Characteristics of Heavy Metals in Seawater and Sediments from Daya Bay (South China): Environmental Fates, Source Apportionment and Ecological Risks

In this study, the spatiotemporal distributions, potential sources, and ecological risks of Hg, Cr, and As in seawater, and Hg, As, Zn, Cd, Pb, and Cu in sediments from Daya Bay were investigated. The five-year average concentrations of Hg, Cr, and As in seawater were 0.020 μg/L, 0.79 μg/L, and 2.08 μg/L, respectively. The five-year average concentrations of Hg, As, Zn, Cd, Pb, and Cu in surface sediments were 0.04 mg/kg, 7.34 mg/kg, 63.81 mg/kg, 0.23 mg/kg, 25.60 mg/kg, and 11.78 mg/kg, respectively. Annual variations in Hg, Cr, and As in seawater exhibited different trends. HMs in sediments, such as As, Zn, Pb, and Cu, exhibited similar annual variations, whereas Hg and Cd exhibited different annual variations. The spatial distribution of metal species in seawater and sediments showed significant variability, and the concentrations decreased gradually from the coast to the open sea. The comprehensive potential ecological hazard index (RI) of HMs in sediments indicated a relatively high risk, especially for Hg and Cd contamination. The geoaccumulation indices (Igeo) of As, Zn, Pb, and Cu suggested that these metals did not pollute Daya Bay, whereas those of Cd and Hg indicated mild and moderate pollution. The environmental fates of HMs were discussed based on Pearson correlation analysis, revealing that concentrations of HMs were greatly affected by parameters, such as pH, salinity, dissolved oxygen (DO), and total organic carbon (TOC). Principal component and factor analyses indicated that Hg, Cr, As, and dissolved inorganic nitrogen (DIN) in water originated from similar sources, including domestic sewage and wastewater from fishing ports, runoffs, and outlets. For sediments, it was proposed that Cu, Zn, As, Pb, and TOC exhibited similar sources, including cage culture and waste discharge from outlets. Meanwhile, Hg and Cd originated from other point sources, such as a harbor. The study suggests that sustainable management and economic development be integrated to control pollutant emissions in Daya Bay.

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Distribution of Geochemical Fractions of Phosphorus in Surface Sediment in Daya Bay, China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17124430 ◽

2020 ◽

Vol 17 (12) ◽

pp. 4430

Author(s):

Hongping Liao ◽

Ciguang Pan ◽

Lian Gan ◽

Zhixin Ke ◽

Huijuan Tang

Keyword(s):

Surface Sediment ◽

Pearson Correlation ◽

Principal Component ◽

Extraction Methods ◽

Molar Ratio ◽

Daya Bay ◽

Internal Source ◽

Spatial Distributions ◽

Dominant Form ◽

Geochemical Fractions

Surface sediment samples were collected from 19 sites throughout Daya Bay, China, to study the concentrations, and spatial distributions of different fractions of phosphorus through sequential extraction methods. Like many coastal and marine areas, De-P was the dominant form of P, contributing 47.5% of TP, followed by O-P, contributing 25.5% of TP. Ex-P and Fe-P contribute the lowest to TP. The concentration of sedimentary TP ranged from 290.3~525.1 µg/g, with the average of 395.3 µg/g, which was a similar range to other estuaries and coastal areas. Based on the spatial distribution, Pearson correlation and Principal component analysis, different fractions of phosphorus showed different spatial distributions due to different sources. The molar ratio of organic carbon to phosphorus (TOC/O-P) ranged from 199 to 609, with the average of 413, which was much higher than the Redfield ratio, suggesting terrestrial sources of organic matter in Daya Bay surface sediment. The average bioavailable phosphorus was 149.6 µg/g and contributed 37.8% (24.6~56.0%) of TP, indicating that the surface sediments of Day Bay act as an important internal source of P.

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Heavy Metals in Marine Surface Sediments of Daya Bay, Southern China: Spatial Distribution, Sources Apportionment, and Ecological Risk Assessment

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.755873 ◽

2021 ◽

Vol 9 ◽

Author(s):

Huijuan Wang ◽

Zhengqiu Fan ◽

Zexing Kuang ◽

Yuan Yuan ◽

Huaxue Liu ◽

...

Keyword(s):

Heavy Metals ◽

Spatial Distribution ◽

Ecological Risk ◽

Southern China ◽

Anthropogenic Activities ◽

Pearson Correlation ◽

Primary Standard ◽

Principal Component ◽

Daya Bay ◽

Human Beings

Daya Bay, especially in the northwestern region, which is a nature reserve with larval economic fish and shrimp populations, is no longer an unpolluted marine environment due to the recent increases in anthropogenic activities. This study collected seasonal surface sediment samples from 20 sites in northwestern Daya Bay to evaluate pollution and ecological risks and to identify possible sources and transport pathways of heavy metals (Cd, Pb, Cr, Cu, Zn, Hg, As). The results showed that all the heavy metal concentrations were below the established primary standard criteria, except for concentrations of Cr in spring, as well as Cu and Zn in autumn at several sampling stations, which had excess rates of 35, 4.76, and 4.76%, respectively. The geoaccumulation index (Igeo) values of heavy metals indicated that all sites had unpolluted to moderate pollution levels. In comparison to the samples collected in autumn, those in spring experienced a higher degree of pollution, particularly Cr and As. The ecological risk indices of heavy metals in sediments ranged from 225.86 to 734.20 in spring and from 196.69 to 567.52 in autumn, suggesting that most sites had a moderate ecological risk or a considerable ecological risk, and very few a had high ecological risk. Moreover, ArcGIS10.2 software was used to visualize their spatial distribution, and the results were similar in both spring and autumn. The results of the Pearson correlation analysis and principal component analysis showed that Cu, Hg, and Pb might be affected by anthropogenic activities, and As might be derived from natural sources such as atmospheric inputs. A cluster analysis showed that heavy metals were mainly affected by the negative impacts of human beings on the environment.

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Bioprospecting of Sechium spp. varieties for the selection of characters with pharmacological activity

Scientific Reports ◽

10.1038/s41598-021-85676-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

María Isabel Iñiguez-Luna ◽

Jorge Cadena-Iñiguez ◽

Ramón Marcos Soto-Hernández ◽

Francisco Javier Morales-Flores ◽

Moisés Cortes-Cruz ◽

...

Keyword(s):

Cell Lines ◽

Proliferative Activity ◽

Meta Analysis ◽

Pearson Correlation ◽

Statistical Significance ◽

Economic Value ◽

Principal Component ◽

Malignant Cell ◽

Length Polymorphisms ◽

Relevant Variables

AbstractBioprospecting identifies new sources of compounds with actual or potential economic value that come from biodiversity. An analysis was performed regarding bioprospecting purposes in ten genotypes of Sechium spp., through a meta-analysis of 20 information sources considering different variables: five morphological, 19 biochemical, anti-proliferative activity of extracts on five malignant cell lines, and 188 polymorphic bands of amplified fragment length polymorphisms, were used in order to identify the most relevant variables for the design of genetic interbreeding. Significant relationships between morphological and biochemical characters and anti-proliferative activity in cell lines were obtained, with five principal components for principal component analysis (SAS/ETS); variables were identified with a statistical significance (< 0.7 and Pearson values ≥ 0.7), with 80.81% of the accumulation of genetic variation and 110 genetic bands. Thirty-nine (39) variables were recovered using NTSYSpc software where 30 showed a Pearson correlation (> 0.5) and nine variables (< 0.05), Finally, using a cladistics analysis approach highlighted 65 genetic bands, in addition to color of the fruit, presence of thorns, bitter flavor, piriform and oblong shape, and also content of chlorophylls a and b, presence of cucurbitacins, and the IC50 effect of chayote extracts on the four cell lines.

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Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

Sustainability ◽

10.3390/su13126910 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6910

Author(s):

Adil Dilawar ◽

Baozhang Chen ◽

Arfan Arshad ◽

Lifeng Guo ◽

Muhammad Irfan Ehsan ◽

...

Keyword(s):

Pearson Correlation ◽

Principal Component ◽

Mitigation Strategies ◽

Precipitation Extremes ◽

Climate Mitigation ◽

Mean Annual Temperature ◽

Climate Extreme ◽

Ecological Zones ◽

The Mean ◽

Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

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Biological Risk Assessment of Heavy Metals in Sediments and Health Risk Assessment in Marine Organisms from Daya Bay, China

Journal of Marine Science and Engineering ◽

10.3390/jmse9010017 ◽

2020 ◽

Vol 9 (1) ◽

pp. 17

Author(s):

Zexing Kuang ◽

Yangguang Gu ◽

Yiyong Rao ◽

Honghui Huang

Keyword(s):

Heavy Metals ◽

Risk Assessment ◽

Marine Organisms ◽

Daya Bay ◽

Ecological Risks ◽

The Monte Carlo Method ◽

Accumulation Index ◽

The Mean ◽

Primary Pollutant ◽

Geo Accumulation

The concentrations of heavy metals in sediments and marine organisms in Daya Bay were investigated, and the Monte Carlo method was used to analyze the uncertainty of the results of geo-accumulation characteristics and ecological and health risks. The mean concentrations of metal elements in sediments were in the following order: Zn > Cr > Cu > As > Cd > Hg, while those in marine organisms were Zn > Cu > As > Cr ≈ Cd > Hg. The geo-accumulation index (Igeo) indicated that the primary pollutant was Hg, with 5.46% moderately polluted, and 39.52% for unpolluted to moderately polluted. Potential ecological risks (RI) were between low and high risks, and the contributions of Hg, Cd, and As to ecological risks were 50.85%, 33.92%, and 11.47%, respectively. The total hazard coefficients (THQ) were less than 1, but on the basis of total carcinogenic risks (TCR), the probability of children and adults exceeded the unacceptable risk threshold of 22.27% and 11.19%, respectively. Sensitivity analysis results showed that the concentrations of carcinogenic elements contributed to risk in the order of As > Cd > Cr. Therefore, in order to effectively control heavy metals contamination in Daya Bay, it is necessary to strengthen the management of Hg, Cd, and As emissions.

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Key soil parameters affecting the survival of Panax notoginseng under continuous cropping

Scientific Reports ◽

10.1038/s41598-021-85171-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wumei Xu ◽

Fengyun Wu ◽

Haoji Wang ◽

Linyan Zhao ◽

Xue Liu ◽

...

Keyword(s):

Soil Ph ◽

Pearson Correlation ◽

Principal Component ◽

Panax Notoginseng ◽

Soil Parameters ◽

Continuous Cropping ◽

Poor Growth ◽

Available N ◽

The Poor ◽

Replant Problem

AbstractNegative plant-soil feedbacks lead to the poor growth of Panax notoginseng (Sanqi), a well-known herb in Asia and has been used worldwide, under continuous cropping. However, the key soil parameters causing the replant problem are still unclear. Here we conducted a field experiment after 5-year continuous cropping. Sanqi seedlings were cultivated in 7 plots (1.5 m × 2 m), which were randomly assigned along a survival gradient. In total, 13 important soil parameters were measured to understand their relationship with Sanqi’s survival. Pearson correlation analysis showed that 6 soil parameters, including phosphatase, urease, cellulase, bacteria/fungi ratio, available N, and pH, were all correlated with Sanqi’s survival rate (P < 0.05). Principal component analysis (PCA) indicated that they explained 61% of the variances based on the first component, with soil pH being closely correlated with other parameters affecting Sanqi’s survival. The optimum pH for Sanqi growth is about 6.5, but the mean soil pH in the study area is 5.27 (4.86–5.68), therefore it is possible to ameliorate the poor growth of Sanqi by increasing soil pH. This study may also help to reduce the replant problem of other crops under continuous cropping since it is widespread in agricultural production.

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PSXIII-26 Supplementation with a polyphenolic pine bark extract reduces ammonia nitrogen production in a RUSITEC system as determined by principal component analysis

Journal of Animal Science ◽

10.1093/jas/skab235.779 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 435-436

Author(s):

Nelson Vera ◽

Constanza Gutierrez ◽

Pamela Williams ◽

Cecilia Fuentealba ◽

Rodrigo Allende ◽

...

Keyword(s):

Principal Component Analysis ◽

Repeated Measures ◽

Pearson Correlation ◽

Principal Component ◽

Component Analysis ◽

Ammonia Nitrogen ◽

Pine Bark ◽

Bark Extract ◽

Ruminal Fermentation ◽

Fermentation Parameters

Abstract The aim of the study was to correlate the effects of supplementation with a polyphenolic pine bark extract (PBE) in diets with different forage to concentrate (F:C) ratio on methane (CH4), ammonia nitrogen (NH3–N) production and ruminal fermentation parameters using the Rumen Simulation Technique (RUSITEC). The experimental diets were F:C 70:30 (HF) or F:C 30:70 (HC) with or without 2% PBE on a DM basis. The four diets were isoproteic (15% CP), with similar OM (HF 94% and HC 96%), but different NDF (HF 40% and HC 25%). The treatments, in duplicate, were assigned in an 8 fermenter RUSITEC apparatus. Incubations were run twice, with 5 days of sampling after 10 days adaptation. The experimental design was a 2x2 factorial arrangement in a randomized complete block with repeated measures. Pearson correlation and principal component analysis (PCA) were conducted to elucidate relationships among PBE total polyphenols (TP) and the variables evaluated. The TP was highly correlated with NH3–N (r = –0.98; P < 0.001) and butyrate (r = –0.85; P < 0.001), and had a high correlation with propionate (r = 0.75; P < 0.001) and acetate (r = 0.68; P = 0.001). Correlation with total VFA was moderate (r = –0.59; P = 0.006), and CH4 yield and IVDMD there were not correlated (r ≤ –0.07; P ≥ 0.188). The PCA (KMO = 0.655; BTS < 0.001) shows that 75.2% of the total variation is explained by the first two principal components (PC1 = 46.5% and PC2 = 28.7%). In the score plot, PC1 discriminated between diets with and without PBE, while the PC2 separated based on NDF. The loading plot showed that TP and propionate were clustered, and had inverse directions to NH3–N. In conclusion, the PBE supplementation reduces NH3–N production in a RUSITEC system without decreasing CH4 yield or negatively affecting ruminal fermentation parameters.

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Geochemical and statistical evaluation of groundwater in the Thamirabarani river basin, south India

10.21203/rs.3.rs-163816/v1 ◽

2021 ◽

Author(s):

Gajendran Chellaiah ◽

Basker ◽

Hima Pravin ◽

Suneel Kumar Joshi ◽

Sneha Gautam

Keyword(s):

River Basin ◽

Tamil Nadu ◽

Statistical Evaluation ◽

Anthropogenic Activities ◽

Monsoon Season ◽

Principal Component ◽

Chloride Ion ◽

Temporal Analysis ◽

Point Sources ◽

International Standards

Abstract In the present study, an attempt has been made to develop the dictate metrics using a multi-proxy approach, i.e., spatial-temporal analysis, statistical evaluation, and hydrogeochemical analysis for 45 water samples located in the Thamirabarani river basin in Tamil Nadu, India. In order to evaluate the aptness of developed metrics for agriculture and domestic needs, eleven years dataset was analyzed and compared with national and international standards. Monitoring and analysis results revealed that the concentration of calcium and chloride ion was on the higher side in all the selected locations. These higher values may be attributed to the regional point sources such as untreated water disposal and off-peak sources such as agriculture practices. The principal component analysis resulted in 84.2% of the total variance in the post-monsoon season dataset. The major analyzed cations and anions were observed in the following order: Na+> Ca2+> Mg2+> K+ and Cl−> HCO3−> SO42−> NO3−, respectively. Overall, this study revealed that the studied area's groundwater quality was significantly affected by the high salinity in the region, probably due to anthropogenic activities and unprotected river sites.

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Characterization of Canadian High Arctic glacier surface albedo from MODIS C6 data, 2001–2016

10.5194/tc-2017-160 ◽

2017 ◽

Author(s):

Colleen A. Mortimer ◽

Martin Sharp

Keyword(s):

Large Scale ◽

Surface Albedo ◽

Temporal Trends ◽

Principal Component ◽

High Arctic ◽

Shortwave Radiation ◽

Glacier Surface ◽

Annual Variations ◽

The Mean ◽

Moderate Resolution Imaging Spectroradiometer

Abstract. Inter-annual variations and longer-term trends in the annual mass balance of glaciers in Canada's Queen Elizabeth Islands (QEI) are largely attributable to changes in summer melt. The largest source of melt energy in the QEI in summer is net shortwave radiation, which is modulated by changes in glacier surface albedo. We used measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors to investigate large scale spatial patterns and temporal trends and variability in the summer surface albedo of QEI glaciers and their relationship to observed changes in glacier surface temperature from 2001 to 2016. Mean summer black-sky shortwave broadband albedo (BSA) decreased at a rate of 0.029 ± 0.025 decade-1 over that period. Larger reductions in BSA occurred in July (−0.050 ± 0.031 decade-1). No change in BSA was observed in either June or August. Most of the decrease in BSA, which was greatest at lower elevations around the margins of the ice masses, occurred between 2007 and 2012 when mean summer BSA was anomalously low. The First Principal Component of the 16-year record of mean summer BSA was well correlated with the mean summer North Atlantic Oscillation Index, except in 2006, 2010, and 2016. During this 16-year period, the mean summer LST increased by 0.046 ± 0.036 °C yr-1 and the BSA record was negatively correlated (−0.64, p

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No-tillage system participatory quality index

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v24n2p128-133 ◽

2020 ◽

Vol 24 (2) ◽

pp. 128-133 ◽

Cited By ~ 2

Author(s):

Tiago S. Telles ◽

Ana J. Righetto ◽

Marco A. P. Lourenço ◽

Graziela M. C. Barbosa

Keyword(s):

Principal Component Analysis ◽

Cluster Analysis ◽

Crop Rotation ◽

Quality Index ◽

Pearson Correlation ◽

Principal Component ◽

Component Analysis ◽

Soil Tillage ◽

No Tillage ◽

Tillage System

ABSTRACT The no-tillage system participatory quality index aims to evaluate the quality and efficiency of soil management under no-tillage systems and consists of a weighted sum of eight indicators: intensity of crop rotation, diversity of crop rotation, persistence of crop residues in the soil surface, frequency of soil tillage, use of agricultural terraces, evaluation of soil conservation, balance of soil fertilization and time of adoption of the no-tillage system. The aim of this study was to assess the extent to which these indicators correlate with the no-tillage system participatory quality index and to characterize the farmers who participated in the research. The data used were provided by ITAIPU Binacional for the indicators of the no-tillage system participatory quality index II. Descriptive analyses were performed, and the Pearson correlation coefficient between the index and each indicator was calculated. To assess the relationship between the indicators and the farmers’ behavior toward the indicators, principal component analysis and cluster analysis were performed. Although all correlations are significant at p-value ≤ 0.05, some correlations are weak, indicating a need for improvement of the index. The principal component analysis identified three principal components, which explained 66% of the variability of the data, and the cluster analysis separated the 121 farmers into five groups. It was verified that the no-tillage system participatory quality index II has some limitations and should therefore be reevaluated to increase its efficiency as an indicator of the quality of the no-tillage system.

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