Neighborhood Safety and Physical Activity

Would you go for a walk around the block or in a local park if you thought your neighborhood unsafe and you would be in danger? At BEH, we care a lot about understanding constraints on outdoor physical activity, including (maybe) safety.

The link between neighborhood safety and physical activity has been tricky to assess, in part because physical activity is tricky to measure (questionnaires are vulnerable to reporting biases and don’t capture small-scale differences in activity between people whereas accelerometers and other activity trackers are sensitive to proper positioning), and in part because no single construct completely represents neighborhood safety – some researchers study fear of victimization, others study crime rates, and still others study aesthetic features such as disorder that may affect the perception that a neighborhood is unsafe.


Download the PAA Poster

We recently investigated several measures of safety, including self-reported neighborhood safety, crime rates, and a measure of neighborhood disorder we constructed using Street View imagery in relation to accelerometer-measured and self-reported physical activity, using data from the Physical Activity and Transit survey undertaken by the New York City Department of Health and Mental Hygiene. We found that independently observed measures of neighborhood safety and disorder were not associated with any measures of physical activity, but that reporting the neighborhood to be unsafe was associated with increased odds of reporting no recreational physical activity.

The initial results of our work were presented as a poster at the recent annual meeting of the Population Association of America.

Posted in Aesthetics, Physical Disorder, Safety | Leave a comment

Spatial Patterns of Exposure to Tree Pollen in Cities

Betula sp. pollen [Birch Pollen] photo by Guy Robinson, Fordam University

Betula sp. pollen [Birch Pollen] photo by Guy Robinson, Fordam University

BEH investigator Gina Lovasi has recently worked with colleagues from Environmental Health Sciences (EHS) on a systematic review of how tree pollen levels vary spatially within cities (available at  This review is part of our larger effort to inform refinement and evaluation of massive urban tree planting efforts currently underway in cities such as NYC and Los Angeles.

Seasonal allergies to tree pollen and other outdoor allergens (grasses, ragweed, mold) trigger respiratory symptoms and asthma exacerbations in urban populations.  Tree pollen in particular tends to affect people early in mid-spring.  While current pollen levels can readily be compared across broad areas of the US (for example see, less is known about small scale variation of exposure within a city.  Single rooftop monitors tracking daily pollen counts are often used to represent the experience of the entire city.  Yet multiple monitoring points would be needed to help us understand how much exposure to tree pollen is driven by a city’s overall tree canopy and regional context versus vegetation in the immediate vicinity. Continue reading

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A SMART START: A Symposium on Preventing Childhood Obesity

On April 16th the Mailman School is presenting an afternoon long symposium, “A SMART START:  A Symposium on Preventing Childhood Obesity“, focused on prenatal and early childhood determinants of obesity.  This symposium is part of a month long series of events in April we are calling “Public Health Fights Obesity”.   You can RSVP to attend the symposium by clicking HERE


1:00–5:00 P.M.

A Symposium on Preventing Childhood Obesity

Black Building, 650 West 168th Street
Alumni Auditorium

PLENARY: Why Focus on Pregnancy and Early Childhood?

Andrew Rundle, DrPH, Associate Professor of Epidemiology; Co-Director of Obesity Prevention Initiative, Columbia Mailman School of Public Health

PANEL 1: Gestational Weight Change, Prenatal Factors and Childhood Obesity

Moderator: Virginia Rauh, ScD, Professor of Population and Family Health, Columbia Mailman School of Public Health


Dympna Gallagher, EdD, Associate Professor of Nutritional Medicine, Institute of Human Nutrition, Columbia University College of Physicians & Surgeons

David A Savitz, PhD, Vice President for Research, Professor of Epidemiology, Professor of Obstetrics and Gynecology, Brown University

Cynthia Gyamfi-Bannerman, MD, Associate Professor of Maternal-Fetal Medicine, Director of Maternal-Fetal Medicine Fellowship Program, Medical Director of Perinatal High-Risk Clinic, Columbia University Medical Center

PANEL 2: Early Childhood Factors and Early Childcare Practice and Policies

Moderator: Gretchen Van Wye, PhD, MA, Assistant Commissioner, Bureau of Vital Statistics, NYC Department of Health and Mental Hygiene, Division of Epidemiology


Cynthia Colen, PhD, MPH, Assistant Professor of Sociology, The Ohio State University

Cathy Nonas, MS, RD, Senior Advisor, NYC Department of Health and Mental Hygiene

Sally E Findley, PhD, Professor of Population and Family Health & Sociomedical Sciences, Columbia Mailman School of Public Health

Round Table: Future Directions for Research and Action

Moderator: Y. Claire Wang, MD, ScD, Associate Professor of Health Policy and Management and Co-Director of Obesity Prevention Initiative, Columbia Mailman School of Public Health


Kiyah Duffey, PhD, Director of Global Scientific Affairs, LA Sutherland Group; Parenting blogger and proud mother of three, ages 5 and under

Tina Kauh, PhD, Program Officer, Research-Evaluation-Learning, Robert Wood Johnson Foundation

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NE-WAS: Welcoming Big Data to the Neighborhood

Like most researchers investigating neighborhood determinants of health, we are excited that both government and the private sector are making more and more spatially located data available. But even as new data sources allow us to characterize study subjects’ environments more completely, the sheer number of potentially interacting contextual variables we can now study introduces analytic complexity. Drawing an analogy with genomic research, we propose the ‘neighborhood environment-wide association study’ (or NE-WAS) as one approach to address the complexity.

Three VsNeighborhood research is increasingly a high-volume, high-variety ‘Big Data’ endeavor. Even as neighborhood research mainstays like the US Census and American Community Survey continue to be updated, new forms and sources of data like social media, remote sensing, and commercial aggregators are providing increasingly detailed insight into neighborhood conditions. Furthermore, through GIS tools and spatial analytic approaches, researchers are defining neighborhoods in creative new ways including network buffers, pill buffers, and neighborhood hulls. With more data at more spatial resolutions, we can characterize study subjects’ neighborhoods in high-dimensional space – for example, one dataset we work with has 1,485 separate variables that describe some aspect of each subject’s residential neighborhood. Continue reading

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CANVAS featured on


The Science of Cities blog over at featured the CANVAS system and our work developing methods to conduct virtual neighborhood audits. In the article’s Henry Grabar describes his experience using CANVAS to collect neighborhood audit data on four blocks in Washington DC.


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Evidence Based Investment in Public Spaces

NYRP_TheHavenProject_LogoThrough the development of numerous initiatives directed at transforming green spaces across the city, the New York Restoration Project (NYRP) has improved the quality of life for New Yorkers. Due to her track record of studying green spaces and streetscapes, BEH investigator Gina Lovasi was invited by NYRP to join the planning team for an emerging effort: The Haven Project. The Haven Project aims to renovate a network of open spaces in the Mott Haven and Port Morris neighborhoods of the South Bronx, while simultaneously demonstrating measurable health and social outcomes resulting from an improved physical environment. Since the fall of 2014 Gina Lovasi, along with Lori Fingerhut, has led our engagement in this planning effort.  Our role included conducting a rapid literature review tailored to the needs of the project (download the report).  This literature review focused on informing strategies for redesigning public spaces to enhance opportunities for population health.

NYRP_The_Haven_ProjectCommunity meetings and discussions within the planning team shaped the literature review sections and areas of emphasis.  Our review focused first on three health-related outcomes of particular concern in Mott Haven and Port Morris: physical activity, clean air, and pedestrian safety. We reviewed the key drivers of these outcomes in the local physical environment, with a focus on leverage points that could support improvements in these outcomes. Next, our review examined three modifiable aspects of the local physical environment with potential relevance to health needs of the area residents: parks, trees, and pedestrian path enhancements.  For each of these, we sought to describe the range of potential health impacts, and the multipliers that seem to maximize health benefits. Finally, we briefly discussed literature on the processes driving neighborhood change, and how process itself may be crucial to realizing behavioral health benefits. Continue reading

Posted in Community Needs Assessment, Parks, Urban Forestry | Leave a comment

New Research Using Google Street View to Conduct Neighborhood ‘Virtual Audits’

Viewing 125th Street

Viewing 125th Street

We recently published three papers describing our use of Google Street View to conduct ‘virtual-audits’ to collect observational data on neighborhood characteristic and conditions.

A long established approach to collecting data on neighborhood conditions is to send trained observers to neighborhoods to collect data using standardized audit tools – an approach known as Systematic Social Observation and also Neighborhood Auditing.  Essentially observers go to specified blocks in a neighborhood and complete checklists noting the presence or absence of neighborhood amenities or disamenities.  However, this approach is time consuming – in our studies about 75% of researcher’s time is spent traveling to and from the observation sites – which limits the number of blocks that can be observed and the size and number of neighborhoods that can be included in a study.  As an alternative we have developed a system known as CANVAS (Computer Assisted Neighborhood Visual Assessment System) that uses Google Street View and a series of customized add-on tools to allow researchers to conduct neighborhood audits from their desk-tops. Continue reading

Posted in CANVAS, Methods, Physical Disorder, Street View, Urban Design, Walkability | Leave a comment

BEH selected as charter members of the AIA Design and Health Research Consortium

Today the American Institute of Architects (AIA), the AIA Foundation, and the Association of Collegiate Schools of Architecture (ACSA), named Columbia’s Mailman School of Public Health and Graduate School of Architecture, Planning and Preservation as charter members of the AIA Design & Health Research Consortium, which will help fund basic research on how design affects public health (see the press release here and the Scientific American article here).  In September we teamed up with our friends Hilary Sample, Associate Professor at Columbia’s Graduate School of Architecture, Planning and Preservation and Dr. Karen Lee, who while at NYC DOHMH helped create NYC’s Active Design Guidelines, to submit a proposal to AIA’s Call for Qualifications and we were selected to join the consortium.

As part of the Consortium we will focus our research and translation activities on physical activity and identifying the ways in which architecture and urban design create built environments that support physically active lifestyles. While physical activity prevents cancer, cardiovascular disease, diabetes, obesity and reduces blood pressure less than 50% of Americans meet current recommendations for activity.  The team will use GPS and GIS technologies to study how neighborhood built environments can support physical activity among residents of New York City and will develop methods to conduct similar research in Rio das Pedras, a favela community in Rio de Janeiro, Brazil.   Our choice of research sites is motivated by two key UN projections: (1) by 2025, 379 million people are expected to live in megacities such as New York City and (2) by 2030, 2 billion people will live in “informal communities” such as Rio das Pedras.

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Latino USA on NPR covers our work on Hispanic immigrant women’s perspective on healthy foods

Latino USA, which is broadcast on NPR, did a story about our research findings on Hispanic immigrant women’s perspectives on healthy food and local neighborhood food access.  Our research used in-depth, hour long interviews to gather data on these women’s perspectives on healthy food and where they preferred to buy their food.  They generally reported being skeptical of the quality, freshness and flavor of produce and meat purchased in supermarkets and reported that even though the prices were higher, they preferred to buy produce and meat at farmer’s markets and small, local slaughter houses. They felt that these retail outlets provided food that more closely matched their values and preferences for food.  When we did a spatial analyses for a larger sample of Hispanic immigrant women, we found that having a farmer’s market in their residential neighborhood was associated with significantly higher consumption of fruit and vegetables.  Furthermore we found that having a farmer’s market and/or a small slaughter house in their neighborhood was associated with significantly higher consumption of meat.  Having local access to a supermarket was not associated with any of the measured dietary outcomes.

The Latino USA story can be heard here and the original research paper is here.

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Rio das Pedras Community Needs Assessment

View of a favella in Rio

View of a favella in Rio

The global rise of informal settlements have brought unique health challenges into the heart of urban centers. It is estimated that 2 billion people will live in informal urban settlements by 2030.  The 2014 World Cup and the 2016 Olympics have brought renewed recognition of the informal favella communities of  Brazil.

Led by Dr. Gina Lovasi, we have teamed up with an interdisciplinary group of global experts to perform an initial community needs assessment in Rio das Pedras, Rio de Janeiro, Brazil to assess the feasibility of large scale data collection on health, mobility, and the microbiome in these settings.

Electricity distribution in Rio das Pedras

Informal distribution of electricity in Rio das Pedras

Rio das Pedras is the third largest informal community in Rio de Janeiro, Brazil. Home to approximately 63,500 individuals, Rio das Pedras is a vibrant community, however residents of this favela face seasonal flooding, vehicle traffic, improvised construction methods, and limited waste disposal. These factors, coupled with limited access to municipal services and transportation likely predispose residents to injury and poor health. However, little reliable data exists that can accurately characterize the health of residents of Rio das Pedras, and fewer data that can point out areas of intervention that will be most impactful in these settings. As a result, little is known regarding the present health risks that exist throughout the community.

Through an initial community health diagnosis, our team will map the mobility and public health resources driving population health patterns across the favela. The team will also take an initial look at the microbiome of informal settlements and analyze the quality and use of water throughout Rio das Pedras. This preliminary needs assessment will begin to create a health profile of the population and highlight the areas of intervention that can most improve the health and living conditions of the residents of Rio das Pedras and surrounding areas of Rio de Janeiro.  Ultimately, this pilot will tailor and test a set of methods so future data collection efforts will more accurately reflect the needs of vulnerable populations living in these complex settings.

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