Seasonal, spatial variation, and pollution sources of heavy metals in the sediment of the Saigon River, Vietnam

Hasanuzzaman

Enviro Toxic and Chemistry

et al. 2020

The positive matrix factorization (PMF) receptor model was used for the first time to quantify the source contributions to heavy metal pollution of sediment on a national basin scale in the upstream, midstream, and downstream rivers (Teesta and Kortoya-Shitalakkah and Meghna-Rupsha and Pasur) of Bangladesh. The metal contamination status, cooccurrence, and ecotoxicological risk were also investigated. Sediment samples were collected from 30 sites at a depth range of 0 to 20 cm for analysis of 9 metals using inductively coupled plasma-mass spectrometry. The mean concentrations of metals varied for upstream, lower midstream, and downstream river segments. The results showed that chromium (Cr) exhibited a strong significant co-occurrence network with other metals (e.g., manganese [Mn], iron [Fe], and nickel [Ni]). Monte Carlo simulation results of the geo-accumulation index (Igeo; 63.3%) and risk indices (48.5%) showed that cadmium (Cd) was the main contributor to sediment pollution. However, the cumulative probabilities of sediments being polluted by metals were ranked as "moderate to heavily polluted" (Igeo 46.6%; risk index 16.7%). Toxicity unit results revealed that zinc (Zn) and Cd were the key toxic contributors to sediments. The PMF model predicted metal concentrations and identified 4 potential sources. The agricultural source (factor 1) mostly contributed to copper (Cu; 78.9%) and arsenic (As; 62.8%); Ni (96.9%) and Mn (83.5%) exhibited industrial point sources (factor 2), with 2 hot spots in northwestern and southwestern regions. Cadmium (93.5%) had anthropogenic point sources (factor 3), and Fe (64.3%) and Cr (53.5%) had a mixed source (factor 4). Spatially, similar patterns between PMF apportioning factors and predicted metal sources were identified, showing the efficiency of the model for river systems analysis. The degree of metal contamination in the river segments suggests an alarming condition for biotic components of the ecosystem.

Section: Resultssupporting

confidence: 83%

Quantifying Source Apportionment, Co‐occurrence, and Ecotoxicological Risk of Metals from Upstream, Lower Midstream, and Downstream River Segments, Bangladesh

Hasanuzzaman

Enviro Toxic and Chemistry

et al. 2020

“…In general, wet season may cause soil erosion and bring eroded material to the water body. The dry season may cause river water lost through evaporation, increasing concentrations of suspended materials and dissolved elements (Nguyen et al 2020).…”

Section: Seasonal Variation Of Pollutants Concentrationmentioning

confidence: 99%

Estrogenic Hormones in São Paulo Waters (Brazil) and Their Relationship with Environmental Variables and Sinapis alba Phytotoxicity

Coelho

Jesus

Kohatsu

et al. 2020

Water Air Soil Pollut

Present study evaluated the relationship between estrogenic hormones concentrations (17ethinylestradiol and 17β-estradiol) in surface waters in the Metropolitan Region of São Paulo (Brazil) and environmental variables. Four sampling stations were monitored ranging from a protected area to streams discharging human effluent in and around Billings Reservoir. Four sampling campaigns were carried out in each seasonal period: DRY and WET. Samples for hormone analysis (in ng L -1 ) were concentrated (1000X) using solid phase extraction C 18 cartridges and analysed by liquid chromatography coupled to quadrupole mass spectrometry detection, with 100 ng L -1 limit of quantification. Water temperature, pH, electrical conductivity (EC) and total dissolved solids were determined in situ; total phosphorus and Sinapis alba bioassays were performed subsequently. Reservoir active capacity (AC) and precipitation were also obtained. Estrogenic hormones concentrations were always below limit of quantification at pristine site; at the other sampling stations, 17β-estradiol concentrations varied from below limit of quantification to 1,720 ng L -1 and 17ethinylestradiol from below limit of quantification to 1,200 ng L -1 , with the highest concentrations found in the streams discharging into the reservoir. These streams showed higher Pearson's correlation between 17-ethinylestradiol, total phosphorus, and electrical conductivity when compared with reservoir stations. Germination index and EC presented negative correlation (Pearson's r = -0.61), denoting a phytotoxicity increase with EC increment. AC influenced the dilution of pollutants and showed negative correlations with total phosphorus (Pearson's r = -0.56). These results highlight the relevance of including streams in water monitoring programs, since they are important pollutants loads into watersheds.

“…Nevertheless, without any substantial observations, this would not be assumed (Ashaiekh et al, 2019). Higher concentrations of Pb and Ni indicate maybe their presence were regulated by the feed used in the respective studied location or by the parameters of the geochemical properties of the area or because of the rapid industrialization in the study area (Hossain et al, 2015;Nguyen et al, 2020) whereas Cu and Cr contents could be accumulated from feed supplied in the studied area.…”

Section: Carcinogenic Risk Calculationmentioning

confidence: 94%

Assessment of Human Health Risks Associated with Heavy Metals Accumulation in the Freshwater Fish Pangasianodon hypophthalmus in Bangladesh

et al. 2021

In this study, pangas and feed samples were analyzed to estimate the levels of metallic elements and to profile the human health risks due to consumption of contaminated fish. This investigation confirmed significant variations in heavy metal concentrations among different tissues of pangas in the order of Ni> Cu> Pb> Cd> Cr in pre-monsoon; and Ni> Cd= Cu> Pb= Cr in post-monsoon. Considerably higher concentrations of Pb, Cu and Cr were estimated in liver; and Cd and Ni were detected in muscle than other organs (p>0.05). Statistically significant higher amount of Cd, Ni, and Cu were observed in pre-monsoon than post-monsoon. Furthermore, three metal pairs showed significant association (Pb-Ni and Pb-Cu involved positively; Cd-Ni acted negatively). In pre-monsoon, Cd, Pb, Ni, Cu concentrations of feed significantly differed than pangas contents; whereas only Cu varied during the post-monsoon. Regression analysis revealed the significant effect of Ni content in feed on the Cu deposition of pangas (p-value 0.027, that was <0.05). For the assessment of potential human health risk of the studied metals, estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and carcinogenic risk (CR) indices were calculated. Studied EDI indicated that an average adult ingested a higher amount of Ni and Cu than the recommended intake limit. Nevertheless, only the higher EDI of Ni increases the value of THQ and HI than standard limit indicates adverse non-carcinogenic risk. However, lower CR of Pb confirmed no serious health hazard due to the ingestion of pangas. Factor analysis through principal component and cluster analysis suggested that higher concentrations of Pb and Ni may regulate by the feed used, geochemical properties or rapid industrialization in the study area. A proper monitoring for controlling the quality of fish feed with sustainable planning for industrialization could secure the booming of pangasius aquaculture in Bangladesh.