May 28 | 2020

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Global Land Use Regression Model for Nitrogen Dioxide Air Pollution.

Andrew Larkin, Jeffrey A. Geddes, Randall V. Martin, Qingyang Xiao, Yang Liu, Julian D. Marshall, Michael Brauer, and Perry Hystad.

Environ. Sci. Technol. 2017, 51, 12. DOI: 10.1021/acs.est.7b01148.

Abstract

Nitrogen dioxide is a common air pollutant with growing evidence of health impacts independent of other common pollutants such as ozone and particulate matter. However, the worldwide distribution of NO2 exposure and associated impacts on health is still largely uncertain. To advance global exposure estimates we created a global nitrogen dioxide (NO2) land use regression model for 2011 using annual measurements from 5,220 air monitors in 58 countries. The model captured 54% of global NO2 variation, with a mean absolute error of 3.7 ppb. Regional performance varied from R2 = 0.42 (Africa) to 0.67 (South America). Repeated 10% cross-validation using bootstrap sampling (n = 10,000) demonstrated a robust performance with respect to air monitor sampling in North America, Europe, and Asia (adjusted R2 within 2%) but not for Africa and Oceania (adjusted R2 within 11%) where NO2 monitoring data are sparse. The final model included 10 variables that captured both between and within-city spatial gradients in NO2 concentrations. Variable contributions differed between continental regions, but major roads within 100 m and satellite-derived NO2 were consistently the strongest predictors. The resulting model can be used for global risk assessments and health studies, particularly in countries without existing NO2 monitoring data or models.

May 4 | 2020

/dans /par

Health impact assessment of Philadelphia’s 2025 tree canopy cover goals.

 

Kondo MC, Mueller N, Locke DH, Roman LA, Rojas-Rueda D, Schinasi LH, Gascon M, Nieuwenhuijsen MJ.

 

Lancet Planet Health. 2020 Apr;4(4):e149-e157. doi: 10.1016/S2542-5196(20)30058-9

 

Abstract

BACKGROUND:

Cities across the world are undertaking ambitious projects to expand tree canopy by increasing the number of trees planted throughout public and private spaces. In epidemiological studies, greenspaces in urban environments have been associated with physical and mental health benefits for city dwellers. Greenworks Philadelphia is a plan to increase tree cover across Philadelphia (PA, USA) by the year 2025. We aimed to assess whether an increase in tree canopy or greenspace in Philadelphia could decrease mortality.

METHODS:

We did a greenspace health impact assessment to estimate the annual premature mortality burden for adult residents associated with projected changes in tree canopy cover in Philadelphia between 2014 and 2025. Using up-to-date exposure-response functions, we calculated the number of preventable annual premature deaths city-wide, and for areas of lower versus higher socioeconomic status, for each of three tree canopy scenarios: low, moderate and ambitious. The ambitious scenario reflected the city’s goal of 30% tree canopy cover in each of the city’s neighbourhoods; and low and moderate scenarios were based on the varying levels of plantable space across neighbourhoods.

FINDINGS:

We estimated that 403 (95% interval 298-618) premature deaths overall, including 244 (180-373) premature deaths in areas of lower socioeconomic status, could be prevented annually in Philadelphia if the city were able to meet its goal of increasing tree canopy cover to 30%.

INTERPRETATION:

Bringing all of Philadelphia, and particularly its poorer neighbourhoods, up to the 30% goal of tree canopy cover is not without challenge. Nevertheless, policies are warranted that value urban greening efforts as health-promoting and cost-saving measures.