nancy et al., 2014).

The cosmetic industry heavily relies on iron (Fe) for its diverse color range. However, an excessive amount of Fe in the body can be toxic, causing damage to mitochondria, microsomes, and other cellular organelles through the production of free Fe from percutaneous absorption (Arshad et al., 2020). This study found that cosmetics products that come in a variety of colors have a higher Fe concentration, with imported lipstick having the maximum Fe level and local cream samples having the minimum Fe level (Figure 2d). Based on the results, there was a disparity in Fe concentration between local and imported cosmetics, but no significant difference was observed between the means. The order of Fe levels in local cosmetics was cream ˂ lotion ˂ eyeliner ˂ lipstick, while the same trend was observed in imported cosmetics with cream ˂ eyeliner ˂ lotion ˂ lipstick. Although there are differences between the Fe concentrations reported in this study and those of previous publications by Ekere et al (Ekere et al., 2014). and Elzbieta et al (Elzbieta et al., 2018), they are consistent with the results reported by Arshad et al (Arshad et al., 2020).

Nickel exposure in humans is a consequence of the use of various products, including cosmetics, detergents, and jewelry (Adepoju-Bello, 2012). When exposed to elevated levels of Ni, humans are more susceptible to prostate cancer, lung cancer, larynx cancer, and nose cancer (Jaishankar et al., 2014). The concentration of Ni detected was considerably low in comparison to other metals (Figure 2e). The Ni concentration range for both locally produced and imported cosmetics was 0.00 ± 0.00–0.02 ± 0.01 mg/kg (Table 2). Despite the low concentrations of Ni detected in the cosmetic samples, prolonged use of such products may trigger the bioaccumulation of Ni in the body, leading to several adverse effects, such as hypersensitivity, skin irritation, and nephrotoxicity, as reported in previous studies (Elzbieta et al., 2018). Moreover, there was no substantial variance in the Ni concentrations observed in both local and imported cosmetic samples. A Belgian woman who used an eye pencil containing Ni, experienced several symptoms, including itching, dermatitis, erythema, and moderate scaling of the eyelids, as well as infiltration (Elzbieta et al., 2018).

Chromium (VI) compounds are potent toxins, capable of inducing carcinogenicity in human cells. In contrast, Chromium (III) plays a vital role in the body’s metabolic processes, being an essential nutrient for proper physiological function (Rajagopal et al., 2015). Elevated levels of chromium exposure may instigate the development of skin ulcers and other associated hypersensitivity reactions characterized by erythema and edema. Prolonged use of cosmetics containing chromium (IV) are capable of inflicting significant harm on multiple vital organ systems such as the liver, kidney, circulatory, and nervous systems (Somaye et al., 2019). Evidence links Cr exposure to numerous maladies, including kidney disease, lung cancer, and skin allergies such as dermatitis (Rajagopal et al., 2015). Exposure to Cr⁶⁺ has been demonstrated to elicit numerous deleterious health outcomes such as nasal irritation, rhinitis, pulmonary congestion, and tympanic membrane perforation (Ullah et al., 2017). Results of our investigation revealed a conspicuous elevation in Cr levels among imported cosmetics relative to their domestically manufactured counterparts, as evidenced by the data presented inFigure 2f. Our analyses of local cosmetic samples indicate Cr concentrations ranging from 0.33 ± 0.21 mg/kg (cream) to 7.26 ± 4.96 mg/kg (lipstick) (Table 2). Conversely, imported cosmetics demonstrated maximum and minimum Cr concentrations of 7.68 ± 3.67 mg/kg (lotion) and 4.94 ± 0.88 mg/kg (eyeliner), respectively. Furthermore, statistical analyses reveal no significant variation in Cr concentration between locally manufactured and imported cosmetics. In the context of locally manufactured cosmetics, the descending order of Cr concentration was as follows: lipstick > eyeliner > lotion > cream, whereas imported cosmetics demonstrated a Cr concentration order of lotion > lipstick > cream > eyeliner. These findings are in agreement with the results of Usman et al (Yahya et al., 2021), who determined Cr concentrations in various cosmetics, including lipstick, eyeliner, and body cream. Importantly, the observed Cr levels in this study were substantially lower than those reported by Nancy et al (Nancy et al., 2014). In contrast, the results of Arshad et al (Arshad et al., 2020). demonstrated notably low Cr concentrations in certain imported lotion brands, which is in contrary to our study’s findings.

Mercury is utilized in skin-lightening cosmetics, including soap and body creams, with significant health implications. Absorption of the mercury present in these cosmetic products through the skin results in toxic accumulation within the body, causing severe poisoning (Jaishankar et al., 2014). Even chronic exposure to low levels of mercury can result in debilitating neurological and renal diseases (Sankhla, 2019). Individuals who use cosmetics containing trace levels of mercury can experience skin rashes, skin discoloration, and weakened skin immunity to microbial agents (ES et al., 2016). Surprisingly, Hg was not detected in either locally or imported lipstick samples. Maximum Hg concentrations were recorded in cream samples for both locally manufactured and imported cosmetics, as indicated in Table 2. The present study’s results affirm the elevated usage of Hg in body creams. Notably, the lowest Hg concentrations were detected in eyeliner and lotion for both local and imported cosmetic samples, as indicated in (Figure 2g). The Hg concentration order in local cosmetics was as follows: eyeliner ˂ lotion ˂ cream, whereas the order in imported cosmetics was lotion ˂ eyeliner ˂ cream. Nonetheless, there were no significant variations in the Hg concentrations observed between local and imported cosmetic samples. Ghaderpoori et al (Ghaderpoori et al., 2020). also examined the Hg levels in several cosmetic products, such as creams, lipsticks, and eye pencils, and reported Hg levels ranging from ND − 0.00077 mg/kg, which were considerably lower than the findings obtained in this study. Conversely, the results obtained by Yoeza et al (Yoeza et al., 2018). and Nasirudeen and Amaechi (Nasirudeen & Amaechi, 2015) were comparatively higher than those observed in the present study.

4.2. Health risk assessment

4.2.1. Margin of safety (MoS)

The margin of safety (MoS) index was computed to evaluate the potential hazards associated with human exposure to metal(loid) impurities in cosmetic products. The MoS levels for the heavy metals were determined based on 100% bioaccessibility and tabulated in Table 3. According to WHO safety standards, for a cosmetic product to be deemed safe for use, the MoS should exceed 100. However, the computed MoS values for all metals analyzed in the cosmetic samples were below the WHO safety threshold of 100. This finding suggests that both the local and imported cosmetic products sampled were not safe and could pose considerable health risks to sensitive sub-population of consumers. Furthermore, these study results highlight a critical public health concern since numerous individuals, particularly young people, use cosmetic products regularly. The highest MoS index of 1.68 was recorded in a local lotion for Pb, while the lowest MoS value was 4.26 × 10⁻⁹ for Ni (as outlined in Table 3). The MoS values in this study were dissimilar to those documented by Ghaderpoori et al (Ghaderpoori et al., 2020). and Usman et al (Usman et al., 2021). Moreover, in lotion cosmetics, Arshad et al (Arshad et al., 2020). demonstrated MoS values for Cd, Cr, and Pb that were above 100. These findings by Arshad et al (Arshad et al., 2020). contrast with those of this study. The decreased MoS in this study would mean that current intakes of metal(loid)s through the use of cosmetics are likely to be harmful. This presents a higher exposure risk that is not acceptable. Patrons of cosmetics in this part are encouraged to use cosmetics products with care.

4.3. Non-carcinogenic risks

The hazard quotient (HQ) was computed to evaluate the non-carcinogenic risk of heavy metal(loid)s at 100% bioaccessibility in the cosmetic samples. When the HQ exceeds 1, it indicates that the exposed population is at risk of experiencing adverse health effects. As depicted in Table 4, most of the HQ values for nearly all metals, except Ni, in the cosmetic samples exceeded 1, indicating a health risk associated with the cosmetics. In the case of local cosmetics, the HQ value of As in lotion was the highest, while the lowest HQ value was identified in Ni in lipstick (as shown in Table 4). In the case of imported cosmetics, the highest HQ value was observed in Fe for lotion samples, with a value of 9840, while the lowest HQ value of 0.0177 was found in Hg in eyeliner. A hazard index (HI) exceeding 1 indicates that the exposed consumer is at risk. Figure 3 shows that both local and imported cosmetics had HI values greater than 1, indicating that the cosmetic samples pose a threat to human health. The highest HI value of 24,300 was found in imported lotion, while the lowest HI value of 1.11 was observed in imported eyeliner. In contrast, previous studies by Alam et al (Alam et al., 2019). and Ghaderpoori et al (Ghaderpoori et al., 2020). reported HI values less than 1.

Figure 3. HI values versus cosmetic samples.

4.4. Carcinogenic risks

This study could only estimate the carcinogenic risk associated with two metals (Cr and As) present in the cosmetic samples at 100% bioaccessibility. The cancer risk (CR) estimation indicates the potential cancer risk for heavy metal exposure through cosmetic use. According to Zheng et al (Amartey et al., 2011), the acceptable CR range is between 1 × 10⁻⁶ and 1 × 10⁻⁴. As shown in Table 5, the CR values for local and imported creams were 6.70 × 10⁻² and 1.03 × 10⁻¹, respectively, for Cr, exceeding the acceptable range. The study demonstrated similar CR trends in Cr for imported lotion. As presented in Table 6, the CR values of As in both lotion and cream samples exceeded the permissible limit. Furthermore, cream and lotion were selected for CR estimation due to their large application area and quantity, in contrast to lipstick and eyeliner with smaller application areas and quantities. The CR values obtained in this study were consistent with those obtained by Arshad et al (Arshad et al., 2020), which were also above the permissible limits.

The margin of safety index, carcinogenic risk, and non-carcinogenic estimates in this study show that using the examined cosmetic goods carries a significant risk of metal(loid) exposure. The high risk is unacceptable, which indicates that using cosmetics could expose you to metal(loid)s and pose adverse carcinogenic and non-carcinogenic health effects to vulnerable population.

4.5. International regulatory guidelines

To regulate the presence of these metals in cosmetics, international regulatory bodies such as WHO, USFDA, EU and FDA Ghana have established acceptable thresholds. Nevertheless, the regulations for the various heavy metals differ from one regulatory body to another. As shown in Figure 4-6, the concentration of Pb in all cosmetic samples, except for local lotion, exceeded the EU threshold of 0.5 mg/kg. The acceptable limit for Pb in cosmetics set by WHO is 10 mg/kg. It is noteworthy to mention that among the cosmetic samples tested, only one (imported lipstick) contained Pb content that exceeded the limit set by the WHO. However, all cosmetic samples had Pb content within the permissible limit set by the USFDA. The concentration of Cd in all samples was higher than the acceptable limit set by the EU (0.5 mg/kg) and the WHO (0.3 mg/kg), as shown in Figure 5. These findings are in agreement with the results reported by Alam et al (Alam et al., 2019). Six (6) samples were found to contain Hg, but only one (local eyeliner) had a Hg level below the limit of 1.0 mg/kg set by both the WHO and USFDA. Notably, all cosmetic samples, except local eyeliner, had Hg content exceeding the permissible limits set by WHO and USFDA (Figure 6). Similarly, the concentrations of other heavy metals such as Pb and Cd were also above the acceptable thresholds set by some international regulatory bodies. Consequently, consumers who use these cosmetics are at an increased risk of exposure to heavy metals.

Figure 4. Comparing Pb concentration with EU, WHO, and USFDA limits.

Figure 5. Comparing the Cd concentration with EU and WHO limits.

Figure 6. Comparing Hg concentration with WHO and USFDA limit..

5. Conclusion

In this study, higher concentrations of certain metals were found in imported cosmetics compared to local cosmetics. Additionally, the Margin of Safety (MoS) values for all metal(loid)s in the cosmetic samples were below the WHO standard of 100, and the Hazard Quotient (HQ) and Hazard Index (HI) values for nearly all metals in the cosmetic samples were above their permissible limits. These findings suggest that both local and imported cosmetic samples are not safe for use and pose potential health risks to consumers. Additionally, concentrations of some metals surpassed regulatory levels, raising concerns about the safety of the consumer. But in order to assess the quantities of heavy metal(loid) in other cosmetic items besides those included in this study, further thorough research is required. Cosmetic manufacturing industries are encouraged to adhere to the permissible limits set by regulators as that would protect the health of consumers. We admonish the regulatory agencies to unforce regulations on permissible limits of heavy metals in cosmetics through monitoring of production processes and products on the market.

List of abbreviations

Table

AAS	Atomic Absorption Spectroscopy
CR:	Carcinogenic Risk
CR:	Carcinogenic Risk
EU:	European Union
FDA	Food and Drugs Authority
HI	Hazard Index
HQ	Hazard Quotient
LOQ	Level of Quantification
LOD	Level of Detection
MF	Modifying Factor
MoS	Margin of Safety
NOAEL	No Observable Adverse Effect Level
NIST	National Institute of Standards and Technology
RFD	Reference Dose
SED	Systemic Exposure Dosage
SF	Slope Factor
SPSS	Statistical Package for Social Science
UF	Uncertain Factor
USFDA	United States Food and Drugs Authority
USFDA	United States Food and Drugs Authority
USEPA	United States Environmental Authority
WACOMP	West Africa Competitiveness Programme
WHO	World Health Organization

Acknowledgments

This study received no funding but the authors are grateful to Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development for allowing the use of their laboratory for some of the analysis

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data is found in the manuscript or immediately available from the authors

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.