scholarly journals Exposure to Toxic Metals (As, Cd, Hg, Pb) in Two Artisanal and Small-scale Gold Mining (ASGM) Areas in Zimbabwe

2020 ◽  
Author(s):  
Stefan Rakete ◽  
Given Moonga ◽  
Anna-Maria Wahl ◽  
Viola Mambrey ◽  
Dennis Shoko ◽  
...  
Keyword(s):  
Reference Values ◽  
Toxic Metals ◽  
Limit Of Detection ◽  
Descriptive Analysis ◽  
Reference Value ◽  
Small Scale ◽  
Mining Areas ◽  
Mercury Analysis ◽  
Contaminate Drinking Water ◽  
Gf Aas

Abstract Background: People living and working in ASGM areas are exposed to toxic metals such as arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb). Whereas Hg is purposely used to extract the gold from the ore, the other toxic metals can be liberated from the ore during the mining process. These metals can contaminate drinking water and food and are thus, a source of exposure for people living in these mining areas. However, there is limited to no data about the exposure to toxic metals of people living in ASGM areas. Therefore, the purpose of this study was to conduct biomonitoring of people identifying themselves as artisanal gold miners. Methods: Blood and urine were collected from 207 people living and working in two ASGM areas in Zimbabwe. Hg in whole blood and urine was analyzed by direct mercury analysis, Pb in blood as well as As and Cd in urine were analyzed by GF-AAS. The results were evaluated by descriptive analysis and correlated with the location, age, fish consumption, years living and working in the area. Results: Median As level in urine was 10.0 µg/l (range from below limit of detection to 460 µg/l). Median Cd level in urine was 0.3 µg/l (range from below limit of detection to 11.4 µg/l). Median Hg levels in blood / urine were 2.7 / 5.2 µg/l (range from 0.2 to 167 µg/l / 0.1 to 612 µg/l). Median Pb level in blood was 19.9 µg/l (range from 6.6 to 276 µg/l). As expected, the Hg levels were frequently above international reference values (e. g. NHANES, blood: 34%, urine: 69%). For Pb and Cd, a considerable number of participants (32% and 22% respectively) were above the reference values (NHANES / National Health and Nutrition Examination Survey) and for As 33% of the participants were above the reference value (UBA/ German Environment Agency). Conclusions: Hg levels were, as expected in ASGM areas, mainly above reference and threshold values. A high proportion of As, Cd and Pb levels were also above reference levels. Therefore, the exposure to toxic metals in the two ASGM areas in Zimbabwe is relevant for public health.

scholarly journals Biomonitoring of arsenic, cadmium and lead in two artisanal and small-scale gold mining areas in Zimbabwe

2021 ◽  
Author(s):  
Stefan Rakete ◽  
Given Moonga ◽  
Anna-Maria Wahl ◽  
Viola Mambrey ◽  
Dennis Shoko ◽  
...  
Keyword(s):  
Toxic Metals ◽  
Gold Mining ◽  
Limit Of Detection ◽  
Elemental Mercury ◽  
Cross Sectional Study ◽  
Internal Exposure ◽  
Small Scale ◽  
Gold Extraction ◽  
Cross Sectional ◽  
Mining Areas

AbstractPeople living and working in artisanal and small-scale gold mining (ASGM) areas are frequently exposed to elemental mercury (Hg), which is used for gold extraction. However, additional exposure to other toxic metals such as arsenic (As), cadmium (Cd) and lead (Pb) may result from mining-related activities and could be ingested via dust, water or food. In these areas, only limited biomonitoring data is available for toxic metals other than Hg. In particular, data about the exposure to As, Cd and Pb is unavailable for the Zimbabwean population. Therefore, we conducted a cross-sectional study in two ASGM areas in Zimbabwe to evaluate the internal exposure to these metals. In total, urine and blood samples from 207 people that identified themselves as miners were collected and analysed for As and Cd in urine as well as Pb in blood by GF-AAS. Median levels (interquartile ranges in μg/l) of As and Pb were 9.7 μg/l (4.0, 18.5) and 19.7 μg/l (12.5, 34.5), respectively. The 25th percentile and the median for Cd were below the limit of detection (0.5 μg/l); the 75th percentile was at 0.9 μg/l. The results were compared to reference values found for the general population in the USA and Germany, and a significant number of participants exceeded these values (As, 33 %; Cd, 27 %; Pb, 32 %), indicating a relevant exposure to toxic metals. Although not representative for the Zimbabwean population, our results demonstrate that the exposure to toxic metals is relevant for the public health in Zimbabwe and requires further investigation.

Managing the impacts of mining on Ghana’s water resources from a legal perspective

2018 ◽  
Vol 1 (3) ◽  
pp. 156-165 ◽  
Author(s):  
Nasirudeen Abdul Fatawu
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Environmental Protection Agency ◽  
Large Scale ◽  
Small Scale ◽  
Mining Activities ◽  
Protection Agency ◽  
Environmental Laws ◽  
Mining Areas ◽  
Legal Perspective

Recent floods in Ghana are largely blamed on mining activities. Not only are lives lost through these floods, farms andproperties are destroyed as a result. Water resources are diverted, polluted and impounded upon by both large-scale minersand small-scale miners. Although these activities are largely blamed on behavioural attitudes that need to be changed, thereare legal dimensions that should be addressed as well. Coincidentally, a great proportion of the water resources of Ghana arewithin these mining areas thus the continual pollution of these surface water sources is a serious threat to the environmentand the development of the country as a whole. The environmental laws need to be oriented properly with adequate sanctionsto tackle the impacts mining has on water resources. The Environmental Impact Assessment (EIA) procedure needs to bestreamlined and undertaken by the Environmental Protection Agency (EPA) and not the company itself.

scholarly journals The outbreak of illegal gold mining in the Brazilian Amazon boosts deforestation

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Juliana Siqueira-Gay ◽  
Luis E. Sánchez
Keyword(s):  
Gold Mining ◽  
Brazilian Amazon ◽  
Small Scale ◽  
Political Pressure ◽  
Deforestation Rate ◽  
Mining Areas ◽  
Mineral Supply ◽  
Regional Policies ◽  
Illegal Mining ◽  
Conservation Of Biodiversity

AbstractIncreased prices and political pressure are boosting illegal gold mining in the Brazilian Amazon, threatening forests, indigenous people, and conservation of biodiversity in protected areas. The rate of illegal mining deforestation increased more than 90% from 2017 to 2020, reaching 101.7 km2 annually in 2020 compared to 52.9 km2 annually in 2017. In that period, illegal mining deforestation rate grew more than the rate of clearing within mining leases. While formal mining is required to comply with environmental regulations, most small-scale or artisanal mining and especially illegal mining areas are abandoned after reserves are exhausted, without proper rehabilitation. Deforestation due to illegal mining is likely to increase in the next years, calling for coordination between local and regional policies as well as for strengthening and expanding international mechanisms to increase traceability of mineral supply chains with certification schemes to help to curb illegal mining.

scholarly journals From evidence to practice: development of web-based Dutch lipid reference values

2021 ◽  
Author(s):  
N. S. Nurmohamed ◽  
D. Collard ◽  
J. W. Balder ◽  
J. A. Kuivenhoven ◽  
E. S. G. Stroes ◽  
...  
Keyword(s):  
The Netherlands ◽  
Reference Values ◽  
Plasma Lipids ◽  
Digital Health ◽  
Reference Value ◽  
Lipid Lowering ◽  
Lipid Lowering Therapy ◽  
Lowering Therapy ◽  
Cascading Style Sheets ◽  
Age And Sex

Abstract Introduction In the Netherlands, the total number of yearly measured lipid profiles exceeds 500,000. While lipid values are strongly affected by age and sex, until recently, no up-to-date age- and sex-specific lipid reference values were available. We describe the translation of big-cohort lipid data into accessible reference values, which can be easily incorporated in daily clinical practice. Methods Lipid values (total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides) from all healthy adults and children in the LifeLines cohort were used to generate age- and sex-specific percentiles. A combination of RStudio, Cascading Style Sheets and HyperText Markup Language was used to interactively display the percentiles in a responsive web layout. Results After exclusion of subjects reporting cardiovascular disease or lipid-lowering therapy at baseline, 141,611 subjects were included. On the website, input fields were created for age, sex and all main plasma lipids. Upon input of these values, corresponding percentiles are calculated, and output is displayed in a table and an interactive graph for each lipid. The website has been made available in both Dutch and English and can be accessed at www.lipidtools.com. Conclusion We constructed the first searchable, national lipid reference value tool with graphical display in the Netherlands to use in screening for dyslipidaemias and to reduce the underuse of lipid-lowering therapy in Dutch primary prevention. This study illustrates that data collected in big-cohort studies can be made easily accessible with modern digital techniques and preludes the digital health revolution yet to come.

scholarly journals Assessment of oxygen-uptake efficiency slope in healthy children and children with heart disease: Generation of appropriate reference values for the OUES variable

2018 ◽  
Vol 26 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Carlos AC Hossri ◽  
Isabela PM Alves de Souza ◽  
Joana ST de Oliveira ◽  
Luiz E Mastrocola
Keyword(s):  
Heart Disease ◽  
Oxygen Uptake ◽  
Children And Adolescents ◽  
Surface Area ◽  
Reference Values ◽  
Functional Capacity ◽  
Body Surface ◽  
Congenital Heart ◽  
Reference Value ◽  
Oxygen Uptake Efficiency Slope

Background Oxygen-uptake efficiency slope (OUES) is an objective measure of functional capacity that does not require a maximal effort but is considerably dependent on anthropometric variables and requires the generation of an appropriate reference value in children. This study aimed to establish normal reference values for OUES/kg in children with and without congenital heart diseases. Besides that, reference values are presented secondarily for OUES per body surface area (OUES/BSA). Design Cross-sectional. Methods Six hundred and seventy-six children and adolescents performed a maximal cardiopulmonary exercise test (305 healthy controls and 371 individuals with congenital heart defect), between four and 21 years old (481 males and 195 females, with a mean age of 12 years). Results The OUES reference value for the classification of children and adolescents with normal functional capacity (>80% of predicted maximum oxygen uptake) was 34.63 (sensitivity 77% and specificity 83%, p < 0.05). Regarding the body surface area, considering healthy patients and those with heart disease, the cutoff value of the OUES/BSA was 1151 with sensitivity of 79% and specificity of 79%. Conclusions OUES/kg may be an important marker tool in the differentiation between preserved or abnormal functional capacity in children and adolescents with and without congenital heart disease, even at the submaximal level of exercise.

scholarly journals ELIMINASI GANGGUAN MATRIKS DALAM ANALISIS MERKURI HG SEBAGAI SENYAWA KOMPLEKS THIO MICHLER’S KETON SECARA SPEKTROFOTOMETRI

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Sukib Sukib ◽  
Muti'ah Muti'ah
Keyword(s):  
Solvent Extraction ◽  
River Water ◽  
Complex Compound ◽  
Limit Of Detection ◽  
Standard Addition ◽  
Analysis Method ◽  
Addition Method ◽  
Matrix Interferences ◽  
Mercury Analysis

Abstrak. Telah dilakukan penelitian tentang penyusunan metode analisis merkuri melalui pembentukan senyawa kompleks dengan 4,4'-Bis(dimethylamino)thio-benzophenone TMK. Senyawa kompleks tersebut berwarna biru kehijauan yang dapat dideteksi dengan  spektrofoto-meter pada kondisi: lmax 574 nm;  pH 3; konsentrasi TMK 0,0002 M, dan waktu tunggu selama 4–10 menit. perbandingan volume pereaksi: Hg(II), bufer pH 3, TMK 0,002 M, H2O bebas ion adalah 1:1:1:7. Dari hasil penelitian menunjukkan bahwa metode ini telah memenuhi validitas, yaitu: linieritas 0,05–2,0 mg/L, limit deteksi 0,008 mg/L, dan % recovery antara 98% – 102%. Gangguan matriks akibat adanya ion–ion Au(III), Ag(I), Pd(II), Cu(II), Co(II), dan Fe(II) dapat dieliminasi dengan metode ekstraksi pelarut dan adisi standar. Metode adisi standar terbukti mampu memberikan data hasil pengukuran yang dapat dipercaya pada a 5%, yaitu untuk sampel buatan sebesar (0,053 ± 0,001) mg/L, air sungai (0,034 ± 0,004) mg/L, dan sedimen sebesar (4,172 ± 0,050) mg/kg. Dari hasil penelitian ini dapat disimpulkan bahwa metode ekstraksi pelarut dan adisi standar mampu mengeliminasi gangguan matriks pada analisis merkuri sebagai kompleks Hg-TMK secara spektrofotometriKata kunci: Metode analisis merkuri, Thio Michler’s keton, eliminasi, gangguan matriks  Abstract. A research  of analysis method for determination of mercury through formation of complex with 4,4'-bis(dimethylamino)thiobenzophenone TMK has been conducted. The green blue complex compound can be detected with spectrophoto-meter in conditions: lmax 574 nm, buffer acetate pH 3, concentration of TMK 0,0002 M, and the absorbance of complex remains stable for 4–10 minutes. The formula of reagents volume for: Hg(II): buffer acetate pH 3: TMK 0,002 M : de-ionized water is 1:1:1:7. This method is valid, with parameters such as linearity 0.05–2.00 mg/L, limit of detection 0.008 mg/L, and recovery in the range 98%-102%. Matrix interferences that are caused by Au(III), Ag(I), Pd(II), Cu(II), Co(II), and Fe(III) ions can be eliminated with solvent extraction and standard addition methods. Standard addition method is able to give data of trusty measurement result at a 5%, that is for synthesis sample as (0.053 ±  0.001) mg/L, river water (0.034 ± 0.004) mg/L, and for sediment (4.172 ± 0.050) mg/kg. From the result of this research, it can be concluded that solvent extraction and standard addition methods are able to eliminated matrix interferences in mercury analysis as Hg-TMK complex spectrophotometrically Key waords: mercury analysis method, Thio Michler’s ketone, elimination, matrix interferences

scholarly journals Total Fat Gravimetric Method Workflow in Portuguese Olives Using Closed-Vessel Microwave-Assisted Extraction (MAE)

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2364
Author(s):  
João Gonçalo Lourenço ◽  
Daniel Ettlin ◽  
Inês Carrero Cardoso ◽  
Jesus M. Rodilla
Keyword(s):  
Limit Of Detection ◽  
Gravimetric Method ◽  
Reference Value ◽  
Microwave Assisted Extraction ◽  
Closed Vessel ◽  
Limit Of Quantification ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Total Fat

A simple and rapid method for the quantitation of total fat in olive samples is designed, evaluated, and presented. This method is based on an innovative closed-vessel microwave-assisted extraction (MAE) technique. A method was designed for olives, and some figures of merits were evaluated: limit of detection (LOD), limit of quantification (LOQ) and expanded uncertainty (U). The data obtained in these experiences show that the workflow of the MAE method in a closed container is statistically equivalent to the other two methods, showing in this case better performance indicators (LOD = 0.02%, LOQ = 0.06%, and U = 15%). In addition, it is also demonstrated that the complete MAE method workflow allows the determination of total fat in a maximum of 12 analyses simultaneously for about 100 min in each run, which is the capacity of the rotor. This is a much better productivity when compared to the traditional Soxhlet-based method. Considering the sample workflow, the closed-vessel MAE method greatly simplifies sample handling, therefore minimizing sample loss during sample preparation and reducing analysis time. When MAE is compared to NIR-based methods, the advantage comes from there being no need for any type of calibration in the sample matrix. The MAE method itself can be used to determine the reference value for NIR calibration purposes. The results obtained for CRM using MAE were equivalent to the ones shown on the certificate.

A model for the effect of bias for cholesterol on the population at risk.

1988 ◽  
Vol 34 (11) ◽  
pp. 2256-2259 ◽  
Author(s):  
M H Kroll ◽  
M Ruddel ◽  
R J Elin
Keyword(s):  
At Risk ◽  
Standard Deviation ◽  
Reference Values ◽  
Gaussian Distribution ◽  
Population Distribution ◽  
Reference Value ◽  
Mean Value ◽  
The Body ◽  
Methodological Bias ◽  
The Mean

Abstract The location of the Reference Value for an analyte within the population distribution affects the magnitude of error due to methodological bias. Using the gaussian distribution, we evaluated the effects of systematic and proportional biases of the method (positive and negative), mean value, and standard deviation on the magnitude of error. We chose four Reference Values for cholesterol as a model. For a population with a mean of 2.0 and SD of 0.36 g of cholesterol per liter, a 3% positive proportional bias causes sixfold more error at the 50th percentile than at the 97.5th. In general, the error for a given bias (proportional or systematic) is greater for a Reference Value within the body than at the tails of the distribution. Further, the magnitude of the error varies as a function of the mean and standard deviation of the population.

Sign in / Sign up

Export Citation Format

Share Document