In vitro bioaccessibility round robin testing for arsenic and lead in standard reference materials and soil samples

In this study, we assessed the suitability of using a standard reference material (SRM) other than National Institute of Standards and Technology (NIST) 2710a or NIST 2711a in USEPA Method 1340 to determine arsenic (As) and lead (Pb) in vitro bioaccessibility (IVBA) and the capabilities of Canadian-based laboratories to perform the method. Five laboratories participated in an initial round robin study and analyzed NIST 2710a, NIST 2711a, BGS119, and Enviromat SS-2. Intra- and inter-laboratory variability were generally acceptable with percentage relative standard deviations (RSD) of less than 20%. The mean total As and Pb concentrations obtained for BGS119 (332 and 936 mg/kg, respectively) and the mean IVBA values (As = 14.3% and Pb = 78.1%) suggested it may be a suitable and acceptable SRM, whereas the concentration of As in Enviromat SS-2 as received (3.2 mg/kg) was deemed too low. Ten soil samples from sites with varying land use were analyzed in a follow-up round robin study using the modified IVBA method that included BGS119 as SRM. The concentrations of As and Pb in the IVBA extracts reported by the participating laboratories were comparable. The mean As IVBA values for the field-collected samples ranged from 0.1% to 56.4%; for Pb, they ranged from 7.0% to 121%. The lowest IVBA values were measured in mine site samples; the highest values were associated with smelter-affected soils. The low IVBA values correlated with high iron content. Intra- and interlaboratory reproducibility were acceptable (RSD < 30%). Based on the findings of the study, laboratories can use the modified method to provide reproducible and comparable As and Pb IVBA data. The use of BGS119 as an alternative SRM to assess contaminated sites in the province of British Columbia for regulatory purposes is recommended, as it is representative of As and Pb concentrations in contaminated soils in British Columbia. Integr Environ Assess Manag 2024;00:1-10. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Distribution and in-vitro bioaccessibility of potentially toxic metals in surface soils from a mining and a non-mining community in Ghana: implications for human health

The concentration and bioaccessibility of potentially toxic metals, including As, Cd, Cr, Cu, Mn, Ni, Pb and Zn, were determined in surface soil samples from a mining community (Kenyasi) and a non-mining community (Sunyani) in Ghana, to investigate the contribution of mining activities to the environmental burden of potentially toxic metals. The study found significant differences in metal concentrations (p < 0.05) in As, Cd, Cu, Mn, Ni, and Zn, but no significant difference (p > 0.05) in Pb and Cr between the two communities. The study found a moderate correlation between pH and metal concentrations in the mining community and a moderate positive correlation with As, Cd, Cr, Cu, Ni, and Zn in the non-mining community. The distribution pattern revealed elevated levels of toxic metals in the southeastern corridor of the mining community, which is close to a gold mine. Most heavy metals were concentrated in the commercial community's southern zone, with more residents and private elementary schools. Metal bioaccessibility was variable, and except for Cu and Zn, the mean bioaccessibility was less than 50% for a given metal. Contamination factor, geoaccumulation index, and soil enrichment factor suggested very high contamination of Cd, and a considerable to moderate contamination of As, Ni, Zn, and Cu at both the mining and non-mining communities. The above observations and the pollution and risk indices employed in this study confirmed that the mining community was more polluted (PLI = 2.145) than the non-mining community (PLI = 1.372). The total metal hazard (HI) exceeded thresholds by three and four times at non-mining and mining sites. Regular monitoring is necessary, especially in the mining community, to prevent soil metal accumulation.

Human health risk assessment of potentially toxic elements in soil and air particulate matter of automobile hub environments in Kumasi, Ghana

Rapid urbanization and uncontrolled industrial activities in developing countries have raised concerns about potentially toxic metal contamination of the environment. This study assessed the levels of potentially toxic elements in soil and airborne particulate matter in the Suame and Asafo areas in the Kumasi metropolis, characterized by a high concentration of auto mechanic workshops and residential settlements. X-ray fluorescence analysis and inductively coupled plasma-mass spectrometry were used to determine the metal concentrations in the samples. The results showed high concentrations of potentially toxic elements in the soil and air samples, indicating contamination from automotive activities. Metals such as Co, Ni, Pb, and Zn were found to be present at concentrations (13.42-6101.58 mg/kg and 14.15-11.74 mg/kg for Suame and Asafo respectively) that pose potential health risks to exposed populations. Mathematical models such as pollution indices were used to assess the extent of contamination and determine the potential sources of the metals - the automotive repairs. The findings highlight the urgent need for environmental management and remediation strategies to mitigate the health risks of exposure to potentially toxic elements in the Kumasi metropolis automotive hub.

Human health risk associated with metal exposure at Agbogbloshie e-waste site and the surrounding neighbourhood in Accra, Ghana

Agbogbloshie in Accra, Ghana, was a center for informal e-waste recycling until it was closed recently. This study investigated the potential health risks of toxic metals (including As, Cd, Cu, Ni, Pb, Sb, and Zn) found in the surface soils based on their concentrations and in vitro bioaccessibility. Mean concentrations at the burning sites were As: 218; Cd: 65; Cr: 182; Cu: 15,841; Ni: 145; Pb: 6,106; Sb: 552; and Zn: 16,065 mg/kg while the dismantling sites had mean concentrations of As: 23; Cd: 38; Cr: 342; Cu: 3239; Ni: 96; Pb: 681; Sb: 104; and Zn: 1658 mg/kg. The findings confirmed the enrichment of potentially toxic metals at the dismantling and burning sites, exceeding international environmental soil quality guidelines. Based on the total metal concentrations, bioaccessibility, and calculated risk indices, the risks associated with incidental ingestion of soil-borne metal contaminants at the dismantling and burning sites were very high. Despite evidence of higher metal concentrations in the communities near the burning and dismantling sites, the human health risk associated with soil ingestion was significantly lower in the surrounding neighborhood.

Potential health risk and bio-accessibility of metal and minerals in saltpetre (a food additive)

Food additives are used to enhance freshness, safety, appearance, flavour, and texture of food. Depending on the absorbed dose, exposure method, and length of exposure, heavy metals in diet may have a negative impact on human health. The X-Ray Fluorescence (XRF) Analyzer from Niton Thermo Scientific (Mobile Test S, NDTr-XL3t-86956, com 24) was used in this work to measure the heavy metal content in saltpetre, a food additive that mostly contains potassium nitrate. The average essential metal concentrations in the samples were determined to be 27044.27 ± 10905.18 mg kg^-1, 24521.10 ± 6564.28 mg kg^-1, 2418.33 ± 461.50 mg kg^-1, and 4.615 ± 3.59 mg kg^-1 for Ca, K, Fe and Zn respectively. Toxic metals (As, Pb) were present in the saltpetre samples at 4.13 ± 2.47 mg kg^-1 and 2.11 ± 1.87 mg kg^-1 average concentrations. No traces of mercury or cadmium were detected. Studies on exposure, health risks, and bio-accessibility identified arsenic as a significant risk factor for potential illnesses. The need to monitor heavy metal content of saltpetre and any potential health effects on consumers is brought to light by this study.

Rehabilitation versus surgical reconstruction for non-acute anterior cruciate ligament injury (ACL SNNAP): a pragmatic randomised controlled trial

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a common debilitating injury that can cause instability of the knee. We aimed to investigate the best management strategy between reconstructive surgery and non-surgical treatment for patients with a non-acute ACL injury and persistent symptoms of instability.

METHODS

We did a pragmatic, multicentre, superiority, randomised controlled trial in 29 secondary care National Health Service orthopaedic units in the UK. Patients with symptomatic knee problems (instability) consistent with an ACL injury were eligible. We excluded patients with meniscal pathology with characteristics that indicate immediate surgery. Patients were randomly assigned (1:1) by computer to either surgery (reconstruction) or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment), stratified by site and baseline Knee Injury and Osteoarthritis Outcome Score-4 domain version (KOOS4). This management design represented normal practice. The primary outcome was KOOS4 at 18 months after randomisation. The principal analyses were intention-to-treat based, with KOOS4 results analysed using linear regression. This trial is registered with ISRCTN, ISRCTN10110685, and ClinicalTrials.gov, NCT02980367.

FINDINGS

Between Feb 1, 2017, and April 12, 2020, we recruited 316 patients. 156 (49%) participants were randomly assigned to the surgical reconstruction group and 160 (51%) to the rehabilitation group. Mean KOOS4 at 18 months was 73·0 (SD 18·3) in the surgical group and 64·6 (21·6) in the rehabilitation group. The adjusted mean difference was 7·9 (95% CI 2·5-13·2; p=0·0053) in favour of surgical management. 65 (41%) of 160 patients allocated to rehabilitation underwent subsequent surgery according to protocol within 18 months. 43 (28%) of 156 patients allocated to surgery did not receive their allocated treatment. We found no differences between groups in the proportion of intervention-related complications.

INTERPRETATION

Surgical reconstruction as a management strategy for patients with non-acute ACL injury with persistent symptoms of instability was clinically superior and more cost-effective in comparison with rehabilitation management.

FUNDING

The UK National Institute for Health Research Health Technology Assessment Programme.

Is being a victim of bullying or cyberbullying in secondary school associated with subsequent risk-taking behavior in adolescence? A longitudinal study in secondary schools

INTRODUCTION

Neurobiological and social changes in adolescence can make victims of bullying more susceptible to subsequent impulsive behavior. With the high prevalence of bullying in schools and rise in cyberbullying in the United Kingdom, it is important that the health impacts of bullying victimization, including on risk-taking, are understood. Our study aims to investigate whether bullying/cyberbullying victimization is associated with subsequent health risk-taking behavior in adolescence. Risk-taking behavior includes electronic cigarette and cigarette smoking, alcohol consumption, illicit drug use, early sexual debut, weapon carrying, damaging property, and setting fire.

METHODS

A secondary quantitative analysis of data from 3337, English, secondary school students in the control arm of the INCLUSIVE trial, constituting an observational cohort. Bullying victimization was measured at baseline (age 11/12 years) using the gatehouse bullying scale and a separate question on cyberbullying victimization. Logistic regression was used to test for an association between bullying/cyberbullying victimization at baseline and risk-taking behavior at 36 months, adjusting for baseline risk-taking behavior and other potential confounders, and accounting for school clustering.

RESULTS

There was strong evidence (p ≤ .02) for a positive dose-responsive association between being bullied at baseline and nearly all risk-taking behavior at follow-up. Although there was no evidence for an association between being bullied at baseline and weapon carrying (p = .102), there was evidence for a positive association between being cyberbullied at baseline and weapon carrying (p = .036).

CONCLUSIONS

It is plausible that bullying/cyberbullying victimization increases the likelihood of subsequent risk-taking behavior in adolescence. Policy options should focus on implementing evidence-based antibullying school interventions.

Gastric bioaccessibility and human health risks associated with soil metal exposure via ingestion at an E-waste recycling site in Kumasi, Ghana

Over 1000 people make a living by processing electronic and electrical waste (E-waste) and scrap metals for the recovery of valuable metals and integrated circuits at Dagomba Line, Kumasi, Ghana. The processing includes activities such as dismantling, open burning and open dumping of E-waste which can potentially release toxic metals into the environment and thus impact the health of recyclers and nearby residents. This study investigated the distribution of toxic metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Sb and Zn) in surface soils at the E-waste recycling sites and determined the associated human health risk via ingestion incorporating bioaccessibility measurements. Metal concentrations in the activity sites were highly elevated, significantly higher than those in the surrounding area and exceeded international soil quality guidelines such as the Canadian soil quality guidelines for residential land use and the Dutch Intervention Value. Bioaccessibility was high for Pb (70.8%), Cd (64.1%), Cu (62.3%) and Ni (53.6%) which could be credited to the existence of oxidized species as a result of the E-waste burning. Non-carcinogenic effects were unacceptably high (hazard indices > 1) at 14 out of 31 sites, and the cancer risk for arsenic for adult workers was greater than 1 × 10^-5 at five of the sampling sites.

Accumulation and bioaccessibility of toxic metals in root tubers and soils from gold mining and farming communities in the Ashanti region of Ghana

The presence of metal contaminants in agricultural soils and subsequent uptake by food crops can pose serious human health risk. In this study, we assessed the levels of toxic metals - arsenic, chromium, copper, iron, manganese, nickel, and zinc - in soils and some edible root tuber crops from two gold mining and two non-mining communities in Ghana to evaluate the potential human health risks associated with exposure to these metals. Concentrations of the metals in 154 soil and edible root tuber samples were analyzed using field portable x-ray fluorescence spectrometer prior to confirmation by inductively coupled plasma mass spectrometry. Bioaccessibility of the metals was determined using an in vitro physiologically based extraction technique. Concentrations of the metals were generally higher in the gold mining communities than in the non-mining communities. The contamination indices indicated low to moderate contamination of the soil and food crops. Bioaccessibility for the metals varied from 1.7% (Fe) to 62.3 (Mn). Overall, the risks posed by the metals upon consumption of the tubers were low.

Exaggerated elastin turnover in childhood and adolescence in Marfan syndrome – correlation with age – new insights from the AIMS trial

Background

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutations in the Fibrillin1 gene (FBN1) that leads to impaired elastin formation and extra-cellular matrix homeostasis. Elastin synthesis and related lamellae formation in the aorta is completed in the newborn. Thereafter further elastin turnover is thought to be minimal during life. Elastin homeostasis is little studied in patients with MFS who have been reported to have reduced elastin in their aorta and are at risk of aortic dilatation and consequent life-threatening dissection. It is not clear if elastin loss is due to reduced elastin formation in utero or accelerated degradation during life. However, aortopathy develops early in MFS with 70% of patients developing aortic dilatation by the age of 20 years. Therefore, the longitudinal and circumferential aortic growth that occurs in childhood may involve elastic lamellae remodelling that is impaired in MFS. Desmosine is the cross-link component in the elastin molecule and is exclusively released from mature elastin breakdown, thus is a physiologically relevant biomarker of elastin turnover. We hypothesise that physiologic aortic growth is associated with elastic lamellae remodelling and increased elastin turnover, detected by elevated plasma desmosine (pDES), and that elastin turnover is exaggerated during the fast-growing period in MFS.

Purpose

The aims of this study were 1. To investigate the relationship between elastin turnover and age in the control subjects, and 2. To compare the elastin turnover in MFS with control subjects.

Methods

pDES was measured by stable isotope dilution LC-MS/MS in 113 MFS subjects (48% male, mean age 18.2±9.4 (SD) years), mean aortic root 33.8±2.1mm and Z-score 3.4±2.1 in the AIMS trial at baseline before intervention, and in 109 healthy controls (46% male, mean age 26.1±9.5 years).

Results

pDES levels were associated positively with age, body surface area and negatively with diastolic BP in the control group (p=0.05 and 0.21 respectively after correcting for age). In MFS subjects pDES also positively correlated with age and male sex (p&lt;0.05). Interestingly, the age-dependent association with pDES showed a peak distribution in both control and MFS groups (Figure 1) where teenage children expressed the highest pDES levels. MFS subjects had significantly higher pDES compared to controls before the age of 20 (p=0.01) but in adulthood, there was no difference (Figure 2).

Conclusion

Elastin turnover is highly dynamic before early adulthood, and peaks in adolescence and is exaggerated in MFS, suggesting that this period of growth is critical in developing aortopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart FoundationTENOVUS Scotland Figure 1Figure 2

The impact of COVID-19 on recovery after heart surgery: preliminary findings from the CardiacCovid Study

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

The COVID-19 pandemic has had far-reaching effects on everyday life leading to stress and anxiety, which may be heightened in those undergoing cardiac surgery. Health impacts following a traumatic event may be apparent at one month but can also present after many months.

Purpose

The aim of the CardiacCovid study was to explore the effect of the pandemic on recovery from cardiac surgery. We report the preliminary results from a single centre study in the UK during the early phase of the COVID-19 pandemic.

Methods

Patients >18 years old undergoing any form of cardiac surgery between 23rd March 2020 (UK lockdown) to 4th July 2020 (lifting of most restrictions) were recruited to this prospective observational study. Those too unwell or unable to give consent/complete study questionnaires were excluded. Participants completed a Quality of Life (QoL) (EQ-5D), impact of event (IES-R), depression (CES-D) and health service use questionnaire at baseline, 1 week after hospital discharge, and 6 weeks after surgery. Questionnaires were completed electronically on the Amplitude platform or via post. Ethics approval (20/YH/0132) was obtained and the study was registered (Clinicaltrials.gov:NCT04366167).

Results

A total of 395 patients had surgery of which 298 (91.7%) were screened and 203 (68.1%) were enrolled to the study.  Participants were mostly male (74.6%), with a mean age of 63 years, undergoing urgent/emergency (57.9%) CABG +/-valve (70.1%). Mean inpatient stay was 8.6 days and in-hospital mortality was 0.5%. No patients had Covid-19. The initial findings suggest a deterioration of QoL at 1 week post discharge with near restoration to baseline level at 6 weeks post-surgery. Mean scores for CES-D and IES-R remained within subclinical levels at all available time points. However, at 6 weeks, a proportion of patients reached levels for depression on the CES-D and had high IES-R scores indicating possible post-traumatic stress.

Conclusion

We believe that this is the largest/only study exploring the impact of the pandemic on cardiac surgery recovery, including QoL, spanning the immediate recovery phase but will continue until 1 year. The findings so far show that recovery from cardiac surgery during the Covid-19 pandemic is similar to that reported prior to the pandemic (Cromhout et al 2018) and reinforces the need for psychosocial assessments to identify patients who may require additional support during the immediate recovery phase.

127 A Student Pilot For A Feasibility Study of the Theoretical 3S Trial (SPFT3S): Patient Questionnaire and Demographics

Introduction

There is conflicting evidence on the benefit of statins for primary prevention of cardiovascular disease (CVD) in non-diabetics over 75. Emerging evidence shows they may be ineffective, yet current guidance supports their use in those up to 85. The objectives of this study were to assess patients’ understanding of statins, willingness to participate in a theoretical randomised controlled trial (RCT), where they would be randomised to stop their statin and to compare the trial population with national data.

Methods

The survey took place in 8 GP practices with 4 students involved in questionnaire distribution. A patient search identified those over 75 and on a statin. Patients were excluded if they had a history of CVD or diabetes. 36 patients were identified and completed questionnaires, 5 were removed because they reported exclusion criteria. Demographic data was compared to the UK population from the 2011 census.

Results

Of 31 participants, 71% understood why they took statins, most were unconcerned about side effects and only 1 patient stopped statins due to the media. Opinions on the theoretical “stopping statins trial” were varied. 35% of people responded positively. 29% would not want to take part and 36% of people were unsure. Comparison of our trial population against the national population shows that 903,505 people would be eligible for a UK trial.

Conclusions

The purpose of this exercise was to see if patients would be willing to participate in a trial where 50% stopped taking their statin. Approximately a third said yes and only a third said no. As there are nearly a million people in this population, it suggests a fully funded, larger-scale feasibility study of this theoretical randomised control trial is warranted.

126 A Student Pilot for A Feasibility Study of the Theoretical 3S Trial (SPFT3S): GP and Ethics Committee Members Questionnaire

Introduction

Emerging research suggests that statin use for primary prevention in people without diabetes aged 75 and older has no benefit. This study aims to determine the feasibility of the theoretical Stop Statin Study (3S), a double-blind randomised controlled trial carried out in general practice, which would test this hypothesis. 50% of trial patients would stop taking statins for 5 years in an event driven study. The questionnaires aim to identify the attitudes of general practitioners (GPs) and ethics committee members (ECMs) regarding stopping statins for 5 years in patients aged 75 and older without diabetes or history of cardiovascular disease and their willingness to allow patients to participate in the 3S study.

Method

Questionnaires comprised of 6 questions were designed. 4 students distributed the questionnaire and it was completed by 19 GPs based at 8 practices in the North-East of England. 31 ECMs (12 expert and 19 lay) responded by email.

Results

95% of GPs who completed the survey would agree to their patients participating in the theoretical study with 47% of GPs indicating that their willingness to participate in the study is patient dependent. 95% of GPs would also consider stopping statins in this population group if sufficient research had been carried out or if the guidelines were changed. 42% of GPs have a negative attitude to prescribing statins in this population group. All the ECMs would approve the study, citing over-prescribing and polypharmacy as their reason.

Conclusions

The majority of GPs will participate in the theoretical 3S study, if their patients are willing to participate. There is already a negative perception amongst GPs towards the use of statins in elderly people without disease. The 3S study appears to be feasible from the GP and ethics perspective but would require a larger feasibility study.

Human Health Risk and Bioaccessibility of Toxic Metals in Topsoils from Gbani Mining Community in Ghana

BACKGROUND

Anthropogenic activities such as artisanal mining pose a major environmental health concern due to the potential for discharge of toxic metals into the environment.

OBJECTIVES

To determine the distribution and pollution patterns of arsenic (As), iron (Fe), nickel (Ni), cobalt (Co), chromium (Cr), manganese (Mn), copper (Cu) and zinc (Zn) in the topsoil of a mining community in Ghana, along with potential human health risks and in vitro bioaccessibility.

METHODS

Concentrations of metals were determined using X-ray fluorescence techniques and validated using inductively coupled plasma-mass spectrometry.

RESULTS

Concentrations of the metals in topsoil were in the order of magnitude of Cu (31.38 mg/kg) < Ni (45.39 mg/kg) < As (59.66 mg/kg) < Cr (92.87 mg/kg) < Zn (106.98 mg/kg) < Mn (1195.49 mg/kg) < Fe (30061.02 mg/kg). Geo-statistical and multivariate analyses based on hazard indices including contamination, ecological risks, geo-accumulation, and pollution load suggest that the topsoils are contaminated in the study area. The potential ecological risk index (PERI) showed high ecological risk effects (PERI=269.09), whereas the hazard index (1×10-7) and carcinogenic risk index (1×10-5) indicated low human health risks. Elevated levels of As, Cr, Ni, and Zn were found to emanate from anthropogenic origins, whereas Fe, Mn, and Cu levels were attributed mainly to geological and atmospheric depositions. Physicochemical parameters (pH, electrical conductivity and total organic carbon) showed weak positive correlations to the metal concentrations. Elemental bioaccessibility was variable, decreasing in the order of Mn (35± 2.9%) > Cu (29± 2.6%) > Ni (22± 1.3%) > As (9± 0.5%) > Cr (4± 0.6%) > Fe (2± 0.4%).

CONCLUSIONS

Incorporation of in-vitro bioaccessibility into the risk characterization models resulted in a hazard index of less than 1, implying low human health risks. However, due to accumulation effects of the metals, regular monitoring is required.

COMPETING INTERESTS

The authors declare no competing financial interests.

Elemental concentrations and in vitro bioaccessibility in Canadian background soils

Elemental concentrations and bioaccessibility were determined in background soils collected in Canada as part of the North American Geochemical Landscapes Project. The concentrations of As, Cr, Cu, Co, Ni and Zn were higher in the C-horizon (parent material) compared to 0-5 cm (surface soil), and this observation along with the regional distribution suggested that most of the variability in concentrations of these elements were governed by the bedrock characteristics. Unlike the above-stated elements, Pb and Cd concentrations were higher in the surface layer reflecting the potential effects of anthropogenic deposition. Elemental bioaccessibility was variable decreasing in the order Cd > Pb > Cu > Zn > Ni > Co > As > Cr for the surface soils. With the exception of As, bioaccessibility was generally higher in the C-horizon soils compared to the 0-5 cm soils. The differences in metal bioaccessibility between the 0-5 cm and the C-horizon and among the provinces may reflect geological processes and speciation. The mean, median or 95th percentile bioaccessibility for As, Cr, Cu, Co, Ni and Pb were all below 100 %, suggesting that the use of site-specific bioaccessibility results for these elements will yield more accurate estimation of the risk associated with oral bioavailability for sites where soil ingestion is the major contributor of human health risk.

The minimal leak test technique for endotracheal cuff maintenance

Endotracheal tube (ETT) cuff pressure management is an essential part of airway management in intubated and mechanically ventilated patients. Both under- and over-inflation of the ETT cuff can lead to patient complications, with an ideal pressure range of 20-30 cmH₂O defined. A range of techniques are employed to ensure adequate ETT cuff inflation, with little comparative data. We performed an observational cross-sectional study in a tertiary metropolitan ICU, assessing the relationship between the minimal leak test and cuff manometry. Forty-five mechanically ventilated patients, over a three-month period, had ETT cuff manometry performed at the same time as their routine cuff maintenance (minimal leak test). Bedside nurse measurements were compared with investigator measurements. At the endpoint of cuff inflation, 20 of 45 patients (44%) had cuff pressures between 20 and 30 cmH₂O; 11 of 45 patients (24%) had cuff pressures <20 cmH₂O; 14 of 45 patients (31%) had cuff pressures ≥30 cmH₂O. Univariate analysis demonstrated an association between both patient obesity and female gender requiring less ETT cuff volume (P=0.008 and P <0.001 respectively), though this association was lost on multivariate analysis. No association was demonstrated between any measured variables and cuff pressures. Inter-operator reliability in performing the minimal leak test showed no evidence of bias between nurse and investigators (Pearson coefficient = 0.897). We conclude the minimal leak test for maintenance of ETT cuffs leads to both over- and under-inflation, and alternative techniques, such as cuff manometry, should be employed.

Distribution and bioaccessibility of metals in urban soils of Kumasi, Ghana

To assess the potential risk associated with incidental ingestion of metal contaminants in soils from areas where most of the commercial activities are concentrated in Kumasi, Ghana, total and bioaccessible concentrations of metals were determined in surface soil samples. Arsenic, Cr, Cu, Pb, and Zn in some of the samples exceeded international environmental soil quality guidelines. The use of geoaccumulation and enrichment factor indices also indicated high contamination in select areas of the commercial hub. Multivariate analyses of the data suggested that As, Cr, Cu, Ni, Pb, and Zn were mainly derived from anthropogenic sources whereas Al, Cd, Hg, and Fe were attributable to either soil parent materials or atmospheric deposition. Based on the total metal concentrations, the risk associated with exposure to metals in the contaminated soils was found to be high; the hazard quotient based on the mean concentration for a child receptor was greater than 1 for As, Cr, and Pb. Metal bioaccessibility was variable; decreasing in the order Zn (73 ± 15%) > Pb (62 ± 16%) > Cu (47 ± 14%) > Co (28 ± 11%) > Ni (24 ± 11%) > As (14 ± 13%) > Cr (2.8 ± 2.6%). Incorporation of the bioaccessibility data in the risk characterization resulted in hazard quotients of less than 1 indicating that the general risk associated with incidental ingestion of metals in the soils for both children and adults is low except for the contaminated hotspots. Lead and As contributed most to the overall risk.

Heavy metal content and potential health risk of geophagic white clay from the Kumasi Metropolis in Ghana

Geophagia is the craving for non-food substances and commonly practiced among pregnant women and children. Consumption of geophagic clay samples can have serious implications on the health of the consumers as a result of the presence of toxic metals such as Pb, As, Hg and Cd. This study sought to determine the levels of heavy metals in the studied geophagic clay samples and to determine the potential risks of heavy metals as cumulative carcinogenic and non-carcinogenic risks to the health of the consumers via oral (ingestion) and dermal exposure routes. A total of thirty (30) white clay samples were analysed using Niton Thermo scientific XRF Analyser (Mobile Test S, NDTr-XL3t-86956, com 24). The clay samples were found to contain essential elements such as Ca, Fe, K and Zn as well as toxic metals such as As and Pb. There were isolated cases of the presence of Hg and all samples had Cd levels below detection. Health risk indices such as hazard quotient and cancer risk were calculated and the results indicated that consumers are likely to suffer from cancer through ingestion of geophagic clay. Bioaccessibility studies were done on zinc and it did not indicate any potential toxicity due to zincs essential nature. The levels of heavy metals in some of the geophagic clay consumed by some residents in the Kumasi were high compared to the Permitted Maximum Tolerable Daily Intake (PMTDI) by (WHO/FAO) and may pose potential health threat over time.

Solid-liquid separation method governs the in vitro bioaccessibility of metals in contaminated soil-like test materials

An in vitro gastrointestinal model was used to explore the role of solid-liquid separation method on the bioaccessibility of trace elements in a smelter-impacted soil (NIST-2711) from Helena, MT and a mine overburden from an open-pit gold and silver mine in Mount Nansen, YK (YK-OVB). Separation methods studied included centrifugation (5,000 g, 12,000 g), syringe microfiltration (0.45 μm), and ultrafiltration (1,000 kDa, 50 kDa, 30 kDa, 10 kDa, 3 kDa). Results indicated that the use of syringe microfiltration generally yields the same bioaccessibility as the use of centrifugation and that the speed of centrifugation does not typically affect metal bioaccessibility. However, ultrafiltration consistently yields a significantly lower bioaccessibility than the use of centrifugation and syringe microfiltration. There are rarely any differences between bioaccessibility estimates generated using a low-resistance (1,000 kDa) and a high-resistance (3 kDa) ultrafiltration membrane; therefore, under the in vitro gastrointestinal conditions modeled herein, negligible quantities of trace elements are complexed to small molecules between 3 and 1,000 kDa. The primary exceptions to these trends were observed for Pb in NIST-2711 (5,000 g>12,000 g>0.45 μm>ultrafiltration) and for Tl in NIST-2711 and YK-OVB (5000 g∼12,000 g>0.45 μm>ultrafiltration). These results provide valuable information to researchers attempting to expand the use of in vitro bioaccessibility beyond soil Pb and As.

Variability of bioaccessibility results using seventeen different methods on a standard reference material, NIST 2710

Bioaccessibility is a measurement of a substance's solubility in the human gastro-intestinal system, and is often used in the risk assessment of soils. The present study was designed to determine the variability among laboratories using different methods to measure the bioaccessibility of 24 inorganic contaminants in one standardized soil sample, the standard reference material NIST 2710. Fourteen laboratories used a total of 17 bioaccessibility extraction methods. The variability between methods was assessed by calculating the reproducibility relative standard deviations (RSDs), where reproducibility is the sum of within-laboratory and between-laboratory variability. Whereas within-laboratory repeatability was usually better than (<) 15% for most elements, reproducibility RSDs were much higher, indicating more variability, although for many elements they were comparable to typical uncertainties (e.g., 30% in commercial laboratories). For five trace elements of interest, reproducibility RSDs were: arsenic (As), 22-44%; cadmium (Cd), 11-41%; Cu, 15-30%; lead (Pb), 45-83%; and Zn, 18-56%. Only one method variable, pH, was found to correlate significantly with bioaccessibility for aluminum (Al), Cd, copper (Cu), manganese (Mn), Pb and zinc (Zn) but other method variables could not be examined systematically because of the study design. When bioaccessibility results were directly compared with bioavailability results for As (swine and mouse) and Pb (swine), four methods returned results within uncertainty ranges for both elements: two that were defined as simpler (gastric phase only, limited chemicals) and two were more complex (gastric + intestinal phases, with a mixture of chemicals).

An investigation of the effect of gastrointestinal microbial activity on oral arsenic bioavailability

In vitro gastrointestinal (GI) microbial activity in the colon compartment facilitates the arsenic release from soils into simulated GI fluids. Consequentially, it is possible that in vitro models that neglect to include microbial activity underestimate arsenic bioaccessibility when calculating oral exposure. However, the toxicological relevance of increased arsenic release due to microbial activity is contingent upon the subsequent absorption of arsenic solubilized in the GI lumen. The objectives of this research are to: (1) assess whether microbes in the in vitro small intestine affect arsenic solubilization from soils, (2) determine whether differences in the GI microbial community result in differences in the oral bioavailability of soil-borne arsenic. In vitro GI microbial activity in the distal small intestine increased arsenic release from soils; however, these effects were unlikely to be relevant since they were transient and demonstrated small effect sizes. In vivo arsenic absorption for juvenile swine was unaffected by antibiotic treatment. Therefore, it appears that microbial effects on arsenic release do not result in increased arsenic bioavailability. However, it remains to be seen whether the results for the limited set of soils described herein can be extrapolated to arsenic contaminated sites in general.

Ways of coping with cystic fibrosis: implications for treatment adherence

PURPOSE

How individuals cope with aspects of cystic fibrosis (CF) has the potential to influence their self management and the course of their disease. To evaluate how individuals cope with CF, a disease specific coping scale was developed and validated. A second objective of the work was to examine the relationship between coping styles and treatment adherence.

METHODS

The development of the coping scale constituted a longitudinal design. A cross-sectional questionnaire design was used to examine the coping-adherence relationship. The development and validation of the coping scale comprised three phases: (1) Initially, 60 patients were interviewed to identify CF concerns. From this information a list of 23 concerns were recorded; (2) Eighty-three patients were interviewed to identify CF coping responses. For each concern, they were asked what they did or thought to ease the worry. A list of 24 coping strategies were recorded that formed a comprehensive set of items as to how people with CF act, feel and think about aspects of their disease; and (3) Further development and testing of the questionnaire involved 174 patients completing the measure. Four distinct ways of coping with CF were identified by factor analysis. These were termed optimistic acceptance, hopefulness, distraction and avoidance. The cronbach alpha coefficients were 0.74 (optimistic acceptance), 0.69 (hopefulness). 0.71 (distraction) and 0.76 (avoidance). To evaluate the relationship between coping and treatment adherence 60 patients completed the CF Coping Questionnaire and the Manchester Adult Cystic Fibrosis Compliance Questionnaire.

RESULTS

Compared with patients who were non-adherent, those who were adherent scored higher on the optimistic acceptance scale (physiotherapy p < 0.05, enzymes p < 0.003, vitamins p < 0.05) and hopefulness scale (physiotherapy p < 0.002, enzymes p < 0.001). Those who were partially adherent reported using distraction as a way of coping to a greater extent than adherent or non-adherent patients (all p's < 0.05). Non-adherent patients used avoidance strategies to a greater extent than those who were adherent (physiotherapy p < 0.05, enzymes p < 0.04), although interestingly, adherence with exercise was associated with avoidant coping (p < 0.004).

CONCLUSIONS

The degree of adherence to treatments was influenced by a person's style of coping. The identification of effective coping strategies to aid both long-term psychological and clinical well-being should improve the management of non-adherence.