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The Science of the Total Environment Sep 2016Lead and zinc (PbZn) mines are a common occurrence worldwide; and while approximately 240 mines are active, the vast majority have been abandoned for decades. Abandoned... (Review)
Review
Lead and zinc (PbZn) mines are a common occurrence worldwide; and while approximately 240 mines are active, the vast majority have been abandoned for decades. Abandoned mining wastes represent a serious environmental hazard, as Pb, Zn and associated metals are continuously released into the environment, threatening the health of humans and affecting ecosystems. Iron sulfide minerals, when present, can form acid mine drainage and increase the toxicity by mobilizing the metals into more bioavailable forms. Remediation of the metal waste is costly and, in the case of abandoned wastes, the responsible party(ies) for the cleanup can be difficult to determine, which makes remediation a complex and lengthy process. In this review, we provide a common ground from a wide variety of investigations about concentrations, chemical associations, and potential mobility of Pb, Zn and cadmium (Cd) near abandoned PbZn mines. Comparing mobility results is a challenging task, as instead of one standard methodology, there are 4-5 different methods reported. Results show that, as a general consensus, the metal content of soils and sediments vary roughly around 1000mg/kg for Zn, 100 for Pb and 10 for Cd, and mobilities of Cd>Zn>Pb. Also, mobility is a function of pH, particle size, and formation of secondary minerals. New and novel remediation techniques continue to be developed in laboratories but have seldom been applied to the field. Remediation at most of the sites has consisted of neutralization (e.g. lime,) for acid mine discharge, and leveling followed by phytostabilization. In the latter, amendments (e.g. biochar, fertilizers) are added to boost the efficiency of the treatment. Any remediation method has to be tested before being implemented as the best treatment is site-specific. Potential treatments are described and compared.
Topics: Environmental Monitoring; Lead; Metals, Heavy; Mining; Soil; Soil Pollutants; Water Pollutants, Chemical; Zinc
PubMed: 27179321
DOI: 10.1016/j.scitotenv.2016.04.143 -
Environmental Science and Pollution... Jan 2022Interindividual genetic variations determine human's susceptibility to heavy metal-induced toxicity. Thus, we analyzed blood concentrations of lead (Pb) and cadmium (Cd)...
Glutathione S-transferase gene polymorphisms in association with susceptibility to lead toxicity in lead- and cadmium-exposed children near an abandoned lead-zinc mining area in Kabwe, Zambia.
Interindividual genetic variations determine human's susceptibility to heavy metal-induced toxicity. Thus, we analyzed blood concentrations of lead (Pb) and cadmium (Cd) in 140 lead-exposed children. Genotyping of the glutathione S-transferase (GST) genes, GSTM1, GSTT1, and GSTP1 genes, was carried out to investigate their possible association with heavy metal concentrations and the risk of susceptibility to Pb toxicity. Exposure to both heavy metals was prevalent among the children. The blood Pb level ranged from 3.30 to 74.0 μg dL with an average value of 26.8 μg dL that is five times above its reference level. The average Cd level (0.22 μg L) was below its reference level. The metal-gene interaction showed positive correlation between GSTT1 null genotype and Pb and Cd levels (β = 0.11; p = 0.02 and β = 0.10; p = 0.01, respectively). More pronounced effects (β = 0.19; p < 0.01 and β = 0.25; p = 0.04) were found for the mixture of the three putative genes with blood Pb concentration. The susceptibility analysis using 10 μg dL as blood Pb cutoff level showed a high risk of Pb toxicity (OR = 2.54; 95% CI: 1.02-6.32, p = 0.04) for children carrying the GSTP1 Ile/Val genotype. Further, the combined effect of GSTP1 Ile/Val with GSTT1 null genotype was more pronounced and showed an increased risk of susceptibility to Pb toxicity (OR = 11.7; 95% CI: 1.36-102.1, p = 0.02). In summary, this study suggests that GSTT1 null and GSTP1 Ile/Val genotypes are the main genetic factors, and individual and specific combinations of GSTP1 Ile/Val with GSTM1 and GSTT1 GST polymorphisms are associated with susceptibility to Pb toxicity.
Topics: Cadmium; Case-Control Studies; Child; Genotype; Glutathione Transferase; Humans; Lead; Mining; Polymorphism, Genetic; Risk Factors; Zambia; Zinc
PubMed: 34453679
DOI: 10.1007/s11356-021-16098-1 -
Magnetic Resonance in Medicine Jan 2022During MR scans, abandoned leads from active implantable medical devices (AIMDs) can experience excessive heating at the lead tip, depending on the type of termination...
PURPOSE
During MR scans, abandoned leads from active implantable medical devices (AIMDs) can experience excessive heating at the lead tip, depending on the type of termination applied to the proximal contacts (proximal end treatment). The influence of different proximal end treatments (ie, [1] freely exposed in the tissue, [2] terminated with metal in contact with the tissue, or [3] capped with plastic, and thereby fully insulated, on the RF-induced lead-tip heating) are studied. A technique to ensure that MR Conditional AIMD leads remain MR Conditional even when abandoned is recommended.
METHODS
Abandoned leads from three MR Conditional AIMDs ([1] a sacral neuromodulation system, [2] a cardiac rhythm management pacemaker system, and [3] a deep brain stimulator system) were investigated in this study. The computational lead models (ie, the transfer functions) for different proximal end treatments were measured and used to assess the in vivo lead-tip heating for four virtual human models (FATS, Duke, Ella, and Billie) and compared with the lead-tip heating of the complete MR Conditional AIMD system.
RESULT
The average and maximum lead-tip heating for abandoned leads proximally capped with metal is always lower than that from the complete AIMD system. Abandoned leads proximally insulated could lead to an average in vivo temperature rise up to 3.5 times higher than that from the complete AIMD system.
CONCLUSION
For the three investigated AIMDs under 1.5T MR scanning, our results indicate that RF-induced lead-tip heating of abandoned leads strongly depends on the proximal lead termination. A metallic cap applied to the proximal termination of the tested leads could significantly reduce the RF-induced lead-tip heating.
Topics: Heating; Humans; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Phantoms, Imaging; Prostheses and Implants; Radio Waves
PubMed: 34378816
DOI: 10.1002/mrm.28967 -
MRI in pediatric and congenital heart disease patients with CIEDs and epicardial or abandoned leads.Pacing and Clinical Electrophysiology :... Aug 2020Heart Rhythm Society guidelines outlining magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) excluded children and...
BACKGROUND
Heart Rhythm Society guidelines outlining magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) excluded children and epicardial or abandoned leads due to theoretical risks of harm. Research investigating these risks is lacking. The primary objective of our study is to determine the incidence of adverse events to patients or CIEDs from MRI imaging. The secondary objective is to describe CIED-related artifact on MRI images.
METHODS
A single-center retrospective review was performed on all patients with CIEDs who underwent 1.5 Tesla MRI between July 2007 and May 2019. We subdivided patients among four cohorts: (1) patients <18 years of age, (2) epicardial leads, (3) abandoned endocardial leads, and (4) abandoned epicardial leads. Descriptive statistics pre- and post-MRI and at follow-up within 1.5 years were conducted.
RESULTS
Fifty-four MRIs were performed on 40 patients. Median age was 21.2 years (IQR 12.0-25.0). Eighteen (33%) MRIs contained abandoned leads; 20 (37%) contained epicardial leads. Three patients, one with abandoned epicardial leads and two with abandoned endocardial leads, experienced mild discomfort at the CIED site. One adult with endocardial leads experienced a pause in the heart rate while programmed in a nonpacing mode. No clinically important changes to CIED parameters occurred. Nine MRIs (17%), especially those with functional cardiac imaging, were uninterpretable due to image artifact.
CONCLUSION
In this study, pediatric and adult CHD patients with CIEDs, many with epicardial or abandoned leads, underwent MRIs without clinically significant complications. In some, CIED artifact reduced cardiac MRI image quality due to CIED position.
Topics: Adolescent; Adult; Artifacts; Child; Defibrillators, Implantable; Electrodes, Implanted; Female; Heart Defects, Congenital; Humans; Magnetic Resonance Imaging; Male; Patient Safety; Retrospective Studies
PubMed: 32533566
DOI: 10.1111/pace.13984 -
Pacing and Clinical Electrophysiology :... Nov 2021The Medtronic Sprint Fidelis® and Abbott Riata®/Riata ST® leads are at risk of failure and are subject to FDA recall. Comparative risks of various lead management... (Comparative Study)
Comparative Study
BACKGROUND
The Medtronic Sprint Fidelis® and Abbott Riata®/Riata ST® leads are at risk of failure and are subject to FDA recall. Comparative risks of various lead management strategies during elective generator change in a multi-center population are unknown. We aim to describe patients with functional, recalled ICD leads undergoing elective generator replacement and report outcomes according to lead management strategies.
METHODS
Using data from the NCDR ICD Registry, patients with a functioning Riata® or Fidelis® lead undergoing generator replacement are described according to lead management: reuse, abandon/replace, and extract/replace. Adjusted rates of death and pre-discharge complications are reported.
RESULTS
There were 13,144 generator replacement procedures involving a functioning, non-infected Riata® or Fidelis® lead (extraction n = 414, abandonment n = 427). Extraction patients were younger (mean 58 vs. 67 years) with fewer comorbidities than the reuse group. Maximum lead dwell time was similar between groups with average 94, 90, and 99 months in the extraction, abandonment, and reuse groups, respectively. In-hospital complications or mortality were more common in the extraction group (10.14%, 4.35%) compared with abandonment (1.64%, 0.47%) and reuse (0.22%, 0.07%). Compared with reuse, the adjusted odds of death or pre-discharge complication were significantly higher in the extraction group (OR 7.77 95% CI 2.42-24.95, p < .001) but not the abandonment group (OR 1.70 95% CI 0.52-5.61, p = .38).
CONCLUSIONS
In this real-world population, extraction of functional recalled ICD leads was associated with significant risk of in-hospital mortality and complications. Additional work is needed to clarify whether longer term outcomes balance these peri-procedural risks.
Topics: Aged; Defibrillators, Implantable; Electrodes, Implanted; Equipment Design; Equipment Failure; Female; Humans; Male; Middle Aged; Registries
PubMed: 34520564
DOI: 10.1111/pace.14361 -
Environmental Pollution (Barking, Essex... Dec 2022Glass manufacturing operations lead to an increasing number of abandoned slag heaps contaminated with metallic trace elements (MTE). However, the relative influence of...
Glass manufacturing operations lead to an increasing number of abandoned slag heaps contaminated with metallic trace elements (MTE). However, the relative influence of edaphic factors on the biodiversity of glasswork wastelands is still poorly understood although closely related to sustainable land management practices. Therefore, the objectives of this research were to provide new insights into glasswork wastelands through the investigation of (i) Orthoptera, diurnal Lepidoptera, plant communities, and (ii) abiotic parameters in the topsoils. To that end, biodiversity indices were computed from ecological inventories performed on the herbaceous layer. In addition, soil samples were taken from the topsoil layer (0-10 cm) to assess agronomic properties, actually (CEC-exchangeable) and potentially bioavailable MTE fractions (DTPA-extractable) and pseudo-total MTE contents. On the one hand, the studied site was able to support a substantially higher than excepted biodiversity with orthopteran assemblages similar to grasslands and a diurnal Lepidoptera diversity comparable to urban parks. We also noted a positive influence of plant richness on the diurnal Lepidoptera community structure. On the other hand, topsoil analysis revealed a severe Pb contamination (1800-3100 mg kg) and a high potentially bioavailable Pb fraction (800-1300 mg kg). However, CEC-exchangeable MTE concentrations were all below the analytical quantification limits. Moreover, the site was characterized by a medium soil fertility. From these results, Pb contamination does not appear to be a primary limiting factor for the establishment of these communities. We assume that glasswork wasteland ecosytems are more affected by soil fertility or land management practices. To conclude, these sites are able to provide biodiversity ecosystem services, acting as wildlife sanctuaries for Orthoptera and diurnal Lepidoptera, and strategic metals by phytoextraction in a circular economy model. Thus, wasteland management practices should consider the local-scale drivers of biodiversity in order to reach at least the zero net loss of biodiversity.
Topics: Ecosystem; Lead; Soil; Biodiversity; Soil Pollutants; Trace Elements; Plants
PubMed: 36244497
DOI: 10.1016/j.envpol.2022.120431 -
Environmental Research Mar 2021Lead is a potent neurotoxin that is particularly detrimental to children's cognitive development. Batteries account for at least 80% of global lead use and unsafe...
Child lead exposure near abandoned lead acid battery recycling sites in a residential community in Bangladesh: Risk factors and the impact of soil remediation on blood lead levels.
Lead is a potent neurotoxin that is particularly detrimental to children's cognitive development. Batteries account for at least 80% of global lead use and unsafe battery recycling is a major contributor to childhood lead poisoning. Our objectives were to assess the intensity and nature of child lead exposure at abandoned, informal used lead acid battery (ULAB) recycling sites in Kathgora, Savar, Bangladesh, as well as to assess the feasibility and effectiveness of a soil remediation effort to reduce exposure. ULAB recycling operations were abandoned in 2016 due to complaints from residents, but the lead contamination remained in the soil after operations ceased. We measured soil and blood lead levels (BLLs) among 69 children living within 200 m of the ULAB recycling site once before, and twice after (7 and 14 months after), a multi-part remediation intervention involving soil capping, household cleaning, and awareness-raising activities. Due to attrition, the sample size of children decreased from 69 to 47 children at the 7-month post-intervention assessment and further to 25 children at 14 months. We conducted non-parametric tests to assess changes in soil lead levels and BLLs. We conducted baseline surveys, as well as semi-structured interviews and observations with residents throughout the study period to characterize exposure behaviors and the community perceptions. We conducted bivariate and multivariate regression analyses of exposure characteristics to determine the strongest predictors of baseline child BLLs. Prior to remediation, median soil lead concentrations were 1400 mg/kg, with a maximum of 119,000 mg/kg and dropped to a median of 55 mg/kg after remediation (p < 0.0001). Among the 47 children with both baseline and post-intervention time 1 measurements, BLLs dropped from a median of 21.3 μg/dL to 17.0 μg/dL at 7 months (p < 0.0001). Among the 25 children with all three measurements, BLLs dropped from a median of 22.6 μg/dL to 14.8 μg/dL after 14 months (p < 0.0001). At baseline, distance from a child's residence to the nearest abandoned ULAB site was the strongest predictor of BLLs and baseline BLLs were 31% higher for children living within 50 m from the sites compared to those living further away (n = 69, p = 0.028). Women and children spent time in the contaminated site daily and relied on it for their livelihoods and for recreation. Overall, this study highlights the intensity of lead exposure associated with the ULAB recycling industry. Additionally, we document the feasibility and effectiveness of a multi-part remediation intervention at a contaminated site embedded within a residential community; substantially reducing child BLLs and soil lead concentrations.
Topics: Bangladesh; Child; Environmental Exposure; Female; Humans; Lead; Lead Poisoning; Risk Factors; Soil
PubMed: 33412099
DOI: 10.1016/j.envres.2020.110689 -
Journal of Clinical Medicine Dec 2023(1) Background: Transvenous lead extraction (TLE) can become far more complex when unanticipated difficulties arise. The aim was to develop a simple scoring system that...
(1) Background: Transvenous lead extraction (TLE) can become far more complex when unanticipated difficulties arise. The aim was to develop a simple scoring system that allows for the prediction of the difficulty and complexity of this significant procedure. (2) Methods: Based on analysis of 3741 TLE procedures with and without complicating factors (extended fluoroscopy time, need for second-line instruments, and advanced techniques and instruments), a five-point Complex Indicator of Difficulty of (TLE) Procedure (CID-TLEP) scale was developed. Two or more points on the CID-TLEP scale indicate a higher level of procedure complexity. (3) Results: Patient age below 51 years at first CIED implantation, number of abandoned leads, number of previous procedures, passive fixation and multiple leads to be extracted, and a ratio of dwell time of oldest lead to patient age during TLE of >0.13 are significant predictors of higher levels of lead extraction complexity. The ROC analysis demonstrates that a point total (being the sum of the odds ratios of the above variables) of >9.697 indicates a 21.83% higher probability of complex TLE (sensitivity 74.08%, specificity 74.46%). Finally, a logistic function was calculated, and we constructed a simple equation for lead extraction complexity that can predict the probability of a difficult procedure. The risk of complex extraction (as a percentage) is calculated as [1/(1 + 55.34 · 0.754)] · 100 ( < 0.001). (4) Conclusion: The LECOM score can effectively predict the risk of a difficult transvenous lead extraction procedure, and predicting the probability of a more complex procedure may help clinicians in planning lead removal and improving patient management.
PubMed: 38137637
DOI: 10.3390/jcm12247568 -
Journal of Biological Rhythms Jun 2022The chronobiology community advocates ending the biannual practice in many countries of adjusting their clocks to observe Daylight Saving Time (DST). Many governments...
The chronobiology community advocates ending the biannual practice in many countries of adjusting their clocks to observe Daylight Saving Time (DST). Many governments are actively considering abandoning this practice. While sleep and circadian experts advocate the adoption of year-round standard time, most jurisdictions are instead considering permanent DST. In guiding advocacy, it is useful to understand the factors that lead governments and citizens to prefer the various options. In October 2021, the Canadian province of Alberta conducted a province-wide referendum on adopting year-round DST, in which more than 1 million valid votes were cast. As this referendum was tied to province-wide municipal elections, the results of the referendum were reported at the community level, allowing a geospatial analysis of preference for permanent DST. While the referendum proposal was narrowly defeated (49.8% in favor), a community-level analysis demonstrated a significant East-West gradient, with eastern communities more strongly in favor and western communities more strongly opposed to the year-round DST. Community size and latitudinal position also contributed to preference, with smaller and more northern communities showing more preference for year-round DST. These findings help identify how geospatial location can influence how citizens feel about the various time options and can further help guide public advocacy efforts by the sleep and circadian communities.
Topics: Canada; Circadian Rhythm; Emotions; Seasons; Sleep
PubMed: 35382618
DOI: 10.1177/07487304221089401 -
International Journal of Health... Apr 2017Twenty years ago, many of Canada's provinces began to introduce regional health authorities to address problems with their health care systems. With this action, the...
Twenty years ago, many of Canada's provinces began to introduce regional health authorities to address problems with their health care systems. With this action, the provinces sought to achieve advances in community decision-making, the integration of health services, and the provision of care in the home and community. The authorities were also to help restrict health care costs. An assessment of the authorities indicates, however, that over the past two decades they have been unable to meet their objectives. Community representatives continue to play little role in determining the appropriate health services for their regions. Gains have been made towards integrating health services, but the plan for a near seamless set of health services has not been realized. Funding for health services remains focused on hospital and physician care, and health care expenditures have until very recently been little affected by regional authorities. This disappointing performance has caused some provinces to abandon their regional authorities, but this article argues that the provision of greater autonomy and a better public appreciation of their role and potential may lead to more successful regional authorities. Accordingly, the objective of this article is to reveal the shortcomings of regional health authorities in Canada while at the same time arguing that changes can be made to increase the chances of more workable authorities.
Topics: Canada; Efficiency, Organizational; Health Plan Implementation; Humans; Organizational Objectives; Regional Health Planning
PubMed: 28292228
DOI: 10.1177/0020731416681229