Patient costs associated with accessing HIV/AIDS care in Malawi

PubMed Central

Pinto, Andrew D; van Lettow, Monique; Rachlis, Beth; Chan, Adrienne K; Sodhi, Sumeet K

2013-01-01

Introduction The decentralization of HIV services has been shown to improve equity in access to care for the rural poor of sub-Saharan Africa. This study aims to contribute to our understanding of the impact of decentralization on costs borne by patients. Such information is valuable for economic evaluations of anti-retroviral therapy programmes that take a societal perspective. We compared costs reported by patients who received care in an urban centralized programme to those in the same district who received care through rural decentralized care (DC). Methods A cross-sectional survey on patient characteristics and costs associated with accessing HIV care was conducted, in May 2010, on 120 patients in centralized care (CC) at a tertiary referral hospital and 120 patients in DC at five rural health centres in Zomba District, Malawi. Differences in costs borne by each group were compared using χ2 and t-tests, and a regression model was developed to adjust for confounders, using bootstrapping to address skewed cost data. Results There was no significant difference between the groups with respect to sex and age. However, there were significant differences in socio-economic status, with higher educational attainment (p<0.001), personal income (p=0.007) and household income per person (p=0.005) in CC. Travel times were similar (p=0.65), as was time waiting at the clinic (p=0.63) and total time spent seeking care (p=0.65). There was a significant difference in travel-related expenses (p<0.001) related to the type of travel participants noted that they used. In CC, 60% of participants reported using a mini-bus to reach the clinic; in DC only 4% reported using a mini-bus, and the remainder reported travelling on foot or by bicycle. There were no significant differences between the groups in the amount of lost income reported or other out-of-pocket costs. Approximately 91 Malawi Kwacha (95% confidence intervals: 1–182 MKW) or US$0.59 represents the adjusted difference in total costs per visit between CC and DC. Conclusions Even within a system of HIV/AIDS care where patients do not pay to see clinicians or for most medications, they still incur costs. We found that most costs are travel related. This has important implications for poorer patients who live at a distance from health facilities for whom these costs may be significant. PMID:23517716

Practical Efficiency of Photovoltaic Panel Used for Solar Vehicles

NASA Astrophysics Data System (ADS)

Koyuncu, T.

2017-08-01

In this experimental investigation, practical efficiency of semi-flexible monocrystalline silicon solar panel used for a solar powered car called “Firat Force” and a solar powered minibus called “Commagene” was determined. Firat Force has 6 solar PV modules, a maintenance free long life gel battery pack, a regenerative brushless DC electric motor and Commagene has 12 solar PV modules, a maintenance free long life gel battery pack, a regenerative brushless DC electric motor. In addition, both solar vehicles have MPPT (Maximum power point tracker), ECU (Electronic control unit), differential, instrument panel, steering system, brake system, brake and gas pedals, mechanical equipments, chassis and frame. These two solar vehicles were used for people transportation in Adiyaman city, Turkey, during one year (June 2010-May 2011) of test. As a result, the practical efficiency of semi-flexible monocrystalline silicon solar panel used for Firat Force and Commagene was determined as 13 % in despite of efficiency value of 18% (at 1000 W/m2 and 25 °C ) given by the producer company. Besides, the total efficiency (from PV panels to vehicle wheel) of the system was also defined as 9%.

Understanding the knowledge and attitudes of commercial drivers in Ghana regarding alcohol impaired driving

PubMed Central

Asiamah, G; Mock, C; Blantari, J

2002-01-01

Objectives: The knowledge and attitudes of commercial drivers in Ghana as regards alcohol impaired driving were investigated. This was done in order to provide information that could subsequently be used to develop antidrunk driving social marketing messages built upon the intrinsic values and motivation of these drivers. Methods: Focus group discussions were held with 43 bus and minibus drivers in the capital city, Accra. A structured discussion guide was used to capture information related to values, risk perceptions, leisure time activities, and attitudes on alcohol impaired driving. Results: The majority of drivers expressed an understanding that drunk driving was a significant risk factor for crashes. There was a significant under-appreciation of the extent of the problem, however. Most believed that it was only rare, extremely intoxicated drivers who were the problem. The drivers also had a minimal understanding of the concept of blood alcohol concentration and related legal limits. Despite these factors, there was widespread support for increased enforcement of existing antidrunk driving laws. Conclusions: In Ghana, commercial drivers understand the basic danger of drunk driving and are motivated to assist in antidrunk driving measures. There are misconceptions and deficits in knowledge that need to be addressed in subsequent educational campaigns. PMID:11928975

A design methodology of magentorheological fluid damper using Herschel-Bulkley model

NASA Astrophysics Data System (ADS)

Liao, Linqing; Liao, Changrong; Cao, Jianguo; Fu, L. J.

2003-09-01

Magnetorheological fluid (MR fluid) is highly concentrated suspension of very small magnetic particle in inorganic oil. The essential behavior of MR fluid is its ability to reversibly change from free-flowing, linear viscous liquids to semi-solids having controllable yield strength in milliseconds when exposed to magnetic field. This feature provides simple, quiet, rapid-response interfaces between electronic controls and mechanical systems. In this paper, a mini-bus MR fluid damper based on plate Poiseuille flow mode is typically analyzed using Herschel-Bulkley model, which can be used to account for post-yield shear thinning or thickening under the quasi-steady flow condition. In the light of various value of flow behavior index, the influences of post-yield shear thinning or thickening on flow velocity profiles of MR fluid in annular damping orifice are examined numerically. Analytical damping coefficient predictions also are compared via the nonlinear Bingham plastic model and Herschel-Bulkley constitutive model. A MR fluid damper, which is designed and fabricated according to design method presented in this paper, has tested by electro-hydraulic servo vibrator and its control system in National Center for Test and Supervision of Coach Quality. The experimental results reveal that the analysis methodology and design theory are reasonable and MR fluid damper can be designed according to the design methodology.

Knowledge of commercial bus drivers about road safety measures in Lagos, Nigeria.

PubMed

Okafor Ifeoma, P; Odeyemi Kofoworola, A; Dolapo Duro, C

2013-01-01

Road traffic injuries have persisted as a serious public health problem and much of the health burden is in developing countries. Over-speeding, poor enforcement of traffic regulations and commuter buses have been highly implicated in road traffic injuries in developing countries. The aim of this study was to determine drivers' knowledge of selected road safety measures, i.e. the pre-requisites for driver's license, road signs and speed limits. This was a cross-sectional study carried out in Lagos, Nigeria. Simple random sampling was used to select the two motor parks used for the study and all the consenting commercial minibus drivers operating within the parks (407) were included in the study. Data was collected with a pre-tested, structured, interviewer-administered questionnaire and analyzed with epi-info statistical software. Two hundred and sixty-one (64.1%) of them knew that Visual Acuity test should be done before obtaining driver's license and 53.8% knew the correct minimum age for obtaining driver's license. Only 1% of the drivers had correct knowledge of the driver's license authorities in Nigeria. The drivers had poor knowledge of road signs (59.0%) and poor knowledge of maximum speed limits (100%). The oldest, least educated and least experienced drivers had the poorest level of knowledge. The drivers demonstrated poor knowledge of road safety measures. There is need for driver education to improve their knowledge.

It is not all bad for the grey city - A crossover study on physiological and psychological restoration in a forest and an urban environment.

PubMed

Stigsdotter, Ulrika K; Corazon, Sus Sola; Sidenius, Ulrik; Kristiansen, Jesper; Grahn, Patrik

2017-07-01

Today, urbanization presents a challenge to urban planning with regard to creating healthy living environments. The aim of this research is to gain further knowledge of the restorativeness of a best case urban and natural environment: that is a historic down town urban environment and forest environment located in an arboretum. The study has a cross-over design where 51 (N) female university students are exposed to the two environments through both seated viewing and walking. A mixed method approach is used with both physiological measurements of blood pressure (BP) and heart rate variability (HRV) and psychological measurements of mood change and perceived restorativeness. The HRV results show no significant differences between the two environments, and both environments are found to be more physiologically restorative than being at the office or on the minibus. The results of the psychological measures indicate that the forest walk has a positive effect on mood, while the walk in the urban environment has no effect. The forest environment is also rated more highly with regard to perceived restorativeness than the urban environment. The results support the current research that shows natural environments as more restorative than urban environments. The study also adds to the ongoing debate on healthy urban planning by indicating that architectural and historical qualities may be associated with the physiological well-being of citizens. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Current patterns of prehospital trauma care in Kampala, Uganda and the feasibility of a lay-first-responder training program.

PubMed

Jayaraman, Sudha; Mabweijano, Jacqueline R; Lipnick, Michael S; Caldwell, Nolan; Miyamoto, Justin; Wangoda, Robert; Mijumbi, Cephas; Hsia, Renee; Dicker, Rochelle; Ozgediz, Doruk

2009-12-01

Uganda currently has no organized prehospital emergency system. We sought to measure the current burden of injury seen by lay people in Kampala, Uganda and to determine the feasibility of a lay first-responder training program. We conducted a cross-sectional survey of current prehospital care providers in Kampala: police officers, minibus taxi drivers, and Local Council officials, and collected data on types and frequencies of emergencies witnessed, barriers to aid provision, history of training, and current availability of first-aid supplies. A context-appropriate course on basic first-aid for trauma was designed and implemented. We measured changes in trainees' fund of knowledge before and after training. A total of 309 lay people participated in the study, and during the previous 6 months saw 18 traumatic emergencies each; 39% saw an injury-related death. The most common injury mechanisms were road crashes, assault, and burns. In these cases, 90% of trainees provided some aid, most commonly lifting (82%) or transport (76%). Fifty-two percent of trainees had previous first-aid training, 44% had some access to equipment, and 32% had ever purchased a first-aid kit. Before training, participants answered 45% of test questions correctly (mean %) and this increased to 86% after training (p < 0.0001). Lay people witness many emergencies and deaths in Kampala, Uganda and provide much needed care but are ill-prepared to do so. A context-appropriate prehospital trauma care course can be developed and improve lay people's knowledge of basic trauma care. The effectiveness of such a training program needs to be evaluated prospectively.

Understanding road safety in Kenya: views of matatu drivers.

PubMed

Raynor, Nicolas J; Mirzoev, Tolib

2014-09-01

Road traffic accidents (RTAs) are estimated to cause 1.3 million deaths and 20-50 million injuries worldwide. Road safety is a challenge in Kenya with causes being multi-factorial. Matatus (minibuses) are involved in a large proportion of accidents. A literature review was completed to identify key issues and refine the scope of the study. The fieldwork included 20 semi-structured interviews with matatu drivers. All participants were male, with driving experience of 1-20 years. Thematic framework was used for analysis. Some unstructured observations on different road users and their behaviours were also recorded. Literature showed that the causes of RTAs in Kenya are multi-factorial, but that human factors play a large part. There is also an evidence gap concerning matatu drivers, who are key stakeholders in road safety. Fieldwork showed that the matatu industry creates financial pressures on drivers and an excessive level of competition, leading to dangerous driving. Corruption of traffic police appears to be a major barrier to improving road safety, as road safety legislation is not enforced, and bribery has become the cultural norm. The general public, including passengers and private vehicles owners, also cause problems by failing to understand their role in road safety and placing the blame on others. The key policy implication for improving road safety in Kenya is seeking measures to ensure responsibility by all road users through awareness raising in the short-term and reforming the matatu industry and addressing the root causes of corruption in the longer term. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Compliance with driver's license laws and illegal licensing among commercial bus drivers in Lagos, Nigeria: policy implications and evidence for action.

PubMed

Okafor, I P; Odeyemi, K A; Dolapo, D C; Adegbola, A A

2014-09-01

To determine the level of compliance with driver's license laws among commercial bus drivers in Lagos, Nigeria. Two intercity motor parks were selected by simple random sampling and all consenting minibus drivers participated in the study. Key Informant Interviews (KIIs) were also conducted with selected officials in the driver training and licensing authorities. Compliance with the minimum age for driving was high (93.6%), so also was having driving test prior to driver's license procurement (83.3%). Formal driver training and VA testing were very low, (26.1% and 32.9% respectively) Overall, only 9.3% of them were found to have fulfilled all the pre-license obligations before obtaining their first driver's license. The odds of a driver with a secondary education having formal driver training is 3.33 times higher than those with no education (OR 3.33, 95% CI 1.01-11.35). Drivers who were 60 years or older were 3.62 times more likely to be compliant than those who were between 20-29 years (OR 3.62, 95% CI 0.56-29.19). For the 98.3% of them who possessed valid licenses, 52.3% of them obtained them illegally. All the key officials saw RTIs as a serious public health problem but faced several challenges in the course of their work. Overall compliance with pre-license regulations was very poor. There is need for a review and strict enforcement of driver's license laws to improve compliance. Also vital are fostering inter-sectoral collaboration and improvement in the operations of all establishments involved in driver training and license procurement in Nigeria.

Car crash fatalities associated with fire in Sweden.

PubMed

Viklund, Åsa; Björnstig, Johanna; Larsson, Magnus; Björnstig, Ulf

2013-01-01

To study the epidemiology and causes of death in fatal car crashes on Swedish roads in which the victim's vehicle caught fire. The data set is from the Swedish Transport Administrations in-depth studies of fatal crashes 1998-2008. Autopsies from all cases provided data on injuries, toxicological analyses, and cause of death. In total, 181 people died in 133 burning cars, accounting for 5 percent of all deaths in passenger cars, sport utility vehicles, vans, and minibuses during 1998 to 2008. The cause of death for a third of the victims was fire related, as burns and/or smoke inhalation injuries, with no fatal trauma injuries. Twenty-five of these 55 deaths were persons 19 years or younger and included 15 of 18 rear seat deaths. Over half of the 181 deaths were in vehicles that had collided with another vehicle and, of these cases, half were killed in collisions with heavy vehicles. The percentage of drivers with illegal blood alcohol concentrations (27%) and suicides (5.5%) were not higher than in other fatal crashes on Swedish roads. The ignition point of the fire was indicated in only half of the cases and, of those, half started in the engine compartment and one fourth started around the fuel tank or lines. Car fires are a deadly postcrash problem. Reducing this risk would be primarily a responsibility for the automotive industry. A multifactor approach could be considered as follows: risk-reducing design, insulation, reduced flammability in motor compartment fluids and plastics, and automatic fire extinguishing equipment. Inspiration could be found in how, for example, the auto racing and aviation industries handle this problem.

Effectiveness of media awareness campaigns on the proportion of vehicles that give space to ambulances on roads: An observational study.

PubMed

Shaikh, Shiraz; Baig, Lubna A; Polkowski, Maciej

2017-01-01

The findings of the Health Care in Danger project in Karachi suggests that there is presence of behavioral negligence among vehicle operators on roads in regards to giving way to ambulances. A mass media campaign was conducted to raise people's awareness on the importance of giving way to ambulances. The main objective of this study was to determine the effectiveness of the campaign on increasing the proportion of vehicles that give way to ambulances. This was a quasi-experimental study that was based on before and after design. Three observation surveys were carried out in different areas of the city in Karachi, Pakistan before, during and after the campaign by trained observers who recorded their findings on a checklist. Each observation was carried out at three different times of the day for at least two days on each road. The relationship of the media campaign with regards to a vehicle giving space to an ambulance was calculated by means of odds ratios and 95% confidence intervals using multivariate logistic regression. Overall, 245 observations were included in the analysis. Traffic congestion and negligence/resistance, by vehicles operators who were in front of the ambulance, were the two main reasons why ambulances were not given way. Other reasons include: sudden stops by minibuses and in the process causing obstruction, ambulances not rushing through to alert vehicle operators to give way and traffic interruption by VIP movement. After adjustment for site, time of day, type of ambulance and number of cars in front of the ambulance, vehicles during (OR=2.13, 95% CI=1.22-3.71, p=0.007) and after the campaign (OR=1.73, 95% CI=1.02-2.95, p=0.042) were significantly more likely give space to ambulances. Mass media campaigns can play a significant role in changing the negligent behavior of people, especially when the campaign conveys a humanitarian message such as: giving way to ambulances can save lives.

Taxi 'sugar daddies' and taxi queens: male taxi driver attitudes regarding transactional relationships in the Western Cape, South Africa.

PubMed

Potgieter, Cheryl; Strebel, Anna; Shefer, Tamara; Wagner, Claire

2012-11-01

Media reports are emerging on the phenomenon of young girls who travel with older mini-bus taxi drivers, and who are thought to have sex with the drivers in exchange for gifts and money. The extent to which such relationships might facilitate unsafe sexual practices and increased risks for both the men and the young women, often referred to as taxi queens, remains an important question in the light of the current challenges of HIV/AIDS in sub-Saharan Africa. However, very little research has been undertaken on this issue, especially regarding the perceptions and experiences of taxi drivers. Thus this paper aims to provide some preliminary findings on taxi drivers' attitudes and beliefs about taxi queens and their relationships with taxi drivers. A 22-item questionnaire was administered to 223 male taxi drivers in two regions in the Western Cape Province, South Africa. Taxi drivers in this study largely saw the relationship between taxi drivers and the young girls who ride with them as providing status for both the girls and drivers, and there seemed to be recognition of the transactional nature of the relationship between taxi drivers and taxi queens. The stigmatisation of young girls who ride with taxi drivers was evident. Drivers had knowledge and awareness of the risks of unsafe sex and supported condom use, although there appeared to be some uncertainty and confusion about the likelihood of HIV infection between drivers and girls. While taxi drivers recognised the role of alcohol in relationships with young girls, they seemed to deny that the abuse of drugs was common. The study highlights a number of key areas that need to be explored with men in the taxi industry, in order to address risk behaviours for both taxi drivers and the girls who ride with them.

Effectiveness of media awareness campaigns on the proportion of vehicles that give space to ambulances on roads: An observational study

PubMed Central

Shaikh, Shiraz; Baig, Lubna A; Polkowski, Maciej

2017-01-01

Background and Objective: The findings of the Health Care in Danger project in Karachi suggests that there is presence of behavioral negligence among vehicle operators on roads in regards to giving way to ambulances. A mass media campaign was conducted to raise people’s awareness on the importance of giving way to ambulances. The main objective of this study was to determine the effectiveness of the campaign on increasing the proportion of vehicles that give way to ambulances. Methods: This was a quasi-experimental study that was based on before and after design. Three observation surveys were carried out in different areas of the city in Karachi, Pakistan before, during and after the campaign by trained observers who recorded their findings on a checklist. Each observation was carried out at three different times of the day for at least two days on each road. The relationship of the media campaign with regards to a vehicle giving space to an ambulance was calculated by means of odds ratios and 95% confidence intervals using multivariate logistic regression. Results: Overall, 245 observations were included in the analysis. Traffic congestion and negligence/resistance, by vehicles operators who were in front of the ambulance, were the two main reasons why ambulances were not given way. Other reasons include: sudden stops by minibuses and in the process causing obstruction, ambulances not rushing through to alert vehicle operators to give way and traffic interruption by VIP movement. After adjustment for site, time of day, type of ambulance and number of cars in front of the ambulance, vehicles during (OR=2.13, 95% CI=1.22-3.71, p=0.007) and after the campaign (OR=1.73, 95% CI=1.02-2.95, p=0.042) were significantly more likely give space to ambulances. Conclusion: Mass media campaigns can play a significant role in changing the negligent behavior of people, especially when the campaign conveys a humanitarian message such as: giving way to ambulances can save lives. PMID:28367204

Using bayesian model to estimate the cost of traffic injuries in Iran in 2013

PubMed Central

Ainy, Elaheh; Soori, Hamid; Ganjali, Mojtaba; Bahadorimonfared, Ayad

2017-01-01

Background and Aim: A significant social and economic burden inflicts by road traffic injuries (RTIs). We aimed to use Bayesian model, to present the precise method, and to estimate the cost of RTIs in Iran in 2013. Materials and Methods: In a cross-sectional study on costs resulting from traffic injuries, 846 people per road user were randomly selected and investigated during 3 months (1st September–1st December) in 2013. The research questionnaire was prepared based on the standard for willingness to pay (WTP) method considering perceived risks, especially in Iran. Data were collected along with four scenarios for occupants, pedestrians, vehicle drivers, and motorcyclists. Inclusion criterion was having at least high school education and being in the age range of 18–65 years old; risk perception was an important factor to the study and measured by visual tool. Samples who did not have risk perception were excluded from the study. Main outcome measure was cost estimation of traffic injuries using WTP method. Results: Mean WTP was 2,612,050 internal rate of return (IRR) among these road users. Statistical value of life was estimated according to 20,408 death cases 402,314,106,073,648 IRR, equivalent to 13,410,470,202$ based on the dollar free market rate of 30,000 IRR (purchase power parity). In sum, injury and death cases came to 1,171,450,232,238,648 IRR equivalents to 39,048,341,074$. Moreover, in 2013, costs of traffic accident constituted 6.46% of gross national income, which was 604,300,000,000$. WTP had a significant relationship with age, middle and high income, daily payment to injury reduction, more payment to time reduction, trip mileage, private cars drivers, bus, minibus vehicles, and occupants (P < 0.01). Conclusion: Costs of traffic injuries included noticeable portion of gross national income. If policy-making and resource allocation are made based on the scientific pieces of evidence, an enormous amount of capital can be saved through reducing death and injury rates. PMID:28971031

Buckling up in Singapore: residency and other risk factors for seatbelt non-compliance - a cross-sectional study based on trauma registry data.

PubMed

Wong, Ting Hway; Lim, Gek Hsiang; Chow, Khuan Yew; Zaw, Nyi Nyi; Nguyen, Hai Van; Chin, Hoong Chor; Ong, Marcus Eng Hock

2016-05-14

Seatbelt non-compliance is a problem in middle income countries, and little is known about seatbelt compliance in populations with a high proportion of non-residents. This study analyses the profile of seatbelt non-compliance in Singapore based on trauma registry data from five of the six public hospitals. This is a cross-sectional study of seatbelt compliance of patients aged over 18 years, attending the emergency departments of five public hospitals in Singapore after road collisions from 2011-2014. Seatbelt data was obtained from paramedic and patient history. There were 4,576 patients studied. Most were Singapore citizens (83.4 %) or permanent residents (2.4 %), with the largest non-resident groups from Malaysia, India, and China. Overall seatbelt compliance was 82.1 %. On univariate analysis, seatbelt compliance was higher in older patients (OR 1.02, 95 % CI 1.001-1.021, p < 0.0001); drivers, followed by front passengers (OR 0.65, 95 % CI 0.51-0.83, p < 0.0001), were more compliant than rear passengers (OR 0.08, 0.06-0.09, p < 0.0001); occupants of larger vehicle types (buses, heavy transport vehicles, minibuses and vans) were more non-compliant compared to occupants of private cars and taxis. Morning peak travel (0700 h-0900 h) and being a non-resident were other risk factors for non-compliance. On multivariable analysis, older age (OR 1.01, 95 % CI 1.001-1.014, p = 0.03) was associated with compliance, while non-residents from China (OR 0.43, 95 % CI 0.18-0.99, p = 0.05), seat position (front passenger compared to driver, OR 0.64, 95 % CI 0.48-0.85, p = 0.002; rear passenger compared to driver, OR 0.067, 95 % CI 0.05-0.09, p < 0.0001), vehicle type (bus compared to car, OR 0.04, 95 % CI 0.017-0.11, p < 0.0001, van compared to car, OR 0.55, 95 % CI 0.36-0.83, p = 0.004), and travel at morning peak periods were independent predictors of seatbelt non-compliance. When the sub-group of drivers was analysed, only vehicle type was a significant predictor of seatbelt compliance, with bus drivers least likely to be compliant to seatbelts (multivariable analysis, OR 0.057 compared to cars, 95 % CI 0.019-0.18, p < 0.0001). While overall seatbelt compliance in our study is high, efforts can be made to increase compliance for morning rush hour passengers, rear seat passengers, and occupants of buses, heavy transport vehicles, and vans or pickups.

NEWS: Post-16 update

NASA Astrophysics Data System (ADS)

1999-05-01

(post16) Making physics connect Doesn't Melvyn Bragg do a wonderful job, engaging both scientists and artists in sensitive discussion on Radio 4 about their methods and their purposes? But every week teachers have the chance to show their students that physics is a way of seeing the world that is well-connected with other aspects of knowledge and culture. The stakes are high: students who fail to appreciate this generally choose not to study the subject beyond GCSE. Most students find our preoccupation with technical detail off-putting. Accepting that we have a syllabus to cover, it's still a question of balance. In our teaching we should aim for variety in order to find ways to connect with every student's interests. Also, we can show that we (the nearest embodiment of a physicist some students will experience) are multidimensional and so fully human. Most important, teachers need flexibility to both encourage and respond to student comment and questions. The first booklet in the discussion series Shaping the Future takes up these themes. Rich in ideas for both immediate use and the longer term, it aims to stimulate debate and improve teaching. Copies cost £5.50 including postage and are available from Ingrid Ebeyer, Post-16 Initiative, Institute of Physics, 76 Portland Place, London W1N 3DH. How far is it? This question is asked in many family cars and school minibuses at the start of a journey, and answered by most in terms of hours and minutes rather than miles. What a good idea for introducing a social and historical perspective to a lesson on distance, velocity and time. How far can you actually get in a day? What is the range of human activity? Walking for eight hours will get many people about 25 miles. A pack horse will progress at much the same rate, but fast riding or a coach and team of horses will get further. Motorway driving (when the cones are on holiday) would take you nearly 500 miles. The 05.15 am train from Penzance arrives in Inverness at 7.15 pm. Twelve hours travel by air will reach the other side of the world. Given such a change in the range of human activity, is it surprising that society has changed and adapted, and some historical incidents and lifestyles hardly make sense? The journals of Dorothy Wordsworth describe a life spent at walking pace. Jane Austen's novels take place at horse speed. Many modern novels are of the jet age, and world travel is part of the plot. Reading accounts of warfare, we must remember that an army perhaps moved 15 miles a day if it hurried (and arrived exhausted). It becomes very clear why Britain could be several independent kingdoms. Turning to another area of physics, we might even speculate how easy life for Romeo and Juliet would have been with a mobile phone each.

The London low emission zone baseline study.

PubMed

Kelly, Frank; Armstrong, Ben; Atkinson, Richard; Anderson, H Ross; Barratt, Ben; Beevers, Sean; Cook, Derek; Green, Dave; Derwent, Dick; Mudway, Ian; Wilkinson, Paul

2011-11-01

On February 4, 2008, the world's largest low emission zone (LEZ) was established. At 2644 km2, the zone encompasses most of Greater London. It restricts the entry of the oldest and most polluting diesel vehicles, including heavy-goods vehicles (haulage trucks), buses and coaches, larger vans, and minibuses. It does not apply to cars or motorcycles. The LEZ scheme will introduce increasingly stringent Euro emissions standards over time. The creation of this zone presented a unique opportunity to estimate the effects of a stepwise reduction in vehicle emissions on air quality and health. Before undertaking such an investigation, robust baseline data were gathered on air quality and the oxidative activity and metal content of particulate matter (PM) from air pollution monitors located in Greater London. In addition, methods were developed for using databases of electronic primary-care records in order to evaluate the zone's health effects. Our study began in 2007, using information about the planned restrictions in an agreed-upon LEZ scenario and year-on-year changes in the vehicle fleet in models to predict air pollution concentrations in London for the years 2005, 2008, and 2010. Based on this detailed emissions and air pollution modeling, the areas in London were then identified that were expected to show the greatest changes in air pollution concentrations and population exposures after the implementation of the LEZ. Using these predictions, the best placement of a pollution monitoring network was determined and the feasibility of evaluating the health effects using electronic primary-care records was assessed. To measure baseline pollutant concentrations before the implementation of the LEZ, a comprehensive monitoring network was established close to major roadways and intersections. Output-difference plots from statistical modeling for 2010 indicated seven key areas likely to experience the greatest change in concentrations of nitrogen dioxide (NO2) (at least 3 microg/m3) and of PM with an aerodynamic diameter < or = 10 microm (PM10) (at least 0.75 microg/m3) as a result of the LEZ; these suggested that the clearest signals of change were most likely to be measured near roadsides. The seven key areas were also likely to be of importance in carrying out a study to assess the health outcomes of an air quality intervention like the LEZ. Of the seven key areas, two already had monitoring sites with a full complement of equipment, four had monitoring sites that required upgrades of existing equipment, and one required a completely new installation. With the upgrades and new installations in place, fully ratified (verified) pollutant data (for PM10, PM with an aerodynamic diameter < or = 2.5 microm [PM2.5], nitrogen oxides [NOx], and ozone [O3] at all sites as well as for particle number, black smoke [BS], carbon monoxide [CO], and sulfur dioxide [SO2] at selected sites) were then collected for analysis. In addition, the seven key monitoring sites were supported by other sites in the London Air Quality Network (LAQN). From these, a robust set of baseline air quality data was produced. Data from automatic and manual traffic counters as well as automatic license-plate recognition cameras were used to compile detailed vehicle profiles. This enabled us to establish more precise associations between ambient pollutant concentrations and vehicle emissions. An additional goal of the study was to collect baseline PM data in order to test the hypothesis that changes in traffic densities and vehicle mixes caused by the LEZ would affect the oxidative potential and metal content of ambient PM10 and PM2.5. The resulting baseline PM data set was the first to describe, in detail, the oxidative potential and metal content of the PM10 and PM2.5 of a major city's airshed. PM in London has considerable oxidative potential; clear differences in this measure were found from site to site, with evidence that the oxidative potential of both PM10 and PM2.5 at roadside monitoring sites was higher than at urban background locations. In the PM10 samples this increased oxidative activity appeared to be associated with increased concentrations of copper (Cu), barium (Ba), and bathophenanthroline disulfonate-mobilized iron (BPS Fe) in the roadside samples. In the PM2.5 samples, no simple association could be seen, suggesting that other unmeasured components were driving the increased oxidative potential in this fraction of the roadside samples. These data suggest that two components were contributing to the oxidative potential of roadside PM, namely Cu and BPS Fe in the coarse fraction of PM (PM with an aerodynamic diameter of 2.5 microm to 10 microm; PM(2.5-10)) and an unidentified redox catalyst in PM2.5. The data derived for this baseline study confirmed key observations from a more limited spatial mapping exercise published in our earlier HEI report on the introduction of the London's Congestion Charging Scheme (CCS) in 2003 (Kelly et al. 2011a,b). In addition, the data set in the current report provided robust baseline information on the oxidative potential and metal content of PM found in the London airshed in the period before implementation of the LEZ; the finding that a proportion of the oxidative potential appears in the PM coarse mode and is apparently related to brake wear raises important issues regarding the nature of traffic management schemes. The final goal of this baseline study was to establish the feasibility, in ethical and operational terms, of using the U.K.'s electronic primary-care records to evaluate the effects of the LEZ on human health outcomes. Data on consultations and prescriptions were compiled from a pilot group of general practices (13 distributed across London, with 100,000 patients; 29 situated in the inner London Borough of Lambeth, with 200,000 patients). Ethics approvals were obtained to link individual primary-care records to modeled NOx concentrations by means of post-codes. (To preserve anonymity, the postcodes were removed before delivery to the research team.) A wide range of NOx exposures was found across London as well as within and between the practices examined. Although we observed little association between NOx exposure and smoking status, a positive relationship was found between exposure and increased socioeconomic deprivation. The health outcomes we chose to study were asthma, chronic obstructive pulmonary disease, wheeze, hay fever, upper and lower respiratory tract infections, ischemic heart disease, heart failure, and atrial fibrillation. These outcomes were measured as prevalence or incidence. Their distributions by age, sex, socioeconomic deprivation, ethnicity, and smoking were found to accord with those reported in the epidemiology literature. No cross-sectional positive associations were found between exposure to NOx and any of the studied health outcomes; some associations were significantly negative. After the pilot study, a suitable primary-care database of London patients was identified, the General Practice Research Database responsible for giving us access to these data agreed to collaborate in the evaluation of the LEZ, and an acceptable method of ensuring privacy of the records was agreed upon. The database included about 350,000 patients who had remained at the same address over the four-year period of the study. Power calculations for a controlled longitudinal analysis were then performed, indicating that for outcomes such as consultations for respiratory illnesses or prescriptions for asthma there was sufficient power to identify a 5% to 10% reduction in consultations for patients most exposed to the intervention compared with patients presumed to not be exposed to it. In conclusion, the work undertaken in this study provides a good foundation for future LEZ evaluations. Our extensive monitoring network, measuring a comprehensive set of pollutants (and a range of particle metrics), will continue to provide a valuable tool both for assessing the impact of LEZ regulations on air quality in London and for furthering understanding of the link between PM's composition and toxicity. Finally, we believe that in combination with our modeling of the predicted population-based changes in pollution exposure in London, the use of primary-care databases forms a sound basis and has sufficient statistical power for the evaluation of the potential impact of the LEZ on human health.