Hazard Index Values Research Articles

Insight into heavy metal chemical fractions in ash collected from municipal and industrial waste incinerators in northern Vietnam.

This investigation involved the collection of fly ash and bottom ash specimens from seven waste incinerators situated in the northern provinces of Vietnam, aimed at assessing the composition and distribution patterns of five chemical fractions of heavy metals (Pb, Cr, As, Cd Cu, and Zn) present in incinerator waste ash. The outcomes reveal that fly ash exhibited a relatively elevated concentration of industrial waste metals (25-66%) such as As, Cd, and Pb primarily in exchangeable (F1) and carbonate fractions (F2), which are mobile forms susceptible to environmental dissolution and consequential bioaccumulation posing health risks to humans. The predominant states of the metals Cr, Cu, and Zn were identified as residual, Fe-Mn oxide, and carbonate, respectively, with their relative proportions showing minimal variation. Conversely, heavy metals were predominantly present in residual residue and Fe-Mn bound form (F3) in bottom ash derived from both residential and commercial waste incineration operations. The non-carcinogenic hazard indices (HI) associated with the examined metals, ranked for both adults and children, were as follows: Pb > Cr > As > Cd > Cu > Zn. Notably, the HI values for Pb, Cr, and As exceeded the permissible threshold (HI > 1) for children. However, the risk of As, Cd, and Pb-related cancer via exposure pathways remained within acceptable limits for both age groups. Conversely, the probability of carcinogenic effects attributable to Cr surpassed the permissible threshold (>10-4), indicating significant health concerns associated with heavy metals in waste incinerators for humans, particularly children.

Evaluation of Natural Radioactivity Level in Surface Soil from Bambasi District in Benishangul Gumuz Region, Ethiopia.

The study assessed the concentration of natural radionuclides in soil samples from the Bambasi district in Ethiopia's Benishangul Gumuz region using a gamma-ray spectrometer equipped with a high-purity germanium (HPGe) detector. The measured activity concentrations of 238U, 232Th, and 40K in soil samples varied from 46.2 ± 2.25 to 88.49 ± 5.73 Bq/kg, 73.4 ± 4.12 to 119.65 ± 8.45 Bq/kg, and 176.78 ± 8.63 to 396.71 ± 25.39 Bq/kg, respectively. The average concentration of 238U and 232Th exceeded the recommended worldwide population weighted average values of 32.0 and 45.0 Bq/kg, respectively, while the average concentration of 40K was below the recommended value of 420.0 Bq/kg. The mean absorbed dose rate was calculated to be 91.6 ± 5.1 nGy/h, which is above the recommended safe value of 59 nGy/h. The average annual effective dose equivalents for indoor and outdoor exposure were determined to be 2.65 ± 0.14 mSv/y and 0.66 ± 0.1 mSv/y, respectively. The calculated mean values of the internal hazard index, external hazard index, and gamma index across all soil samples were 0.72 ± 0.05, 0.55 ± 0.02, and 0.72 ± 0.02, respectively, all below the recommended safe threshold of one. These findings suggest that the activity concentrations observed in the soil samples exceed safe levels, indicating the necessity for further investigation into radioactivity levels and epidemiological studies regarding potential hazards from high background radiation.

Spatio-temporal variability of public water supply characteristics and associated health hazards for children and adults in selected locations of Ambala, India.

The contamination of public water supply and groundwater resources is a major concern in many parts of developing nations. Polluted water poses serious health risks to humans and the environment. This research was conducted to investigate the seasonal variations of the water quality parameters in the public water supply. To assess the supply water quality in different blocks of Ambala District, hydro-chemical analysis was conducted after a series of systematic sampling in various locations. The statistical tools for water quality indexing including water quality indexing (WQI), heavy metal pollution indexing (HMPI), pollution indexing (PI), overall pollution indexing (OPI), metal indexing (MI), and hazard indexing (HI) were used for data as well as the health hazard analysis through water pathway. Overall, 40 water samples were taken from the public water supply systems covering winter and summer seasons, and the levels of pH, total dissolved solids (TDS), EC, F- , Cl- , NO3 - , SO4 2- , HCO3 - , As, B, Cd, Co, Pb, Zn, Cr, Fe, and Mn were investigated. The weight arithmetic index method was used for WQI, and water pollution indices such as HMPI, PI, OPI, and MI were calculated using different models to check the severity of contamination. The mean hazard quotient and hazard index values calculated using the concentration levels of As, B, Cd, Co, Pb, Cr, Fe, Mn, Zn, F- , and NO3 - reveal that supply water may pose a significant health risk to both adults and children that further varies with temporal and spatial changes. During both seasons, a high carcinogenic risk for both adults and children was observed in the studied area because of high levels of As, Pb, Cd, and NO3 - . PRACTITIONER POINTS: The quality of public supply water was assessed at the selected sites of Ambala, India. High levels of NO3 - , As, Cd, and Pb were observed posing a health risk to adults and children via water pathway. 95% of the samples qualified for the excellent water quality category with respect to the levels of F- , Cl- , NO3 - , SO4 2- , HCO3 - , pH, EC, and TDS. Statistical analysis (HMPI, PI, MI, OPI, HI) using different models revealed water contamination with reference to the levels of NO3 - , As, Pb, Cr, Ni, and Cd. Immediate measures are needed to uphold the safety and health of the natives.

Determination of metals in different tissues of Trachurus trachurus from the Marmara Sea and evaluation of their health risks

The present study aimed to determine the differences in metal levels of Aluminum (Al), Cadmium (Cd), Chromium (Cr), Copper (Cu), İron (Fe), Manganese (Mn), Nickel (Ni), Lead (Pb) and Zinc (Zn) between muscle and liver tissues of Trachurus trachurus, the correlation of metal accumulation in tissues with fish length and weight was examined. Health risks and nutritional adequacy were evaluated based on metal levels accumulated in fish muscle. The results demonstrated that fish liver accumulated higher metal levels than muscle. The investigation revealed that the majority of metals present in the tissues of the fish did not exhibit a significant correlation with their size (p>0.05). It can be concluded that fish are not an adequate source of these nutrients because their nutrient levels are below reference values. The fish were found to be nutrient deficient, as the levels of nutrients were below reference values. The estimated daily intakes of all metals accumulated in muscle were below reference doses. The target hazard coefficient and target hazard index values were less than 1. Lifetime carcinogenic risk values were below 10-4, and total carcinogenic risk values were within the acceptable range. Pb and Cd concentrations in muscle exceeded the tolerable limit. The daily amount of fish that could be consumed without non-carcinogenic health risk was 181 grams for Cd and 295 grams for Pb. The daily amount of fish that could be consumed without carcinogenic health risk was 1.21 grams for Cd and 231 grams for Pb.

Beneath the Surface: Uncovering Heavy Metal Contamination in Public Drinking Well Water and the Public Health Implications in Kaduna South LGA, Nigeria

Unsafe drinking water has emerged as a critical global public and environmental health concern, particularly in underdeveloped nations. Evidence indicates that unsafe water sources are responsible for approximately 1.2 million deaths annually, most of which are the result of heavy metal (HM) contamination, which poses a severe threat to public health. This study explored selected HM contamination and the likely non-carcinogenic and carcinogenic health risks to the consumers of public drinking well water sources in Kaduna South LGA, Nigeria. Atomic absorption Spectroscopy was adopted for HM analysis, and potential health risks were evaluated using the established Human Health Risk Exposure Assessment Indices. The findings indicated an unsafe quantity of HMs, with the mean concentration above the recommended limit prescribed by the Standard Organization of Nigeria (2007) and the World Health Organization (2011) for most HMs in the order; Zn (33.523) > Mn (2.805) > Pb (0.793) > Cr (0.05), as well as a substantial non-carcinogenic and carcinogenic health risk for adults and children with the Hazard Index and Cancer Risk values above the recommended standards. The findings will prove useful to public health authorities in developing evidence-based monitoring and active interventions tot facilitate the delivery of safe drinking water to the local population.

Size-classified aerosol-bound heavy metals and their effects on human health risks in industrial and remote areas in Japan

Airborne aerosols were collected in six size classes (PM<0.1, PM0.1–0.5, PM0.5–1, PM1–2.5, PM2.5–10 and PM>10) to investigate aerosol health risks in remote and industrial areas in Japan. We focused on heavy metals and their water-dispersed fractions. The average concentration of heavy metals was 18 ± 25–86 ± 48 ngm−3 for PM<0.1, 46 ± 19–154 ± 80 for PM0.5–1 ngm−3, 98 ± 49–422 ± 186 ngm−3 for PM1–2.5, 321 ± 305–1288 ± 727 ngm−3 for PM2.5–10 and 65 ± 52–914 ± 339 ngm−3 or PM>10, and these concentrations were higher in industrial areas. Heavy metals emitted from domestic anthropogenic sources were added to the long-range transport component of the aerosols. The water-dispersed fraction of heavy metals contained 3.3–40.1% of the total heavy metals in each size class. The relative contribution of Zn and other species (As, Cd, Cr, Ni, Pb, Mn, V and Cu) increased in the water-dispersed fraction. Smaller particles contained greater proportions of the water-dispersed heavy metal fraction. Carcinogenic risk (CR) and the hazard index (HI) were estimated for each size class. The CR of carcinogens was at acceptable levels (<1 ×10−6) for five particle size fractions. The HI values for carcinogens and noncarcinogens were also below acceptable levels (<1) for the same five size fractions. The estimated CR and HI values were dominated by contributions from the inhalation process.

Contamination and health risk assessment of potentially toxic elements in agricultural soil of the Al-Ahsa Oasis, Saudi Arabia using health indices and GIS

The current work aimed to assess contamination and human health risk of potentially toxic elements (PTEs) in agricultural soil of the Al-Ahsa Oasis, Saudi Arabia. For the purpose of evaluating the potential risks to human health associated with ingestion, skin contact, and inhalation, the chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI), cancer risk (CR), and total lifetime cancer risk (LCR) were calculated in 30 soil samples. The spatial distribution and possible sources of HMs were investigated using GIS and multivariate analysis. The descending order of PTE averages (dw, µg/g) was Fe (11790) > Mn (176.43) > Zn (54.43) > Cr (28.67) > Ni (14.53) > V (12.33) > Cu (10.83) > Pb (5.23) > Co (2.87) > As (2.27). The average CDI for all PTEs from ingestion pathway in children indicates an increase of approximated 9 times compared to adults. The HI values varied from 1.969 × 10-4 to 2.318 × 10-2 for Adults, and from 1.835 × 10-3 to 2.158 × 10-1 for children, suggesting there is no significant non-carcinogenic risk to the people inhabiting the Al-Ahsa Oasis. The CRs and LCR for Cr, As, and Pb in children was found to be significantly greater than that of adults. LCR values for As, Pb, and Cr varied from lower than 1 × 10-6 to 1 × 10-4, indicating no significant health hazards to acceptable carcinogenic risk.

Spatial and variety distributions, risk assessment, and prediction model for heavy metals in rice grains in China.

In this study, 6229 brown rice grains from three major rice-producing regions were collected to investigate the spatial and variety distributions of heavy metals in rice grains in China. The potential sources of heavy metals in rice grains were identified using the Pearson correlation matrix and principal component analysis, and the health risks of dietary exposure to heavy metals via rice consumption were assessed using the hazard index (HI) and total carcinogenic risk (TCR) method, respectively. Moreover, 48 paired soil and rice samples from 11 cities were collected to construct a predicting model for Cd accumulation in rice grains using the multiple linear stepwise regression analysis. The results indicated that Cd and Ni were the main heavy metal pollutants in rice grains in China, with approximately 10% of samples exceeding their corresponding maximum allowable limits. The Yangtze River basin had heavier pollution of heavy metals than the Southeast Coastal Region and Northeast Plain, and the indica rice varieties had higher heavy metal accumulation abilities compared with the japonica rice. The Cu, Pb, and Cd mainly originated from anthropogenic sources, while As, Hg, Cr, and Ni originated from both natural and anthropogenic sources. The mean HI and TCR values of dietary exposure to heavy metals via rice consumption ranged from 2.92 to 4.31 and 9.74 × 10-3 to 1.44 × 10-2, respectively, much higher than the acceptable range, and As and Ni were the main contributor to the HI and TCR for Chinese adults and children, respectively. The available Si (ASi), total Cd (TCd), available Mo (AMo), and available S (AS) were the main soil factors determining grain Cd accumulation. A multiple linear stepwise regression model was constructed based on ASi, TCd, AMo, and AS in soils with good accuracy and precision, which could be applied to predict Cd accumulation in rice grains and guide safe rice production in contaminated paddy fields.

Ecological and Health Risk Assessment of Heavy Metals Bioaccumulation in Ganges Fish Near Varanasi, India.

Heavy metal contamination in river Ganga is one of the factors for deterioration in its water quality and also adds to human health risks. We designed our study to achieve a holistic approach by not only estimating the concentration of heavy metals (lead, manganese, chromium, and cadmium) in the river water at different sites based on human anthropogenic activities but also in the fishes residing in the same sites that are collected for human consumption on daily basis. We found that Ganga River in Varanasi is highly loaded with metals (PLI = 6.698). Mean concentration in water was 1.29mg/L for Pb, 1.325mg/L for Mn, 0.169mg/L for Cr, and 0.161mg/L for Cd, which were above the permissible limits stated by Environment Protection Agency (EPA) in drinking water. Fish, including exotic and invasive species, were collected from the wild and were processed for the presence of these metals in their tissues. Degree of heavy metal concentration followed liver > gills > muscles. The highest accumulation of Pb was observed in Carpio (Cyprinus carpio) liver (8.86µg/g) and lowest in Baikari (Clupisoma garua) muscles (0.07µg/g). Total target hazard quotient (THQ) value, i.e., hazard index (HI) showed values in following sequence: Cyprinus carpio > Oreochromis niloticus > Channa gachua > Johnius coitor > Mastacembelus armatus > Mystus tengara > Clupisoma garua. Maximum HI value was recorded in C. carpio, which is highly consumed fish by humans, hence, may be harmful to them.

Seasonal variation in metals concentration associated with settled dust and their risk assessment in school children of Agra (India)

Metals associated with indoor dust are shown to be a key pollutant and resuspension of dust in critical microenvironments like schools can lead to detrimental health effects to children. The present study was carried out from December 2021 to November 2022 to examine variations in metal concentration with season and associated health risks from school dust in Agra, India. Dust samples were digested in aqua-regia followed by analysis for metals concentration by ICP-AES. Geo-accumulation (Igeo), pollution (PI), integrated pollution (IPI), and pollution load (PLI) indexes were used to determine metals contamination, Principal Component Analysis and Cluster Analysis were employed for the identification of causative sources of metals while USEPA health risk assessment models were utilized to assess the health risks in children. The results indicated that in all seasons settled dust of roadside schools of both regions accumulated higher concentrations of metals as compared to residential schools except semi-urban schools in post-monsoon season. The total metal concentration (mgkg−1) in school dust samples of Agra ranged from 62507–85037, 72477–97022, 48912–66083 to 58605–92290 in winter, summer, monsoon, and post-monsoon respectively. In all seasons, the PLI values of settled dust of all schools ranged from less than one to greater than unity which indicates pollution levels by metals. Further, Igeo values revealed that school dusts were moderately and heavily contaminated by Cd in all seasons. The assessment of health risk specifies ingestion as the main exposure route followed by dermal intake and inhalation. The Hazard Index value for all examined metals was lower than the safer limit of one while on the contrary for Pb, total cancer risk was higher the than safer limit via inhalation pathway. The findings of the study indicate that more investigations are required on potentially toxic metal contaminations in schools of Agra, especially for Pb, Cd and Cr.

Assessment of Heavy Metals in Biscuit Samples Available in Iraqi Markets.

Baby foods contain these toxic heavy metals which occur naturally or from pollution in the environment. The purpose of this research is to investigate the concentration of heavy metals in the biscuit samples that are commonly used in Iraq as food babies. The concentrations of three metals viz zinc (Zn), lead (Pb), and cadmium (Cd) are measured using atomic absorption spectroscopy (Buck Scientific/USA, 210 VGA). Health risk parameters such as Estimated Daily Intake (EDI), Target Hazard Quotients (THQ), Hazard Index (HI), and Carcinogenic Risk (CR), are determined. The average values of the concentrations of Zn, Pb, and Cd in these samples of biscuits are 0.584 ± 0.099 mg/kg, 0.066 ± 0.008 mg/kg, and 0.205 ± 0.011 mg/kg, respectively, while the average values of HI and CR × 10-6 for all samples are 0.768 ± 0.040 and 1.94 ± 0.25, respectively. On the basis of comparing these elements, the study finds that the average value of Zn is dominating with the highest concentration, followed by Cd, and Pb. This is relied on the statistical examination that revealed a weak correlation and no significance (p > 0.05) in the amounts of these heavy metals in all samples. The concentrations of Cd, in seven samples, are relatively higher than their permissible limits according to FAO/WHO (0.2 mg/kg). Conversely, the concentrations of Zn and Pb are lower than their permissible limits which was 9.4 mg/kg and 0.3 mg/kg, respectively. The values of health risk parameters for Zn, Pb, and Cd for all samples do not surpass their permissible intake limits according to FAO/WHO, Therefore, it is concluded that the overall estimated healthy risk, due to the heavy metals, is safe since it is within the permissible limits; thus, there are no concerns for a baby who consume biscuit consistently daily.

Accumulation, ecological health risks, and source identification of potentially toxic elements in river sediments of the Qinghai-Tibet Plateau, China

The Qarhan Salt Lake is the largest brine lake on the Qinghai-Tibet Plateau (QTP), which contains some potentially toxic elements (PTEs) due to the increase of human activities. This study endeavor encompassed the collection of 62 sediment samples from eight rivers that recharge the Qarhan Salt Lake, and the measurement of seven PTEs' concentrations (As, Hg, Pb, Cd, Cu, Ni, and Zn). Results indicated that the concentrations of most PTEs were lower than their local soil background values, except for Hg and Cd, which surpassed the background contents by 6.8 and 1.1 times, respectively. The Igeo and PLI outcomes demonstrated a relatively low level of Hg contamination. Hg was the most hazardous elements with the mean ecological risk factor of 273.88. The Hazard Index (HI) values for PTEs were computed at 0.20 and 0.46 for adults and children, respectively, indicating that neither group was at a non-carcinogenic risk. Through the utilization of source identification methods, this study identified three predominant sources responsible for PTEs in the area: natural geogenic sources, anthropogenic sources and atmospheric deposition inputs. The findings of this study provide a robust scientific foundation for the management of the ecological environment security of rivers in the QTP.

Heavy metal bioaccumulation and risk assessment in fishery resources from the Gulf of Thailand

The muscle tissues of 19 fish species, two crab species, and one shrimp species collected from the Gulf of Thailand (GoT) were analyzed to determine the levels of heavy metals, including Cu, Zn, Fe, Mn, Ni, Pb, Cd, and Hg. The results revealed that the mean concentrations of the heavy metals, in descending order, were Zn > Cu > Fe > Cd > Hg > Mn > Pb > Ni. Among the examined metals, zinc was found to be the most prevalent in fish tissues. Based on the risk assessment indices, the estimated average daily doses (ADD) of the heavy metals were found to be below the provisional tolerable daily intake (PTDI) recommended by the joint Committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) on food contaminants. The results of the target cancer risk analysis revealed no related cancer risk from the consumption of the fishes considered for the study. However, the target hazard quotient (THQ) values exceeded the threshold of 1 (THQ > 1) specifically for mercury in Gymnothorax spp. and Terapon spp. Furthermore, the calculated hazard index (HI) values for fish muscles were all below 1, indicating that there is no significant health risk for humans at the current consumption rates, except in Terapon species for both normal and habitual consumers. Notably, habitual consumers of Gymnothorax species showed the highest HI value (>1), suggesting potential long-term effects on human health when consuming larger quantities of these fishes.

Evaluation of Heavy Metal Pollution in Commonly Consumed Mollusc (Crassostrea gasar) from Elechi Creek, River State, Nigeria and the Health Risk Implications

Marine biotas are used to assess potential adverse human health risks associated with consuming protein-rich aquatic organisms. Heavy metal content of Mangrove oysters (Crassostrea gasar) was evaluated between January and June 2022 in 3 stations. Six heavy metals (copper, cadmium, zinc, lead, arsenic and iron) were determined using standard methods. Target Hazard Quotient (THQ) and Hazard Index (HI) were used for the non-carcinogenic assessment while Target Cancer Risk (TR) was used for the carcinogenic assessment of the potential human health risk of consuming the oysters. The heavy metal values recorded were Cu (473.2 – 596.7 mg/kg), Cd (2.33 – 3.84 mg/kg), 209.02 – 246.41 mg/kg), Pb (6.16 – 12.07 mg/kg), As (0.012 – 0.016 mg/kg) and Fe (1609.0 – 1846.0 mg/kg). All the heavy metals were above the acceptable limits except arsenic. Stations 2 and 3 had relatively higher values; attributed to anthropogenic activities. The THQ and HI values were less than 1 in all the metals and stations while TR for Pb and arsenic were within the negligible range in all the stations. However, Cd was unacceptable among the children in station 2. Station 3 had relatively higher values while the children were more vulnerable to both non-carcinogenic and carcinogenic risks. In conclusion, the consumption of oysters from Elechi Creek is considered safe based on acceptable levels of the THQ, HI and TR; though Cd-TR for children (Station 2) was unacceptable.

Characterization, source identification and hazard index assessment of ingested microplastics in farmed tilapia Oreochromis niloticus

Plastic pollution is ubiquitous in marine and freshwater environments. Tilapia Oreochromis niloticus is one of the most important cultured fish species in South Asia. However, limited research has been conducted on the impact and hazard risk assessment of microplastic (MP) pollution on tilapia. This study characterized ingested MPs and identified potential sources of MPs in the gastrointestinal tracts (GTs) of farmed tilapia and their health risk assessment. GTs of 36 fish samples were collected from 12 tilapia fish farms in the Noakhali District, Bangladesh. A total of 199 MPs particles were extracted from all fish samples. Mean MPs abundance in tilapia GTs did not significantly vary among fish farms (F = 1.464, p = 0.209). The highest MPs numbers were 8 to 10 MPs/GT in tilapia collected from Farm 2, while the lowest MPs numbers were 3 to 5 MPs/GT from Farm 9. This study revealed that fibres were the dominant MPs shape in tilapia GTs (90.95 %). In the GT of tilapia, black (25.13 %), blue (24.12 %), and red (23.12 %) were the dominant colour of MPs. Most MPs found in tilapia GTs were within 300–1500 µm in size and accounted for 80.90 % of the total extracted MP particles. Identified polymers in GT samples were polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polyvinyl chloride (PVC), which were consistent with reported results in the literature. Observed polymer hazard index (PHI) value of this study demonstrated that PP (PHI = 14.79) and PET (PHI = 33.12) were “High” risk category (hazard level III), while PE (PHI = 507.65) and PVC (PHI = 307,730.77) fell under “Danger” (hazard level IV) and “Extreme danger” (hazard level V) risk category, respectively. When ingested, these polymers could enter the human body directly and have adverse health effects that require additional research. Hopefully, this study will increase our understanding of the hazard index assessment of ingested microplastics through the farmed Tilapia O. niloticus and guide future research.

Determination of Heavy Metals in Various Tissues of Locally Reared (Country) Chicken in major districts of Karnataka, India: Assessment of Potential Health Risks

Food is one of the most prevalent ways that humans are exposed to metals. Heavy metals including Cadmium (Cd), iron (Fe), zinc (Zn), lead (Pb), and mercury (Hg) are harmful to humans and have a detrimental impact on health because they accumulate in biological organs. The concentration levels of these heavy metals were tested in different edible parts of country (locally raised) chicken from various districts in Karnataka, India, namely Bengaluru, Tumakuru, Mangaluru, and Udupi, using an Atomic-Absorption Spectrophotometer (AAS). Heavy metal concentrations in various chicken parts were found to be below detectable limits (BDL)-0.0062, 0.027-3.178, and 0.262-2.103 ppm for Cd, Fe, and Zn, respectively, whereas Hg and Pb were BDL. Zinc contents were found to be significantly higher in all chicken samples from all examined districts, followed by iron and cadmium. Mercury and lead concentrations, on the other hand, were below the detection level in all samples. The estimated daily intakes (EDIs) of the observed metals from country chicken consumption were found to be lower than their respective FAO/WHO reference oral doses (RfD). The non-carcinogenic health hazards posed by the tested metals to the target population were estimated using the Hazard Quotient (HQ) and Hazard Index (HI) values. The HQ and HI values observed in this estimation were less than one, indicating that exposure to these heavy metals through consumption of country chicken is unlikely to provide possible health concerns to the examined region's human population.

Chemical profile and toxicological analysis of Pluerotus pulmonarius grown on different substrates

Mushrooms are rich sources of bioactive compounds; however, their safety for human consumption is a public health concern. This study investigated the chemical profile and toxicological effects of Pluerotus pulmonarius (mushroom) grown on three substrates (corn cob, sawdust, and palm bunch). The mushrooms were designated corn cob mushroom (CCM), sawdust mushroom (SDM), and palm bunch mushroom (PBM), respectively. The mushrooms' bioactive compounds and heavy metals were characterized using a GC-MS and ICP-AES, respectively. Acute and sub-acute tests of the mushrooms were conducted in mice fed mushroom-supplemented diets at a 1:1 (w/w) proportion. Heavy metals bioaccumulation factor (Ka) estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) were calculated. Twelve major bioactive compounds and three heavy metals (Cu, Zn, and Fe) were detected in the mushrooms. PBM-fed mice had the highest total plasma protein and GSH levels, and GPx activity, but the lowest ALT and AST activities, and LDH and urea levels. The SDM-fed mice exhibited the lowest cholesterol level in the sub-acute test, while the CCM-fed mice had the highest cholesterol in both the acute and sub-acute toxicity test. CCM-fed mice also showed the highest HDL level in both the acute and sub-acute toxicity studies. The mushrooms bio-accumulated more Zn than Fe, but their EDI were below the permissible tolerable daily intake. The mushrooms' THQ of Cu, Zn and Fe were greater than 1, except that of Cu in CCM (THQ, 0.96), but their HI values were less than 5, except in PBM (HI, 6.40). The mushroom-fed mice had a normal kidney morphology, and a mild-to-moderate portal inflammation of their liver tissues. Hence, P. pulmonarius from different substrates caused no severe toxicity in mice, but their HI for Cu, Zn, and Fe suggests a potential risk to humans.

Geochemical distribution and environmental assessment of potentially toxic elements in farmland soils, sediments, and tailings from phosphate industrial area (NE Algeria)

This study investigates the extent and spatial distribution of Potentially Toxic Elements (PTEs) in the Djebel Onk phosphate mine area in south-eastern Algeria, as well as the associated risks to human health. Various scales are considered and sampled, including tailing waste (n = 8), surrounding farmland soil (n = 21), and sediments (n = 5). The samples were mineralogically and chemically analyzed using XRD, FTIR, XRF, and ICP-MS techniques. Principal Component Analysis (PCA) was applied after transforming the raw data into centered-log ratios (clr) to identify the dominant factors controlling the distribution of PTEs. Furthermore, pollution assessment was conducted using several indices, including geo-accumulation, pollution load, contamination security indices, and enrichment and contamination factors. The results reveal that the analyzed samples are mostly P-enriched in the mine tailings, farmland soil, and sediments, with P2O5 concentrations ranging from 13.37 wt% to 26.17 wt%, 0.91–21.70 wt%, and 17.04–29.41 wt%, respectively. The spatial distribution of PTEs exhibits clearly a decrease in the contents of CaO, P2O5, Cr, Sr, Cd, and U with increasing distance from the mine discharge site, while other oxides, such as MgO, Al2O3, SiO2, K2O, and Fe2O3, and associated elements (Cu, Co, Pb, and Zn), show an increase. PCA confirms the influence of minerals such as, apatite, dolomite, and silicates on the distribution PTEs. It denoted that the highest contamination level of all PTEs in soils and sediments was observed in the southern part of the plant and mine tailings compared to the northern part. In terms of human health risks, the assessment reveals that the hazard index (HI) values for both non-carcinogenic and carcinogenic risks associated with PTEs in the study area are below 1, suggesting no significant risk. However, regardless of the sample type, the lifetime cancer risk (LCR) values vary from 1.69E-05–2.11E-03 and from 1.03E-04–2.27E-04 for Cr, Ni, As (children) and Cd (adults), respectively, exceeding the safe levels recommended by the United States Environmental Protection Agency. The study highlights that oral ingestion poses the greatest risk, followed by dermal contact and particle inhalation. Importantly, all these indices decrease with increasing distance from the sampling site to the waste discharge point and the factory, which indicates that the phosphate mining activity had caused some extent risks. These findings provide valuable insights for mitigating the adverse health impacts and guiding environmental management efforts.

Spatial and seasonal variations, ecological and human risks of trace metals in major rivers within the oil producing zone of Nigeria

The concentrations of Mn, Fe, Cu, Zn, Pb, and Cd in sediments from Great Kwa, Calabar, Cross River, Imo, and Qua Iboe Rivers were investigated during the dry and wet seasons using standard techniques. Results indicated that the mean concentrations of all the metals were within their acceptable limits although; higher concentrations were obtained during the wet season. Cd was the major contaminant in the studied sediments; the ecological risks of all the metals except Cd were in the low class. The potential ecological risks of the metals were in the low and moderate categories during the dry and wet seasons, respectively. Sediments from Qua Iboe River exhibited very high human health risks for both seasons. Factor analysis revealed anthropogenic and natural factors as the major sources of these metals in sediments from the rivers investigated for both seasons. The estimated daily intake (EDI) rates of these metals via exposure to the studied sediments were within their recommended oral reference doses however; higher wet season values were recorded. The hazard index (HI) values of the trace metals were less than one (1) but, higher during the wet season. Pb and Cd were the major contributors to the total HI during the dry and wet seasons. The relative risk analysis for both seasons also confirmed Cd as the major human risk in the studied sediments. This research has exposed the levels of trace metals and their associated human risks in sediments from the rivers investigated.

Impact of particle size on heavy metal contamination in human health from sandstorms in Iraq

BackgroundThe Middle East, including Iraq, is undergoing significant climate change, which has accelerated desertification, drought, and dust storms. Rapid industrialization and urbanization, which frequently contaminate the atmosphere with hazardous metals, are to blame for these changes. MethodsThe human health risks of six common heavy metals, including lead (Pb), chromium (Cr), cadmium (Cd), copper (Cu), zinc (Zn), and nickel (Ni), were examined in dust particles that were collected from five major administrative districts in Iraq in order to understand the impact of particle size on heavy metals in a sandy dust storm. The hazard quotient (HQ), hazard index (HI), and carcinogenic risk (RI) were used to evaluate the health risk for both carcinogenic and non-carcinogenic substances. Resultssmaller particles' Cu and Cd concentrations generally increased from 63 μm to 75 μm, and the maximum Cr content was discovered in the particles (75 μm). The HI values of heavy metals were less than 1 and suggested that these elements did not offer a non-cancer risk to either adults or children. TCR values for Ni were higher than 1 × 10−6 in particle size (63 μm, 75 μm, and 200 μm) for children. Moreover, TCR values for Cr were higher than 1 × 10−6 in particle size (63 μm and 200 μm) with the exception that Cr in all sites were higher than TCR 1 × 10−4 in particle size (75 μm) for children ConclusionThe amounts of six metals varied according on the size of the dust storm's particles. Given their health hazard, these metals' health concerns, particularly those of chromium and nickel for children, should receive significant attention.