Carcinogenic and non-carcinogenic risk assessment of exposure to trace elements in groundwater resources of Sari city, Iran

Geochemical characterization and health risk assessment of groundwater in Wadi Ranyah, Saudi Arabia, using statistical and GIS-based models

Groundwater in Wadi Ranyah, the main water source for local communities, was analyzed using 77 samples to evaluate physicochemical properties, major ions, and heavy metal concentrations. While most parameters met World Health Organization (WHO) standards, levels of arsenic, lead, cadmium, chromium, and nickel exceeded permissible limits. Hydrochemical analyses were conducted using Piper and Durov diagrams, alongside health risk assessments based on statistical ratios established by the United States Environmental Protection Agency (US EPA). The analysis identified two dominant water types (SO4·Cl-Ca·Mg and HCO3-Ca·Mg), influenced by ion exchange, evaporite dissolution, and silicate weathering. Health risk assessment, based on US EPA models, revealed significant non-carcinogenic and carcinogenic risks, particularly for children. Oral ingestion accounted for the majority of exposure, with arsenic and lead being the most hazardous. Dermal exposure risks were comparatively lower. The identified health threats include potential dermatological, cardiovascular, and neurological effects, and an increased cancer risk. Based on these findings, groundwater in Wadi Ranyah is unsuitable for drinking without treatment. Mitigation strategies such as reverse osmosis, ion exchange filtration, and continuous monitoring are recommended to reduce heavy metal contamination and protect public health.

Detection of human health risks resulting from contamination of borehole drinking water with harmful volatile organic chemicals and potentially toxic elements around petroleum products dispensing outlets

Detection of human health risk caused by gasoline volatile organic chemicals and potentially toxic elements using an integrated approach to optimise data interpretation. The area is an urban centre with petroleum dispensing outlet and depending largely on borehole drinking water. Organic and toxic elements were analysed using gas chromatography and atomic absorption spectrophotometer, respectively. The study combined multivariate statistics and human health risk calculations. The water is moderately acidic causing low dispersion of toxic elements. Turbidity mean value of 15.64 NTU exceeded World Health Organization standard of 5NTU for potable water reflecting water pollution. Mean levels of benzene 2.20 mg/L and toluene 1.62 mg/L exceeded world standards for potable water. Benzene possesses higher daily intake levels in children than in adults through both ingestion and dermal contact. In children, benzene obtained hazard quotient ranging from 4.8 to 6.6 through dermal contact and 71.9-102.6 via ingestion pathway. Hazard risk of benzene ranged from 1.05 to 9.6 and 2.5-3.4 and toluene from 1.1-1.7 in children and adults. These values are greater than 1 reflecting non-carcinogenic risk. Cadmium, arsenic and antimony displayed non-carcinogenic risk in locations 2, 3, 4, 7, 9, 12, 14, 15 and 17. Carcinogenic risk of benzene and ethyl benzene in children via ingestion show that 1 in 0.0001 % and 1 in 0.01 % are susceptible to cancer in a lifetime of 70 years. Cadmium and arsenic has carcinogenic risk through ingestion pathway and dermal contact in children and adults. Incremental lifetime cancer risk of benzene, ethylbenzene, arsenic, lead and cadmium were above acceptable standard of 1.0E-06-1.0E-04 in children than adults through ingestion pathway than dermal contact. Buried petroleum storage tanks contributed to pollutants in the borehole water. Dissolution, dispersion and migration of benzene, toluene and ethyl benzene to boreholes adjacent to petroleum products outlets has harmful effects to water consumers. Integrating multivariate analysis, human health risks, odour hazard and risk index factor advances our understanding compared to previous works.

Pollution and health risk assessment of rare earth elements in soil, water and vegetables from an ion-adsorption rare earth mining area in Ganzhou, China

Rare earth elements (REEs) are increasingly recognized as significant environmental pollutants due to their environmental persistence, bioaccumulation, and chronic toxicity. This study assessed REEs pollution in soil, water, and vegetables in an ion-adsorption rare earth mining area in Ganzhou, and evaluated the associated health risks to the local population. Results indicated that the REEs content in soil ranged from 168.58 to 1915.68 mg/kg, with an average of 546.71 mg/kg, substantially surpassing the background level for Jiangxi Province (243.4 mg/kg) and the national average (197.3 mg/kg). Vegetables displayed an average REEs content of 23.17 mg/kg in fresh weight, far exceeding the hygiene standard of 0.7 mg/kg. Water samples contained REEs at a concentration of 4.09 μg/L. The estimated daily intake (EDI) of REEs from vegetables exceeded the threshold for subclinical damage, posing potential health risks, particularly for children and adolescents. Further analysis of the adjusted average daily intake (ADI) and non-carcinogenic risk suggested that while most vegetable consumption remains within safe threshold, the intake of REEs from high-risk vegetables such as pakchoi should be limited. Overall, carcinogenic risks associated with lifetime cancer risk (LCR) model for REEs exposure through vegetables and water were found to be low in this area.

Appraisal of potential toxic elements pollution, sources apportionment, and health risks in groundwater from a coastal area of SE China

Groundwater is a vital natural resource, but the presence of potentially toxic elements (PTEs) poses significant risks to both groundwater safety and human health. This study collected 120 groundwater samples from a coastal area in southeastern China during wet and dry seasons to assess PTE levels, identify their sources, and evaluate pollution and health risks. Results showed that Mn, Zn, and Al had the highest average concentrations in both seasons, with Mn, Cd, and Zn frequently exceeding safe limits. PTE levels were higher during the wet season. Natural background levels (NBLs) were determined, revealing that most elements met quality standards except for Mn and Cd. Four PTE sources were identified using principal component analysis and the APCS-MLR model: industrial emissions (25.5% dry, 23.8% wet), geological background (21.2% dry, 19% wet), natural sources (27.2% dry, 16.2% wet), and mining activities (20.8% dry, 23.4% wet). Heavy metal pollution was significant (moderate to heavy: 72.73% dry, 45.76% wet), but ecological risks were low (low risk: 92.73% dry, 66.10% wet). Health risk assessments and Monte Carlo simulations indicated low carcinogenic and non-carcinogenic risks, slightly higher in children than adults. Risks were more severe in the southwestern part of the study area. These findings support local groundwater management efforts.

Monitoring of Essential and Toxic Elements in Multivitamin/Mineral Effervescent Tablet Supplements and Safety Assessment

Multivitamin/mineral (MVM) supplements are the most commonly utilized dietary supplements by many populations. However, there is a severe concern about their adverse effects due to elemental impurities. In the present study, it was aimed to determine the levels of 11 elemental impurities (Cd, Pb, As, Hg, Co, V, Ni, Se, Mo, Cu, and Cr) by inductively coupled plasma-mass spectrometry (ICP-MS) and evaluate the human health risk associated with the consumption of 33 MVM effervescent tablet supplements available in Turkey. The precision of the method in terms of relative standard deviation (RSD) was less than 4.6%. The accuracy of the method was tested with recovery experiments, and the results ranged between 86 and 107%. The impurity levels for Cd, Pb, As, Co, V, Ni, Se, Mo, Cu, and Cr were found between 0.011-0.050, 0.025-0.098, 0.018-0.056, 0.010-0.626, 0.027-0.290, 0.026-1.65, 1.92-21.83, 0.034-34.09, 0.140-183.9, and 0.033-13.10 µg/g, respectively, and Hg was not detected in any sample. The calculated concentrations for elemental impurities complied with EMA and USP guidelines, except one supplement for Se (21.83 µg/g) with a permitted limit of 15 µg/g. The hazard quotient (HQ) and hazard index (HI) levels were below 1 for all samples within the ranges of 3.4 × 10-1-1.4 × 10-6 for HQ and 7.8 × 10-1-1.4 × 10-6 for HI indicating that there is no risk for consumption. The carcinogenic risk (CR) of As was between 1.7 × 10-6 and 5.9 × 10-6, below the threshold value of 1 × 10-4. The results showed that there is no risk to human health.

Assessing health risks of polycyclic aromatic hydrocarbons (PAHs) in cooked fish using monte carlo simulation: a global review and meta-analysis

Cooking food at high temperatures can lead to the formation of harmful chemical compounds called polycyclic aromatic hydrocarbons (PAHs). The purpose of this study was to conduct a systematic review and meta-analysis to evaluate the concentrations of 16 PAHs in cooked fish using roasting, barbecuing, or grilling techniques. The Monte Carlo simulation method was employed to accurately assess and quantify the uncertainties associated with risk estimation. This study compiled data on PAH levels in cooked fish using gas or charcoal from 57 original published articles in the PubMed, Science Direct, Scopus, Google Scholar, and Web of Science databases between January 1, 2010 to December 30, 2023. The investigation showed that 55.1% of cooked fish was made by grilling, 35.1% by barbecuing, and 9.8% by roasting. Based on the 95th percentile Hazard Quotient (HQ) from fish consumption, the ranking of 8 PAHs was as follows: Benzo[a]pyrene (BaP = 14.10) > Pyrene (Pyr = 0.29) > Fluorene (Flu = 0.23) > Naphthalene (Nap = 0.22) > Fluoranthene (Flrt = 0.12) > Acenaphthene (Ace = 0.11) > Acenaphthylene (Acy = 0.04) > Anthracene (Anth = 0.02). However, the non-carcinogenic risk ratio for other PAH compounds in fish consumption, excluding BaP, was found to be less than one (HQ < 1). The 95th percentile lifetime excess cancer risk (LTCR) values for 8 PAH compounds (BaP (4.35E- 9) > Anth (6.10E- 11) > Flrt (9.35E- 12) > Pyr (7.04E- 12) > Ace (6.56E- 12) > Flu (4.97E- 12) > Nap (4.39E- 12) > Acy (2.57E- 12)) from fish consumption were negligible and can be disregarded (LTCR < 10- 6). Based on the analysis of the findings, it can be concluded that the consumption of cooked fish using various methods worldwide does not present a carcinogenic risk linked to PAHs.

Assessing drinking water quality based on water quality indices, human health risk, and burden of disease attributable to heavy metals in rural communities of Yazd County, Iran, 2015-2021

The water quality indices, health risk, and burden of disease attributable to heavy metals in rural communities of Yazd County, Iran during 2015-2021 were studied. The drinking water quality index (DWQI) based on 27 parameters (including heavy metals) and heavy metal pollution index (HPI) were used for assessing drinking water quality. The health risk and burden of disease from heavy metals in drinking water were estimated in terms of hazard quotient (HQ), hazard index (HI), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY). Based on the DWQI scores by community, the drinking water quality in rural communities of Yazd County was characterized as good for 61 %, fair for 25 %, marginal for 2 %, and poor for 12 %. The distribution of the rural communities into the HPI categories was as follows: 43 % for excellent, 36 % for good, 14 % for poor, and 7 % for unsuitable. In about 20 % of the rural communities, the average HI level of heavy metals was higher than the boundary limit of one. The highest average HQ level at the county level was related to arsenic (As) to be 0.44. In all the communities, the total ILCR values of the heavy metals were in the category of significant increased cancer risk (10-6 to 10-4). At the county level, As and cadmium (Cd) exhibited the two highest cancer risk levels to be 1.96 × 10-4 and 1.87 × 10-4 for ILCR, respectively. The DALY rate (per 100,000 people) induced by exposure to the heavy metals via drinking water was 13.9, which was considered relatively high as compared to that of other drinking water pollutants obtained in the previous studies. The drinking water quality improvement through decreasing Cd and As levels below the standard values can drastically reduce the attributable burden of disease and promote the public health in the rural communities.

Examining carcinogenic and noncarcinogenic health risks related to arsenic exposure in Ethiopia: A longitudinal study

Background

The carcinogenic properties of arsenic make it one of the most hazardous chemicals globally. Nevertheless, the exact level of human exposure to arsenic and the associated risks of cancer and non-cancer effects through different pathways in Ethiopia are still uncertain.

Objective

The primary aim of this study was to evaluate the risk of both cancer and non-cancer outcomes among children and adults who have been exposed to arsenic through drinking water in the Adami Tulu Jido Kombolcha district of Ethiopia.

Methods

For this study, a longitudinal study design was employed. A total of 45 groundwater sources were sampled using the census sampling method. The concentrations of total arsenic were measured using Agilent 7900 series inductively coupled plasma mass spectrometry. Carcinogenic and noncarcinogenic risk assessments were conducted by calculating lifetime cancer risk and hazard quotients. Microsoft Office Excel was utilized to calculate human health risk indices, and descriptive statistical analysis were performed using SPSS software.

Results

Our findings revealed that during the dry season, the mean arsenic concentration in the groundwater samples was 11.15 ± 9.38 µg/L, while during the rainy season, it was 10.67 ± 8.16 µg/L. The total cancer risk for children, resulting from oral ingestion and skin contact, was 1.15 × 10-2 and 1.07 × 10-2 during the dry and rainy seasons, respectively. For adults, the total cancer risk from oral ingestion and skin contact during the dry and rainy seasons was 4.95 × 10-3 and 4.59 × 10-3, respectively. Furthermore, the total hazard quotients for children via oral ingestion and skin absorption were 25.9 and 24.0 during the dry and rainy seasons, respectively. For adults, the total hazard quotients from ingestion and dermal contact during the dry and rainy seasons were 11 and 10, respectively.

Conclusions

The findings indicate that the risks of cancer and non-cancer effects resulting from arsenic exposure through ingestion and dermal exposure were found to exceed the acceptable thresholds in both seasons. These results emphasize the urgent need for focused attention on the study population in the study area due to the high likelihood of experiencing adverse health outcomes.

Quantitative microbial risk assessment of gastrointestinal illness due to recreational exposure to E. coli and enterococci on the southern coasts of the Caspian Sea

Background

Gastrointestinal illness refers to a broad range of diseases that affect the digestive system, including infections caused by bacteria, viruses, and parasites. Quantitative Microbial Risk Assessment (QMRA) is a powerful tool used to evaluate the risks associated with microbial pathogens in various environments. The main objective of this study was to conduct a quantitative assessment of gastrointestinal illnesses that occur as a result of exposure to E. coli and enterococci during recreational activities on the southern coasts of the Caspian Sea.

Methods

Samples were collected from the recreational beaches along the border line of the Caspian Sea. The samples were analyzed for the presence and enumeration of E. coli and enterococci using the microplate method and membrane filtration techniques. Then, the annual and daily infection risks were computed using the Monte Carlo simulation approach.

Results

The results revealed that the risk of daily and annual infections on the coasts of Babolsar was higher than that on the coasts of Sari. Also, in the recreational waters of these beaches, the risk of infection by enterococci was higher than that posed by E. coli. In Babolsar, the average annual infection risk caused by E. coli and enterococci was 0.365 and 1 for children and 0.181 and 0.986 for adults. Also, in Sari, the average annual infection risk caused by E. coli and enterococci was 0.060 and 0.908 for children and 0.027 and 0.815 for adults. In addition, children were more likely than adults to become infected.

Conclusion

In light of the study's findings, due to the entry of untreated urban wastewater into the southern part of the Caspian Sea (northern Iran) and the high risk of infectious diseases for children, more control and health measures are necessary for children's swimming.

Systematic review and meta-analysis of arsenic concentration in drinking water sources of Iran

Recent studies have found arsenic contamination of drinking water in some parts of Iran, as in many other countries. Thus, a comprehensive systematic review is necessary to assess the distribution and concentration of arsenic in drinking water sources. For this purpose, articles published from the first identification until December 2023, were retrieved from various national and international databases. Of all the studies examined (11,726), 137 articles were selected for review based on their conceptual relationship to this survey. A review of the extracted studies presented that ICP methods (ICP-MS, ICP-OES, 56%) and atomic absorption spectrophotometry (AAS, 34.1%) were the two most commonly used techniques for the analysis of arsenic in water samples. The order of arsenic content in the defined study areas is descending, as follows: northwest ˃ southeast ˃ southwest ˃ northeast. A review of studies performed in Iran depicted that provinces such as Kurdistan, Azerbaijan, and Kerman have the highest arsenic concentrations in water resources. Accordingly, the maximum concentration of arsenic was reported in Rayen, Kerman, and ranged from < 0.5-25,000 µg/L. The primary cause of elevated arsenic levels in water resources appears to be geologic structure, including volcanic activity, biogeochemical processes, sulfur-bearing volcanic rocks, Jurassic shale, the spatial coincidence of arsenic anomalies in tube wells and springs, and, to some extent, mining activities. The findings of the presented survey indicate that it is essential to take serious measures at the national level to minimize the health risks of arsenic contamination from drinking water consumption.

Exposure assessment of nitrate and phenol derivatives in Tehran's water distribution system

The presence of organic and inorganic contaminants in drinking water is a global concern. Nitrate and phenol derivatives are examples of pollutants that could be of anthropogenic origin. They are associated with numerous health risks, underscoring the importance of monitoring their presence in drinking water. This study aimed to measure nitrate and phenol derivatives, including 2,4-Dichlorophenol (2,4-DCP), Pentachlorophenol (PCP), 2,4,5-Trichlorophenol (2,4,5-TCP), 2-Chlorophenol (2-CP), 4-Chlorophenol (4-CP), and phenol, in Tehran's water distribution system (WDS). The pollutants in Tehran's WDS were significantly and positively correlated with precipitation. The Hazard Quotient (HQ) and the Excess Lifetime Cancer Risk (ELCR) of the detected pollutants were estimated. The results showed that the regional mean of nitrate and PCP in Tehran's WDS were 35.58±8.71mg L-1 and 76.14±16.93 ng L-1 lower than the guideline values of 50 mg L-1 and 1000 ng L-1, respectively. Some districts exhibited nitrate concentration exceeding the allowable limit by a factor of 1.2 to 2.3. Consequently, the nitrate intake in some districts constituted approximately 50% of the reference dose. While PCP as a phenol derivative with more health concerns was identified in Tehran's WDS, the likelihood of its health effects was determined to be negligible.

Global review, meta-analysis and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in chicken kebab using Monte Carlo simulation method

The primary concern with Polycyclic Aromatic Hydrocarbons (PAHs) is their harmful effects on health, including the risk of causing cancer. This study aimed to investigate the occurrence and concentration of 16 priority PAHs (PAH16) in chicken kebabs using a systematic review approach with meta-analysis. Additionally, the study estimated the possible risk assessment of the potential carcinogenic and non-carcinogenic effects of PAHs on consumers of chicken kebabs using the Monte Carlo simulation (MCS) method. The researchers collected data on the concentration of PAHs in chicken kebabs (grilled, smoked, roasted, or barbecued) from 99 original articles searched in the Web of Science, PubMed, Scopus, Science Direct, and Google Scholar databases from 2012 to April 2022. The concentration of PAHs was then analyzed using meta-analysis, and the Monte Carlo simulation (MCS) was used to evaluate the associated human health risks. The analysis showed that 68.6%, 21.1%, 7.1%, and 3.2% of chicken kebabs were prepared by grilling, smoking, barbecuing, and roasting, respectively. The meta-analysis and health risk assessment indicated that the mean values of HQ (hazard quotient) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant PAHs were 1.64, 1.38 × 10^-2, 1.10 × 10^-1, 1.09 × 10^-1, 2.55 × 10^-2, 1.60 × 10^-1, 8.13 × 10^-1, and 6.20 × 10^-3, respectively. Additionally, the mean values of LTCR (Incremental Lifetime Cancer Risk) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant were 4.85 × 10^-10, 8.06 × 10^-13, 6.65 × 10^-12, 3.23 × 10^-12, 1.01 × 10^-12, 6.38 × 10^-12, 1.62 × 10^-11, and 6.20 × 10^-3, respectively. The consumption of chicken kebabs prepared by barbecuing was found to be associated with an increased risk of cancer due to the formation of carcinogenic compounds, including benzo[a]pyrene (BaP). However, the non-cancer risk ratio of consuming grilled chicken other than BaP was found to be less than 1 (HQ < 1), indicating that there is no risk of carcinogenesis caused by PAHs from the consumption of chicken kebabs worldwide. The calculated values of the LTCR caused by PAHs in the consumption of chicken kebab throughout life were compared to the maximum acceptable risk value suggested by the EPA, which in the strictest case equals one cancer case per 10,000 people. The results indicate that there is no risk of carcinogenesis caused by PAHs due to the consumption of chicken kebab worldwide.