Reconsidering access: park facilities and neighborhood disamenities in New York City.

With increasing concern about rising rates of obesity, public health researchers have begun to examine the availability of parks and other spaces for physical activity, particularly in cities, to assess whether access to parks reduces the risk of obesity. Much of the research in this field has shown that proximity to parks may support increased physical activity in urban environments; however, as yet, there has been limited consideration of environmental impediments or disamenities that might influence individuals' perceptions or usage of public recreation opportunities. Prior research suggests that neighborhood disamenities, for instance crime, pedestrian safety, and noxious land uses, might dissuade people from using parks or recreational facilities and vary by neighborhood composition. Motivated by such research, this study estimates the relationship between neighborhood compositional characteristics and measures of park facilities, controlling for variation in neighborhood disamenities, using geographic information systems (GIS) data for New York City parks and employing both kernel density estimation and distance measures. The central finding is that attention to neighborhood disamenities can appreciably alter the relationship between neighborhood composition and spatial access to parks. Policy efforts to enhance the recreational opportunities in urban areas should expand beyond a focus on availability to consider also the hazards and disincentives that may influence park usage.

Disparities in neighborhood food environments: implications of measurement strategies.

Public health researchers have begun to map the neighborhood "food environment" and examine its association with the risk of overweight and obesity. Some argue that "food deserts"­areas with little or no provision of fresh produce and other healthy food­may contribute to disparities in obesity, diabetes, and related health problems. While research on neighborhood food environments has taken advantage of more technically sophisticated ways to assess distance and density, in general, it has not considered how individual or neighborhood conditions might modify physical distance and thereby affect patterns of spatial accessibility. This study carried out a series of sensitivity analyses to illustrate the effects on the measurement of disparities in food environments of adjusting for cross-neighborhood variation in vehicle ownership rates, public transit access, and impediments to pedestrian travel, such as crime and poor traffic safety. The analysis used geographic information systems data for New York City supermarkets, fruit and vegetable markets, and farmers' markets and employed both kernel density and distance measures. We found that adjusting for vehicle ownership and crime tended to increase measured disparities in access to supermarkets by neighborhood race/ethnicity and income, while adjusting for public transit and traffic safety tended to narrow these disparities. Further, considering fruit and vegetable markets and farmers' markets, as well as supermarkets, increased the density of healthy food outlets, especially in neighborhoods with high concentrations of Hispanics, Asians, and foreign-born residents and in high-poverty neighborhoods.

Disparities in the food environments of New York City public schools.

BACKGROUND: Studies of the food environment near schools have focused on fast food. Research is needed that describes patterns of exposure to a broader range of food outlet types and that examines the influence of neighborhood built environments. PURPOSE: Using data for New York City, this paper describes the prevalence of five different food outlet types near schools, examines disparities by economic status and race/ethnicity in access to these food outlets, and evaluates the extent to which these disparities are explained by the built environment surrounding the school. METHODS: National chain and local fast-food restaurants, pizzerias, small grocery stores ("bodegas"), and convenience stores within 400 m of public schools in New York City were identified by matching 2005 Dun & Bradstreet data to 2006-2007 school locations. Associations of student poverty and race/ethnicity with food outlet density, adjusted for school level, population density, commercial zoning, and public transit access, were evaluated in 2009 using negative binomial regression. RESULTS: New York City's public school students have high levels of access to unhealthy food near their schools: 92.9% of students had a bodega within 400 m, and pizzerias (70.6%); convenience stores (48.9%); national chain restaurants (43.2%); and local fast-food restaurants (33.9%) were also prevalent within 400 m. Racial/ethnic minority and low-income students were more likely to attend schools with unhealthy food outlets nearby. Bodegas were the most common source of unhealthy food, with an average of nearly ten bodegas within 400 m, and were more prevalent near schools attended by low-income and racial/ethnic minority students; this was the only association that remained significant after adjustment for school and built-environment characteristics. CONCLUSIONS: Nearly all New York City public school students have access to inexpensive, energy-dense foods within a 5-minute walk of school. Low-income and Hispanic students had the highest level of exposure to the food outlets studied here.

Neighborhood food environment and walkability predict obesity in New York City.

BACKGROUND: Differences in the neighborhood food environment may contribute to disparities in obesity. OBJECTIVES: The purpose of this study was to examine the association of neighborhood food environments with body mass index (BMI) and obesity after control for neighborhood walkability. METHODS: This study employed a cross-sectional, multilevel analysis of BMI and obesity among 13,102 adult residents of New York City. We constructed measures of the food environment and walkability for the neighborhood, defined as a half-mile buffer around the study subject's home address. RESULTS: Density of BMI-healthy food outlets (supermarkets, fruit and vegetable markets, and natural food stores) was inversely associated with BMI. Mean adjusted BMI was similar in the first two quintiles of healthy food density (0 and 1.13 stores/km2, respectively), but declined across the three higher quintiles and was 0.80 units lower [95% confidence interval (CI), 0.27-1.32] in the fifth quintile (10.98 stores/km2) than in the first. The prevalence ratio for obesity comparing the fifth quintile of healthy food density with the lowest two quintiles combined was 0.87 (95% CI, 0.78-0.97). These associations remained after control for two neighborhood walkability measures, population density and land-use mix. The prevalence ratio for obesity for the fourth versus first quartile of population density was 0.84 (95% CI, 0.73-0.96) and for land-use mix was 0.91 (95% CI, 0.86-0.97). Increasing density of food outlets categorized as BMI-unhealthy was not significantly associated with BMI or obesity. CONCLUSIONS: Access to BMI-healthy food stores is associated with lower BMI and lower prevalence of obesity.

Disparities in urban neighborhood conditions: evidence from GIS measures and field observation in New York City.

Although many low-income urban areas are highly walkable by conventional measures such as population density or land use mix, chronic diseases related to lack of physical activity are more common among residents of these areas. Disparities in neighborhood conditions may make poor areas less attractive environments for walking, offsetting the advantages of density and land use mix. This study compared poor and nonpoor neighborhoods in New York City, using geographic information systems measures constructed from public data for US census tracts within New York City (N=2,172) as well as field observation of a matched-pair sample of 76 block faces on commercial streets in poor and nonpoor neighborhoods. Poor census tracts had significantly fewer street trees, landmarked buildings, clean streets, and sidewalk cafes, and higher rates of felony complaints, narcotics arrests, and vehicular crashes. The field observation showed similar results. Improving aesthetic and safety conditions in poor neighborhoods may help reduce disparities in physical activity among urban residents.

Creating and validating GIS measures of urban design for health research.

Studies relating urban design to health have been impeded by the unfeasibility of conducting field observations across large areas and the lack of validated objective measures of urban design. This study describes measures for five dimensions of urban design - imageability, enclosure, human scale, transparency, and complexity - created using public geographic information systems (GIS) data from the US Census and city and state government. GIS measures were validated for a sample of 588 New York City block faces using a well-documented field observation protocol. Correlations between GIS and observed measures ranged from 0.28 to 0.89. Results show valid urban design measures can be constructed from digital sources.