Assessment of surface water quality of the bois river (Goiás, Brazil) using an integrated physicochemical, microbiological and ecotoxicological approach.

The data on water pollution is scarce in developing countries, including Brazil. The water quality assessment is important implementing the monitoring and remediation programs to minimize the risk of hazardous substances in freshwaters. Thus, this study evaluated the surface water quality of a stretch of the Bois River (Brazil), based on the physicochemical, microbiological and ecotoxicological analyses conducted in 2017, using Standard Methods and fish embryo acute toxicity (FET) test with zebrafish (Danio rerio). The results indicated that the quality of water samples located close to the discharge of tannery effluents was most impaired. Total phosphorus, BOD, DO, ammoniacal nitrogen, and thermotolerant coliforms parameters in P4 were not in accordance with the standards of current Brazilian legislation. Iron, lead, and copper levels were higher than environmental standards. The physicochemical quality of water samples was lower in the dry season than the rainy season. All samples (P1, P3, and P5) in rainy and dry seasons did not induce significant acute toxicity for zebrafish early-life stage; however other trophic levels (algae and microcrustacean) should be investigated to gain a better understanding of the toxicity during water quality analysis. In conclusion, the physicochemical and microbiological changes in the water of the Bois River can affect aquatic organisms as well as humans when it is used for drinking or in agriculture.

Assessment of Potential Heavy Metal Contamination in the Peri-urban Agricultural Soils of 31 Provincial Capital Cities in China.

To obtain a general understanding of heavy metal contamination in peri-urban agricultural soils in China, this study investigates the concentrations of eight heavy metals, i.e., Cd, Pb, Zn, As, Cu, Cr, Hg, and Ni, in the peri-urban agricultural soils of 31 provincial capital cities in China. The data were obtained via exhaustive literature searches in both the Web of Science and China National Knowledge Infrastructure (CNKI) as well as from statistical yearbooks published in China. To evaluate the pollution status of each city and identify a variety of potential sources, various contamination indexes, e.g., the enrichment factor (EF), geoaccumulation index (Igeo), and integrated pollution index (IPI), were calculated based on the peri-urban agricultural soil dataset. The results of the analysis of the heavy metal concentrations, EF values and Igeo values showed that the peri-urban agricultural soils were enriched in most heavy metals, and Cd and Hg concentrations greatly exceeded the Chinese Environmental Protection Administration (CEPA) guidelines. The IPI results showed that 15 of the 31 cities, i.e., 48%, exhibited varying extents of heavy metal pollution. Although the mean IPI value for peri-urban agricultural soils in all cities (0.83) was slightly lower than that for urban soil (0.9), the IPI values for peri-urban agricultural soils from 65% of the cities were greater than those for urban soils, indicating that peri-urban agricultural soils are more polluted than urban soils in these large cities. These results are important for guiding future research on heavy metal pollution in peri-urban agricultural soils of presently expanding Chinese cities.

Base alteration of some heavy metal concentrations on local and seasonal in Bartin River.

Fresh water resources have always been an extremely invaluable economic and strategic resource in the world. There are about 1.4 billion people who have no access to pure water resources mainly due to the discharge of 95% of unpurified wastewater and 70% of industrial wastes into water resources in underdeveloped and developing countries. More than half of the world's rivers are contaminated. Eighty percent of diseases are caused by contaminated waters in developing countries. Among the pollutants in these streams, heavy metals are of particular significance, as heavy metals do not dissolve and degenerate easily in nature. They also tend to bio-accumulate. This is why determining heavy metal concentrations is of great importance because it can help detect risk zones and risk levels. This study aims to determine the alteration of some heavy metal concentrations during a year in Bartin River on a point and seasonal base. Within the scope of the study, samples were collected from 5 chosen locations on Bartin River during a year and the alteration of Cu, Fe, Zn, Mn, Ni, and Pb concentration amounts were determined monthly. As a result of the study, it was determined that there were various rates of contamination with heavy metals at all stations, and that the amount of all studied heavy metal concentrations decreased depending on seasonal alteration when precipitation and hence the flow rates were high, and the highest concentrations were calculated in samples that were collected from L3 and L5 stations. Results shows that some of the toxic metals' accumulations are higher than the suggestion of value, which recommended that the Bartin River is to some extent a toxic metal polluted river and that animals are not totally safe. Since this study constitutes a sample, all international samples should be controlled especially in the Organized Industrial Zone and foundation areas and the wastewater entering the river should be controlled and the pollution source should be determined and precautions should be taken. According to the results of the study, it also shows the water quality of the rivers in general. Pollution levels of rivers should be taken into account in the use of river water and care should be taken to use river water directly or indirectly in agricultural activities that may cause harm to human health. The results of this study can be a guide for identifying suitable areas to use the water of rivers. In future river planning, these studies will have an important guide value.

The association between whole blood concentrations of heavy metals in pregnant women and premature births: The Japan Environment and Children's Study (JECS).

BACKGROUND: Heavy metals are widely distributed in the environment. Recent reports have demonstrated the risk of preterm birth following heavy metal exposure. Preterm births are classified as early and late, depending on the duration of pregnancy, and are associated with increased risk of congenital illnesses such as heart failure, asthma, etc. Particularly, early preterm births carry a higher risk of mortality; however, the differential effects of heavy metal exposure on early and late preterm births are unknown. OBJECTIVES: To analyze the association between maternal whole blood concentrations of heavy metals, such as cadmium (Cd), lead (Pb), mercury (Hg), selenium (Se), and manganese (Mn) that are common toxicants in Japan, and early and late preterm births. METHODS: The data of 14,847 pregnant women who were participants of the Japan Environment and Children's Study were used. Data of the self-questionnaire pertaining to the first trimester (T1), second/third trimester (T2), and medical records after delivery were analyzed. We divided preterm birth into two groups: early preterm (22 to < 34 weeks) and late preterm (34 to < 37 weeks). Maternal blood samples for measuring heavy metal concentrations were collected in T2 (pregnancy weeks: 14-39). The participants were classified into four quartiles (Q1-Q4) according to increasing heavy metal levels. RESULTS: The rate of preterm birth was 4.5%. After controlling for confounding factors, such as age, pre-pregnancy body mass index, smoking, partner's smoking, drinking habits, gravidity, parity, number of cesarean deliveries, uterine infections, household income, educational levels, and sex of infant, Cd levels were found, by multivariable logistic regression analysis, to be significantly associated with early preterm birth (p = 0.002), with odds ratio for early preterm birth of 1.91 (95% confidence interval: 1.12-3.27, P = 0.018) in subjects of Q4 compared with in subjects with term birth (≧ 37 weeks). CONCLUSION: Maternal blood Cd levels during pregnancy are positively associated with the risk of early preterm birth among Japanese women. Identification of the main source of maternal Cd exposure may contribute to the prevention of early preterm births and health maintenance of mothers and their infants in the future.

Concentration of heavy metals in vegetables and potential health risk assessment in China.

Food safety is an important issue in the world. This study assessed the health risk for the Chinese public when consuming vegetables grown in China, based on 1335 data records from 220 published papers during 2007-2016. The results showed that the average of Pb, Cd, and Hg concentration in vegetables was 0.106, 0.041, and 0.008 mg/kg, which were lower than the maximum allowable concentrations, respectively. Leaf vegetables contained higher heavy metals than root vegetables and fruit vegetables. On a provincial scale, the highest Pb, Cd, and Hg concentrations in vegetables were determined by those in soil and atmosphere. The total health risk index showed that people in Guizhou, Yunnan, Guangxi, Hunan, Guangdong, Hubei provinces in southern China, and Liaoning Province in northeast China, faced a high risk of Pb, Cd, and Hg when consuming vegetables.

Exploring the temporal toxicity signature: A baseline evaluation of the heavy metal concentration in estuarine core sediments in the coastal region of cauvery delta, bay of bengal.

Globally, the concentration of heavy metals and sediment toxicity analysis are significant liabilities to aquatic environments. This scrutiny outlines the sediment textures, heavy metals and toxicity status associated with environmental pollution indices in the core sediment of the Cauvery and Vettar estuaries, East coast of India. The impact of rapid industrialization, urbanization, harbour activities and agricultural activities influences on the twain estuary is a significant concern to designate the environment. The contamination status of the sediments affects the potential biodiversity, ecological risks and human health. A total of two core sediments were recovered from the Cauvery and Vettar estuaries in March 2023 to decipher the environmental pollution status. Meticulous observation of the textural studies underscores the prevalence of sand content in Cauvery, and Vettar sediments consist of predominate clay content and minor silt contents. Furthermore, the organic matter is augmented in the Vettar River due to the higher input of waste disposal, seaweeds and algae due to the surrounding landmass. Twain core sediments argue that heavy metal concentration is decreasing in order as Fe > Zn > Ni > Pb > Cu > Cr by using portable X-ray fluorescence (pXRF) spectrometry. Remarkable results of environmental pollution indices such as Igeo, Ef, Cf, Cd and mCd state very highly polluted, extreme enrichments, high contamination and very high degree of contamination. Furthermore, the potential ecological risk indices such as PLI, SQGs, and PERI argue polluted, medium to high toxicity and moderate adverse ecological risk to the estuarine regions. Statistical analysis of the heavy metal affirms the enrichment of Fe metals may derive from lithogenic and/or anthropogenic influences, and the other studied metals such as Cu, Ni, Zn, Pb and Cr may be influenced by the anthropogenic activities in the aspect of point and non-point pollution sources. This could result from both estuaries undergoing higher pollution, in which the Vettar estuary is a considerable environmental risk zone compared to the Cauvery river due to the impact of industrial effluents and rapid urbanization activities. This finding underscores the urgent need for enhanced estuarine sediment quality study and comprehensive assessment of sediment toxicity, regulating the beneficial acumen for the government to follow the suitable remediation on the embellish policy of river and marine environments.

A robust, low-temperature, closed-loop anaerobic system for high-solid mixed farm wastes: advancing agricultural waste management solutions in Canada.

This study investigates the effectiveness of low-temperature (20 ± 1 °C) anaerobic digestion (AD) for two organic multiple farm substrate combinations: Set 1 comprising chicken manure (CM), dairy manure (DM), and waste corn silage (CS) and Set 2 comprising CM, DM, pig manure (PM), and CS. Inoculum adaptation steps were carried out using CM and CM+DM for Set 1 and Set 2, respectively. Over three consecutive operating cycles spanning 245 days with increasing organic loads, 4.3 and 2.8 g VS L-1 d-1 for Sets 1 and 2 during Cycles 1 to 5.1 and 4.6 g VS L-1 d-1for Sets 1 and 2 during Cycle 3, a closed-loop two-stage liquid-solid AD system was employed, with performance assessed via stability ratios of short-chain volatile fatty acids and alkalinity. Results demonstrate that mono-digestion of CM with adapted inoculum yielded the highest biogas production of 424 ± 4 L over 77 days, indicating superior performance by Set 1 during Phase I, whereas a similar performance was observed during Phase 2, where Sets 1 and 2 exhibited highest specific methane yields of 0.233 ± 0.028 and 0.262 ± 0.004 L g-1 VSfed, respectively, over 68 days. Analysis of heavy metal concentrations in digestates revealed a significant decrease compared to initial raw substrate concentrations, highlighting their role as nutrients for microbial growth. This study, the first of its kind, highlights the potential of low-temperature AD systems to manage diverse organic residues/byproducts and offers insights into effective performance monitoring without compromising system integrity.

Effect of pesticides on nitrification activity and its interaction with chemical fertilizer and manure in long-term paddy soils.

Effect of pesticides on nitrification activity and its interaction among heavy metal concentrations (HMCs), antibiotic resistance genes (ARGs), and ammonia monooxygenase (amoA) genes of long-term paddy soils is little known. The aim was to study the effect of pesticides on net nitrification rate (NR), potential nitrification rate (NP), HMCs, ARGs (sulI, sulII, tetO, and tetQ), and amoA (amoA-AOA, amoA-AOB, and amoA-NOB) genes in long-term treated paddy soils. NR and NP were significantly decreased (p < 0.05), whereas HMCs (Pb2+, Cu2+, Zn2+, and Fe3+) were a significantly increased (p < 0.05) in chemical fertilizer with pesticide treated paddy soils as compared with chemical fertilizer treated paddy soils. The scatter plot matrix indicated that total carbon (TC), soil organic carbon (SOC), total nitrogen (TN), and Fe were linearly correlated with NR and NP in long-term treated paddy soils. ARGs and amoA genes were significantly decreased (p < 0.05) in chemical fertilizer and manure with pesticide treated paddy soils. Overall, the result indicated the response of pesticide and their combination of manure with pesticide interaction present in long-term paddy soils, which will play a great role in the control uses of pesticides, manure, and chemical fertilizers in paddy soils and protect the nitrogen cycle as well as environment.

Heavy metal contamination in the muscle of Aegean chub (Squalius fellowesii) and potential risk assessment.

Especially after the industrial revolution, the amount of contaminants released in aquatic ecosystems has considerably increased. For this reason, the necessity to carry on research on the existence of contaminants, specifically heavy metals, has emerged. In this study, heavy metal concentrations in muscle tissues of Aegean chub, which was an endemic species of south western part of Turkey, gathered from Tersakan River were examined. Heavy metal concentrations of the samples were analyzed with ICP-MS. Estimated daily intakes (EDI), target hazard quotient (THQ), and carcinogenic risk (CR) of elements were calculated. The heavy metals detected in muscle tissues were Zn > Cu > Cr > Mn > Pb > Cd, consecutively. According to the results of the applied health risk assessment (EDI, THQ and CR) for heavy metal exposure from fish consumption in children and adults, it was determined that there was no any significant threat to human health.

The impact of freshwater metal concentrations on the severity of histopathological changes in fish gills: A statistical perspective.

The purpose of this study was to relate the severity of histopathological changes in fish gills with changes in metal concentrations of freshwater samples, and to use the relationships as premature warnings of impairment in aquatic fauna populations. The investigated species were the native barbel (Luciobarbus bocagei) and boga (Pseudochondrostoma sp.), and the introduced trout (Oncorhynchus mykiss), collected from 6 northern Portuguese rivers in a total of 249 individuals. The sampling sites have been linked to different ecological status by the official authorities. The sampling has been repeated 4 times to cover different hydrologic and environmental conditions. The analyzed metals were aluminum, arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead and zinc. For each fish, 30 filaments of a gill arch were observed in a light microscope, and the histopathological changes evaluated according to a 6-degree gradation scale that combines the extent and severity of each lesion. The relationships between the histopathological and the chemical results were investigated by the non-parametric Goodman Kruskal gamma correlation and Partial Least Squares regression (PLS). The statistical results highlighted the importance of filament epithelium proliferation (FEP) as key biomarker to the toxicity of sub lethal concentrations of metals, because FEP was significantly correlated with all analyzed metals and explained through PLS regression by concentration changes of Cu, Zn, Mn, Cr and As. A refined regression analysis, where histopathological data on the 3 species were processed in separate, revealed that FEP severity is especially sensitive to changes in metal concentrations in boga. Thus, monitoring studies on the ecological status of northern Portuguese rivers would benefit in time and cost if FEP is used as biomarker and boga as species. Naturally, the option for this species depends on the availability of boga individuals along the stream reaches selected for the monitoring programs.

[Estimating heavy metal concentrations in topsoil from vegetation reflectance spectra of Hyperion images: A case study of Yushu County, Qinghai, China.] / 基于Hyperionå½±åƒæ¤è¢«å ‰è°±çš„åœŸå£¤é‡é‡‘å±žå«é‡ç©ºé—´åˆ†å¸ƒåæ¼”­­ä»¥é’æµ·çœçŽ‰æ ‘åŽ¿ä¸ºä¾‹.

In this study, we explored the feasibility of estimating the soil heavy metal concentrations using the hyperspectral satellite image. The concentration of As, Pb, Zn and Cd elements in 48 topsoil samples collected from the field in Yushu County of the Sanjiangyuan regions was measured in the laboratory. We then extracted 176 vegetation spectral reflectance bands of 48 soil samples as well as five vegetation indices from two Hyperion images. Following that, the partial least squares regression (PLSR) method was employed to estimate the soil heavy metal concentrations using the above two independent sets of Hyperion-derived variables, separately constructed the estimation model between the 176 vegetation spectral reflectance bands and the soil heavy metal concentrations (called the vegetation spectral reflectance-based estimation model), and between the five vegetation indices being used as the independent variable and the soil heavy metal concentrations (called synthetic vegetation index-based estimation model). Using RPD (the ratio of standard deviation from the 4 heavy metals measured values of the validation samples to RMSE) as the validation criteria, the RPDs of As and Pb concentrations from the two models were both less than 1.4, which suggested that both models were incapable of roughly estimating As and Pb concentrations; whereas the RPDs of Zn and Cd were 1.53, 1.46 and 1.46, 1.42, respectively, which implied that both models had the ability for rough estimation of Zn and Cd concentrations. Based on those results, the vegetation spectral-based estimation model was selected to obtain the spatial distribution map of Zn concentration in combination with the Hyperion image. The estimated Zn map showed that the zones with high Zn concentrations were distributed near the provincial road 308, national road 214 and towns, which could be influenced by human activities. Our study proved that the spectral reflectance of Hyperion image was useful in estimating the soil concentrations of Zn and Cd.