Heavy Metal Residues Research Articles

Immobilization of phototroph-derived extracellular polymer for simultaneous removal of antibiotics and heavy metals: A sustainable approach for advanced treatment of secondary effluent

Antibiotic and heavy metal residues in secondary effluent are mainly responsible for the spread of antibiotic-heavy metal resistance genes and cannot be efficiently removed by traditional wastewater treatment processes. A sustainable approach by using alginate immobilized phototroph-derived extracellular polymer (EPS) for simultaneous inducing photolysis of antibiotic (sulfadiazine, SDZ) and adsorptive removal of heavy metal (Cd2+) from simulated secondary effluent was firstly explored. The results showed that immobilization of Rhodopseudomonas palustris-derived EPS (R-EPS-Alginate) led to the fastest SDZ photolysis due to its highest amounts of proteins (3.76 mg/g). With the optimum R-EPS-Alginate dosage of 6 g/L, 60 mg/L of immobilized EPS concentration and pH of 5.6, 86% of the SDZ was degraded within 96 h. 1O2 generated from 3EPS* was mainly responsible for the SDZ photodegradation which was decomposed into less toxic substances. 61% of Cd2+ was immediately adsorbed by R-EPS-Alginate within 60 min with a maximum adsorption capacity of 88.1 mg/g. Cd2+ adsorption moderately enhanced SDZ photolysis, probably due to the generation of CdS, while the latter almostly does not adversely impact the former.

Assessment of Heavy Metal Residues in Soil and Vegetables along Urban-peri-urban gradient of Lagos State Nigeria

Several studies have been carried out on leafy vegetables but many did not assess the heavy metals in soil and leafy vegetables along urban-peri-urban gradient of Lagos State. The study assessed the concentration of heavy metals in the soil and leaves of three commonly consumed vegetables (Amaranthus hybridus, Celosia argentea and Corchorus olitorius) in Lagos State. Sampling was conducted in 2019 and 2020. Fe, Pb, Cu and Cd residues in the soil and the leafy vegetables samples were digested and determined using Atomic Absorption Spectrophotometer. The collected data were analyzed using simple descriptive statistics and Analysis of Variance. The range of values of the mean concentrations of the heavy metals in soil showed that Fe =20.76±0.20mg/kg – 107.83±17.02mg/kg, Pb = 0.13±0.07mg/kg –2.47± 0.45mg /kg, Cd=0.08 ± 0.02mg/kg – 6.07 ± 2.90mg/kg and Cu = 0.24±0.11mg/kg–40.20±4.90mg/kg. The range of values of the mean concentrations of the heavy metals in the leafy vegetables showed that Fe = 113.10±14.05mg/kg – 1.51±0.02mg/kg, Pb=0.51±0.09mg/kg - 0.001±0.001 mg/kg, Cd=0.51±0.01mg/kg-0.001±0.01amg/ kg, Cu=7.54±0.97 mg/kg - 0.36±0.03mg/kg. The Level of heavy metals residues in soil and the three leafy vegetables were at safe levels set by WHO/FAO except for Pb and Cd found in vegetables in Ketu and Yaba study locations.

Portable AIE hydrogel sensor for rapid and visual field detection of heavy metal residue in food

Mercury contamination causes a wide range of symptoms in organisms, and affects human brain, kidneys and nervous system in particular. Most food sources high in mercury come from saltwater species like fish and other sea animals. Recently, fluorescent biofilm, electrostatic spinning film, and hydrogel were used for the potable detection of mercury. However, the photostability of the fluorescent probe in the film and the challenge of solid food sample analysis are the main issues to be addressed. In this work, sodium alginate hydrogel (SA) was used for developing a hydrogel sensor in combination with the phenanthroline modified-tetraphenylethylene (TPE) derivatives (DTPEP). Based on its aggregation-induced emission (AIE) characteristic and high specificity to mercury, the AIE hydrogel mercury sensor was coated on different carriers, such as gloves, sticky notes, etc., as flexible sensors for portable and rapid field testing of mercury contamination. The visualization results were analyzed using the greyscale-based Android software “Detect” to Quantification of Hg2+. The detection limit could be as low as 0.06 μM with the detection time within 15 min. The gray value was linearly related to the concentration of Hg2+, ranging from (0–2 μM). The flexible Visual and rapid sensing systems have not only great potential applications in the detection of mercury in food samples but are also suitable for the detection of environmental and food contaminants.

Heavy Metal Residues in Some Marketed Fish with a Trial of Decontamination using Lactobacillus rhamnosus

Heavy Metal Residues in Some Marketed Fish with a Trial of Decontamination using Lactobacillus rhamnosus

Assessment of Heavy Metal Residues in Hides of animals Singed with Tyres, and Public Health Implications Associated with such Practice in Lokoja Metropolis

The safety of food has been an issue of concern in developing countries like Nigeria where the processing method can pose some environmental health challenge. The use of scrap automobile tires to singe meat has been reported to possess some toxic materials that can pose health challenge to humans. Hence, this study was conducted to determine the concentration of heavy metals in meat singed with fire wood and scrap tires in Lokoja, Nigeria. Samples of cattle hides singed with firewood and scrap tires were collected from four (4) different abattoirs and analyzed for the concentration of Cu, Pb, Fe and Zn using Atomic Absorption Spectrophotometry. There was significant increase in the concentration of Cu, Zn and Pb of the cattle hides singed with firewood and scrap tires when compared to the unsinged. The concentration of heavy metals for firewood singed cattle hide is within recommended Maximum Permissible Levels (MPLs) of the European Commission Regulations while the concentration of scrap tires is above the recommended Maximum Permissible Levels (MPLs) of the European Commission Regulations for Cu, Zn and Fe. Though there was increase in the concentration of Fe it is within the recommended Maximum Permissible Levels. The presence of heavy metals concentration above the permissible levels in cattle hides singed with scrap tires makes it unsafe for human consumption hence safer method should be adopted by the abattoirs.

The Occurrence of Arsenic, Cadmium, and Lead Residues in Cattle Feed Collected in Kırıkkale, Türkiye: A Preliminary Study

The aim of this study is to investigate the occurrence of arsenic (As), cadmium (Cd), and lead (Pb) residues in 15 cattle feed collected from dairy and beef cattle breeding farms located in 6 different districts (Kırıkkale Province, Yahşihan, Karakeçili, Balışeyh, Delice and Keskin) of Kırıkkale. The quantitative analysis of the As, Cd and Pb levels of the samples was analyzed by ICP-MS. Arsenic and Pb residues were found in all of the collected samples, while Cd residues were found in 13 (86. 67%) of the collected samples. In the samples with heavy metal residues; the mean value ± standard deviation for As, Cd, and Pb were found as 0.1475±0.1060 mg/kg, 0.0382±0.0079 mg/kg and 0.1944±0.1074 mg/kg respectively. The maximum tolerable limit in cattle feed is 2 mg/kg for As, 5 mg/kg for Pb, and for Cd in cattle feed is 1 mg/kg for Cd according to an official announcement (2014/11) of the Ministry of Agriculture and Forestry Turkey. The results of this study showed that detected As, Cd and Pb levels in cattle feeds were below the tolerable limit. Therefore, it is suggested that the heavy metal pollution in terms of As, Cd, and Pb in feed does not pose a risk for cattle farming in Kırıkkale province.

Impact of processing pre-treatments on color and the level of heavy metal reduction of the green alga Ulva sp.: A preliminary study

Ulva sp. is an abundant green alga in Gunungkidul waters, Indonesia, considered a source of nourishing food, sought after by food industries. This green alga could be served as a dish, a seasoning, or an ingredient; hence, the assessment of its safety is important. The present study was conducted to reduce heavy metal residues in Ulva sp. collected from Sepanjang beach, Gunungkidul, Indonesia by using two different processing treatments, i.e., washing with citric acid and blanching at various times and seaweed-to-solution ratios. The number of heavy metal residues (As, Cd, Pb, and Hg) was determined by Inductive Coupled Plasma Mass Spectrometry (ICP-MS) and visual green color loss was measured by a color spectrophotometer. The result showed that the concentration of As and Cd in the unprocessed sample was higher than SNI 2690:2015 specification for raw seaweed as well as the National Food and Drug Agency of the Government of Indonesia (BPOM Indonesia) permissible limits in food. Washing Ulva sp. with citric acid 0.5% for 10 min in a seaweed-to-solution ratio of 1:20 could reduce the level of as up to 42.53%, whereas washing Ulva sp. with citric acid 0.5% for 15 min in a seaweed-to-solution of 1:10 could reduce the level of Cd up to 96.12%. All processing treatments affected the appearance of Ulva sp. which is indicated by the increase in color differences (ΔE) > 2.

Quantification and Reduction in Heavy Metal Residues in Some Fruits and Vegetables: A Case Study Galați County, Romania

One of the main issues for sustainable global development with high priority is food security. The negative effects of contaminants on crop quality have threatened both food security and human health. Long-term heavy metal exposure from food, drinking water, or other occupational sources causes serious problems, such as kidney failure, hepatotoxicity, and neurotoxicity. This study was conducted to determine the concentrations of three toxic trace elements (As, Cd, Pb) and one microelement (Zn) in fruits and vegetables using ICP-MS, and it also sought to reduce the concentrations of metals by washing with vinegar (5% and 10% acetic acid). The potential of vinegar to influence heavy metal contents may be due to its effect on pH values that influence the solution chemistry of the heavy metals, such as hydrolysis, redox reactions, precipitation, and availability of heavy metals. Sample origin has a significant influence in terms of metal accumulation; values up to 35%, 68%, 67%, and 3% lower were recorded in the case samples originating from amateur farmers (for As, Cd, Pb, and Zn, respectively). Regarding the efficiency of the vinegar, As and Zn recorded levels up to 8% lower for samples washed with 10% vinegar, and Cd showed levels up to 20% lower for samples washed with 10% vinegar, while Pb did not register any differences.

Na2O induced stable heavy metal silicates phase transformation and glass network depolymerization

The pollution of heavy metals and chlorine salts widely exists in solid/hazardous waste, while the stable heavy metal silicates limit the heavy metals removal. This work proposed mechanism of Na2O induced stable heavy metal silicates phase transformation and glass network depolymerization to promote heavy metals chlorination volatilization. Medical waste incineration slag (MWI S) containing heavy metal silicates was used as typical sample. Compared with the control, Cu and Zn volatilization efficiencies sharply increased from 77.54% to 92.22% and 18.70% to 93.82% at 3% Na2CO3, 1200 °C, 40 min. It showed that Na2O successfully induced phase transformation from stable Zn2SiO4 and CuSiO3 to ZnO and CuO easy to react with chloride by destroying the Si–O of Zn–O–Si and Cu–O–Si, respectively. Meanwhile, Na2O effectively destructed Si–O bond to depolymerize the glass network, resulting in the percentage of Q0 and Q1 increase from 25.14% to 38.29%, reducing melt viscosity and improvement of volatilization environment to form bigger bubbles. Medical waste incineration fly ash (MWI FA) was applied as Na source to further verify that the mechanism was significantly enhance Cu and Zn volatilization efficiencies. This study provided new method to reduce heavy metal residues in glass products prepared by melting treatment of solid/hazardous wastes.

Impact of substrate depth and fertilizer type on growth, production, quality characteristics and heavy metal contamination of tomato and lettuce grown on urban green roofs

Urban farming on rooftops is a contemporary approach that combines the benefits of green roofing with food production within the city sprawl. The present study aims at assessing plant growth, nutritional value, and consumer safety of two vegetables, lettuce (Lactuca sativa L.) and tomato (Solanum lycopersicum L.) grown on urban green roof. Treatments included: (a) two substrate depths (7.5 and 15 cm) and (b) three types of fertilization (granulated complex fertilizer [GF], slow nitrogen release complex fertilizer [SR], and liquid fertigation [LF]). Measurements included plant growth, total fresh yield, dry weight, and quality characteristics such as nutrient content, nitrate accumulation in lettuce and firmness, and total soluble solids [TSS] in tomatoes. Production safety was evaluated through tissue analyses of the edible parts for heavy metal residues. Results showed that 15 cm substrate depth improved the total yield for both vegetables, and the firmness of tomato fruit, compared to 7.5 cm depth. Fertilization type had no impact on tomato productivity but GF increased TSS in tomato fruits while LF enhanced lettuce yield. The deeper substrate increased N, P, K, Ca, Mg in lettuce leaves but only P and Mn in tomato fruits. In contrast, fertilization type affected leaf nutrient levels in lettuce, where N, P, and Mg were increased using LF. In tomato, the LF increased the fruit P, K, Ca, Mg, and Fe concentration. LF increased the concentration of nitrates in lettuce to levels exceeding the maximum safety limits according to the European Food Safety Authority (EFSA) but not according to EU regulation No 1258/2011. The leaf Mn concentrations in lettuce were higher than the health limits for young children in all measured samples irrespective of the experimental treatments. Selenium (Se) exceeded the health limits in tomato fruits for adults and toddlers using SR but only for toddlers using LF, while GF maintained the Se content below the safety levels. Lead (Pb) and aluminium (Al) were high for both vegetables but did not exceed the EFSA safety limits for adults. However, Pb exceeded the EU Commission Regulation No 420/2011 limit, for both vegetables and fertilization treatments. Washing the leaves of lettuce reduced only Fe and Al concentration but the remaining elements were unaffected. In conclusion, our results suggest that lettuce and tomato of adequately high quality for human consumption can be produced on urban green roofs with shallow substrate depths ranging from 7.5 to 15 cm but, further research is needed to ensure production safety.

Determination of Heavy Metal Residues in Tropical Fruits near Industrial Estates in Rayong Province, Thailand: A Risk Assessment Study

This study determined the extent of heavy metal contamination of local fruit in Rayong, Thailand, an area where an industrial base is adjacent to agricultural areas. Dietary exposure to agricultural products grown in contaminated areas can cause multiple adverse effects to the human body. In order to avoid such undesirable effects, concentrations of heavy metals [arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn)] were investigated in popular tropical fruits from three districts of Rayong, namely Wang Chan, Klang and Mueang. The levels of heavy metals were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and cold vapor-atomic absorption spectrometry (CV-AAS). Levels of the six heavy metals in sampled fruits (durian, jackfruit, pineapple, rambutan, long kong, and mangosteen) were in the range of 0.0004-6.7095 mg/kg; 16.7% of fruit samples exceeded maximum permissible limits of Pb. Based on health risk assessments, values of estimated daily intake (EDI) were less than those of maximum tolerable daily intake. However, for non-carcinogenic risks, high hazard index (HI) values were found in some markets while for carcinogenic risks (CRs), CR values of three fruits (durian, jackfruit, and mangosteen) exceeded acceptable levels. Therefore, long-term fruit consumption could impact health of local consumers. These results provided insight into the need for regular monitoring of heavy metal concentrations in potentially contaminated fruits and for prevention of its potential effects.

Evaluation of physicochemical parameters of Acacia catechu Willd.

Introduction: Acacia catechu willd. (Mimosoideae) is a deciduous, thorny tree which grows up to 15m height; widely distributed throughout India. This plant is rich source of flavonoids, tannins and phenolic compounds. It is used traditionally for the treatment of asthma, bronchitis, pain in chest, ulceration, wound healing, mouth ulcer, colic, vitiligo, cancer, sore throats, and diarrhoea. It possesses antioxidant, antipyretic, antileprotic, antimicrobial, antiviral, antifungal, spasmolytic, antibacterial, hypoglycaemic, antifertility, immunomodulatory, hepatoprotective, hypotensive and wound healing properties. Material and Method: In the present study, plant has been explored for detailed pharmacognostic and microscopic study. Preliminary phytochemical screening has been performed for evaluation of various phyto-constituents present in the plant. Physicochemical parameters such as moisture content, ash value, extractive values have been determined as per procedure given in IP. Presence of heavy metal, aflatoxin, microbial contamination and pesticidal residue has been assessed as per WHO guidelines. Result: A. catechu stem is reddish brown, cylindrical, hard to fracture and astringent in taste. Microscopy showed the presence of medullary rays, vessels, xylem fibres, parenchyma, fibres and calcium oxalate crystals. Heavy metal, aflatoxin, microbial contamination and pesticidal residue contents were found within limits as per WHO guidelines. Preliminary phytochemical screening showed the presence of tannins, flavonoids and reducing sugar. Conclusion: Present study was carried out to establish quality parameters for A. catechu plant which will be further utilised for evaluation of pharmacological activity.

Blood lead monitoring in a former mining area in Euskirchen, Germany: results of a representative random sample in 3- to 17-year-old children and minors

Heavy metal residues in former mining areas can pose a burden to the local environment and population even decades after closure of the mining sites. In the North Rhine-Westphalian (Germany) communities of Mechernich and Kall, both parts of the district of Euskirchen, lead residues are a source of health concerns for local residents. A statistically representative collective of both communities depending on sex, age, and area of residence was created, mirroring the local underage population. The blood lead levels (BLL) of 182 children and minors in the two adjacent communities were assessed via ICP-MSMS. The results were compared to German lead reference values, valid for the general underage population. In total, 32 (17.6%) of the subjects investigated exceeded the according reference values of 15 µg/L and 20 µg/L, respectively, depending on sex and age, thus pointing out an additional lead burden affecting children in the area. Potential lead sources contributing to the BLL were evaluated using a questionnaire. Factors that showed significant impact on the BLL were, other than age, sex, height, and weight, the factors occupancy, time spend in the garden, garden hand-to-mouth contact, consumption frequency of homegrown products, and lifestyle factors. The data presented enable both residents and the local authorities to further reduce lead exposure and to take appropriate personal and public action.

The ignored risk: heavy metal pollution of medicine and food homologous substances.

A survey was conducted to investigate the effects of cadmium (Cd), arsenic (As), chromium (Cr), lead (Pb), and copper (Cu) in medicine and food homologous substances (MFHs) on human health. Nine common and typical MFHs (Dendrobium, Bulbus lilii, Poria, Semen nelumbinis, Radix puerariae, Gardenia jasminoides, Hordeum vulgare L, Semen coicis, and Ganoderma Karst) in the form of medicinal slices ready for decoction were purchased from pharmacies. Five among the MFHs (Dendrobium, Bulbus lilii, Poria, Semen nelumbinis, and Radix puerariae) were further obtained from a local field as raw materials for comparison. The results showed that raw materials of MFHs collected from the field had higher contents of heavy metal and greater health risks than medicinal slices purchased from pharmacy. Generally, the heavy metal residues in MFHs of different medicinal parts were different, and MFHs from roots or stems had significantly higher contents of heavy metals than those from fruits or seeds. Most importantly, the contents of Cd in Bulbus lilii and As in wild Poria from field were higher than the contents described in the Pharmacopoeia of the People's Republic of China (ChP). Non-carcinogenic and carcinogenic risk assessments revealed that Poria from field had larger non-carcinogenic and carcinogenic risks to human health; Bulbus lilii showed no non-carcinogenic risk but exhibited carcinogenic risks, whereas Cr showed carcinogenic risks in all samples. Given that MFHs are incorporated in regular foods, care should be taken to minimize health hazards caused by heavy metals to human. This study creates awareness on the safety issues associated with MFHs, and provides basic information for establishing the maximum allowable contents of medicinal and food substances in normal diets.

Animals Organs Pathological Changes of Heavy Metals Toxicity

Heavy metal toxicity in livestock animals will affect and damage the body organs. The animals that are exposed to heavy metal residues will suffer pain and experience pathological changes in body organs that support the metabolic function of the body's work. Some organs lead to the specific diagnosis of specific contaminating heavy metals. Examination of pathological changes in the body of animals will help a lot in diagnosing, handling animals that are exposed to certain heavy metal toxicity. The respiratory tract, digestive tract and reproductive tract in animals can direct the detection of the effects of toxicity of certain heavy metal. Organs that experience pathological changes can also to help diagnose contamination due to certain heavy metals. The purpose of this writing is to help adding the knowledge of pathological changes regarding heavy metal toxicity Arsenic (As), Cadmium (Cd), Cooper (Cu), Mercury (Hg), Mangan (Mn) and Lead (Pb), in the organs of animals.

Sidestream materials show potential as top-dressed soil improvers for peatland forests.

The effects of top-dressing of several industrial and farming sidestream materials on the growth of downy birch (Betula pubescens Ehrh.) and Scots pine (Pinus sylvestris L.) seedlings in natural sphagnum peat soil were evaluated. Wood fly ash, industrial filter cake waste, mine tailings sand (quartz feldspar from lithium orebody), and digestate and liquid reject of cow manure from a biogas plant were studied for their physical and chemical properties, as well as for their effects as soil ameliorants on seedling growth during one growing period in a greenhouse. Each material was top-dressed on unfertilised peat in pots in quantities that corresponded to the amounts of ash used in Finnish peatland forest fertilisation (2-6tha-1). During growing, the pH of percolate water from the growing pots was below 4, and in the treatments with filter cake even below 3. However, no clear impairment of seedling growth due to acidity was observed. In all treatments, birch and pine seedlings grew at least as well as in the unfertilised peat (control treatment). Growth was strongest in the peat top-dressed with additives originating from cow manure, in which the high N and P contents promoted growth so much that foliar N was found to be diluted with respect to a high P content in the birch seedlings. No harmful concentrations of heavy metal residues were observed from the materials used. Overall, the results suggest that all the used sidestream materials show potential as soil improvers on forested peatlands.

Low-dose florfenicol and copper combined exposure during early life induced health risks by affecting gut microbiota and metabolome in SD rats

The potential health risks associated with simultaneous presence of residues of heavy metals and antibiotics in the environment and food have been of wide concern. However, the adverse health effects of combined heavy metal and antibiotic exposure at low doses remain unclear. In this study, the effects of combined exposure to florfenicol and copper at low doses during early life on toxicity, gut microbiota, drug resistance genes, and the fecal metabolome were investigated in Sprague–Dawley (SD) rats. The results showed that combined exposure induced inflammatory responses and visceral injury as well as faster weight gain compared with florfenicol or copper exposure alone. Alpha and beta diversity indices indicated that the composition of the gut microbiota and the abundance of bacteria related to energy intake and disease in the combined exposure group were significantly altered. The increase in resistance genes (floR, fexA) induced by florfenicol exposure was suppressed under combined exposure to florfenicol and copper. The fecal metabolome also demonstrated that metabolic pathways related to energy intake and liver injury were significantly affected in the combined exposure group. In conclusion, this study shows that combined exposure to florfenicol and copper during early life can pose a nonnegligible health risk even if the exposure concentration of florfenicol or copper is below the safe limit.

Black Soldier Fly (Hermetia illucens) as a Potential Agent of Organic Waste Bioconversion

The use of black soldier fly (BSF) as a bioconversion agent has become an emerging breakthrough in waste processing. Organic wastes, such as household waste and livestock manure, can be used as a growth medium for BSF larvae and converted into favorable products. The average composting time of BSF larvae is around 12– 15 days, which is faster than that of microbes or earthworms (4–5 weeks). BSF shows potential as a feed and food ingredient because it has a high nutritional content, such as enzyme, chitin, medium-chain fatty acid, and antimicrobial peptides, and can be used as a functional food ingredient. From an economical perspective, the short composting period and the role of BSF as a feed and food alternatives can benefit producers and consumers. The safety aspects of BSF utilization, including microbial safety, chemical safety, and environmental safety, warrant clarification to ensure BSF safety. However, some challenges arise regarding the use of BSF larvae (BSFL) as a bioconversion agent, such as for heavy metal residues, pesticide residues, pathogens, and antimicrobial gene transmission and residues that require the best composting strategy for mitigation. The environmental safety of organic waste treated with BSFL has a good impact; therefore, this strategy can be used to reduce global warming. Research must focus on effectively and safely enhancing the cultivation and processing of BSF and its applications as a functional food. In conclusion, BSF is a profitable alternative for organic waste bioconversion in developed and developing countries.

One‐pot synthesis of copper nanocluster/Tb‐MOF composites for the ratiometric fluorescence detection of Cu2+

The increasing degradation of ecosystems due to heavy metal residues has led to environment and food contamination, prompting the development of convenient platforms for monitoring heavy metals. Here, a new dual-emission fluorescent sensor CuNCs@Tb@UiO-66-(COOH)2 for the detection of copper ions (Cu2+ ) has been synthesized using one-pot encapsulation of Tb(III) and glutathione-stabilized copper nanoclusters (CuNCs) into metal-organic frameworks (MOFs) UiO-66-(COOH)2 . In this ratiometric sensor, the fluorescence intensity of Tb3+ decreased significantly upon the addition of Cu2+ , whereas that of CuNCs showed good stability, together with an apparent colour change. Therefore, ratiometric fluorescence detection of Cu2+ can be accomplished by measuring the ratio of the fluorescence intensity at the 450 nm (F450 ) wavelength of CuNCs to the 548 nm (F548 ) emission of Tb3+ in the fluorescence spectra of the CuNCs@Tb@UiO-66-(COOH)2 suspension. Moreover, the obtained fluorescent probe showed good results in the detection of actual samples. This work can provide the basis of method for the exploration of ratiometric fluorescence and visual sensors of trace pollutants analysis in complicated samples.

Residues of Pesticides and Heavy Metals in Polish Varietal Honey.

The levels of chemical pollutants were determined in 30 samples of varietal honey from southeastern Poland, including 223 pesticides (insecticides, herbicides, fungicides, acaricides, plant growth regulators, and veterinary drugs) and 5 heavy metals (Pb, Cd, Hg, Cu, and Zn). In 10% of the samples, no pesticide residues were found. The most frequently identified pesticides were thiacloprid (90% of the samples, max 0.337 mg/kg), acetamiprid (86.6%, max 0.061 mg/kg), carbendazim (60%, max 0.049 mg/kg), DMF (56.6%, max 0.038 mg/kg), total amitraz (53.3%, max 0.075 mg/kg), thiamethoxam (26.6%, max 0.004 mg/kg), thiacloprid-amide (13.3%, max 0.012 mg/kg), dimethoate (10%, max 0.003 mg/kg), azoxystrobin (10%, max 0.002 mg/kg), tebuconazole (6.66%, max 0.002 mg/kg), and boscalid (3.33%, max 0.001 mg/kg). The acceptable limits for the compounds were not exceeded in any sample. The Pb content ranged between 0.044 and 0.081 mg/kg. The concentration of Hg and Cd did not exceed 5.0 µg/kg and 0.02 mg/kg, respectively. The honey variety significantly (p < 0.01) influenced the content of Cu, which ranged from 0.504 (rapeseed honey) to 1.201 mg/kg (buckwheat). A similar tendency (p > 0.05) was observed for the Zn content, which ranged from 0.657 mg/kg (linden) to 2.694 mg/kg (buckwheat). Honey produced in southeastern Poland was shown to be safe for human consumption.