Health Risk Assessment of Heavy Metals in Selected Culinary and Medicinal Herbs: A Case Study of Rose, Thyme, Turmeric, Chamomile, and Fennel

A causation-based method developed for an integrated risk assessment of heavy metals in soil

Environmental risk assessment and bioaccumulation of heavy metals in sediments and macroalgae (Enteromorpha sp.) along the Mersin Coast (Türkiye), Northeastern Mediterranean Sea

Distribution characteristics, risk assessment, and source analysis of heavy metals in typical lake sediments in Inner Mongolia, China

Contamination source apportionment and health risk assessment of heavy metals in soil around municipal solid waste incinerator: A case study in North China

Source apportionment and source-oriented risk assessment of heavy metals in the sediments of an urban river-lake system

Pollution from heavy metals in estuaries poses potential risks to the aquatic environment and public health. The complexity of the estuarine water environment limits the accurate understanding of its pollution prediction. Field observations were conducted at seven sampling sites along the Yangtze River Estuary (YRE) during summer, autumn, and winter 2021 to analyze the concentrations of seven heavy metals (As, Cd, Cr, Pb, Cu, Ni, Zn) in water and surface sediments. The order of heavy metal concentrations in water samples from highest to lowest was Zn > As > Cu > Ni > Cr > Pb > Cd, while that in surface sediments samples was Zn > Cr > As > Ni > Pb > Cu > Cd. Human health risk assessment of the heavy metals in water samples indicated a chronic and carcinogenic risk associated with As. The risks of heavy metals in surface sediments were evaluated using the geo-accumulation index (Igeo) and potential ecological risk index (RI). Among the seven heavy metals, As and Cd were highly polluted, with Cd being the main contributor to potential ecological risks. Principal component analysis (PCA) was employed to identify the sources of the different heavy metals, revealing that As originated primarily from anthropogenic emissions, while Cd was primarily from atmospheric deposition. To further analyze the influence of water quality indicators on heavy metal pollution, an artificial neural network (ANN) model was utilized. A modified model was proposed, incorporating biochemical parameters to predict the level of heavy metal pollution, achieving an accuracy of 95.1%. This accuracy was 22.5% higher than that of the traditional model and particularly effective in predicting the maximum 20% of values. Results in this paper highlight the pollution of As and Cd along the YRE, and the proposed model provides valuable information for estimating heavy metal pollution in estuarine water environments, facilitating pollution prevention efforts.

Incorporating source apportionment and bioaccessibility into human health risk assessment of heavy metals in a soil-rice system in the Jiulong River basin, southeast China

In order to study the concentration, distribution characteristics, and health risk assessment of toxic heavy metals, Cu, Mn, Pb, Ti, V, Cd, Cr, Co, Mo, and Ni, in atmospheric particulate matter (PM) and dust, the PM and dust samples were collected in all four seasons in 2014 in Beijing using two high volume air samplers (Echo Tecora Inc., Italy) and a dust tank, respectively. Selected metals were quantified by ICP-MS. Annual average concentrations of PM2.5 and PM10 were 153.40 μg·m-3 and 232.93 μg·m-3, which were five and three times higher than the Ambient Air Quality Standard values (GB 3095-2012), respectively. The average PM2.5/PM10 was 0.74, implying that PM2.5 predominated the particulate matter concentrations. The results of backward trajectory analysis suggested that exogenous particles originated from the northwest, north-northeast, southeast, and southeast-northwest during winter, spring, summer, and autumn, respectively. The order of annual average concentrations of selected metals in PM2.5 and PM10 was Ti > Mn > Pb > Cu > Cr > Ni > V > Cd > Mo > Co. The sum of the concentrations of Ti, Mn, Pb, Cu, and Cr accounted for 91.93% and 92.49% of the total concentration of target metals in PM2.5 and PM10, respectively. The metal content of dust followed the order of Ti > Mn > Pb > Cu > Ni > Cr > V > Co > Mo > Cd and Ti (2561.48 μg·g-1) accounted for 72.57% of the total metal content of dust. The geo-accumulation index (Igeo) of Cd, Pb, Cu, and Ni were 4.03, 2.49, 1.33, and 0.43, which represented the states of heavily to extremely contaminated, moderately to heavily contaminated, moderately contaminated and uncontaminated to moderately contaminated, respectively, indicating that dust in the target area included significant amounts of Cd, Pb, and Cu. The health risk assessment suggested that non-carcinogenic and carcinogenic risks of selected metals in PM10 and dust were within safe limits, but their long-term impact cannot be ignored.

A pollution risk assessment and source analysis of heavy metals in sediments: A case study of Lake Gehu, China

Occurrence and health risk assessment of residual heavy metals in the Chinese mitten crab (Eriocheir sinensis)

This study evaluated the environmental risk assessment of sediment heavy metals of Nun River at Gbarantoru and Tombia town in Bayelsa state, Nigeria. Sediment samples were collected in triplicate from three locations (viz: Location A around oil and gas installations, B- Gbarantoru and C- Tombia town). The samples were dried, processed and heavy metals concentration was determined using atomic adsorption spectrometry. Heavy metals results in the sediment ranged from 0.005 – 0.012 mg/kg cadmium, 0.001 – 0.003 mg/kg chromium, 0.001 – 0.002 mg/kg cobalt, 0.001 – 0.032 mg/kg nickel, 0.007 – 0.017 mg/kg lead, 0.082 – 0.126 mg/kg zinc and 0.138 – 0.314 mg/kg iron. There was significant variation (P<0.05) among the different various locations. The heavy metals showed positive significant correlations (P<0.05). The results showed low to moderate risk for contamination factor, degree of contamination and pollution load index; low to moderate contamination for index of geo-accumulation. Over 50% of the heavy metals in the various locations had positive quantification of contamination, which suggest pollution due to anthropogenic activities. On the overall, the ecological risk was within low risk. Hence, there is the need for sustainable management of anthropogenic activities that could impact on water and sediment quality.

For the ecological risk assessment of heavy metals and microplastics in Marala wetlands in Sialkot, Pakistan, samples of sediments, water, aquatic plants (Alternanthera philoxeroides, Typha latifolia, and Ipomoea carnea), and fish (Labeo rohita) were studied from five different locations. Pb, Cd, and Cr concentrations were above permissible limits devised by WHO in sediments and water at most of sites. High concentrations of Cd were recorded in water samples compared to sediments with maximum values recorded at Site-2 (52.08 ± 9.55mgkg-1) and Site-5 (62.29 ± 10.12mgkg-1). The maximum concentrations of Cr (7.23 ± 0.40mgkg-1) and Pb (22.87 ± 0.83mgkg-1) were found at Site-4 in water samples. The maximum abundance of microplastics (3047 pieces kg-1 of sediments) was at Site-1 with filaments in the highest proportion among the other types. Zn, Ni, and Cu remained generally low in concentrations in both sediments and waters. Plants showed accumulation of heavy metals, notably the amount of Cd (33.36 ± 0.26 mgkg-1) and Ni (163.3 ± 1.30 mgkg-1) absorbed by T. latifolia and A. philoxeroides, respectively were high. Also, photosynthetic pigments in plants seemed to be affected. However, estimated daily intake (EDI) and provisional tolerable weekly intake (PTWI) calculations for the human population consuming fish from this wetland remained below the FAO/WHO limits. PCA analysis revealed the anthropogenic origin of metals that might be causing adverse effects on the biota which depend on this wetland for their food.

As medicinal plants can accumulate harmful metals from the native soil, people's consumption of these materials may cause the human body to accumulate toxic metal elements. This has given rise to people’s concerns about the quality and safety of Chinese medicinal materials. This research aims to determine the levels of Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in four medicinal plant species (Aster tataricus L.f., Salvia miltiorrhiza Bge, Radix Aucklandiae, Scutellaria baicalensis Georgi) and their native soil. All samples were collected from Qian’an city, beside Yanshan Mountain Range in Tangshan city, east Hebei Province, north China. The contents of heavy metals we detected in the soil conformed to the current limits. However, the Cd and Hg in the soil had a very high potential ecological risk because of their contents higher than the base level of local soil. The contents of Cu, Cd, Hg and Pb in some medicinal herbs exceeded the standards. The content of Cu in Radix Aucklandiae exceeded the standard by 3 times, and others exceeded the standard by less than one time. The comprehensive health risk assessment of heavy metals with chronic non-carcinogenic effects for human body showed that none of the four medicinal herbs can create a health risk. Thus, there is no strong positive correlation between heavy metal pollution in medicinal herbs and that in the native soil. Further research should be investigated to the connection between the heavy metal levels in the soil and plants, and the comprehensive effects of soil, air and irrigation water on heavy metal pollution of Chinese herbal medicines. We also recommend that Chinese herbal medicines should be cultivated and gathered only from controlled or uncontaminated areas.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10653-021-00978-z.

The total contents and chemical speciation analysis of Zn, Cu, Pb, Cr, Mn, Ni, Cd, and As in pig manure (PM), liquefaction residues (LRs), and bio-oils (BOs) derived from PM by liquefaction with ethanol as a solvent at 180-300 °C were thoroughly investigated in this study. The environment risk assessment, leachability, and bioavailability of heavy metals in PM and LRs were studied. The results showed that more than 75% of heavy metals remained in LRs. The total contents of heavy metals in LRs were markedly elevated, but those in BOs gradually decreased with the increase in liquefaction temperature. Moreover, the acid soluble/exchangeable fraction and reducible fraction (F1 + F2) of heavy metals in LRs and BOs was significantly reduced, while oxidizable fraction and stable fraction (F3 + F4) desirably increased after liquefaction. Furthermore, the potential risk of heavy metals in LRs was decreased in comparison to that in PM, but the risk of Pb, Mn, and As had not been obviously reduced; therefore, the LRs from the liquefaction of PM should be pretreated before recycling. Temperatures from 220 to 260 °C were the optimum conditions for disposing of PM by liquefaction with ethanol.

The present study was carried out to assess the seasonal variations, source apportionment, and risk assessment of heavy metals (Cd, Cr, Cu, Fe, Mn, Pb, and Zn) in the surface sediments from the Khanpur Lake, Pakistan. Composite samples are collected and processed to measure the concentrations of heavy metals in Ca(NO3)2 extract and acid extract of the sediments using flame atomic absorption spectrophotometry. The highest concentrations in acid extracts of the sediments are found for Fe, followed by Mn, while the least concentrations are noted for Cd. Relatively higher extraction efficiencies in Ca(NO3)2 extract are observed for Pb and Cd, which also reveal extremely severe enrichment in the sediments as shown by the enrichment factor. Geoaccumulation index shows moderate and strong to extreme pollution of Pb and Cd, respectively, whereas potential ecological risk factor exhibits low to very high risk by Cd; the cumulative ecological risk index reveals low to very high risk of contamination in the sediments as a whole. Principal component analysis and cluster analysis reveal dominant anthropogenic contributions of Cd, Pb, Cr, and Zn. Measured concentrations of Cd, Cr, Cu, Mn, and Pb in the sediments exceed the sediment quality guideline for the lowest effect levels (LEL), while the concentrations of Cd and Pb are also higher than the effects range low (ERL) values, manifesting occasional adverse biological effects to the surrounding flora and fauna. Moreover, the mean effects range medium (ERM) quotient reveals 21% probability of toxicity in the sediments.