Conor C. O. Reynolds

Route Infrastructure and the Risk of Injuries to Bicyclists: A Case-Crossover Study

OBJECTIVES We compared cycling injury risks of 14 route types and other route infrastructure features. METHODS We recruited 690 city residents injured while cycling in Toronto or Vancouver, Canada. A case-crossover design compared route infrastructure at each injury site to that of a randomly selected control site from the same trip. RESULTS Of 14 route types, cycle tracks had the lowest risk (adjusted odds ratio [OR] = 0.11; 95% confidence interval [CI] = 0.02, 0.54), about one ninth the risk of the reference: major streets with parked cars and no bike infrastructure. Risks on major streets were lower without parked cars (adjusted OR = 0.63; 95% CI = 0.41, 0.96) and with bike lanes (adjusted OR = 0.54; 95% CI = 0.29, 1.01). Local streets also had lower risks (adjusted OR = 0.51; 95% CI = 0.31, 0.84). Other infrastructure characteristics were associated with increased risks: streetcar or train tracks (adjusted OR = 3.0; 95% CI = 1.8, 5.1), downhill grades (adjusted OR = 2.3; 95% CI = 1.7, 3.1), and construction (adjusted OR = 1.9; 95% CI = 1.3, 2.9). CONCLUSIONS The lower risks on quiet streets and with bike-specific infrastructure along busy streets support the route-design approach used in many northern European countries. Transportation infrastructure with lower bicycling injury risks merits public health support to reduce injuries and promote cycling.

Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design

Background This study examined the impact of transportation infrastructure at intersection and non-intersection locations on bicycling injury risk. Methods In Vancouver and Toronto, we studied adult cyclists who were injured and treated at a hospital emergency department. A case–crossover design compared the infrastructure of injury and control sites within each injured bicyclists route. Intersection injury sites (N=210) were compared to randomly selected intersection control sites (N=272). Non-intersection injury sites (N=478) were compared to randomly selected non-intersection control sites (N=801). Results At intersections, the types of routes meeting and the intersection design influenced safety. Intersections of two local streets (no demarcated traffic lanes) had approximately one-fifth the risk (adjusted OR 0.19, 95% CI 0.05 to 0.66) of intersections of two major streets (more than two traffic lanes). Motor vehicle speeds less than 30 km/h also reduced risk (adjusted OR 0.52, 95% CI 0.29 to 0.92). Traffic circles (small roundabouts) on local streets increased the risk of these otherwise safe intersections (adjusted OR 7.98, 95% CI 1.79 to 35.6). At non-intersection locations, very low risks were found for cycle tracks (bike lanes physically separated from motor vehicle traffic; adjusted OR 0.05, 95% CI 0.01 to 0.59) and local streets with diverters that reduce motor vehicle traffic (adjusted OR 0.04, 95% CI 0.003 to 0.60). Downhill grades increased risks at both intersections and non-intersections. Conclusions These results provide guidance for transportation planners and engineers: at local street intersections, traditional stops are safer than traffic circles, and at non-intersections, cycle tracks alongside major streets and traffic diversion from local streets are safer than no bicycle infrastructure.

Health and Climate-Relevant Pollutant Concentrations from a Carbon-Finance Approved Cookstove Intervention in Rural India

Efforts to introduce more efficient stoves increasingly leverage carbon-finance to scale up dissemination of interventions. We conducted a randomized intervention study to evaluate a Clean Development Mechanism approved stove replacement impact on fuelwood usage, and climate and health-relevant air pollutants. We randomly assigned 187 households to either receive the intervention or to continue using traditional stoves. Measurements of fine particulate matter (PM2.5) and absorbance were conducted in cooking areas, village center and at upwind background site. There were minor and overlapping seasonal differences (post- minus preintervention change) between control and intervention groups for median (95% CI) fuel use (-0.60 (-1.02, -0.22) vs -0.52 (-1.07, 0.00) kg day(-1)), and 24 h absorbance (35 (18, 60) vs 36 (22, 50) × 10(-6) m(-1)); for 24 h PM2.5, there was a higher (139 (61,229) vs 73(-6, 156) μg m(-3))) increase in control compared to intervention homes between the two seasons. Forty percent of the intervention homes continued using traditional stoves. For intervention homes, absorbance-to-mass ratios suggest a higher proportion of black carbon in PM2.5 emitted from intervention compared with traditional stoves. Absent of field-based evaluation, stove interventions may be pursued that fail to realize expected carbon reductions or anticipated health and climate cobenefits.

Traffic-related air pollution and health in Canada

Canadian cities generally have good air quality; however, exposure to outdoor air pollution continues to elicit considerable negative health effects. Estimates suggest that there are 21 000 premature deaths attributable to air pollution in Canada each year,[1][1] nearly 9 times higher than the

Severity of urban cycling injuries and the relationship with personal, trip, route and crash characteristics: analyses using four severity metrics

Objective To examine the relationship between cycling injury severity and personal, trip, route and crash characteristics. Methods Data from a previous study of injury risk, conducted in Toronto and Vancouver, Canada, were used to classify injury severity using four metrics: (1) did not continue trip by bike; (2) transported to hospital by ambulance; (3) admitted to hospital; and (4) Canadian Triage and Acuity Scale (CTAS). Multiple logistic regression was used to examine associations with personal, trip, route and crash characteristics. Results Of 683 adults injured while cycling, 528 did not continue their trip by bike, 251 were transported by ambulance and 60 were admitted to hospital for further treatment. Treatment urgencies included 75 as CTAS=1 or 2 (most medically urgent), 284 as CTAS=3, and 320 as CTAS=4 or 5 (least medically urgent). Older age and collision with a motor vehicle were consistently associated with increased severity in all four metrics and statistically significant in three each (both variables with ambulance transport and CTAS; age with hospital admission; and motor vehicle collision with did not continue by bike). Other factors were consistently associated with more severe injuries, but statistically significant in one metric each: downhill grades; higher motor vehicle speeds; sidewalks (these significant for ambulance transport); multiuse paths and local streets (both significant for hospital admission). Conclusions In two of Canadas largest cities, about one-third of the bicycle crashes were collisions with motor vehicles and the resulting injuries were more severe than in other crash circumstances, underscoring the importance of separating cyclists from motor vehicle traffic. Our results also suggest that bicycling injury severity and injury risk would be reduced on facilities that minimise slopes, have lower vehicle speeds, and that are designed for bicycling rather than shared with pedestrians.

Carbon Nanotube and Fullerene Emissions from Spark-Ignited Engines

Particles were collected from the exhaust of Indian autorickshaws with natural gas and gasoline-fueled spark-ignited engines. Transmission electron microscopy was used to determine the size and shape of 2121 systematically selected particles. Particles were largely soot agglomerates and other types documented in the literature, but approximately 10% of the nonvolatile particles were multiwalled carbon nanotubes and fullerenes, forms of crystalline carbon distinct from soot. Autorickshaw fullerenic particle number emissions can be above 1011 per kg of fuel consumed. The nanotubes identified from the exhaust of autorickshaws average 168 nm in length. This is shorter than those nanotubes of greatest health concern, but given the paucity of toxicological data on carbon nanotubes and fullerenes, the potential environmental abundance from engine sources warrants closer attention. In particular, a broader range of engine types should be considered. [Supplemental materials are available for this article. Please go to the publishers online edition of Aerosol Science & Technology to view the online files.] Copyright 2012 American Association for Aerosol Research

Bicycling crash circumstances vary by route type: a cross-sectional analysis

BackgroundWidely varying crash circumstances have been reported for bicycling injuries, likely because of differing bicycling populations and environments. We used data from the Bicyclists’ Injuries and the Cycling Environment Study in Vancouver and Toronto, Canada, to describe the crash circumstances of people injured while cycling for utilitarian and leisure purposes. We examined the association of crash circumstances with route type.MethodsAdult cyclists injured and treated in a hospital emergency department described their crash circumstances. These were classified into major categories (collision vs. fall, motor vehicle involved vs. not) and subcategories. The distribution of circumstances was tallied for each of 14 route types defined in an earlier analysis. Ratios of observed vs. expected were tallied for each circumstance and route type combination.ResultsOf 690 crashes, 683 could be characterized for this analysis. Most (74%) were collisions. Collisions included those with motor vehicles (34%), streetcar (tram) or train tracks (14%), other surface features (10%), infrastructure (10%), and pedestrians, cyclists, or animals (6%). The remainder of the crashes were falls (26%), many as a result of collision avoidance manoeuvres. Motor vehicles were involved directly or indirectly with 48% of crashes. Crash circumstances were distributed differently by route type, for example, collisions with motor vehicles, including “doorings”, were overrepresented on major streets with parked cars. Collisions involving streetcar tracks were overrepresented on major streets. Collisions involving infrastructure (curbs, posts, bollards, street furniture) were overrepresented on multiuse paths and bike paths.ConclusionsThese data supplement our previous analyses of relative risks by route type by indicating the types of crashes that occur on each route type. This information can guide municipal engineers and planners towards improvements that would make cycling safer.

Personal and trip characteristics associated with safety equipment use by injured adult bicyclists: a cross-sectional study

BackgroundThe aim of this study was to estimate use of helmets, lights, and visible clothing among cyclists and to examine trip and personal characteristics associated with their use.MethodsUsing data from a study of transportation infrastructure and injuries to 690 adult cyclists in Toronto and Vancouver, Canada, we examined the proportion who used bike lights, conspicuous clothing on the torso, and helmets on their injury trip. Multiple logistic regression was used to examine associations between personal and trip characteristics and each type of safety equipment.ResultsBike lights were the least frequently used (20% of all trips) although they were used on 77% of trips at night. Conspicuous clothing (white, yellow, orange, red) was worn on 33% of trips. Helmets were used on 69% of trips, 76% in Vancouver where adult helmet use is required by law and 59% in Toronto where it is not. Factors positively associated with bike light use included night, dawn and dusk trips, poor weather conditions, weekday trips, male sex, and helmet use. Factors positively associated with conspicuous clothing use included good weather conditions, older age, and more frequent cycling. Factors positively associated with helmet use included bike light use, longer trip distances, hybrid bike type, not using alcohol in the 6 hours prior to the trip, female sex, older age, higher income, and higher education.ConclusionsIn two of Canada’s largest cities, helmets were the most widely used safety equipment. Measures to increase use of visibility aids on both daytime and night-time cycling trips may help prevent crashes.

Injuries to Adult Cyclists in Toronto and Vancouver: Describing the Circumstances as a First Step towards Injury Prevention

Introduction Bicycling is a sustainable mode of transportation with health benefits, but the risk of injury deters many people. We studied injured cyclists from two urban areas to characterise injury severity and mechanism. Methods Multicentre case-crossover study. Adult cyclists who visit emergency departments in three Toronto and two Vancouver hospitals are being recruited. Canadian Trauma and Acuity Score (CTAS) data are retrieved from hospital records. Descriptive data and comparisons of the first 300 injury events, 150 in each city, are presented. Results The median CTAS score was 3 (IQR: 3–4; n=228). Of the 300 cyclists studied, 27 (9.0%; 95% CI 5.8 to 12.2%) were admitted to hospital. Injury mechanism was classified as a collision in 213 cases (70.9%; 65.9–76.1%) or fall in 87 (29.1%; 23.9–34.1%). Collisions involved motor vehicles in 102 cases (34.1% of all events; 28.6–39.4%), streetcar/train tracks in 46 (15.4%; 10.9–19.0%), curbs/fences/barriers in 38 (12.7%; 8.3–15.7%), pedestrians/other cyclists in 14 (4.7%; 2.3–7.1%), potholes in 9 (3%; 1.1–4.9%) and animals in 3 (1%; 0–2.1%). Manoeuvres to avoid collisions resulted in 28 falls (9.3% of all events). The proportions of injuries involving motor vehicles were almost identical in the two cities, but the odds of an event involving dooring were higher in Toronto than Vancouver (OR 2.83, 95% CI 1.13 to 7.02). Toronto events were more likely to involve streetcar tracks (OR 19.6, 5.9 to 65.0) and less likely to involve pedestrians or cyclists (OR 0.33, 0.13 to 0.83) than those in Vancouver. Conclusions Injury circumstances and differences between cities suggest that transportation infrastructure and interactions with motorised and non-motorised traffic are important factors in cycling injuries.

Effect on blood pressure and eye health symptoms in a climate-financed randomized cookstove intervention study in rural India

Background: Air pollution from cooking with solid fuels is a potentially modifiable risk factor for increased blood pressure and may lead to eye irritation. Objectives: To evaluate whether a climate motivated cookstove intervention reduced blood pressure and eye irritation symptoms in Indian women. Methods: Households using traditional stoves were randomized to receive a rocket stove or continue using traditional stoves. Systolic (SBP) and diastolic blood pressure (DBP), and self‐reported eye symptoms were measured twice, pre‐intervention and at least 124 days post‐intervention in women > 25 years old in control (N = 111) and intervention (N = 111) groups in rural Karnataka, India. Daily (24‐h) fine particle (PM2.5) mass and absorbance (Abs) were measured in cooking areas at each visit. Mixed‐effect models were used to estimate before‐and‐after differences in SBP, DBP and eye symptoms. Results: We observed a lower SBP (−2.0 (−4.5, 0.5) mmHg) and DBP (−1.1 (−2.9, 0.6) mmHg) among exclusive users of intervention stove, although confidence intervals included zero. Stacking or mixed use of intervention and traditional stoves contributed to a small increase in SBP 2.6 (−0.4, 5.7) mmHg) and DBP (1.2 (−0.9, 3.3) mmHg). Exclusive and mixed stove users experienced higher post‐intervention reductions, on average, in self‐reported eye irritation symptoms for burning sensation in eyes, and eyes look red often compared to control. Median air pollutant concentrations increased post‐intervention in all stove groups, with the lowest median PM2.5 increase in the exclusive intervention stove group. Conclusions: Health benefits were limited due to stacking and lower‐than‐predicted efficiency of the intervention stove in the field. Stove adoption and use behavior, in addition to stove technology, affects achievement of health co‐benefits. Carbon‐financing schemes need to align with international guidelines that have been set based on health outcomes to maximize health co‐benefits from cookstove interventions. HighlightsHealth benefits from a climate‐financed cookstove intervention were limited.Blood pressure changes were not significant in homes using intervention stoves.Eye‐irritation generally improved, suggesting unmeasured exposures or reporting bias.Stove adoption and use behavior, in addition to stove technology, can complicate attainment of health benefits.