Screening for Heavy Metals in Tea Leaves from Bangladesh Using X-Ray Fluorescence

Trace metal contamination is a global health issue. This study evaluated boxed and loose-leaf tea from Bangladesh using a Handheld X-ray Fluorescence (XRF) analyzer for lead and other metals to rapidly screen tea as a potential hot spot of heavy metal exposure. Of the 33 elements measured, several priority pollutants were below the limit of detection (LOD) in all samples, including lead (LOD 2.17 mg/kg) and arsenic (LOD 1.68 mg/kg). Loose-leaf tea samples had higher copper (1.5-fold), zinc (1.3-fold), and manganese (1.8-fold) concentrations compared to boxed tea. Estimated daily intake (EDI) of lead from tea was calculated using three assumed extractability levels, 20%, 50%, and 100%, and assuming the lead concentration was at the LOD. The EDI for lead ranged from 0.008 µg/kg/bw day to 0.041 µg/kg/bw for adult males and 0.010 µg/kg/bw day to 0.049 µg/kg/bw day for adult females. Based on these tested samples, tea is not likely a primary source of lead exposure in the two sampled areas, Sirajdikhan and Pabna. Future research can evaluate potential processing steps for why some metals were higher in loose-leaf tea compared to boxed tea, including copper, zinc, and manganese. Other potential lead sources could be tested in the tea preparation process, including water sources and dishware used to prepare and consume the tea

Microwave sensors for in situ monitoring of trace metals in polluted water

Thousands of pollutants are threatening our water supply, putting at risk human and environmental health. Between them, trace metals are of significant concern, due to their high toxicity at low concentrations. Abandoned mining areas are globally one of the major sources of toxic metals. Nowadays, no method can guarantee an immediate response for quantifying these pollutants. In this work, a novel technique based on microwave spectroscopy and planar sensors for in situ real-time monitoring of water quality is described. The sensors were developed to directly probe water samples, and in situ trial measurements were performed in freshwater in four polluted mining areas in the UK. Planar microwave sensors were able to detect the water pollution level with an immediate response specifically depicted at three resonant peaks in the GHz range. To the authors' best knowledge, this is the first time that planar microwave sensors were tested in situ, demonstrating the ability to use this method for classifying more and less polluted water using a multiple-peak approach

Review on the development of truly portable and in-situ capillary electrophoresis systems

Capillary electrophoresis (CE) is a technique which uses an electric field to separate a mixed sample into its constituents. Portable CE systems enable this powerful analysis technique to be used in the field. Many of the challenges for portable systems are similar to those of autonomous in-situ analysis and therefore portable systems may be considered a stepping stone towards autonomous in-situ analysis. CE is widely used for biological and chemical analysis and example applications include: water quality analysis; drug development and quality control; proteomics and DNA analysis; counter-terrorism (explosive material identification) and corrosion monitoring. The technique is often limited to laboratory use, since it requires large electric fields, sensitive detection systems and fluidic control systems. All of these place restrictions in terms of: size, weight, cost, choice of operating solutions, choice of fabrication materials, electrical power and lifetime. In this review we bring together and critique the work by researchers addressing these issues. We emphasize the importance of a holistic approach for portable and in-situ CE systems and discuss all the aspects of the design. We identify gaps in the literature which require attention for the realization of both truly portable and in-situ CE systems

Environ Sci Technol

Chronic exposure to inorganic pollutants adversely affects human health. Inductively coupled plasma mass spectrometry (ICP-MS) is the most common method used for trace metal(loid) analysis of human biomarkers. However, it leads to sample destruction, generation of secondary waste, and significant recurring costs. Portable X-ray fluorescence (XRF) instruments can rapidly and nondestructively determine low concentrations of metal(loid)s. In this work, we evaluated the applicability of portable XRF as a rapid method for analyzing trace metal(loid)s in toenail samples from three populations (| = 97) near the city of Chennai, India. A Passing-Bablok regression analysis of results from both methods revealed that there was no proportional bias among the two methods for nickel (measurement range 3c25 to 420 mg/kg), zinc (10 to 890 mg/kg), and lead (0.29 to 4.47 mg/kg). There was a small absolute bias between the two methods. There was a strong proportional bias (slope = 0.253, 95% CI: 0.027, 0.614) between the two methods for arsenic (below detection to 3.8 mg/kg) and for selenium when the concentrations were lower than 2 mg/kg. Limits of agreement between the two methods using Bland-Altman analysis were derived for nickel, zinc, and lead. Overall, a suitably calibrated and evaluated portable XRF shows promise in making high-throughput assessments at population scales.K01 OH011648/OH/NIOSH CDC HHSUnited States/K01OH011648/ACL/ACL HHSUnited States/P42 ES030990/ES/NIEHS NIH HHSUnited States/2022-10-05T00:00:00Z34529917PMC858201511987vault:3977

X-Ray Fluorescence (XRF) Analyzer - Theory, Utility, and QA/QC for Environmental and Commercial Product Samples in Cambodia

Laboratory facilities in developed countries provide a variety of options for analysis of environmental samples and commercial commodities that could impact human health. The same is not true in developing countries and there is a great need to identify technologies that could be used to provide robust, accurate, cost-effective analysis that minimizes the need for extensive technical training. An X-ray Fluorescence (XRF) analyzer seems to be an analytical technique that could be such a tool for developing countries. Therefore, the objective of this thesis was to assess the performance and utility of a handheld, portable XRF unit in analyzing different types of environmental and commercial commodity samples in Cambodia. Because a number of different materials were analyzed, this thesis has a slightly different format than typical. Each of the following three chapters has its own methodology, results and discussion sections. This approach was taken because the materials analyzed and methods for sampling the materials were so different, it was clearer to separate the analyses into separate, individual chapters. This abstract provides a brief overview of each chapter. 1. Chapter One The need to have a more robust, cost effective and less time-consuming form for environmental samples in the field where samples could not be brought in for the laboratory analysis led to the manufacture of a first X-ray fluorescence (XRF) analyzer. This first chapter outlines the theory of the XRF, its advantages and limitations, and provides some QA/QC of a handheld XRF (XL3t 900, Billerica, MA) on skin whiteners, which were purchased and donated by university students for mercury levels. The results showed that up to 98 samples (16%) of creams analyzed contained mercury higher than 20 ppm, and 64 concoctions out of 192 samples were contaminated with more than 20 ppm mercury. Although there were suppressions (20%) of mercury at concentrations near 15,000 ppm (i.e. an under-estimation), the XRF proved to be an excellent tool capable of detecting metals; particularly mercury in semi-solid solutions. 2. Chapter Two Phnom Penh, the capital city of Cambodia, is home to some 1.4 million people and undergoing urbanization. In spite of its urbanization, Phnom Penh has yet to have a primary wastewater treatment plant and adequate sewage drainage system in place. There are two main interceptor sewer channels that drain wastewater and storm water from the southern part of the city into a natural wetland, Boeung Cheung Ek. These two sewer channels are the Tum Pun Sewer System and the Meanchey Sewer System. These are open sewer systems which collect all types of industrial, hospital, institutional and household wastes, and in turn discharge into the wetland. In Cambodia data related to metals contamination in sediment and street dust are very limited. So, this chapter of the thesis seeks to determine metal concentrations, spatial patterns and sources in sewer, wetland and street dust samples. Metals levels also are compared with United States Environmental Protection Agency (USEPA), New York State Department of Environmental Conservation (NYSDEC), and Provincial Sediment Quality (PSQ), Ontario, Canada guidelines. The results showed that although there are elevated metal concentrations in the sewer and wetland sediments and street dust samples, they are still lower than those reported elsewhere such as in Hong Kong, Greece, China, Korea, the US, and Malaysia. One sewer site (M1) had significantly higher metals levels than any other site of the two sewer systems, because it is geographically surrounded by industries and factories. The metal concentrations, especially Pb, Zn, and Cu, decreased with distance from this site. The levels of Pb in street dust appeared higher in high-density traffic areas and decreased with distance from the busy traffic streets. Although leaded gasoline can be a source of lead in street dust and sediments, Cambodia apparently complies with the EU guideline on the level of lead use in gasoline. In addition to leaded gasoline, diesel fuel can also contain metals but the levels are subject to further analysis. Other sources of metals in street dust include tire abrasion, brake lining and transmission oil. To reduce the levels of metals, the two sewer systems should be dredged periodically. The dredging also would increase channel flow capacity during storm events. Source tracking of metals should be conducted in more detail to inform management strategies. For the management of street dust, street sweeping and washing may be effective means to allay the metal toxicity levels. 3. Chapter Three Lead (Pb), which is a potentially hazardous toxicant, can be an additive agent of jewelry items and children’s toys. It is added to polyvinylchloride (PVC) pipes, so that it would provide rigidity, lower manufacturing costs and resistance to sunlight. Lead also has been a paint additive and this is of great concern in North America. Cambodia imports most of its consumer goods from other countries, but the regulatory inspection on imported products is not strictly enforced due to the lack of customs inspection tools, facilities and trained professionals. The purpose of this chapter is to assess jewelry items, children’s toys and paints for potential metal contamination from various markets in Phnom Penh, Cambodia and Bangkok, Thailand by means of the handheld X-ray fluorescence (XRF) analyzer. The results indicated that significant levels of Pb were used in the products (up to 43% in jewelry items and 4.3% in paints). These findings suggested that more restrictive regulations on the sales and use of toxic products should be imposed, so that health risks can be minimized. The XRF was manufactured, and over the years, has been re-engineered to provide the features necessary to operate in the field where laboratory-based assays not are suited. The XRF has some limitations for some elements like Cr and Hg in soils, the analyses of which necessitate laboratory-based verification such as an AAS or ICP. It also does not have the capacity to assess the degree of dermal and oral absorption of metals, although these aspects are still evolving. Nonetheless, the XRF would be an ideal tool for on-site and in situ investigation in Cambodia; particularly for customs officers, environmental researchers and engineers

Tube-based field-portable x-ray fluorescence (FPXRF) as a qualitative screening tool for resource conservation and recovery act (RCRA) metals in children’s products and comparison to total metals analyses to predict hazardous waste metals toxicity characteristic

This research was performed to assess the efficacy of tube-based field portable x-ray fluorescence (FXPXRF) devices to evaluate RCRA heavy metal concentrations in children\u27s products and determine potential hazardous waste toxicity characteristics by comparative analysis to inductively coupled plasma (ICP) yields per SW6010B. Sample sets consisting of wood, plastic, rubber, bulk, plated/coated, and metal matrices were purchased, size-reduced as necessary and directly analyzed three-times for 120 seconds each via FPXRF operated in the Consumer Goods/Test All mode. Subsequently, the same samples were prepared in accordance to SW3050B and analyzed via ICP at an accredited contract laboratory. Side-by-side results analysis indicates that FPXRF consistently exhibits positive bias compared to standard laboratory methods in the majority of matrices due to XRFs abilities to estimate total metallic analyte concentrations versus extract-labile substances only. Instances in which FPXRFs positive bias was absent were believed attributed to suboptimal sample homogeneity or limited sample area compared to total sample volume of SW3050B extraction. Though FPXRFs overestimation of metallic analyte concentrations does not directly correlate to SW6010B ICP yields without application of correction factors, it does provide a better indication of total versus liberated analyte presence

Analysis of relevant technical issues and deficiencies of the existing sensors and related initiatives currently set and working in marine environment. New generation technologies for cost-effective sensors

The last decade has seen significant growth in the field of sensor networks, which are currently collecting large amounts of environmental data. This data needs to be collected, processed, stored and made available for analysis and interpretation in a manner which is meaningful and accessible to end users and stakeholders with a range of requirements, including government agencies, environmental agencies, the research community, industry users and the public. The COMMONSENSE project aims to develop and provide cost-effective, multi-functional innovative sensors to perform reliable in-situ measurements in the marine environment. The sensors will be easily usable across several platforms, and will focus on key parameters including eutrophication, heavy metal contaminants, marine litter (microplastics) and underwater noise descriptors of the MSFD. The aims of Tasks 2.1 and 2.2 which comprise the work of this deliverable are: • To obtain a comprehensive understanding and an up-to-date state of the art of existing sensors. • To provide a working basis on “new generation” technologies in order to develop cost-effective sensors suitable for large-scale production. This deliverable will consist of an analysis of state-of-the-art solutions for the different sensors and data platforms related with COMMONSENSE project. An analysis of relevant technical issues and deficiencies of existing sensors and related initiatives currently set and working in marine environment will be performed. Existing solutions will be studied to determine the main limitations to be considered during novel sensor developments in further WP’s. Objectives & Rationale The objectives of deliverable 2.1 are: • To create a solid and robust basis for finding cheaper and innovative ways of gathering data. This is preparatory for the activities in other WPs: for WP4 (Transversal Sensor development and Sensor Integration), for WP(5-8) (Novel Sensors) to develop cost-effective sensors suitable for large-scale production, reducing costs of data collection (compared to commercially available sensors), increasing data access availability for WP9 (Field testing) when the deployment of new sensors will be drawn and then realized

Determination of Heavy Metals Contamination of the Environment Around Ziway Floriculture Industry

The aim of this study was to determine the level of environmental pollution by selected heavy metals in soil, water and vegetables around floriculture industry.  The level of the selected heavy metals in soil, water and vegetables were analysed by Flame Atomic Absorption spectroscopy. The detected range of the heavy metals in soil sample collected at different distances from the targeted floriculture area were Cd(ND- 0.10± 0.002), Pb(1.78± 0.003-7.01±0.007), Cr(7.00±0.006 to 14.2±0.003), Ni(7.22±0.006 to 13.76± 0.003), Co(3.12±0.025 to 5.71±0.003), Cu(2.22±0.003-5.89±0.002), Zn(56.2±0.006-70.9 ± 0.003) mg/kg in top soil and subsoil were Cd(ND to 0.10±0.004), Pb(1.7±0.005 to 2±0.015), Cr(4.03±0.002 to 13.8±0.01), Ni(8.39±0.005-10.0±0.003), Co(3.0±0.001-6.95± 0.003), Cu(2.0± 0.002-4.60±0.002), Zn(40.75±0.02-67.9±0.01). The level of metals Cd (0.258±0.0-0.61±0.001), Pb(0.053±0.002 -1.67±0.002), Cr(1.20±0.005-3.01±0.002), Ni(17.15±0.013-34.46±0.009), Cu(1.61±0.002-3.29±0.030), Zn (33.33±0.004-40.53±0.006), Co (0.13± 0.003-1.39±0.003)mg/kg in vegetable .Onion accumulate metals than tomato and cabbage Onion>tomato>cabbage. Concentration of metals in Lake ziway were 0.01±0.001, 0.06± 0.001, 0.012±0.12, 0.117±0.02, and 0.05±0.01mg/L for Ni, Cr, Cu, Zn and Co respectively. Pb and Cd were below the limit of detection. The measured physico chemical parameters in soil sample ranged pH (7.49-8.92) Electrical Conductivity (0.786± 0.010-2.851±0.01).the pH of water was 8.78±0.001and its EC was 0.626±0.003.The level of heavy metals in soil samples was found to increases as sampling distance from the factory decreases .This study indicates that all of the metals are concentrated on the surface soil, and decreased in the lower part of the soil, this is due to reflect their mobility and physical properties of soil and its alkaline pH values. Keywords: Environmental sample, Floriculture industry and Heavy metals