Ecological risk assessment of heavy metals in urban dust in Iran: A systematic review and meta-analysis

Applying Monte Carlo simulation to assess health risks of potentially toxic elements in fruits and nuts grown in the capital of Iran

This study investigated harmful elements (PHEs) in three fruits (figs, oranges, persimmons) and two nuts (walnuts, hazelnuts) grown in Tehran, Iran, using inductively coupled plasma mass spectrometry (ICP-MS) to evaluate health risks. The results showed that chromium (Cr) exceeded the 0.1 mg/kg standard in walnuts (mean = 6.15 mg/kg) and figs (mean = 5.23 mg/kg). Copper (Cu) surpassed 2 mg/kg in all produce except figs. Arsenic (As) exceeded the standard in walnuts, persimmons, and oranges, while cadmium (Cd) surpassed the limit only in persimmons. Iron (Fe) levels were significantly high, peaking in persimmons (mean = 71.79 mg/kg). Lead (Pb), manganese (Mn), and mercury (Hg) exceeded safety limits in all samples, while barium (Ba) was the most abundant metal, especially in hazelnuts and oranges. The correlation and clustering analysis indicated that the sources of PHEs may be influenced by a combination of agricultural practices, atmospheric transport, traffic emissions, historical pollution, and natural background levels. Monte Carlo simulation results show Pb poses the highest non-carcinogenic risk for children (TTHQ50th: 12.56) and adults (TTHQ50th: 5.62). Ni presents the highest carcinogenic risk (TCR50th: 1.58E-03 for children, 3.50E-03 for adults. Hence, urgent monitoring of PHEs in local produce is essential.

Heavy Metals in Particulate Matter-Trends and Impacts on Environment

Heavy metals represent a class of pollutants detected at concentrations lower than 10 ppm in different matrices that are intensively monitored due to having a major impact on human health. Industrial activities including mining, agriculture, and transport, determine their presence in different environments. Corrosion phenomena of various installations, volcanic eruptions, or atmospheric deposition on the soil surface and in water can contaminate the respective environments. Atmospheric pollutants in the form of suspended dust particles with diameters below 10 microns are predominantly composed of different metallic species from Cd, Cr, Cu, Ni, etc. This paper presents a review of the main sources and types of heavy metals present in the atmosphere in the composition of particulate matter (PM), highlighting the main mechanisms of occurrence and detection techniques, including the impact on bio-geo-chemical processes in the soil and food chain, in close correlation with their impact on environment and human health. The purpose of this review is to highlight the current level of knowledge regarding the global situation of heavy metals in PM and to identify gaps as targets for future research.

The synergistic impact of Spirulina and Sulfate reducing bacteria on lettuce growth in Cadmium contaminated soil

Cadmium (Cd) contamination is a critical environmental issue, adversely affecting plant growth and agricultural productivity. While numerous studies have explored the role of various bacteria in mitigating heavy metal toxicity, the specific impacts of sulfate-reducing bacteria ( Desulfovibrio desulfuricans, SRB) and the cyanobacterium Spirulina (Arthrospira platensis, SP), both individually and in combination, on Cd-contaminated plants remain underexplored. This study investigates the effects of SRB and SP on lettuce plants exposed to Cd contamination, aiming to enhance our understanding of their potential in alleviating Cd toxicity and promoting plant health. Results revealed that Cd contamination significantly reduced root growth in all treatments except for the combined application of SRB and SP. This combination also led to a marked decrease in leaf Cd content and improved leaf area, particularly under Cd stress. Furthermore, SP and SRB together increased the relative water content in contaminated soils, and SRB alone induced hydrogen peroxide production in non-contaminated soils. The co-application of SRB and SP significantly boosted catalase and superoxide dismutase activities, enhancing photosynthetic capacity and overall plant growth under Cd stress. These findings underscore the promising potential of using SRB and SP synergistically to mitigate Cd-induced challenges in lettuce cultivation, offering a viable strategy to improve crop productivity in contaminated environments.

Source apportionment, ecological and health risks of potentially toxic elements in street dusts across different land uses in city of Kermanshah, Iran

In this study, the contamination, ecological and human health risks as well as source apportionment of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and V in street dusts of different land-uses in Kermanshah, Iran were investigated. A total of 192 dust samples were taken from 16 sites and were analyzed for their elemental contents using ICP-OES. The computed mean values for the geo-accumulation index (I-geo) and the pollution index (PI) ranged from - 6.07 to 2.67 and from 0.023 to 9.58, respectively, indicating 'unpolluted' to 'moderately to heavily polluted', and 'slight to very high polluted' pollution levels, respectively. The pollution load index (PLI) with a cumulative mean value of 1.03 reflected moderate pollution levels across the entire study area. Moreover, the ecological risk (RI) of 135 indicated moderate ecological risks throughout the study region. The mean hazard index (HI) values for the analyzed potentially toxic elements (PTEs) for both adults and children were all within the safe limit (< 1). Furthermore, the total carcinogenic risk (TCR) values showed that the carcinogenic risks associated with As, Cd, Cr, and Ni for both target populations were at tolerable to unacceptable levels. The positive matrix factorization (PMF) model identified traffic emissions and sources, fossil fuel combustion and natural sources, and industrial emissions as the major sources of tested elements. Hence, a thorough investigation into the sources of ecological health risks associated with dust contamination from potentially toxic elements (PTEs) is recommended for future studies.

Association between exposure to environmental pollutants and increased oral health risks, a comprehensive review

The burden of disease and death attributable to environmental pollution is a growing public health challenge worldwide, particularly in developing countries. While the adverse effects of environmental pollution on oral health have garnered increasing attention, a comprehensive and systematic assessment remains lacking. This article delves into the intricate relationship between environmental pollution and oral health, highlighting significant impacts on various aspects such as dental caries, periodontal diseases, oral facial clefts, cancer, as well as other oral diseases. Our results suggested that secondhand smoke, particulate matters (PM) and heavy metals are the most important risk factors affecting oral health. Additional contributors, such as radiation pollutants, electronic cigarette, phthalates, gaseous air pollutants, pesticides, solvents, wood dust, formaldehyde and excessive fluoride were investigated, though evidence for their impacts remains limited and often inconclusive. The review also explores potential mechanisms underlying these impacts, including microorganism, inflammation, oxidative stress, genetic influences, and toxicant exposures from heavy metals and other pollutants. For instance, PM2.5 may contribute to dental caries by disrupting oral pH balance and absorbing heavy metals such as lead and cadmium which have been considered as caries promoting elements. It is also associated with adverse inflammatory responses and tissue damage in periodontal tissues by causing oxidative stress, potentially leading to periodontitis. Drawing on current evidence, it provides a comprehensive analysis of these associations, offering critical insights to guide the development of preventive strategies and public health interventions. The findings highlight the pressing need for future research to validate the causal links between environmental pollution and oral diseases and to unravel the underlying biological mechanisms. Ultimately, greater attention must be directed toward addressing the relationship between environmental pollution and oral diseases, with a focus on pollution control and the reduction of preventable environmental risks to safeguard oral health on a broader scale.

Short-term and long-term exposure to particles and their consequences in Poldokhtar City (Iran)

In Iran's biggest towns, deaths and hospitalizations from respiratory and cardiovascular diseases have a strong association with PM2.5 pollution concentrations. The WHO recommends assessing the health impacts using the Air Quality and Health Evaluation approach (Air Q 2.2.3). Data of particulates on both clear, dusty days have been provided by the Meteorology Office for Lorestan. Results indicated that in terms of mean AQI, May (162.46), July (121.7), and April (110.23) are the most polluted months in Poldokhtar city in 2022. May (16 days), July (6 days), March (5 days), and April (4 days) are the most contaminated months of the total number of polluted days. The days having the highest amounts of pollution in terms of the daily mean AQI are May 17th (407), April 10th (402), May 24th (393), July 31st (351), and April 18th (341). The maps extracted from HYSPLIT showed that the origin of the dust entering the city of Poldokhtar is the arid and semi-arid regions of Saudi Arabia, Egypt, Kuwait, and Turkey. May shows the maximum amount of pollution in comparison to other months, as shown by the mean AQI of 162.46. Furthermore, with an AQI score of 407 on May 17, it is assumed to be the most polluted day of the year. Hospitalized people who had respiratory diseases were most severely impacted by the short-term adverse effects of fine dust inhalation.

The level, source, and health outcome of PM2.5 exposure in Southwest Iran

Introduction

Dusty storms considerably increase airborne particles in dry and semi-dry locations, such as deserts with no plants and strong winds. Therefore, the environment and people are affected severely. Ahvaz, an important metropolis, is often polluted by neighboring nations. The present research studies the concentration, source, and calculation of these particles' effects.

Material and method

For health consequences evaluation, the WHO suggests the Air Quality Health Impact Evaluation Programmed (Air Q 2.2.3). Khuzestan Meteorology Office recorded particulate matter measurements on both hazy and clear days. The data was gathered voluminously in 2023.

Result

According to data collected from Khuzestan province's meteorology documents, 49 days in 2023 had very unsafe air quality. The most polluted months in terms of the number of dust days are as follows: January (14 days) > December (12 days) > November (11 days) > August (5 days) > May (3 days) > September (2 days) > March, February, June, July, October (1 day) > April (0 days). HYSPLIT maps indicate that Iran causes dust in March, the Great Arabian Desert in December and August, Iraq in April, September, and October, Kuwait in January, Turkey in February and July, Egypt in June and May, and Oman in November.

Conclusion

The meteorology database reveals that Ahvaz is highly polluted and that 49 days had unacceptable dust levels. Based on assessments obtained employing the Air Q+ programs, the people of Ahvaz encountered heart disease, respiratory disease, and stroke caused by their exposure to PM2.5 particulates.

Higher blood manganese level associated with increased risk of adult latent tuberculosis infection in the US population

Background

The associations between blood heavy metal levels and latent tuberculosis infection (LTBI) have not been fully elucidated. The aim of this study was to investigate the potential association between blood heavy metal levels and LTBI in adults using National Health and Nutrition Examination Survey data from 2011 to 2012.

Methods

We enrolled 1710 participants in this study, and compared the baseline characteristics of participants involved. Multivariate logistic regression analysis, restricted cubic splines (RCS) analysis, along with subgroup analysis and interaction tests were utilized to explore the association between blood manganese (Mn) level and LTBI risk.

Results

Participants with LTBI had higher blood Mn level compared to non-LTBI individuals (p < 0.05), while the levels of lead, cadmium, total mercury, selenium, copper, and zinc did not differ significantly between the two groups (p > 0.05). In the fully adjusted model, a slight increase in LTBI risk was observed with each 1-unit increase in blood Mn level (OR = 1.00, 95% CI: 1.00-1.01, p = 0.02). Participants in the highest quartile of blood Mn level had a threefold increase in LTBI risk compared to those in the lowest quartile (OR = 4.01, 95% CI: 1.22-11.33, p = 0.02). RCS analysis did not show a non-linear relationship between blood Mn level and LTBI (non-linear p-value = 0.0826). Subgroup analyses and interaction tests indicated that age, alcohol consumption, and income-to-poverty ratio significantly influenced LTBI risk (interaction p-values<0.05).

Conclusion

Individuals with LTBI had higher blood Mn level compared to non-LTBI individuals, and higher blood Mn level associated with increased LTBI risk.

Bio-availability of potential trace elements in urban dust, soil, and plants in arid northwest China

Potential trace elements pollution in cities poses a threat to the environment and human health. Bio-availability affects toxicity levels of potential trace elementss on organisms. This study focused on exploring the relationship between soil, plant, and atmospheric dust pollution in Urumqi, a typical city in western China. It aims to help reduce pollution and protect residents' health. The following conclusions were drawn: 1) potential trace elementss like Cr, Pb, As, and Ni are more prevalent in atmospheric dust and soil than in plants. Chromium was in the first group, Cadmium and Mercury were in the second, and Plumb, Arsenic, and Nickel were in the third. Atmospheric dust and soil exhibit a significantly higher heavy metal content than plants. For example, The atmospheric dust summary Chromium content was up to 88 mg/kg. 2) Soil, atmospheric dust, and plants have the highest amount of residual form. Residual form had the highest percentage average of 53.3%, whereas Organic matter bound form had the lowest percentage of just 7.7%. The plants contained less residual heavy metal than the soil and atmospheric dust. 3) The correlation coefficient between the carbonated form content of Cd of soil and atmospheric dust is 0.95, which is closely related. Other potential trace elements show similar correlations in their bio-available contents in soil, plants, and atmospheric dust. This study suggests that in urban area, the focus should be on converting potential trace elements into residual form instead of increasing plants' absorption of potential trace elements.

The concentration of phthalates in drinking water in Iran: A systematic review and meta-analysis

PAE and PC polymers, such as BPA, are utilized to make water bottles. Due to the lack of polymer-chemical interaction, PAE can enter drinking bottles during production, wrapping, and keeping. Phthalates can transfer from the bottle to the water depending on keeping conditions (temperature, time, sunlight intensity), pH, and bottle capacity. Since there haven't been previous studies published on the subject, the aim of this meta-analysis and systematic review research is to determine the level of phthalates in drinking water consumed in Iranian cities. Web of Science, Science of Direct, Scopus, and PubMed, databases have been used in this study. Eight studies were selected from 556 initial publications after screening for duplication and irrelevant information. Articles from January 1, 2000, to February 10, 2024, were found in the mentioned databases. Among the types of phthalates, the concentration of DEHP was reported higher than the others Because its concentration has been reported in seven out of eight studies. The highest concentration of DEHP was reported by Mehraie(2.22 µg/l), Zare Jeddi (0.8 µg/l), Yousefi (0.77 µg/l), Abtahi (0.76 µg/l), Zare Jeddi (0.42 µg/l), Abdolahnejad(0.15 µg/l), and Pourzamani (0.08 µg/l). The highest concentration of DEP, DBP, BBP, and PA was reported by Abtahi (0.77 µg/l) and Esteki (2.25 µg/l), Mehraie(0.93 µg/l), and Pourzamani (0.83 µg/l). The results of this study showed that the most important phthalates measured in drinking water include DEP, DEHP, DBP, BBP, and PA. According to the results of the present studies, the most important factor in the increase of phthalates is the storage conditions of drinking water (temperature, sunlight, and the type of pipe or bottle).

Health risk assessment for consuming rice, bread, and vegetables in Hoveyzeh city

Introduction

People are continuously exposed to contamination, which mainly consists of heavy metals (HMs) and organic compounds. Several metals can get into grains, veggies, and bread through various methods. We estimated the health risk of HM exposure from the consumption of bread, veggies, and rice, considering the per capita amounts of these foods in the Iranian food basket, especially in Hoveyzeh and Azadegan Plain.

Material and method

The food products analyzed for the assessment of HMs include different veggies, rice, and bread. The health risk assessment was done with the Hazard Quotient and cancer risk formulae. The buying of vegetables, rice, and bread was done in random order during the fall and wintertime seasons.

Result

Tarom rice has the maximum reported levels of Cd (0.55 mg/kg), but Pakistani rice has the lowest level (0.18 mg/kg). Radish shows the highest concentrations of As, Pb, Cr, and Ni among vegetation, while Cress shows the lowest level. The study findings showed that Lavash bread had the highest levels of As (1.31 mg/kg), Cd (0.2 mg/kg), and Ni (1.2 mg/kg), whereas it indicated the lowest level of Cr (0.056 mg/kg). While the non-carcinogenic risk of HMs was evaluated between two groups of adults and children, both groups' HI and HQ levels were less than 1. The maximum HQ and HI scores for children were associated with Arsenic (As), specifically 0.0127 and 0.0137 for Tarom rice, respectively. Nevertheless, the highest HQ and HI scores for adults were associated with As, namely 0.0059 and 0.0064 for Tarom rice, respectively.

Conclusion

The evaluation of the carcinogenic risk caused by HM exposure in kids and adults showed that both groups' accumulated lifetime CRs and ILCRs were lower than 1*10-6. Hence, the consumption of veggies, rice, and bread within the study's area does not show an association with the occurrence of chronic diseases resulting from hazardous HMs.