Deterioration of groundwater quality by the actions of percolation and leaching from Nala-Lai in Rawalpindi Region, Pakistan

This paper presents a case study on the impact of Nala Lai wastewater in Pakistan on potential contamination of its nearby tube wells, bore water, dug wells and springs through percolation and leaching routes. Nineteen wastewater samples from Nala Lai stream and 68 groundwater samples from its associated and nearby areas were collected during (Season) and were analyzed for different water quality constituents. The parameters which were analyzed for determining the water quality include physiochemical parameters like Biological Oxygen Demand, Chemical Oxygen Demand, pH, temperature, turbidity, color, hardness, dissolved Oxygen, electric conductivity, total dissolved solids, Sulfates, Chlorides, Hardness and globally alarming heavy metals such as Cadmium, Cupper, Iron, Zinc, Manganese, Lead as well as bacterial parameter were recorded too. The results confirmed that all the 19 samples of surface water samples collected from Nala Lai exceeded the desirable limits (by NEQS) of both BOD and COD parameters

In Vitro Assessment of Cadmium Bioavailability in Chinese Cabbage Grown on Different Soils and Its Toxic Effects on Human Health

The minimum concentration of cadmium (Cd), by Chinese cabbage grown on Cd contaminated soils that can initiate toxicity in human liver cells using in vitro digestion coupled with Caco-2/HL-7702 cell models was studied. Cadmium bioaccessibility in the gastric phase for yellow soil (YS) cabbage (40.84%) and calcareous soil (CS) cabbage (21.54%) was significantly higher than small intestinal phase with the corresponding values of 21.2% and 11.11%, respectively. Cadmium bioavailability was higher in YS cabbage (5.27%–14.66%) than in CS cabbage (1.12%–9.64%). Cadmium concentrations (>0.74 μg) transported from YS and CS cabbage were able to induce oxidative (MDA, H2O2) stress by inhibiting antioxidant (SOD, GPx) enzyme activities in human liver cells (HL-7702). Additionally the study revealed that the ingestion of Cd contaminated Chinese cabbage grown in acidic soil (yellow soil) weakened the antioxidant defense system under all levels of contamination (2, 6, and 9 mg·kg−1) which ultimately escalated the oxidative stress in liver cells; however, in case of CS cabbage, a marked oxidative stress was observed only at 9 mg kg−1 Cd level of soil. Therefore, it is necessary to monitor Cd concentrations in leafy vegetables grown on acidic soils to minimize human health risk

Phytoavailability of cadmium (Cd) to Pak choi (Brassica chinensis L.) grown in Chinese soils: a model to evaluate the impact of soil Cd pollution on potential dietary toxicity.

Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg-1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg-1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production

Evaluating the impact of Nalla Lai contamination on drinking quality of groundwater in Rawalpindi city, Pakistan

The scientific report assessed the impact of Nalla Lai wastewater on the groundwater quality of Rawalpindi city, Pakistan. A total of 19 wastewater and 49 groundwater samples were collected during September and October 2016 and have been analyzed in the laboratory to detect different water quality parameters. The results revealed that BOD (biological oxygen demand), COD (chemical oxygen demand), iron, and cadmium values in many wastewater samples were beyond the recommended value of the National Environmental Quality Standards 1997 (NEQs, 1997). In groundwater samples, the results of iron, cadmium, manganese, zinc, TDS (total dissolved solids), pH, color, and hardness were found elevated from the standard values in one or more samples as compared with the National Standard for Drinking Water Quality, 2010 (NSDWQ, 2010). The decreasing metal concentration order in groundwater samples was iron > zinc > manganese > copper > cadmium. Very interestingly, hardness was found at elevated levels in 75% of investigated groundwater samples. Microbiological contamination was detected in 83% of the analyzed groundwater samples. The study revealed the percolation of heavy metals and microbial contamination in the bore water, tube wells, hand pumps, springs, and hand-dug wells located nearby the Nalla Lai wastewater stream. HIGHLIGHTS This scientific study evaluates the impact of Nalla Lai wastewater stream on the groundwater quality.; BOD, COD, iron and cadmium, manganese, zinc, TDS, pH, color, and hardness concentration were detected elevated in one or more samples as compared with the National Standards.; Hardness was elevated in 75% samples and microbial contamination was investigated in 85% of the analyzed groundwater samples.

Impact Assessment of Cadmium Toxicity and Its Bioavailability in Human Cell Lines (Caco-2 and HL-7702)

Cadmium (Cd) is a widespread environmental toxic contaminant, which causes serious health-related problems. In this study, human intestinal cell line (Caco-2 cells) and normal human liver cell line (HL-7702 cells) were used to investigate the toxicity and bioavailability of Cd to both cell lines and to validate these cell lines as in vitro models for studying Cd accumulation and toxicity in human intestine and liver. Results showed that Cd uptake by both cell lines increased in a dose-dependent manner and its uptake by Caco-2 cells (720.15 µg mg−1 cell protein) was significantly higher than HL-7702 cells (229.01 µg mg−1 cell protein) at 10 mg L−1. A time- and dose-dependent effect of Cd on cytotoxicity assays (LDH release, MTT assay) was observed in both Cd-treated cell lines. The activities of antioxidant enzymes and differentiation markers (SOD, GPX, and AKP) of the HL-7702 cells were higher than those of Caco-2 cells, although both of them decreased significantly with raising Cd levels. The results from the present study indicate that Cd above a certain level inhibits cellular antioxidant activities and HL-7702 cells are more sensitive to Cd exposure than Caco-2 cells. However, Cd concentrations <0.5 mg L−1 pose no toxic effects on both cell lines

Development of Cerium Oxide/Corncob Nanocomposite: A Cost-Effective and Eco-Friendly Adsorbent for the Removal of Heavy Metals

This research aims to assess the efficiency of the synthesized corncob as a cost-effective and eco-friendly adsorbent for the removal of heavy metals. Therefore, to carry out the intended research project, initially, the corncob was doped with nanoparticles to increase its efficiency or adsorption capacity. The prepared adsorbent was evaluated for the adsorption of cadmium (Cd) and chromium (Cr) from aqueous media with the batch experiment method. Factors that affect the adsorption process are pH, initial concentration, contact time and adsorbent dose. The analysis of Cd and Cr was performed by using atomic absorption spectrometry (AAS), while the characterization of the adsorbent was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that there is a significant difference before and after corncob activation and doping with CeO2 nanoparticles. The maximum removal for both Cd and Cr was at a basic pH with a contact time of 60 min at 120 rpm, which is 95% for Cd and 88% for Cr, respectively. To analyze the experimental data, a pseudo-first-order kinetic model, pseudo-second-order kinetic model, and intra-particle diffusion model were used. The kinetic adsorption studies confirmed that the experimental data were best fitted with the pseudo-second-order kinetic model (R2 = 0.989) and intra-particle diffusion model (R2 = 0.979). This work demonstrates that the cerium oxide/corncob nanocomposite is an inexpensive and environmentally friendly adsorbent for the removal of Cd and Cr from wastewater

Assessment of Indicators in a Human Liver Cell Line HL-7702 for Tetracycline Toxicity in Farm Soil

Tetracycline (TC) contamination has become hot research topic, but little attention has been paid to its ecotoxicological monitoring. The primary objective of this study is to investigate the impact of TC on human normal liver cells (HL-7702) and find indicators for monitoring their ecotoxicity. The cytotoxicity of TC, at concentrations ranging from 0 to 1000 &mu;g L&minus;1, was assessed on HL-7702 cells. The results showed that TC significantly inhibited the cell viability at a high concentration (1000 &mu;g L&minus;1). The TC at exposure levels &ge; 50&ndash;100 &mu;g L&minus;1 significantly increased the levels of extracellular catalase (CAT), malondialdehyde (MDA), alanine transaminase (ALT), and aspartate transaminase (AST), and a significantly positive correlation between the TC concentrations and the values of the above parameters was observed. Swelling of the mitochondrial cristae (MC) and rough endoplasmic reticulum (RER) and the loss of ribosomes in HL-7702 cells, were observed at high TC levels. There was a positive correlation between soil TC concentration and ALT activities. The above results suggest that TC is cytotoxic to HL-7702 cells and that extracellular ALT activities can be used as a sensitive bioindicator for monitoring soil TC contamination. We, therefore, propose that the HL-7702 cell line can be a novel tool for early antibiotics toxicity monitoring

Mehlich-3 Extractable Cd Contents (mg kg⁻¹) in Seven Chinese Soils at the onset of Containerized Experiment after Aging of 1 year.

<p>Mean values followed by different letters within the same column are significantly different at <i>P</i> <0.05.</p><p>Mehlich-3 Extractable Cd Contents (mg kg⁻¹) in Seven Chinese Soils at the onset of Containerized Experiment after Aging of 1 year.</p

Regression Correlation between Cd Contents in the Edible Shoots of Pak choi and Different Forms of Cd in Various Soils.

<p>Regression Correlation between Cd Contents in the Edible Shoots of Pak choi and Different Forms of Cd in Various Soils.</p

Stepwise Regression Model for Predicting Cd Concentration (Y) in Edible Part of Pak choi based on Soil Properties.

a<p>Cd_T and Zn_T refer to the total Cadmium and Zinc concentrations.</p>b<p>Superscripts * and ** indicate significant levels of probability at 0.05 and 0.01, respectively.</p><p>Stepwise Regression Model for Predicting Cd Concentration (Y) in Edible Part of Pak choi based on Soil Properties.</p