Sunday, March 27, 2011

Cool play spaces needed

As society becomes more plugged in, it is more and more important to get ourselves, and especially our kids, outside to play. Play is important for children in terms of cognitive, emotional, social, and physical development. We know in Canada that children are not getting enough daily physical activity, and we as a nation are not doing nearly enough to combat this problem.  The author, Richard Louv, has even coined the term ‘nature deficit disorder:’ health and well-being problems resulting from a lack of contact with the outdoors – a subject that I will cover in a forthcoming post. This lack of play in the outdoors is a multi-faceted problem that will require solutions at various levels of social organization (the same could be said for diet). However, I’d like to focus on one of those potential solutions – a thought (obviously not unique) that came about during a recent trip to Sweden.

I was at a conference in Stockholm last summer and toured around Sweden a little bit afterwards. One of our last stops was in Sweden’s third-largest city, Malmö – just across the bridge from Copenhagen, Denmark. When searching for one of Malmö’s most famous buildings, the Turning Torso, we came across the coolest skate/climbing park I have ever seen.

Of course, being a climber myself, I had to try out the man-made boulders with realistic rock-like features and climbing-gym holds. Each of the large boulders (there were three) were surrounded by a layer of pebbles about half a foot deep - to absorb the impact of a fall. Climbers and non-climbers alike were trying their hand at different routes to the top.

The skate park was huge with a variety of features ranging from bowls, to rails, steps, gaps, and boxes. There was something for all skill types (certainly not dominated by experts only) and included skateboarders, rollerbladders and cyclists. I couldn’t stop watching the activity – from the very young (about 5 years of age) to the middle-aged (I thought I saw some 40-year olds trying to keep up). I later found out that this is considered by some to be one of the best skate parks in the world.

Famous Skate Park, Malmö, Sweden
This travel blog photo's source is TravelPod page: Malmö

All of this was free, in view of some incredible scenery (the Turning Torso and harbor front), and in a safe, very low vehicular traffic zone. The idea of this park is what we need everywhere – it doesn’t necessarily have to be a skate or climbing park – but something that is of high quality, in an interesting and safe area, will pique children’s curiosity and get them playing. Children can be exposed to different types of play that they wouldn’t normally be able to afford (rock climbing for example).

I realize money is an issue, and likely the reason Sweden can afford to build world class free skate parks may have to do with their welfare taxation system. However, much of a park’s quality and usefulness can come from where it is located. In Hull (a city in Quebec, Canada), for example, a much simpler skate/climbing park was built. It is unfortunately located on a very busy, uninteresting street. This is perhaps why I see only a few children at any one time using it, and never young children (I know it’s not a great comparison when the photo was taken in early spring..nonetheless). Additionally, play spaces can be constructed out of natural materials located nearby and strategic placement of indigenous plants.       

A natural playground. Photo credit: Playscapes 
Safety of play is another issue. Parents fret about children doing things like skateboarding, biking, rock climbing (my mother still does), playing balance beam, etc. Perhaps for good reason, as unintentional injuries are the leading cause of death among children in Canada. On the other hand, in 2005, falls accounted for only 0.3 deaths in 100,000 children (a very small rate).  Falls (including playground falls) and being struck by/against someone/something accounted for a large percentage of hospitalizations due to unintentional accidents (approx 54%). These numbers, however, also include accidents that do not happen in a park or place space, and actually do not occur all that frequently (179 hospitalizations in 100,000 children). It is important to keep these numbers in perspective. Riding in a car is far more dangerous than playing in the park (in terms of number of deaths). And there are certain things parents can do to protect their children – such as providing the necessary protective equipment, as well as supervision (depending on the child’s age).          

On top of other things that we should be doing to increase physical activity, communities should be providing high quality outdoor play spaces that are free, easily accessible, interesting, and safe (mostly from vehicular traffic, but also in the design, in-so-far as is possible). ALL children need to have the opportunity to explore and play in the outdoors!

Healthy Active Living & Obesity Research, Children's Hospital of Eastern Ontario; ParticipACTION (2010). Active Healthy Kids Canada. Healthy Habits Start Earlier Than You Think. The Active Healthy Kids Canada
Report Card on Physical Activity for Children and Youth. Active Healthy Kids Canada

Public Health Agency of Canada (2009). Child and Youth Injury in Review. Spotlight on Consumer Product Safety Injury and Maltreatment Section

Tuesday, March 22, 2011

Be careful of what you study, how you study it, and how you write it up: the case of climate change and obesity

I happened upon an article looking at the association between obesity and climate change that was published in 2009 by the International Journal of Epidemiology (I know I am a little behind the times, but was intrigued by the title). It generated a lot of criticism from the North American public and science blogging community (examples here, here, and here). This has been mostly for good reason I think, but not always well articulated as to why. I don't believe that the authors, P. Edwards and I. Roberts of the London School of Hygiene and Tropical Medicine, set out to blame obese people for climate change, but it certainly came out that way.

The study used computer modeling to compare two hypothetical populations of 1 billion people, with BMI distributions similar to the figure I quickly sketched together below.  They dubbed the one on the left the 'normal' population and the one on the right the 'overweight' population. The labeling is unfortunate because both populations do have normal weight, overweight, obese individuals, and even underweight people, just not in the same proportions. Both distributions were assumed to have the same mean height for men (1.75 m) and women (1.6 m). 

Writers that have critiqued this paper have argued that computer modeling is not science (and are even skeptical of the term 'Population Health'). While I disagree with that sentiment (well both actually), I don't believe that this is truly an epidemiological study either, and am somewhat surprised that IJE published this. Nonetheless, computer modeling can be made more credible with plausible assumptions and statistical tests. Unfortunately, both of these things were lacking in this study. 

The main aim of the paper was to estimate, rather crudely, differences in greenhouse gas (GHG) emissions from the food industry, and from car and aviation travel, between the 'normal' and 'overweight' populations.

To estimate GHG emissions from the food industry, they first estimated the aggregate energy requirements for each population (to maintain weight). Basal metabolic rate was estimated using the Schofield  equations for men and women, and the activities of daily living were considered to be the same for both populations and added to BMR requirements (a simple energy in=energy out equation, which we know is not that simple).  They estimated that the overweight population required 19% more energy than the normal population. Then, based on aggregate GHG data from 2000, they estimated that this would translate into an increase of 0.27 Giga tonnes (GT) of GHG per year from the food industry alone.

Okay so far? It's rather crude and for this to be somewhat credible I am assuming that the two populations are exactly the same in terms of distributions in age, height, and behaviours (which are usually not normally distributed - often depending on socioeconomic status and other factors). This 'exact sameness' between populations, other than their distribution in BMI, was not explicitly stated as far as I can tell (only an age range and mean height were given).

Next, was estimation of GHG from car travel. The assumption was that extra fuel would be needed to transport a heavier population. Makes sense, but the equation for how mass affects mileage was based on a personal communication with Leonard Evans and not a published reference. If Leonard Evans is well-known in his field, great, but readers not familiar with the field (and I am just guessing Traffic Safety based on a quick Google search) need to know that this is a reputable reference.

I get that if a population, on average, is heavier that fuel consumption would likely be higher for the heavier population. I don't get why two different types of cars were used to calculate the GHG emissions from driving (remember we were assuming that behaviours were the same). The normal population was assumed to have a smaller car (because they are thinner?) such as the Ford Fiesta, even though there are overweight and obese people in the normal weight population (remember that it's a distribution). The overweight population was assumed to have a larger car such as a Ford Galaxy (because they are bigger?), even though there are normal weight people in the overweight population (again it's a distribution). Larger cars emit more GHG - the Ford Galaxy emits more CO2 then the Ford Fiesta. I'm pretty sure that in North America, car choice is not totally dependent on body size (i.e. thinner, rich people still buy gas-guzzling SUVs), although I have no reference for that.

The authors then go on to assume that the overweight population would walk less and drive more. Again behaviours are dependent on a lot of other things besides weight. Plus, there are overweight people in the 'normal' population, so why wouldn't they chose to drive more too? With all of these assumptions taken together, and using aggregate GHG emissions for the transportation sector as a whole, the overweight population was obviously estimated to be responsible for more GHG emissions due to car travel; 0.154 GT/y more based on 30 min/d of driving and then an added 0.019 GT/y because of deciding to take the car more often instead of walking.  

Photo credit: Nika Vee
Based on the assumptions of car travel, I'm surprised that the overweight population was not assumed to have chosen a larger jet for their air travel needs compared to the normal population. Alas, no, the same fuel requirements were calculated for each population with just average weight varying between the two. The authors assumed that 5% of each population would take one short-haul flight per year. This resulted in 2.038 more GT/y of GHG emissions for the overweight population. I could also turn the tables here with my own 'out-of-left-field' assumptions and say that because some airlines charge an extra seat for overweight passengers who do not fit comfortably in one seat, overweight people may be less likely to fly and therefore should not be counted in the 5%, or held responsible for extra GHG emissions from flying.  Even if overweight people are just as likely to fly, having to buy an extra seat could offset their extra weight anyway.  

On top of the sometimes absurd assumptions, and simplistic calculations, the authors still failed to adequately explain their findings in context. Even if this study had been perfectly conducted, obesity and climate change are now deeply ingrained socio-political issues, where adept writing is needed. Writing articles that are interpreted as blaming, even if based on epidemiological or experimental studies (which this study was not), are potentially harmful. Judging by the comments to news articles and hate mail that the authors received, I would assume that many people interpreted the article as blaming, as did I. I am not even certain that the differences reported in the paper are actually important in the grand scheme of things...Maybe someone can enlighten me.

Some quotes from the paper:

"We argue that increased population adiposity, because of its contribution to climate change from additional food and transport GHG emissions, should be recognized as an environmental problem."

"Neverless, the assertion that increasing population adiposity will result in an increase in GHG emissions is justifiable and provides further evidence of the link between human health and climate change mitigation."

There was no consideration for time ('before-after') in this study, which is necessary to say that A causes B.  Although a now heavier population may exacerbate climate change (this study can't even provide that level of evidence) it is more than likely not the cause, as both climate change and population shifts in BMI have taken many years to occur. In fact, human induced climate change has been noted as far back as the late 1900s, well before the obesity epidemic. Maybe climate change caused obesity? 

The underlying processes leading to both climate change and to obesity are more important to focus on than simply obesity alone (for example, our dysfunctional food system, culture of convenience and technology, and the way we have designed our communities, to name a few). Given the complexity of society, we as scientists, using the best available evidence, cannot say for certain what causes what, but we are starting to develop a pretty good idea. Focusing on obesity alone will not mitigate climate change, as noted by a climate scientist. Based on the quality of the study as well as this lack of discussion of potential underlying influences, I do not believe that the authors had grounds to make such strong statements, such as the ones quoted above. Other authors share a similar view, and perhaps explain more eloquently than I. Unfortunately the letter is not open access (twitter me if you would like to read it @PhDPopHealth).

It's up to us as researchers to think about how all faucets of our research can have an impact on our specific scientific fields, the larger research community, as well as the public (this includes knowledge translation).  It is our responsibility to ensure that our research is worthwhile, well conducted, and well communicated and thus, for the betterment of society (whether results are positive, negative, or null). Bad research is useless at best and harmful at worst. Research construed as blaming the obese for climate change will do nothing to help obesity or climate change.

Edwards P, & Roberts I (2009). Population adiposity and climate change. International journal of epidemiology, 38 (4), 1137-40 PMID: 19377099

Monday, March 14, 2011

The ties that bind - healthy eating policies, agriculture, the economy, and population health

I am no economics expert nor claim to have all that much knowledge about ‘the economy;’ I have troubles simply deciding where to invest. However, from a population health perspective, I was so intrigued with this recent Lancet article in the series “Chronic Diseases and Development” that I wanted to share it with it you. It highlights the inextricable and complex connections between the global economy (specifically agri-trade), our food consumption patterns, and health – something that is only beginning to be realized. The paper also shows what can happen from an equity perspective – the global winners and losers of adopting healthy eating recommendations.  

There is no doubt that the way we have been eating for the last 30 years, has contributed in some way to the rise in obesity and chronic diseases like diabetes and cardiovascular disease. In fact, middle and low-income countries are now experiencing the ‘nutrition transition’ – a switch from primarily infectious to chronic diseases.
The authors assert that the reduction of the burden of chronic disease by healthier eating necessitates changes in agriculture, and manufacturing and trade world-wide. They first conducted a systematic review, to determine the most prevalent dietary recommendations developed by expert panels internationally (which was interesting in-and-of-itself and highlighted here) to inform their analysis. In short, the authors found broad consensus on the recommendations outlined below:
  • Eat large amounts of cereals, veggies, fruits, and pulses 
  • Try to eat >400 g/d of veggies and fruit 
  • Limit the amount of red and processed meats 
  • Avoid trans fats, saturated fats, and added sugars 
  • Try to get most of protein from plant sources 
  • Try to limit salt to < 5 g/d

The authors then focused on the population health impact of adopting saturated fat recommendations – selected because it has well established links to cardiovascular disease. Important to note here is that the major sources of saturated fat are from animals. What would happen then to the risk of cardiovascular disease in populations that adopted World Health Organization (WHO) recommendations to decrease saturated fat intake to 10% or less of daily caloric intake? The authors compared the UK and Brazil; the UK selected for its high quality population-level dietary data, and high-income status, and Brazil because it is one of the world’s largest exporters of chicken and beef, and a rapidly developing country that keeps 70% of its meat and poultry for domestic consumption.

The meat aisle at Carrefour. Photo credit: J. Michalski

Using present intakes and targeted reductions (to meet recommendations), ischemic heart disease morbidity and mortality as outcomes, and estimated exposure (saturated fat)–disease effect sizes from a meta-analysis (a compilation of the results from 11 cohort studies), the authors estimated that:
  • In the UK, a 22% reduction in population dietary saturated fat consumption could reduce the years- of- life- lost from ischemic heart disease by 7% and years-of-life lived with disability by 4%; 
  • In Brazil, these figures are 7% (showing that Brazilians on average don’t consume as much saturated fat at Brits), 3%, and 2% respectively

Okay, this seems intuitive; if a population’s consumption patterns are not too far above unhealthy, then adopting healthy recommendations likely won’t result in a big effect on health (Brazil) as compared to a population that is comparatively more unhealthy (UK). But Brazil is a developing country, where the majority of its Gross Domestic Product (GDP) is based on agriculture (which often can be said of low and middle income countries), whereas the UK is a high income country that eats a whole lot of meat. See where this is going? What could the adoption of healthy recommendations (like eating less meat to reduce saturated fat intake) by high income countries do to the global economy, and in particular low and middle income countries?

The authors approached this question using computable general equilibrium models, using again, the UK and Brazil as comparators. I can’t comment on the validity of this technique since I am not an economist, but I did find the the different health policy strategies (or ‘shocks’) and their respective outcomes on GDP quite eye-opening. The different shocks included looking at what would happen if consumption from all animal sources fell, just meat, and just dairy, and comparing the effects on UK domestic demand, Brazil domestic demand, Brazil international demand, and a combined effect for Brazilian domestic and international demand (a UK international demand was not modeled - not deemed plausible as they are not major exporters).

The different shocks mainly affect GDP in terms of:

  • Labour - there is an increase in supply and productivity as there are more healthy workers (because of eating better - based on authors' previous estimates for the UK and Brazil); 
  • Domestic consumption of agricultural products with decreasing production of meat and dairy 
  • Imports and exports of agricultural products with decreasing production of meat and dairy

The effects on GDP differed substantially by dietary strategy (shock) and by scenario. Reducing dietary intake from all animal sources had a fairly small effect on GDP in both the UK and Brazil. However, reducing intake from dairy sources had a large negative impact in both countries (-22% to almost -30%). Reducing meat intake only had the largest negative impact for Brazil - specifically when considering a combined domestic-international effect.

A farm in Brazil. Photo credit: AJ Lopes
Important things to keep in mind about this study (among others which are discussed in the paper itself):
  • First, these are estimates, kind of like a simulation 
  • The authors only considered ischemic heart disease; there are many other chronic diseases related to diet such as obesity, diabetes, and cancer 
  • Dietary data from Brazil was not as current or as high quality as that from the UK 
  • The added positive health effects of replacing animal source foods with plant-based sources was not considered 
  • The authors were unable to adequately model how the agricultural sector could adapt - say by switching from exportation of animal sources to plant-sources 
  • The effects of time could not be modeled

Nonetheless, this study lends insight into the complexities of population health and population health interventions. High income countries may have more to gain and less to lose than middle and low income countries, depending on the policy implemented. A global awareness of the interconnectedness of the economy, agriculture, food consumption and health is needed if we are to develop strategies that are sustainable; that is, balancing social, economic, and environmental interests. An example of just such an approach may be a policy to reduce food consumption from all animal sources; this was estimated to have a much smaller impact on GDP than reducing meat sources only, and is likely to still be beneficial in terms of health and the environment. Certainly striving to make diets sustainable world-wide will require further research (like this study) that is inter-disciplinary in nature.

Lock, K., Smith, R., Dangour, A., Keogh-Brown, M., Pigatto, G., Hawkes, C., Fisberg, R., & Chalabi, Z. (2010). Health, agricultural, and economic effects of adoption of healthy diet recommendations The Lancet, 376 (9753), 1699-1709 DOI: 10.1016/s0140-6736(10)61352-9

Sunday, March 6, 2011

Health by Design 2: The Fused-Grid Neighbourhood Street Layout

Remember that neighbourhood street layout I was talking about way back when? The Fused-grid? Well finally we’ll get to see how well it does in terms of sustainability and health in this week’s post.

To recap, the Fused-grid is a synthesis of the curvilinear, loop and lollipop layout and the traditional gridiron street pattern. It increases connectivity for pedestrians (and potentially cyclists) by providing green spaces in the centres of neighbourhood quadrants. It also preserves the discontinuous, meandering driving nature of the conventional subdivision, which has been shown to increase safety for residents relative to living in a grid area. Mixed-use areas are located along arterial roads and are accessible from any neighbourhood quadrant in about 10 min or less. For a more in-depth description see my previous post: Health by Design: Part 1, or visit the creator’s (Fanis Grammenos') website.     

A Fused Grid district with four quadrants and a mixed use zone

The quality and efficiency of the Fused-grid has been tested in a number of studies variously involving  Fanis, The Canadian Mortgage and Housing Corporation, graduate students of Canadian Universities, and Lawrence Frank (Canadian Bombardier Chair of Sustainable Transportation). These studies compare the Fused-grid to alternative street layouts (usually the traditional gridiron and conventional subdivision) to determine if the Fused-grid performs better in terms of vehicular traffic performance and pollution, travel behaviour, safety, and water management. All but one study use simulations and control areas such as Barrhaven (ON) and Stratford (ON) (a technique often used in geography and planning research) to determine how changes in urban form can influence relevant outcomes. However, one study conducted in the Puget Sound Region of the U.S. did use epidemiological methods to assess the cross-sectional (measured at one time point) association between urban form and travel behaviour. Additionally, a developer in Calgary, Alberta has implemented the Fused-grid layout in one of their developments - offering further insight into its applicability.       
So what does this collective body of evidence show?

For a start, the Fused-grid reduces traffic delay more consistently than the gridiron and subdivision layouts and allows for better flow (and possibly less pollution) as the number of residential houses and places of employment increase in an area (1). In fact it has been estimated that pollution exposure would be lower in Fused-grid areas compared to gridiron, subdivisions and new urbanism developments (2).

Figure 1. Comparison of pollution index and number of pedestrian encounters 
between different neighbourhood street layouts, provided by F. Grammenos 
and adapted from Jin, 2010

During peak travel times (rush hour), the Fused-grid was shown to restrict total vehicle kms traveled to just 5% on local roads, whereas this was 11% and 16% for the traditional grid and conventional subdivision, respectively (1). Obviously reducing traffic on local roads (where more people generally live) is a good thing. Safety can also be increased through the use of 3-way intersections over 4-way intersections. The Fused-grid tends to use 3-way intersections in a ratio of around 5:1 and overall has fewer intersections than the gridiron or even the conventional subdivision layout (3).   

Vehicular kilometers traveled per trip in the Fused-grid is not shorter than in the gridiron (this is expected) indicating that the Fused-grid is less connected <for vehicles> (1), but remember that it makes up for this through the use of central open spaces for pedestrians and cyclists. In fact, making driving inconvenient and active commuting more convenient and pleasant is the central premise of this layout. In the only epidemiological study of the Fused-grid, areas with a street pattern similar to the Fused-grid (high pedestrian connectivity and low vehicular connectivity) were found to have the highest percentage of people deciding to walk (18%) compared to areas with low pedestrian connectivity/low vehicular connectivity (10%), low pedestrian connectivity/high vehicular connectivity (10%), and high pedestrian connectivity/high vehicular connectivity (14%)(4). Another study further supported these findings (see Figure 2 below)(2). Additionally, the Fused-grid has been shown to slightly cut down on the average distance required to get to transit stops compared to subdivision layouts (3). 

Figure 2. Comparison of percentage of people walking, driving, and using public transit 
  between different neighbourhood street layouts, provided by F. Grammenos and adapted 
  from Jin, 2010

The Fused-grid layout appears to be highly flexible, which can increase the diversity of the area. For instance, the new Fused-grid neighbourhood in Calgary, Alberta, provides various housing density options including townhouses, apartments, and houses (5). The proposed density (10.5- 12.1 units per acre) was twice that of densities typically found in conventional subdivision layouts. Other studies also show that the Fused-grid has more developable land (60%) than the traditional gridiron (53%)(1), and can connect more easily to future development areas than the conventional subdivision (3), indicating a great deal of flexibility for future growth.  

Given the results thus far, the Fused-grid layout looks promising. However, some gaps remain. These mostly have to do with more intricate planning details that would probably be up to the developer to implement, as well as limited or facilitated by town/city by-laws. Some of these gaps could, on the other hand, be addressed in the layout itself. Recommendations to address these gaps are highlighted below:

Table 1. Recommendations to improve the population health impact of the Fused-Grid layout
1.General guidelines for planting of trees along streets, open areas and residential lots, as well as plans for landscaping of open spaces and common areas should be included in the layout. These plans should include spacing and orientation of trees with respect to buildings to provide efficient energy-reduction and protection from noise  
2.At a minimum, plans for proper lighting of pedestrian connectors as well as way-finding signage should be included. Pedestrian-scale lighting should be designed to adequately light sidewalks (in addition to lighting provided to increase motorists’ safety).  Points where pedestrians must cross vehicular streets should be well marked and easily visible to both motorist and pedestrian. Way-finding signage should point to crossings with the least pedestrian-motor vehicle conflict.
3.More common meeting spaces in the public realm need to be created to facilitate social interaction and physical activity. The routes to these spaces as well as the spaces themselves should make residents feel comfortable. The layout should also include the spatial layout of benches along streets and pedestrian pathways that face visually interesting backdrops (such as ponds, gardens, main streets, etc). The placement of these meeting and resting places should ensure that shade and wind protection are provided
4.Guidelines for designing bike lanes along lower traffic volume streets and/or mixed-use pathways, separate from the road system, should be included. At present, getting to a destination efficiently depends on where one starts within the neighbourhood quadrant.  Providing extra pathways can improve route directness, thereby decreasing travel time. At least one sidewalk per street should also be provided.
5.The plan layout should provide extra areas of mixed land-use within neighbourhood districts (within the four quadrants) and promote mixed building use to commercial developers.  
6.Guidelines should be provided on how to efficiently maximize diversity within the development (or neighbourhood to be retrofitted) in terms of building types and density. Providing rental units in single family homes should be encouraged. The Calgary developer has done this by introducing optional units with an accessory apartment.
7.The layout should strive to minimize impermeable (non-absorptive) surfaces, consider increasing lot size, and provide, not only a centralized green space for connectivity, but also small pockets of green space throughout the area - to improve rainwater management - a previous study did not show that the Fused-grid was any better than the traditional gridiron layout in this regard (6). The Calgary developer constructed rain gardens in each of the open spaces to improve rainwater management (5).

All in all, the Fused-grid layout is a progressive concept that appears to capitalize on the benefits of both the traditional gridiron and conventional subdivision neighbourhood layouts. Further research is needed - as I discussed before - to determine if changing a community to fit the Fused-grid layout (or moving people into a Fused-grid neighbourhood) results in changes to behaviours and perceptions, traffic-related injuries and levels of obesity among residents. This is hard to do, but at the very least I think that future research on the Fused-grid would benefit immensely from incorporating some form of epidemiological method in addition to methods used in the geography and planning literature.  

1. Grammenos F. (2008). Taming the flow - Better traffic and safer neighbourhoods Canada Mortgage and Housing Corporation Research Highlights, Report No.: 08-012.
2. Jin X (2010). Modelling the influence of neighbourhood design on daily trip patterns in urban neighbourhoods Doctoral Thesis Dissertation, Memorial University, Newfoundland
3. Grammenos F., & Gregory K. (2004). Applying Fused-Grid planning in Stratford, Ontario Canada Mortgage and Housing Corporation Research Highlights, Report No.: 04-038
4. Grammenos F., Frank L., & Hawkins C. (2008). Giving pedestrians an edge - Using street layout to influence transportation choice Canada Mortgage and Housing Corporation Research Highlights, Report No.: 08-013
5. Grammenos F. (2008). Breaking ground: A fused grid neighbourhood in Calgary Canada Mortgage and Housing Corporation Research Highlights, Report No.: 08-020
6. Grammenos F., & Pollard D. (2007). A plan for rainy days: Water runoff and site planning Canada Mortgage and Housing Corporation Research Highlights, Report No.: