Determination of potentially toxic metals in depilatory products in the Iranian markets: human health risk assessment

The preventive and carcinogenic effect of metals on cancer: a systematic review

BACKGROUND

Many studies have investigated the role of metals in various types of malignancies. Considering the wide range of studies conducted in this field and the achievement of different results, the presented systematic review was performed to obtain the results of investigations on the prevention and occurrence of various types of cancer associated with metal exposures.

METHODS

In this review, research was conducted in the three databases: Scopus, PubMed, and Web of Science without historical restrictions until May 31, 2024. Animal studies, books, review articles, conference papers, and letters to the editors were omitted. The special checklist of Joanna Briggs Institute (JBI) was used for the quality assessment of the articles. Finally, the findings were classified according to the effect of the metal as preventive or carcinogenic.

RESULTS

The total number of retrieved articles was 4695, and 71 eligible results were used for further investigation. In most studies, the concentration of toxic metals such as lead (Pb), chromium (Cr (VI)), arsenic (As), cadmium (Cd), and nickel (Ni) in the biological and clinical samples of cancer patients was higher than that of healthy people. In addition, the presence of essential elements, such as selenium (Se), zinc (Zn), iron (Fe), and manganese (Mn) in tolerable low concentrations was revealed to have anti-cancer properties, while exposure to high concentrations has detrimental health effects.

CONCLUSIONS

Metals have carcinogenic effects at high levels of exposure. Taking preventive measures, implementing timely screening, and reducing the emission of metal-associated pollutants can play an effective role in reducing cancer rates around the world.

Measurement of Iron in Flour and Commonly-Used Breads Baked in Isfahan, Iran: A Risk Assessment Study with Monte Carlo Simulation

Fortification of highly-consumed foods such as bread is an easy and cheap strategy to combat the iron deficiency anemia. However, there have sometimes been some side effects such as iron overload and digestive problems. Accordingly, this study aimed to examine the amount of iron as well as its non-carcinogenic risks in commonly-used types of Iranian flour and breads (Barbary, Lavash, and Tafton) in Isfahan, Iran. Iron concentration of 100 samples of flour and breads were measured by Inductively Coupled Plasma Optical Emission Spectrometer. Moreover, the non-carcinogenic health risk of iron in fortified breads was estimated by Target Hazard Quotient (THQ) in Monte Carlo Simulation technique. The limit of detection (LOD) and limit of quantification (LOQ), with a recovery level of 95%, were 1.8 × 10-5 and 5.9 × 10-5 mg/kg, respectively. The total mean concentration of iron in flour (53.48 ± 22.49 mg/kg) and bread (39.02 ± 22.63 mg/kg) samples was within the standard recommended range (40-85 mg/kg) in Iran. THQ for adults and children was equal to 0.53 and 2.48. respectively. Hence, non-carcinogenic risk of iron through bread consumption was acceptable for adults, while it was not acceptable for children as a sensitive group. Consequently, it is required to rescreen the flour and bread fortification program in Iran according to the comprehensive risk assessment studies.

Blood-lead level in humans and drug addiction: a comprehensive study in Iran

Drug abuse has a high prevalence worldwide and causes many health-related disorders. There are limited human exposure studies on establishing lead exposure levels and their propensity for drug addiction. In the present study, blood samples were tested for lead (Pb) concentrations in illicit drug users together with the related symptoms in comparison with control group of non-drug users. The study was performed on 250 volunteers divided equally in four drug groups, namely, opioids, hashish, methadone, and methamphetamine, and one control group of non-drug users. Participants were recruited from drug addiction clinics and camps in Kashan city, Iran, who were using drugs continuously for more than 1 year. Control group was recruited from companions of the patients with no drug use history. In the investigated groups of drug users, the highest blood-lead level (BLL) concentrations were observed in the opioid group (mean 37.57 µg/dL) with almost 3.7 times higher than in the control group (mean 3.39 µg/dL). In the methamphetamine group, type of occupation had the significant association with BLL concentrations. The positive correlation was revealed in the opioid and methadone groups for BLL concentrations and the duration of drug usage. In the opioid group, the highest BLL concentrations were observed among users who used both methods of drug use: smoking and eating. Also, several behavioral and life-style factors were identified which influence the blood-lead concentration in the drug users. The results of our study revealed that the BLL concentrations in investigated drug users' groups were significantly higher than in the control group (P < 0.001). That can be related with the Pb contents in illicitly used drugs. Apart other adverse health effects, long-term illicit drug use might cause to lead poisoning.

Bioavailability-based risk assessment of various heavy metals via multi-exposure routes for children and teenagers in Beijing, China

Assessing the health risks of sensitive population, such as children and teenagers, through multiple exposure routes (MERs) such as ingestion, inhalation, and dermal contact is critical for policy creation that protects or reduces exposure to pollutants for all populations. Heavy metal (HM) contents in food and environmental media in Beijing, capital of China, were collected. Furthermore, on the basis of considering the bioavailability of HMs, we evaluated the multiple environmental routes and health risks to HMs in children and teenagers of eight age groups (2-<3, 3-<4, 4-<5, 5-<6, 6-<9, 9-<12, 12-<15, and 15-<18) in Beijing, China by Monte Carlo simulation approach. The main findings are as follows: lead exposure in children aged 2-<3 years exceeds the exposure dose (0.3 μg·kg-1·d-1) of 0.5 point reduction in intelligence quotient. Moreover, children aged 2-<3 and 6-<9 years have relatively high non-carcinogenic risk (NCR) of 1.32 and 1.30, respectively. The carcinogenic risk (CR) for children aged 6-<9 and 9-<12 years is 2.73×10-6 and 2.39×10-6, respectively. Specifically, the contributions of oral ingestion, dermal contact, and inhalation to the NCR were 69.5%, 18.9%, and 11.6%, respectively. Moreover, the combined NCR contributions of copper, cadmium, mercury, and arsenic (As) were about 69.4%. The contributions of the above three routes to the CR were 93.4%, 4.1%, and 2.5%, in that order, with the largest CR contribution of As being about 92.0%. This study can provide new ideas for accurately assessing the exposure and health risks of HMs in the population, and we believe that it is necessary to update the national standards for food and soil based on the bioavailability of HMs.

Associations between parental and postnatal metal mixture exposure and developmental delays in a Taiwanese longitudinal birth cohort of preschool children

Studies have evaluated the impact of environmental exposure to neurotoxic metals on developmental delays (DDs). However, comprehensive understanding regarding the associations between parental and postnatal exposure to metal mixtures and the occurrence of DDs in offspring is limited. In this study, we assessed the relationships between parental and postnatal exposure to three metals (arsenic [As], cadmium [Cd], and lead [Pb], levels of which were measured in toenails) and suspected DDs (SDDs) in preschool children within a Taiwanese longitudinal birth cohort. In total between 2017 and 2021, 154 pairs of parents and their children under the age of 6 years were recruited, and 462 toenail samples and 154 completed questionnaires were collected. Metal concentrations in toenails were quantified using inductively coupled plasma-mass spectrometry after acid digestion of the toenails. We applied multivariable logistic regression and Bayesian kernel machine regression to evaluate the overall effect and to identify key components of the metal mixture that were associated with the SDD risk. Higher concentrations of As, Cd, and Pb were found in the toenails of the parents of children with SDDs compared with the toenails of the parents of children without SDDs. Our examination of the combined effects of exposure to the metal mixture revealed that As concentration in the father's toenail and Cd concentration in the mother's toenail were positively correlated with the risk of SDDs in their offspring. Notably, the effect of exposure to the metal mixture on the risk of SDDs was stronger in boys than in girls. Our findings suggest that parents taking measures to minimize their exposure to metals might enhance their children's developmental outcomes.

Consumer health risk assessment of Arsenic and Mercury in hen eggs through Monte Carlo simulations

BACKGROUND

This study was conducted to assess the concentration of heavy metals (arsenic and mercury) and estimate the probability that consumption of hen egg products collected in Iran has carcinogenic or non-carcinogenic consequences.

METHODS

A total of eighty-four hen eggs from 21 major brands were randomly selected from among thirty local supermarkets in two seasons (winter (January) and summer (August) 2022). Arsenic (As) and Mercury (Hg) was determined by using ICP-MS. The human health risk assessment refers to the formulation of the USEPA standard focused on Estimated Daily Intake (EDI), International Lifetime Cancer Risk (ILCR), Target Hazard Quotient (THQ), and Monte Carlo simulation (MCS) as a probabilistic method. Data analysis was carried out using the statistical software SPSS. Differences in mean concentrations of As and Hg in two seasons were tested by paired t-test.

RESULTS

Over two seasons, the average As and Hg concentrations in hen eggs were 0.79 and 0.18 µg.kg^-1, respectively. Seasonal difference in As concentration (p = 0.451) was not significant, whereas that of Hg concentration (p < 0.001) was significant. The calculated value of EDI was 0.29 µg As/day and 0.06 µg Hg/day. The EWI in the maximum scenario of as level in hen eggs was estimated to be 8.71 µg As and 1.89 µg Hg/month for Iranian adults. THQ's mean for As and Hg in adults was determined to be 0.00385 and 0.00066, respectively. In addition, ILCRs by MCS for As were 4.35E-4.

CONCLUSION

In total, the result indicates that there was not a significant risk of developing cancer; the calculation of THQ was still below the accepted level of 1, indicating that there was no risk while, according to most regulatory programs (ILCR > 10^- 4) shows a threshold carcinogenic risk of arsenic through consuming in hen eggs. Therefore, policymakers need to be aware that it is prohibited to establish chicken farms in heavily polluted urban areas. It is essential to regularly conduct examinations to measure the presence of heavy metals in both ground waters used for agriculture and the feed provided to chickens. Additionally, it is advisable to focus on raising public awareness about the importance of maintaining a healthy diet.

Multiple pollutants in groundwater near an abandoned Chinese fluorine chemical park: concentrations, correlations and health risk assessments

Contamination and adverse effects from various pollutants often appear in abandoned industrial regions. Thus, nine groundwater samples were collected from the vicinity of the fluorochemical industry in Fuxin City, Liaoning Province, to determine concentrations of the ten heavy metals arsenic (As), chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), manganese (Mn), zinc (Zn), iron (Fe) and mercury(Hg), as well as those of fluorine (F⁻) and eighteen poly- and perfluorinated substances (PFASs), analyse correlation relationships, and assess the health risks for different age groups. The results showed that the levels of fluorine (F⁻) (0.92–4.42 mg·L⁻¹), Mn (0.0005–4.91 mg·L⁻¹) and Fe (1.45–5.61 mg·L⁻¹) exceeded the standard limits for drinking water. Short chain perfluorobutanoic acid (PFBA) (4.14–2501.42 ng·L⁻¹), perfluorobutane sulfonate (PFBS) (17.07–51,818.61 ng·L⁻¹) and perfluorohexanoic acid (PFHxA) (0.47–936.32 ng·L⁻¹) were the predominant substances from the PFASs group. No individual PFASs levels had significant relationships with F⁻ or heavy metal contents. There was a positive relationship between short chain PFASs concentrations and water depth and a negative relationship between long chain PFASs concentration and water depth. The hazard quotient (HQ) decreased in the order F⁻ > heavy metals > PFASs and also decreased for older age groups. In addition, As, Fe, Mn and perfluorooctanoic acid (PFOA) were the main sources of risk from the heavy metal and PFASs groups, respectively.