CONSUMPTION OF UNREGULATED DRINKING WATER AND HUMAN HEALTH RISK IN RURAL COMMUNTIES

Establishing safe drinking water for rural populations dependent on unregulated water is a global challenge. Despite initiatives to improve access to drinking water, hazards associated with unregulated sources pose a potential risk to human health for rural populations. In the absence of accurate information and monitoring of water quality, consumers form heuristic perceptions of risk associated with their drinking water. Risk perception affects water consumption contributing to uncertainty in risk exposure. Quantifying risk through human health risk assessments (HHRA) has been implemented since the 1940s and advances in risk assessment modeling have created an opportunity to improve HHRA by applying probabilistic Bayesian risk assessment methods. A holistic HHRA integrating risk perception, as it relates to exposure, can quantify uncertainty and provide feedback to improve risk communication and management. The literature lacks a review or summary that characterizes the type and frequency of HHRAs applied to rural populations dependent on unregulated drinking water. The purpose of this thesis is to: (1) summarize studies with HHRA methods applied to unregulated drinking water and rural communities, and describe the characteristics of methods, publications, and current literature gaps; and, (2) characterize and quantify risk perception as it relates to unregulated groundwater wells, and determine the impact of risk perception on human health risk using a holistic HHRA. A systematic scoping review of peer-reviewed literature (Jan 2000 to May 2014) was used to identify studies with HHRAs applied to unregulated or unspecified drinking water. At least one drinking water source was identified as unregulated (21%) or unspecified (79%) in 100 studies, and 7% identified rural communities dependent on unregulated drinking water. No studies integrated non-traditional factors (e.g. risk perception) into a holistic HHRA. HHRAs applied to rural populations dependent on unregulated water are poorly represented in the literature even though almost half of the global population is rural. The scoping review confirmed a lack of HHRA studies addressing unregulated drinking water risks, and the absence of applied methods that facilitated the quantification and integration of non-traditional factors. Based on the review findings, a community-based participatory observational case study and holistic HHRA was applied using arsenic concentrations and survey responses from two communities dependent on unregulated groundwater wells. Risk perception and human health risk was determined using probabilistic (Bayesian) risk assessment methods. Community tap water quality exceeded at least one health standard at a rate of 56% and 65%. Integration of risk perception did not change the overall risk status but lowered the cancer risk for arsenic by 3% for both communities. The probability of exposure to arsenic concentrations over 1:100,000 negligible risk for the two communities was 23% and 22%. There was no correlation between risk perception and drinking water safety in either community. This study achieved a holistic Bayesian risk assessment through the integration of risk perception and provided a probability of risk that can be used to inform risk communication and management specific to the participating communities

Safety of efavirenz in the first trimester of pregnancy: an updated systematic review and meta-analysis

Article approval pendingEvidence of the risk of birth defects with efavirenz use is limited. We updated a meta-analysis of birth defects in infants with first trimester efavirenz exposure up to July 2011. In 21 studies, there were 39 defects among live births in 1437 women receiving first trimester efavirenz [2.0%, 95% confidence interval (CI) 0.82-3.18]. The relative risk of defects comparing women on efavirenz-based (1290 live births) and nonefavirenz-based regimens (8122 live births) was 0.85 (95% CI 0.61-1.20). One neural tube defect was observed (myelomeningocele), giving an incidence of 0.07% (95% CI 0.002-0.39)

A cross sectional survey of smoking characteristics and quitting behaviour from a sample of homeless adults in Great Britain

Background Smoking is a key contributor to health and social inequalities and homeless smoking prevalence rates are 4 times higher than the general population. Research on homelessness and smoking to date has been concentrated predominantly in the US and Australia. This study aimed to describe smoking and quitting behaviour in homeless adult smokers in Great Britain. Data on perceptions of, and willingness to try, e-cigarettes were also gathered. Methods Cross sectional survey of 283 adult smokers accessing homeless support services in Kent, the Midlands, London and Edinburgh. Participants answered a four-part survey: i) demographics; ii) current smoking behaviour and dependence (including the Fagerström Test of Cigarette Dependence [FTCD]); iii) previous quit attempts; and iv) e-cigarettes perceptions. Results High levels of cigarette dependence were observed (FTCD: M = 7.78, sd ± 0.98). Although desire to quit was high, most had made fewer than 5 quit attempts and 90% of these lasted less than 24 h. 91.5% reported that others around them also smoked. Previous quit methods used included cold turkey (29.7%), NRT (24.7%), varenicline (22.3%) and bupropion (14.5%). 34% were willing or able to spend £20 or more for an e-cigarette and 82% had tried one in the past although 54% reported that they preferred smoking. Conclusion We observed high nicotine dependence, few long-term quit attempts, strong desire to quit and amenability to both traditional cessation methods and e-cigarettes. Community embedded and non-routine approaches to cessation may be promising avenues promoting engagement with the homeless community. Likely barriers to uptake include low affordability, preference for cigarettes and high numbers of smoking acquaintances

A cross-sectional survey of smoking and cessation support policies in a sample of homeless services in the United Kingdom

Background: Smoking is extremely common amongst adults experiencing homelessness. To date, there is no nationally representative data on how tobacco dependence is treated and if and how smoking cessation is supported across the homeless sector. The aim of this study was to document smoking and e-cigarette policies of UK homeless services and identify areas of good practice and where improvements could be made. Methods: A cross-sectional survey with homeless centre staff was conducted between June 2020-December 2020 totalling 99 homeless centres. Quotas were stratified based on population and service type across Scotland, Northern Ireland, Wales, and England. Interviews were conducted over the phone or online in a minority of cases. Survey questions were themed to assess, i) onsite smoking and e-cigarette (vaping) policies ii) screening and recording of smoking status, iii) cessation training and resources available to staff, iv) cessation support for service users. Results: 92% accounted for smoking within their policies in some form (stand-alone policy (56%) or embedded within another health and safety policy (36%)). 84% allowed smoking in at least some (indoor and outdoor) areas. In areas where smoking was not allowed, vaping was also disallowed in 96% of cases. Staff smoking rates were 23% and 62% of centres reported staff smoked with service users. Just over half (52%) reported screening and recording smoking status and 58% made referrals to Stop Smoking Services (SSS), although established links with SSS were low (12%) and most centres did not provide staff training on supporting smoking cessation. Areas of good practice included regular offers of smoking cessation support embedded in routine health reviews or visits from SSS and offering tangible harm reduction support. Areas for improvement include staff training, staff smoking with service users and skipping routine screening questions around smoking. Conclusions: Smoking is accounted for across different policy types and restricted in some areas within most settings. Smoking cessation support is not routinely offered across the sector and there is little involvement with the SSS

Community-supported models of care for people on HIV treatment in sub-Saharan Africa.

Further scale-up of antiretroviral therapy (ART) to those in need while supporting the growing patient cohort on ART requires continuous adaptation of healthcare delivery models. We describe several approaches to manage stable patients on ART developed by Médecins Sans Frontières together with Ministries of Health in four countries in sub-Saharan Africa

A Rapid Electronic Cognitive Assessment Measure for Multiple Sclerosis: Validation of Cognitive Reaction, an Electronic Version of the Symbol Digit Modalities Test

Background: incorporating cognitive testing into routine clinical practice is a challenge in multiple sclerosis (MS), given the wide spectrum of both cognitive and physical impairments people can have and the time that testing requires. Shortened paper and verbal assessments predominate but still are not used routinely. Computer-based tests are becoming more widespread; however, changes in how a paper test is implemented can impact what exactly is being assessed in an individual. The Symbol Digit Modalities Test (SDMT) is one validated test that forms part of the cognitive batteries used in MS and has some computer-based versions. We developed a tablet-based SDMT variant that has the potential to be ultimately deployed to patients' own devices.Objective: this paper aims to develop, validate, and deploy a computer-based SDMT variant, the Cognition Reaction (CoRe) test, that can reliably replicate the characteristics of the paper-based SDMT.Methods: we carried out analysis using Pearson and intraclass correlations, as well as a Bland-Altman comparison, to examine consistency between the SDMT and CoRe tests and for test-retest reliability. The SDMT and CoRe tests were evaluated for sensitivity to disability levels and age. A novel metric in CoRe was found: question answering velocity could be calculated. This was evaluated in relation to disability levels and age for people with MS and compared with a group of healthy control volunteers.Results: SDMT and CoRe test scores were highly correlated and consistent with 1-month retest values. Lower scores were seen in patients with higher age and some effect was seen with increasing disability. There was no learning effect evident. Question answering velocity demonstrated a small increase in speed over the 90-second duration of the test in people with MS and healthy controls.Conclusions: this study validates a computer-based alternative to the SDMT that can be used in clinics and beyond. It enables accurate recording of elements of cognition relevant in MS but offers additional metrics that may offer further value to clinicians and people with MS

Chandra Observations of Candidate Subparsec Binary Supermassive Black Holes

We present analysis of Chandra X-ray observations of seven quasars that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey based on the apparent periodicity in their optical light curves. Simulations predict that close-separation accreting SMBH binaries will have different X-ray spectra than single accreting SMBHs, including harder or softer X-ray spectra, ripple-like profiles in the Fe K-α line, and distinct peaks in the spectrum due to the separation of the accretion disk into a circumbinary disk and mini disks around each SMBH. We obtained Chandra observations to test these models and assess whether these quasars could contain binary SMBHs. We instead find that the quasar spectra are all well fit by simple absorbed power-law models, with the rest-frame 2–10 keV photon indices, Γ, and the X-ray-to-optical power slopes, α_(OX), indistinguishable from those of the larger quasar population. This may indicate that these seven quasars are not truly subparsec binary SMBH systems, or it may simply reflect that our sample size was too small to robustly detect any differences. Alternatively, the X-ray spectral changes might only be evident at energies higher than probed by Chandra. Given the available models and current data, no firm conclusions are drawn. These observations will help motivate and direct further work on theoretical models of binary SMBH systems, such as modeling systems with thinner accretion disks and larger binary separations