https://repository.hanyang.ac.kr/bitstream/20.500.11754/110830/1/Heavy%20metals%20in%20food%20crops%20Health%20risks%2c%20fate%2c%20mechanisms%2c%20and%20management.pdf

Heavy metals in food crops: Health risks, fate, mechanisms, and management

In recent years, nanocrystals of metal sulfide materials have attracted scientific research interest for renewable energy applications due to the abundant choice of materials with easily tunable electronic, optical, physical and chemical properties. Metal sulfides are semiconducting compounds where sulfur is an anion associated with a metal cation; and the metal ions may be in mono-, bi- or multi-form. The diverse range of available metal sulfide materials offers a unique platform to construct a large number of potential materials that demonstrate exotic chemical, physical and electronic phenomena and novel functional properties and applications. To fully exploit the potential of these fascinating materials, scalable methods for the preparation of low-cost metal sulfides, heterostructures, and hybrids of high quality must be developed. This comprehensive review indicates approaches for the controlled fabrication of metal sulfides and subsequently delivers an overview of recent progress in tuning the chemical, physical, optical and nano- and micro-structural properties of metal sulfide nanocrystals using a range of material fabrication methods. For hydrogen energy production, three major approaches are discussed in detail: electrocatalytic hydrogen generation, powder photocatalytic hydrogen generation and photoelectrochemical water splitting. A variety of strategies such as structural tuning, composition control, doping, hybrid structures, heterostructures, defect control, temperature effects and porosity effects on metal sulfide nanocrystals are discussed and how they are exploited to enhance performance and develop future energy materials. From this literature survey, energy conversion currently relies on a limited range of metal sulfides and their composites, and several metal sulfides are immature in terms of their dissolution, photocorrosion and long-term durability in electrolytes during water splitting. Future research directions for innovative metal sulfides should be closely allied to energy and environmental issues, along with their advanced characterization, and developing new classes of metal sulfide materials with well-defined fabrication methods.

Recent advances in metal sulfides: from controlled fabrication to electrocatalytic, photocatalytic and photoelectrochemical water splitting and beyond

The Bulletin of Environmental Contamination and Toxicology provides rapid publication of peer-reviewed articles describing significant advances and discoveries in the fields of air, soil, water, and food contamination and pollution as well as articles on methodology and other disciplines concerned with the introduction, presence and effects of toxicants in the total environment.  With its high standards of scientific quality and clarity, the Bulletin provides a meeting ground for research workers who daily encounter problems related to the contamination of our environment and who welcome opportunities to share in new discoveries as soon as they are made.

Bulletin of Environmental Contamination and Toxicology

Environmental contamination by hazardous environmental pollutants is a widespread and increasingly serious problem confronting society, scientists, and regulators worldwide (Debenest et al 2010; Hajeb et al 2011; Nanthi and Bolan 2012; Shahid et al 2013a) Among these pollutants, the heavy metals, are a loosely-defined group of elements that are similar in that they all exhibit metallic properties, and have atomic masses >20 (excluding the alkali metals) and specific gravities >5 (Rascio and Navari-Izzo 2011) This group mainly includes transition metals, some metalloids, and the lanthanides and actinides Heavy metals can be toxic to plants, animals and humans, even at very low concentrations Heavy metals are natural components of the earth’s crust and are present in different concentrations at different sites (Shahid et al 2012a)

Heavy-metal-induced reactive oxygen species: phytotoxicity and physicochemical changes in plants.

Colorimetric metal ion sensors – A comprehensive review of the years 2011–2016

The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron (Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated water is extensively used for irrigation for growing vegetables like tomato (Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd. More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify the most resistive variety on this particular type of contaminated site.

Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory

Hydrogeochemical investigations are carried out in the different blocks of Burdwan district, West Bengal, India in order to assess its suitability for drinking as well as irrigation water purpose. Altogether 49 representative groundwater samples are collected from bore wells and the water chemistry of various ions viz. Ca2+, Mg2+, Na+, K+, CO
 3
 2−
 , HCO
 3
 −
 , Cl−, SO
 4
 2−
 and NO
 3
 −
 are carried out. The chemical relationships in Piper and Gibbs diagram suggest that the groundwater mainly belongs to alkali type and Cl− group and are controlled by rock dominance. A comparison of groundwater quality in relation to drinking water quality standards proves that most of the water samples are suitable for drinking water purpose whereas groundwater in some areas of the district has high salinity and high sodium adsorption ratio (SAR), indicating unsuitability for irrigation water and needs adequate drainage.

Geochemistry of groundwater, Burdwan District, West Bengal, India

A pyrene-based simple fluorosensor has been synthesized by a one step process. It exhibited high selectivity towards Cu2+ ions via fluorescence enhancement of monomer and excimer emission. The origin of excimer formation was examined and established to be of static in nature from the study of absorption and excitation spectra. The observed monomer and excimer emission in the presence and absence of Cu2+ ion with varying pH was studied and provided probable justification. The effect of varying portions of water content in solvent on the sensor molecule was also examined. The sensor found its proper application in finding accurate and trace amount of Cu2+ ions present in drinking water samples from various sources. The detection limit of the current sensor was found to be 4 × 10−8 M.

A pyrene-based simple but highly selective fluorescence sensor for Cu2+ ions via a static excimer mechanism

Summary: The concentration of fluoride ion (F) in groundwater samples from different sites in Nalhati-1 block of the Birbhum district, West Bengal, was determined by SPADNS colorimetric analysis. Most of the F levels were within permissible limits, whereas a significantly higher concentration of 1.95 mg/L was found in artesian well samples of Nasipur village. The F in groundwater appears to be controlled by the distribution of Ca 2+ and to some extent SO4 2– , ionic strength, and the presence of complex ions. From correlation coefficient analysis, F was found to be inversely related to Ca 2+ and positively related to Na + . Basaltic rock and water interaction with it may be responsible for the increased F in the artesian well samples from the study area.

Fluoride geochemistry of groundwater in nalhati-1 block of the birbhum district, west bengal, india

This study investigated the seasonal variation of ambient air quality status of Burdwan town using GIS approach. Concentration of SOR2R (sulphur dioxide), NOR2R (nitrogen dioxide) and RSPM (respiratory suspended particulate matter) were measured once a week for 24 hour in both premonsoon and postmonsoon season. The seasonal average concentration of the RSPM, SOR2R and NOR2R in premonsoon season was observed to be 188.56 ± 88.63, 5.12 ± 6.27 and 92.51 ± 64.78 mg/mP3P respectively whereas in postmonsoon it was 53.03 ± 38.27, 8.51 ± 7.11 and 162.85 ± 184.80 mg/mP3P respectively. Statistical analysis showed the significant monsoonal effect on mean difference of RSPM, SOR2R and NOR2R concentration. Postmonsoon concentration of ambient SOR2R and NOR2R were observed to be higher than premonsoon, suggesting longer residence times of these pollutants in the atmosphere due to stagnant conditions and low mixing height. Spatial distribution of pollutants throughout the town in both the season was represented by digital elevation model (DEM). On the basis of Air Quality Index (AQI) a GIS based air pollution surface models were generated in both the seasons by means of Inverse Distance Interpolation (IDINT) technique. From the output surface model it was found that in comparison to premonsoon there was a significant increase of clean and fairly clean area and decrease of moderately polluted area of the town during postmonsoon.

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Rajnarayan Saha

Papers

Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory

Geochemistry of groundwater, Burdwan District, West Bengal, India

A pyrene-based simple but highly selective fluorescence sensor for Cu2+ ions via a static excimer mechanism

Fluoride geochemistry of groundwater in nalhati-1 block of the birbhum district, west bengal, india

Spatial and Temporal Variation of Urban Air Quality: A GIS Approach