Distribution, Mobility, and Health Risks Assessment of Trace Metals in River Sediments from Intense Agricultural Activity Areas in West Africa

The economy of West African countries is mainly based on agriculture. However, the trace metal(loid)s contamination status in rivers is relatively unknown in the region. In this work, 45 surface sediments collected from the Bandama, Comoé, and Bia Rivers in south and south eastern Côte d’Ivoire (West Africa), were analyzed for total metal concentrations and chemical speciation. The results showed that the river sediments were considerably contaminated by Cd and moderately contaminated by As, Cu, Pb, and Zn. Significant spatial variations were observed among the stations but not between the rivers. Metals Cd and Cu were likely to cause more ecological risks. The speciation analysis unravelled that the metal(loid)s partitioned mainly in the residual fraction, with the potential mobile fraction varying from 14% to 28%. The study calls for establishment of strict policies relative to the application of fertilizers and agrochemicals and mining activities to protect the environment and human health risks.

Content and Ecological Risk Assessment of Heavy Metals in Surface Sediment in Weishan Lake

[Objective] The aim was to analyze the content of heavy metals in surface sediment in Weishan Lake and further assess its ecological risk.[Method] Heavy metal pollution in surface sediment in Weishan Lake was studied,and the pollution indices and potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were calculated to assess the potential ecological risk of heavy metal pollution.[Result] In surface sediment in Weishan Lake,the average contents of Cu,Zn,Pb,Cd,Cr and Ni were 64.78,185.05,78.76,0.17,37.76 and 46.84mg/kg respectively.Cr and Cd weren’t beyond standards in all stations,while Cu and Pb exceeded standards in all stations,with average super-standard multiple of 0.85 and 0.31,respectively,and Zn content wasn’t beyond standard in S2 station,with average super-standard multiple of 0.24.The average pollution indices of Cu,Zn,Pb,Cd and Cr were 1.85,1.23,1.31,0.34 and 0.47 respectively,with average comprehensive pollution index of 5.21,which showed that heavy metal pollution was light.In addition,heavy metal pollution in entryway portion and sea-route portion were more serious than that of breeding portion.Potential ecological risk assessment showed that the average potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were 9.25,1.23,6.56,10.34 and 0.94 respectively,with average comprehensive potential ecological risk index of 28.33,and it revealed that potential ecological risk of heavy metals was slight.Besides,the potential ecological risk order of heavy metal pollution was sea-route portion>entryway portion>breeding portion.[Conclusion] The study could provide references for the regulation and improvement of ecological environment in Weishan Lake in the east route of south-to-north water transfer project.

Ecological risk assessment of heavy metals in surface seawater and sediment near the outlet of a zinc factory in Huludao City, Liaoning Province, China

At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological effects cannot be achieved. In this study, based on investigation of concentrations of six heavy metals(As, Hg, Pb, Cd, Cu, and Zn) in the surface seawater and sediment near the outlet of a zinc factory, located in Huludao City, Liaoning Province, China, a tiered approach consisting of several probabilistic options was used to refi ne ecological risk assessment for the individuals. A mixture of various heavy metals was detected in the surface seawater, and potential ecological risk index(PERI) was adopted to assess the potential ecological risk of heavy metals in the surface sediment. The results from all levels of aquatic ecological risk assessment in the tiered framework, ranging from comparison of single effects and exposure values to the use of distribution-based Hazard Quotient obtained through Monte Carlo simulation, are consistent with each other. Briefl y, aquatic Zn and Cu posed a clear ecological risk, while Cd, Pb, Hg, and As in the water column posed potential risk. As expected, combined ecological risk of heavy metal mixture in the surface seawater was proved signifi cantly higher than the risk caused by any individual heavy metal, calculated using the concept of total equivalent concentration. According to PERI, the severity of pollution by the six heavy metals in the surface sediment decreased in the following sequence: Cd>Hg>As>Pb>Cu>Zn, and the total heavy metals in the sediment posed a very high risk to the marine environment. This study provides a useful mathematical framework for ecological risk assessment of heavy metals.

MARINOBUFAGENIN AS A POTENTIAL BIOMARKER FOR PRE-ECLAMPSIA RISK ASSESSMENT:PURIFICATION FROM BUFO MARINUS TOAD VENOM AS SUPPORT FOR A HUMAN PLASMA LC-MS/MS ASSAY

Marinobufagenin(MBG)is a bufadienolide compound belonging to the cardiac glycosides class.The bufadienolides are present in humans as well as in some plants and animals.But the major source for these compounds is located in the parotid and skin gland secretions of some toad species.MBG is acting as a human endogenous cardiac inotrope and is demonstrating

Trace heavy metals and harmful elements in roots and rhizomes of herbs:Screening level analysis and health risk assessment

Objective:Heavy metal and harmful element contamination are frequently reported in Chinese herbal medicines(CHMs),and roots and rhizomes parts showed a higher content than other parts.To investigate the residue level and assess the potential human health risk of heavy metals and harmful elements in roots and rhizomes,720 batches of the sample representing 20 species of herbs from different sources were collected.Methods:The content of Pb,Cd,As,Hg,and Cu in the digests was determined using ICP-MS.The chronic hazard index estimate based on non-cancer hazard quotient(HQ)was applied for potential health risk assessment of Pb,Cd,As,Hg,and Cu via consumption of CHMs.Results:Compared with the Chinese limit standard(Chinese Pharmacopoeia Commission,2020 edition)of Pb,Cd,As,Hg,and Cu in Ginseng Radix et Rhizoma,the exceedance percentage of Pb in total samples was 14.1%,which were generally far higher than Cd,As,Hg,and Cu.Health risk assessment results based on hazard quotient calculating showed that total HQ of Cu,Pb,As,Cd,and Hg in Pulsatillae Radix and Clematidis Radix et Rhizoma exceeded 1,with the value of 1.543 and 1.235.Besides,Arsenic had the highest HQ value(0.957)in Pulsatillae Radix.Conclusion:Consuming raw materials of Pulsatillae Radix and Clematidis Radix et Rhizoma may pose a potential risk and Arsenic residues in Pulsatillae Radix deserved special attention.

Assessment of pollution of potentially harmful elements in soils surrounding a municipal solid waste incinerator, China

We assessed the contamination levels of Mn, Zn, Cr, Cu, Ni, Pb, As and Hg and the risks posed by these potentially harmful elements in top-soils around a municipal solid waste incinerator （MSWI）. We collected 20 soil samples, with an average pH of 8.1, and another fly ash sample emitted from the MSWI to investigate the concentrations of these elements in soils. We determined the concentrations of these elements by inductively coupled plasma-optical emission spectrometer （ICP-OES）, except for Hg, which we measured by AF-610B atomic fluorescence spectrometer （AFS）. We assessed the risks of these elements through the use of geoaccumulation index （/geo）, potential ecological risk index （R/）, hazard quotient （HQi） and cancer risk （Riski）. The results showed that concentrations of potentially harmful elements in soil were influenced by the wind direction, and the concentrations of most elements were higher in the area northwest of the MSWI, compared with the area southeast of the incinerator, with the exception of As; these results were in accordance with those results acquired from our contour maps. According to the I^o values, some soil samples were clearly polluted by Hg emissions. However, the health risk assessment indicated that the concentrations of Hg and other elements in soil did not pose non-carcinogenic risks to the local populations. This was also the case for the carcinogenic risks posed by As Cr and Ni. The carcinogenic risk posed by As was higher in the range 6.49 × 10 -9.58 × 10 -6, but this was still considered to be an acceptable level of risk.

Predicting the aquatic risk of realistic pesticide mixtures to species assemblages in Portuguese river basins

Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins（＇Mondego＇, ＇Sado＇ and ＇Tejo＇） on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions（SSDs）, in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions（ms PAFs） were obtained. The median msP AF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters.