Heavy Metal Residues Research Articles

Descriptive analysis of changes in Ghana's food availability and food safety information between 2010 and 2020

Access to safe, nutritious, and sufficient food is essential to ensure food and nutrition security and healthy lives for all. Secure access to nutritious food ensures healthy eating habits, economic growth, and stability in an economy. However, food insecurity and malnutrition persist globally. In Ghana, more than half of food-insecure people reside in the Northern ecological zones of the country. Moreover, Ghana lacks a systematic food security monitoring system to track food insecurity among vulnerable populations. This study reviewed existing evidence on the current situation and changes related to food production, trade, safety, and consumption in Ghana, as part of the process to develop food-based dietary guidelines for the country. The literature review included peer-reviewed articles published from 2010 – 2020 in Ghana to document household-level food production, consumption, and safety issues. In addition, food disappearance data (from 2010 to 2018) from the Food and Agriculture Organization of the United Nations was analysed. Means and compound annual growth rates were calculated for each food item included. The results showed that per capita food production was higher than per capita consumption in all the food categories studied, except for vegetables, and fish and fishery products. Food consumption was centred on a few priority staple crops such as cassava, maize, rice, and yams, with less consideration given to underutilised foods such as akokono (palm weevil larvae). Food imports exceeded food exports in all food categories except 1) cocoa beans and products, 2) root crops and tubers, 3) oil-bearing crops and nuts, and 4) fruits and products. Fruit and vegetable consumption in Ghana has been declining since 2013. There was also a rise in the import and consumption of processed foods, especially tomato paste, sugars, and alcoholic and non-alcoholic beverages. Food safety issues included microbial contamination, aflatoxin contamination, polycyclic aromatic hydrocarbons in smoked fish, mercury in fish, pesticide and heavy metal residues in vegetables and fruits, and food adulteration. The evidence synthesized from this study will be useful to inform the development of food-based dietary guidelines for Ghana. Key words: Food, production, trade, consumption, food security, safety, Ghana

REMOVAL OF HEAVY METALS AND AGROCHEMICALS RESIDUES THROUGH PLANTS

The present paper presents about removal of heavy metals, agrochemicals residues through natural plants. The removal of heavy metals residues and agrochemical residues with the interception of natural plants is called phytoremediation. The advancement of applied research produced various phytoremediation plants like weed plant, aquatic plant, tree and crops. The natural plant eradicates heavy metals and agrochemicals residues through phytostabilization, rhizodegradation, rhizofilteration, phytodegradation and phytovoltalization process. The terrestrial and aquatic plant eradicates heavy metals and agrochemicals residues from soil and water. Indian mustard removes 3 fold Cd, Pb, Se and Cs radioactive metals and diesel fuel spillage. Oryza sativa L. is cereal crop, removes Cu, Cd, from contaminated soil. Spinacia oleracea (Spinach) is vegetable crop, removes Cd, Cu, Fe, Ni, Pb, Zn and Cr from contaminated soil. Cicer arientinum is pulse crop, eradicates Pb and Cr from the contaminated soil. Pea is vegetable crop plant, removes Cd from the contaminated soil. Brassica napus L. oilseed crop, removes Cd, Cu, Zn, Pb from the contaminated soil. Cajanus cajan L. is pulse crop, removes As, Cd from the contaminated soil. Cucumis sativus L. is vegetable crop, removes Pb from the contaminated water. Annual grass and broad leaf weed removes atrazine, simazine, propazine, prometryn from the soil. Chenopodium album L., Hordeum juhatum L., Panicum capillare L., Nepeta cataria L., Caedus nutans L., Poa annua an Fostuca sp. removes atrazine, phosphorus, nitrate, ammonium. The phytoremediation plant recovers natural resources and restricts outbreak of diseases in the nature. Further, the scientific studies and research may build products of phytoremediation controlled plants for removing heavy metal and agrochemicals residue from the soil.

Extent of cadmium stress on plant growth promoting microorganisms at the rhizosphere layers of S. stenocarpa and V. unguiculata accessions

The importance of role microbes in nodulation of leguminous crops helps in the nutritional diet of the Nigerian populace. However, heavy metal residues from heavy fertilization is a major cause of concern to soil and crop production. The study aimed to isolate and characterize free living microbe (bacteria and fungi) from the soil polluted with cadmium at different ecological screening value (0ESV, 2.5ESV and 5ESV) cultivated with Sphenostylis stenocarpa and Vigna unguiculata compared with similar soil but without the plants. The microbial count was estimated using the Most Probable Number (MPN) method. Compared to the control, a decrease of rhizobia number and an increase of the metal concentration were observed. From the results, cadmium toxicity had little to no effect on the bacteria diversity of the bulk soil has the increased bacterial and fungi diversity was recorded in the 2.5 ESV and 5 ESV respectively. The rhizosphere layer of Tss93 in the Cd-2.5 ESV had a significantly increased microbial diversity compared to the other accessions with the lowest total heterotrophic bacteria count recorded in Tss92 irrespective of metal concentration. Cd toxicity resulted in an insignificant difference (p>0.05) in total heterotrophic fungi count irrespective of plant accession or metal concentration, however, the fungi diversity was heightened in the Tss93 (2.5 ESV) and Tss95 (2.5 ESV) respectively. Cd toxicity increased the rhizosphere THB and THF counts of V. unguiculata with the highest microbial diversity recorded in TVu91 and TVu95 sown in the Cd-2.5ESV and Cd-5ESV respectively. The presence of heavy metal degradable bacteria – Pseudomonas aeruginosa and Bacillus subtilis and fungi – Aspergillus niger and penicillum sp. indicates bioremediation capacities of both accessions. This suggest that the survival microbes in polluted soil reveal adaptation of some traits especially those involved in symbiosis. Though cadmium had a significant effect on the soil productive capabilities, the THBC and THFC of Tss91 and Tss95 (S. stenocarpa) and TVu93 and TVu94 (V.unguiculata) were significantly increased as the presence of plant growth promoting bacteria and fungi were reported.

Assessment of heavy metals in feed and beef in Bangladesh: A safety issues

The study was aimed to assess the heavy metal status in feed and beef produced in Bangladesh. In the study, the quantitative presence/absence of heavy metals in livestock feed ingredients, beef feed and their residues in beef of four district of Bangladesh were investigated.Feeds and meats were analyzed by Atomic Absorption Spectrophotometer (AAS) for heavy metals such as lead (Pb), Chromium (Cr), Cadmium (Cd), Zinc (Zn) and Copper (Cu). Concentration of Zn, Cu, Cr, and Pb in feed ingredients ranged from 0.124 to 1.209 mg/kg, 0 to 0.215 mg/kg, 0.095 to 0.286 mg/kg and 0.164 to 0.301 mg/kg, respectively. In all feed ingredients mean concentration of Zn was higher than other heavy metals. Concentration of Zn, Cu, Cr, and Pb in commercial beef cattlefeed ranged from 0.313 to 1.261 mg/kg, 0.004 to 0.140 mg/kg, 0.223 to 0.459 mg/kg and 0.218 to 0.361 mg/kg, respectively.Pb concentrations were 0.084 ± 0.046, 0.364 ± 0.202, 0.263 ± 0.056, 0.278 ± 0.089, 0.094 ± 0.0466 mg/hg in heart, kidney, liver, lungand muscle, respectively. Cd concentrations were 0.003 ± 0.001, 2.339 ± 0.712, 0.299 ± 0.221, 0.024 ± 0.005, 0.014 ± 0.009 mg/hg in heart, kidney, liver, lung and muscle, respectively. Cr concentrations were 0.555 ± 0.451, 0.164 ± 0.039, 0.199 ± 0.091, 0.512 ± 0.018, 0.232 ± 0.023 mg/hg in heart, kidney, liver, lung and muscle, respectively. Zn concentrations were 6.059 ± 3.362, 9.984 ± 1.358, 14.776 ± 0.816, 1.567 ± 2.625, 15.883 ± 0.438 mg/hg in heart, kidney, liver, lung and muscle, respectively. Cu concentrations were 6.059 ± 3.362, 9.984 ± 1.358, 14.776 ± 0.816, 11.567 ± 2.625, 15.883 ± 0.438 mg/hg in heart, kidney, liver, lung and muscle, respectively which was higher in different organs of beef cattle. The results indicate that the heavy metal residues in feed and feed ingredients were below the maximum residue level (MRL) values, whereas Cu in different organs was slightly higher. Heavy metal residues in feed were in lower concentrations except cadmium, yet below the maximum residue level (MRL). Contaminants existed at different levels in cattle feed and beef of Bangladesh.

Adsorption behaviors and reduction strategies of heavy metals in struvite recovered from swine wastewater

Heavy metals in the swine wastewater not only influence phosphorus (P) recovery through struvite but also incorporate with struvite, posing a potential threat to its safe application. We investigated the incorporation of copper (Cu) and zinc (Zn) with struvite in response to several factors (pH, HCO3–, initial metals concentration, and Cu/Zn ratio) by batch experiments and Response Surface Methodology, and to clarify their possible adsorption mechanisms using Minteq and X-ray photoelectron spectroscopy analysis. The results proposed that higher pH and HCO3– in the wastewater both promoted struvite formation and greatly inhibited the adsorption of such heavy metals on the struvite. The performance of Cu and Zn varied under various conditions, meaning their different adsorption mechanisms. Compared with Cu, Zn is more prone to adsorb onto struvite due to the lower stability of Zn(NH3)x2+ and the supersaturation ratio (Sa) of Zn-containing precipitation is greater than that of struvite. The removal of Cu was more susceptible to the interaction of pH with other variables, while that of Zn more determined by the interaction of HCO3– concentration with other factors. ANN provides a range of parameter sets for different requirements of metal adsorption rate, thus maximizing P recovery and suppressing heavy metal residues on struvite based on the Artificial Neural Network. The driving forces for heavy metal-struvite interactions include surface adsorption, complexation, precipitation, immensely associated with the initial metal concentration, wastewater properties, and running parameters. The results will provide theoretical progress and complete parameter sets for recovering struvite from actual wastewater.

Investigation of the nutritional environment of the differences in toxicity levels of some heavy metals and pesticides examined in gilthead bream fishes

In this study, we investigated the differences between the gilthead bream fishes that live in cages and feed by fish feed (CF), had escaped from the cages and started to live in their natural medium (EF), and live in their natural medium and do not feed by fish feed (NF). We would like to demonstrate the micro pollutants and heavy metal residues in CF, EF and NF and reveal out the diversity in living in three different ambient conditions. We analyzed Mn, Cr, Zn, Sn, Ag, Hg, Cd, Cu, Ni and Pb residues and p-p’-DDE, α-BHC, endosulfan-sulfate, endrin, heptachlor, heptachlor epoxide, methoxychlor, p-p’-DDD, p-p’-DDT, β-BHC, aldrin, cypermethrin, dieldrin ve endosulfan pesticides in three types of gilthead bream (CF, EF and NF) and also researched the heavy metal residues in the marine sample that provided from Guvercinlik Cove in three different time intervals by gas chromatography-mass spectroscopy (GC-MS) and Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Physical and chemical parameters of sea water samples were studied to reveal out the effect of fish feed between the regions. Heavy metal and organochlorine pesticides residues of gilthead bream muscle tissues from CF are remarkable higher than other regions when we evaluate the all results. The results show an indication of the significant health risks associated with the consumption of these contaminated fish in the cages. The morphology of gilthead bream fish liver tissue samples were studied by using scanning electron microscopy (SEM).

Analysis method development and health risk assessment of pesticide and heavy metal residues in Dendrobium Candidum.

Herbal medicines that are widely used worldwide are easily contaminated by pesticides and heavy metals, threatening human health. In this study, a modified QuEChERS pre-treatment method combined with HPLC/GC-MS/MS was established for the determination of 24 pesticide residues in Dendrobium candidum. The average recoveries of 24 pesticides in D. candidum were 76.9–110.0% with the relative standard deviation (RSD) of 0.28–11.40%, and their limits of detection (LOD) and limits of quantitation (LOQ) were 0.005–10 and 0.011–22 μg kg−1, respectively. The results showed that 83.33% of all samples had detected pesticide residues with the concentrations of 0.06–312.83 μg kg−1. Meanwhile, microwave digestion combined with ICP-MS was used to detect the residues of 8 heavy metals in D. candidum. The average recoveries of 8 heavy metals were 82.7–108.1% with an RSD of 1.4–8.0%, and their LOD and LOQ were 0.0001–0.05 mg kg−1 and 0.0003–0.2 mg kg−1, respectively. The results indicated that 8 heavy metals were all detected in all samples, and the highest concentration of Zn was 11.97 mg kg−1. Furthermore, the health risk assessment showed that the risk of the detected pesticides and heavy metals in samples to humans, specifically to the general population including adults and children, was acceptable.

Assessment of Heavy Metal Residues in Fish as a Biomarker of Pollution in Suez Province

Assessment of Heavy Metal Residues in Fish as a Biomarker of Pollution in Suez Province

Label-free biosensing of mercury(II) in milk using an aptamer-gated graphene field-effect transistor

• A specific Hg(II) biosensor based on aptamer-modified SGGT is developed. • The sensitivity and selectivity were improved by aptamer and BSA modification. • The biosensor had a high recovery rate for Hg(II) evaluation in real milk samples. Due to the environmental pollution by the growing urban, agricultural and industrial disposals, dairy products are susceptible to heavy metal pollution in the production process. As one of the most toxic heavy metals, mercury cause serious damage to the environment and even public health. Effective monitoring of Hg(II) in large number of diary samples requires the development of rapid assaying methods. In this research work, we report the preparation of a label-free biosensor for Hg(II) using an aptamer-gated graphene field-effect transistor (Apt-SGGT) with the gate electrode modified by a structure-switching aptamer against Hg(II) and blocked with bovine serum albumin. The aptamer immobilized on the gate electrode acts as both a receptor and a reporter for Hg(II) by specifically recognizing Hg(II) through stable T-Hg 2+ -T coordination complex, triggering the folding of the single-stranded aptamer into a duplex structure. The conformational change results in the redistribution of the surface charge on the gate electrode, and produces a large channel current response by the inherent field-effect amplification. This sensing mechanism can effectively enhance the selectivity of the SGGT-based biosensor to mercury ions by significantly reducing the unspecific responses of other interfering cations. The detection limit of Hg(II) by Apt-SGGT sensor was as low as 5 nM, and the linear detection range was from 5 to 200 nM. The sensor can realize the detection of mercury ion residues in milk with a high recovery rate, and has a good application prospect in the detection and analysis of heavy metal residues in complex systems.

Comparative Study on Absorption of Heavy Metal Residues in Broiler Chicken Available in the University Campus Peshawar, Pakistan

Comparative Study on Absorption of Heavy Metal Residues in Broiler Chicken Available in the University Campus Peshawar, Pakistan

Assessment of heavy metal residue, physicochemical properties, and sensory properties of CaC2 treated banana

This study assessed the food safety risks associated with bananas ripened by CaC2. For ripening, calcium carbide concentrations were used per kilogram bananas (1% and 2%of calcium carbide solution; 5 gm, and 10 gm of calcium carbide powder) and compared results of artificially ripened fruits with control samples. Heavy metals like arsenic, phosphorous and calcium content at market banana were found higher than other treated samples. Total sugar, reducing sugar, TSS, pH, titrable acidity, vitamin C, and carotenoid were lower at market sample than other samples. Moisture content increased while total sugar, reducing sugar, TSS, pH, titrable acidity, vitamin C and carotenoid decreased with increasing CaC2 concentration. Other than titrable acidity, pH, total sugar and TSS were negatively correlated with the heavy metals. Sensory properties decreased with increasing CaC2 concentration. In conclusion, the market sample contained more health risk compared to the calcium carbide ripened banana assessed in this study.

Rapid screening and quantification of heavy metals in traditional Chinese herbal medicines using monochromatic excitation energy dispersive X-ray fluorescence spectrometry.

Traditional Chinese herbal medicines are subject to heavy metal contamination. Standard detection methods are too complicated, time-consuming, and expensive for routine analysis, so low-cost methods are in high demand for rapid on-site screening. This study reports a high-sensitivity X-ray fluorescence (HS-XRF) method to determine As, Pb, and Cd residues simultaneously in herbal medicines. It couples monochromatic excitation energy dispersive X-ray fluorescence spectrometry and the fast fundamental parameters method. Each test takes only 10-30 min and costs 1/10th to 1/5th of the standard method. The detection limits, precision and accuracy were evaluated using different approaches, and application notes in practice are also proposed. This study is the first attempt to establish and evaluate HS-XRF in analyzing multiple heavy metals in herbal medicines. This rapid screening method would promote the testing efficiency and thus improve the monitoring of heavy metal contamination in herbal medicines.

Comparative analysis of different chemical and biological adsorbents for the reduction of arsenic and mercury from vegetable species in the Sanganer, Jaipur

Heavy metals (HMs) pollution has become a universal menace to the ecosystem and environment due to a variety of natural and human-induced actions. Vegetables are accounted as nature reserves for nutrients hence they are a vital element of human food. The toxicity of heavy metals to many types of ailments on their ingestion through food is one of the most toxic food pollutants. Irrigation with contaminated water, industrial pollutants, and overuse of metal-containing pesticides, etc. contribute to the contamination of vegetables. Current research work was executed to alleviate the residue of HMs (As and Hg) in Spinach and Reddish collected from agricultural fields near Sanganer industrial area through chemical and biological adsorbent treatments. Physicochemical characteristics of irrigating water samples and field soils were identified. The extent of HMs in soil, water, and vegetable samples was calculated with the help of an Atomic Absorption Spectrophotometer (AAS). The data was statistically examined to find the most effective adsorbent treatment for heavy metal mitigation. The incessant use of contaminated water for irrigation may create the progressive deposition of HMs in the soil, which may eventually lead to increased heavy metal uptake by growing vegetable crops. Adsorbent treated vegetable samples showed a significant reduction in loads of HMs as compared to untreated samples. Amid various chemical adsorbents, 15% sodium carbonate proved maximum reduction potential and among various biological adsorbents, 15% orange peel extract proved maximum reduction potential for amputation of HMs from vegetable samples. On the whole, consumption of vegetables could be safer when treated with these adsorbent solutions as they are intelligible and can mitigate heavy metal residues from vegetables.

Monitoring of Toxic Heavy Metal Residues in Infant Dried Dairy Products

Milk and dairy products are a unique and essential for growth and healthy development not only for the young but also for all ages, the present work was performed to determine some toxic heavy metals in some dried dairy products sold in Alexandria City. A total of 120 samples representative as 60 milk powder,30 infant foods and 30 dried ice cream mix were collected from groceries and supermarkets and analysed for toxic heavy metal residues including (Pb, Cd, Al and Sn) by using atomic absorption flame emission spectrophotometer. The obtained results revealed that the mean(SD) level of Lead in the examined of milk powder, infant food and dried ice cream mix samples were of 0.185 ± 0.138, 0.134 ± 0.033 and 0.159 ± 0.185 ppm, the samples exceeded the permissible stated by Egyptian standards (0.02ppm) were 18(30%), 8(26.66%), and 13(43.33%), respectively. While, Cadmium residues was detected in 13 (21.66%), 7 (23.33%) and 11 (36.66%), the samples exceeded the Egyptian standards permissible limit (0.05 ppm) were 7 (11.66%), 3 (10%) and 6 (20%), respectively. Aluminium was detected in 10 (16.66%), 5 (16.66 %) and 7 (23.33 %) of examined milk powder, infant food and dried ice cream mix, only 3(5%) of examined milk powder samples were exceeded the permissible limit (0.5 ppm). Tin was detected in 13(21.66%), 9 (30 %) and 10 (33.33 %) of examined milk powder, infant food and dried ice cream mix, respectively. All positive samples were within the Egyptian standards permissible limit (200 ppm). Suggestive measures were discussed to prevent or minimize the levels of toxic heavy metals in dried dairy products.

Evaluation of Heavy Metal Residues in Poultry Farms in Ismailia Province

Evaluation of Heavy Metal Residues in Poultry Farms in Ismailia Province

Nutritional Quality - Residues of Pesticides and Heavy Metals (Hg, Cd, Pb, As) in the Flesh of Shrimps of the Genus <i>Macrobrachium</i> Fished in Fresh and Brackish Water of Côte D'Ivoire

Nutritional Quality - Residues of Pesticides and Heavy Metals (Hg, Cd, Pb, As) in the Flesh of Shrimps of the Genus <i>Macrobrachium</i> Fished in Fresh and Brackish Water of Côte D'Ivoire

Quantification of Heavy Metals and Pesticide Residues in Widely Consumed Nigerian Food Crops Using Atomic Absorption Spectroscopy (AAS) and Gas Chromatography (GC).

More still needs to be learned regards the relative contamination of heavy metals and pesticide residues, particularly those found in widely consumed Nigerian food crops like cereals, vegetables, and tubers. In this current study, the heavy metals and pesticide residues detectable in widely consumed Nigerian food crops were respectively quantified using atomic absorption spectroscopy (AAS) and gas chromatography (GC). Specifically, the widely consumed Nigerian food crops included cereals (rice, millet, and maize), legume (soybean), tubers (yam and cassava), as well as leaf (fluted pumpkin, Amaranthus leaf, waterleaf, and scent leaf) and fruit vegetables (okro, cucumber, carrot, and watermelon). Results showed that the detected heavy metals included arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), and nickel (Ni), whereas the pesticide residues included Aldrin, Carbofuran, g-chlordane, Chlorpyrifos, DichloroBiphenyl, Dichlorodiphenyldichloroethane (DDD), Dichlorodiphenyltrichloroethane (DDT), Dichlorvos, Endosulfan, Heptachlor, Hexachlorobenzene (HCB), Isopropylamine, Lindane, t-nonachlor, and Profenofos. Across the studied food crops, the concentrations of heavy metals and pesticides were varied, with different trends as they largely fell below the established maximum permissible limits, and with some exceptions. Our findings suggest there could be a somewhat gradual decline in the concentration of the heavy metals and pesticide residues of these studied food crops when compared to previously published reports specific to Nigeria. To help substantiate this observation and supplement existing information, further investigations are required into the concentration of these heavy metals and pesticide residues specific to these studied food crops at other parts of the country.

Concentrations and Related Health Risk Assessment of Pesticides, Phthalates, and Heavy Metals in Strawberries from Shanghai, China

In the present study, a risk assessment of pesticides, phthalates, and heavy metals in strawberries (n = 335) in recent years was conducted by determining the estimated daily intake, target hazard quotient, and hazard index. The study used 128 pesticides, 18 phthalates, and three heavy metals in this determination. It detected 51 pesticide residues in the strawberry samples, and 97.91% samples had levels of at least 1 of the 51 pesticides above the limit of detection. In addition, 2.39% of samples had pesticides higher than the Chinese maximum residue limit. Multiple pesticide residues were detected in most samples. Bis-2-ethylhexyl phthalate, diisobutyl phthalate, and dibutyl phthalate were detected in the strawberry samples, with a high frequency of detection. Their detectable rates were 100, 100, and 89.9%, respectively. In most samples, lead, cadmium, and nickel were detected, with detectable rates 75.76, 92.93, and 92.93%, respectively. The estimated daily intake of analyzed pesticide, phthalate, and heavy metal residues appears to be relatively low compared with the acceptable daily intake. The average target hazard quotients and hazard indices were less than 1. That means that customers who are exposed to the average contaminant levels may not pose a significant health risk. Our results show that the strawberries may be polluted by many kinds of contaminants. Therefore, monitoring of pesticide, phthalate, and heavy metal residues in strawberries should be increasingly developed to fully protect the health of the consumer.

Development of dispersion layers for dental drills with reduced nickel release

ObjectivesWithout rotating instruments, for example diamond-coated drills with a core made of stainless steel, the dental routine would be unimaginable, since these are used in almost every dental activity and are thus indispensable for the professional practice. Unfortunately, such drills release Nickel particles to a high content into the cooling water of the drill. Values up to 1.3 mg/l Nickel were found by ICP – OES in the cooling water of the drillers which is of course also transferred into the patient's oral cavity with possible severe negative effects. Therefore, novel plating procedures have to be developed to increase the patients (and dentists) safety during treatment. MethodsDispersion layers with the hard metal Tungsten carbide (WC) particles on stainless steel blanks were deposited following two synthesis routines (i) Plasma-Electrolytic Oxidation (PEO) and (ii) galvanic plating out of a Watts bath. Both were accomplished using water-based electrolytes. ResultsIn order to verify the dental applicability of the developed coatings, tests-drills were accomplished under defined conditions on plastic teeth for the sake of reproducibility.Commercially produced drills were compared with the newly plated ones by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and the drilling cooling water was examined for heavy metal residues using Inductively Coupled Plasma (ICP) analytics. The resulting grinding patterns in the plastic teeth were investigated by light microscopy and SEM.It could be shown that dispersion layers plated by a galvanic procedure showed a reduced Nickel release compared to a commercial driller by factor 7.6 and 13.4 compared to PEO plated ones during dental treatments. ConclusionsFollowing the clinical significance the Watts bath plated drillers showed a better WC particle distribution on the surface and better abrasive properties during the drilling experiments compared to PEO plated drillers. In addition the Nickel release during dental use is much less from the galvanic treated ones. By optimising the plating condition from the Watts dispersion bath further novel drilling devices with significantly reduced release of Nickel particles can be developed for the benefit of the patients.

Spatio-temporal analysis of water quality for pesticides and other agricultural pollutants in Deduru Oya river basin of Sri Lanka

The desire to increase agricultural productivity through the high usage of agrochemicals is causing substantial environmental deterioration. Many developing countries lack the capacity to quantify agro-pollution, especially in the case of chemical inputs such as pesticides, preventing them from formulating action plans to mitigate the negative environmental impacts of agro-chemicals. This study aims to address the knowledge gap in Sri Lanka by assessing water quality at a temporal and geospatial scale, focusing on areas with significant agricultural inputs in the Deduru Oya river basin of Sri Lanka. To assess water quality, 183 samples were collected biweekly in the 2019 dry season (Yala) and 2019/2020 wet season (Maha) and analyzed for 39 parameters, including pesticides, heavy metals, minerals and physico-chemical properties. Of the twenty pesticides tested, ten were detected in the water samples (pretilachlor, oxyfluorfen, thiamethoxam, chlorantraniliprole, fenobucarb, fipronil, diazinon, etofenprox, tebuconazole, and captan) and concentrations of all detected pesticides exceeded national regulatory threshold limits. Heavy metal residues were not detected in the water. Pesticide and mineral levels varied widely and exhibited lack of evenness across seasons and locations. Pesticide contamination was higher in the wet season than the dry season. Temporal variation was more pronounced than spatial variation for many of contaminants. No clear trend in contaminant accumulation was observed as sampling progressed downstream from the main reservoir. In both seasons, natural or inorganic fertilizer mineralization and pesticide inputs into the agricultural systems were identified as the main factors underlying water pollution in the study area.