April 29 | 2019

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Global, national, and urban burdens of paediatric asthma incidence attributable to ambient NO2pollution: estimates from global datasets.

Pattanun Achakulwisut PhD, Prof Michael Brauer ScD, Perry Hystad PhD, Susan C Anenberg PhD.

The Lancet Planetary Health Volume 3, Issue 4, April 2019, Pages e166-e178  https://doi.org/10.1016/S2542-5196(19)30046-4

Summary

Background

Paediatric asthma incidence is associated with exposure to traffic-related air pollution (TRAP), but the TRAP-attributable burden remains poorly quantified. Nitrogen dioxide (NO2) is a major component and common proxy of TRAP. In this study, we estimated the annual global number of new paediatric asthma cases attributable to NO2 exposure at a resolution sufficient to resolve intra-urban exposure gradients.

Methods

We obtained 2015 country-specific and age-group-specific asthma incidence rates from the Institute for Health Metrics and Evaluation for 194 countries and 2015 population counts at a spatial resolution of 250 × 250 m from the Global Human Settlement population grid. We used 2010–12 annual average surface NO2concentrations derived from land-use regression at a resolution of 100 × 100 m, and we derived concentration-response functions from relative risk estimates reported in a multinational meta-analysis. We then estimated the NO2-attributable burden of asthma incidence in children aged 1–18 years in 194 countries and 125 major cities at a resolution of 250 × 250 m.

Findings

Globally, we estimated that 4·0 million (95% uncertainty interval [UI] 1·8–5·2) new paediatric asthma cases could be attributable to NO2 pollution annually; 64% of these occur in urban centres. This burden accounts for 13% (6–16) of global incidence. Regionally, the greatest burdens of new asthma cases associated with NO2exposure per 100 000 children were estimated for Andean Latin America (340 cases per year, 95% UI 150–440), high-income North America (310, 140–400), and high-income Asia Pacific (300, 140–370). Within cities, the greatest burdens of new asthma cases associated with NO2 exposure per 100 000 children were estimated for Lima, Peru (690 cases per year, 95% UI 330–870); Shanghai, China (650, 340–770); and Bogota, Colombia (580, 270–730). Among 125 major cities, the percentage of new asthma cases attributable to NO2 pollution ranged from 5·6% (95% UI 2·4–7·4) in Orlu, Nigeria, to 48% (25–57) in Shanghai, China. This contribution exceeded 20% of new asthma cases in 92 cities. We estimated that about 92% of paediatric asthma incidence attributable to NO2 exposure occurred in areas with annual average NO2 concentrations lower than the WHO guideline of 21 parts per billion.

Interpretation

Efforts to reduce NO2 exposure could help prevent a substantial portion of new paediatric asthma cases in both developed and developing countries, and especially in urban areas. Traffic emissions should be a target for exposure-mitigation strategies. The adequacy of the WHO guideline for ambient NO2 concentrations might need to be revisited.

April 22 | 2019

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Estimated Long-term (1981-2016) Concentrations of Ambient Fine Particulate Matter across North America from Chemical Transport Modeling, Satellite Remote Sensing and Ground-based Measurements.

Meng J, Li C, Martin RV, van Donkelaar A, Hystad P, Brauer M.

Environ Sci Technol. 2019 Apr 17. doi: 10.1021/acs.est.8b06875 . [Epub ahead of print]

 

Abstract

Accurate data concerning historical fine particulate matter (PM2.5) concentrations are needed to assess long-term changes in exposure and associated health risks. We estimated historical PM2.5 concentrations over North America from 1981-2016 for the first time by combining chemical transport modeling, satellite remote sensing and ground-based measurements. We constrained and evaluated our estimates with direct ground-based PM2.5 measurements when available and otherwise with historical estimates of PM2.5 from PM10 measurements or total suspended particles (TSP) measurements. The estimated PM2.5 concentrations were generally consistent with direct ground-based PM2.5 measurements over their duration from 1988 onward (R2 = 0.6-0.85) and to a lesser extent with PM2.5 inferred from PM10 measurements from 1985 to 1998 (R2 =0.5-0.6). The collocated comparison of the trends of population-weighted annual average PM2.5 from our estimates and ground-based measurements were highly consistent (RMSD = 0.66 μg m-3). The population-weighted annual average PM2.5 over North America decreased from 22 6.4 μg m-3 in 1981, to 12 3.2 μg m-3 in 1998, and to 7.9 2.1 μg m-3 in 2016, with an overall trend of -0.33 μg m-3 yr-1 (95% CI: -0.35 -0.30).

April 15 | 2019

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Environmental Exposures and Depression: Biological Mechanisms and Epidemiological Evidence.

van den Bosch M, Meyer-Lindenberg A.

Annu Rev Public Health. 2019 Apr 1;40:239-259. DOI: 10.1146/annurev-publhealth-040218-044106

Abstract

Mental health and well-being are consistently influenced-directly or indirectly-by multiple environmental exposures. In this review, we have attempted to address some of the most common exposures of the biophysical environment, with a goal of demonstrating how those factors interact with central structures and functions of the brain and thus influence the neurobiology of depression. We emphasize biochemical mechanisms, observational evidence, and areas for future research. Finally, we include aspects of contextual environments-city living, nature, natural disasters, and climate change-and call for improved integration of environmental issues in public health science, policies, and activities. This integration is necessary for reducing the global pandemic of depression.

DATA SCIENCE TRAINING

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New to data science or looking to pick up a few new skills? Don’t miss these free webinars, guided practical tutorials and online resources featuring CANUE data.

Developed in partnership with Population Data BC

Module 1: Introduction to Machine Learning

  • What is machine learning?
  • Supervised vs unsupervised learning
  • Model- and kernel-based methods
  • Measures of Accuracy (Test/train and cross-validation)
  • Causality and Accuracy
  • Unsupervised learning as feature reduction
Module 2: Regression and Regularization Algorithms

  • Regression with many correlated variables
  • Automatic variable selection, early approaches and problems
  • Gradient descent
  • Regularization  (L1 vs L2 vs ElasticNet)
Module 3: Advanced Supervised Learning 

  • Decision trees
  • Problems in overfit
  • Random Forest
  • Out-of-bag error vs cross-validation
Module 4: Advanced Unsupervised Learning 

  • Who uses unsupervised learning?
  • K-means
  • Expectation-maximization
  • Susceptibility to outliers
  • Dangers of labeling clusters

Dr. Aman Verma  is a Data Engineer with a PhD in Epidemiology from McGill University, and an undergraduate degree in Computer Science. He has experience in developing machine learning systems with large databases, particularly for scientific data in healthcare. While he’s comfortable learning any programming language, he’s recently become particularly interested in R. Aman is currently involved in a number of projects, including measuring how following opioid prescription guidelines can decrease the risk of opioid overdose, modelling trajectories of chronic obstructive pulmonary disease, and assessing how to best prioritize ambulance calls using secondary healthcare data.

 

AN INTRODUCTION TO DATA MANAGEMENT AND CLEANING FOR ANLAYSIS IN ‘R’  

This self paced free online course will provide you with an introduction to Data Management and Cleaning for Analysis using R Software. Each of the four modules includes a Power Point slide deck, CANUE training data, R code and associated exercises for practice.

To access this resource please create a Population Data BC account here: https://my.popdata.bc.ca/accounts/register/

Once your account has been approved you will be able to access the Education and Training site and self enroll in this and other free online courses.

Topics covered include:

  • Introduction and theory of data cleaning and management
  • Getting started with R software
  • Subsetting variables and data cleaning
  • Creating variables, subset observations and data cleaning
  • Merging, joining and reshaping data

 

Megan Striha currently works as a Data Analyst. She has a Masters of Public Health degree and three years of experience in health data analysis, including working with survey, administrative and census data.

April 8 | 2019

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Risk of acute respiratory infection from crop burning in India: estimating disease burden and economic welfare from satellite and national health survey data for 250 000 persons.

Suman Chakrabarti, Mohammed Tajuddin Khan, Avinash Kishore, Devesh Roy, Samuel P Scott.

International Journal of Epidemiology, dyz022, https://doi.org/10.1093/ije/dyz022

Published: 28 February 2019

Abstract

Background

Respiratory infections are among the leading causes of death and disability globally. Respirable aerosol particles released by agricultural crop-residue burning (ACRB), practised by farmers in all global regions, are potentially harmful to human health. Our objective was to estimate the health and economic costs of ACRB in northern India.

Methods

The primary outcome was acute respiratory infection (ARI) from India’s fourth District Level Health Survey (DLHS-4). DLHS-4 data were merged with Moderate-Resolution Imaging Spectroradiometer satellite data on fire occurrence. Mutually adjusted generalized linear models were used to generate risk ratios for risk factors of ARI. Overall disease burden due to ACRB was estimated in terms of disability-adjusted life years.

Results

Seeking medical treatment for ARI in the previous 2 weeks was reported by 5050 (2%) of 252 539 persons. Living in a district with intense ACRB—the top quintile of fires per day—was associated with a 3-fold higher risk of ARI (mutually adjusted risk ratio 2.99, 95% confidence interval 2.77 to 3.23) after adjustment for socio-demographic and household factors. Children under 5 years of age were particularly susceptible (3.65, 3.06 to 4.34 in this subgroup). Additional ARI risk factors included motor-vehicle congestion (1.96, 1.72 to 2.23), open drainage (1.91, 1.73 to 2.11), cooking with biomass (1.73, 1.58 to 1.90) and living in urban areas (1.35, 1.26 to 1.44). Eliminating ACRB would avert 14.9 million disability-adjusted life years lost per year, valued at US$152.9 billion over 5 years.

Conclusions

Investments to stop crop burning and offer farmers alternative crop-residue disposal solutions are likely to improve population-level respiratory health and yield major economic returns.

Spotlight: Dan Fuller

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Dr. Daniel Fuller is a Canada Research Chair in Population Physical Activity and assistant professor in the School of Human Kinetics and Recreation at Memorial University. His research with CANUE is developing new Canadian indicators of urban sprawl, public transit accessibility, and active living environments.  

“My ultimate goal is a physically active Canadian population” says Dr. Fuller.

With that ambitious goal, is a motivated team of student researchers to match. Hui (Henry) Luan, Kassia Orychock, Javad Rahimipour Anaraki, and Melissa Tobin work alongside Dr. Fuller, to contribute to CANUE’s vision of increasing scientific understanding of the interactions among the physical features of the urban environment and health.  

“Our research is developing new, standardized, Canada-wide measures for urban environments. We are working with many Canadian researchers who are contributing their expertise to this large national initiative.”

Along with Dr. Michael Widener at the University of Toronto, we are also developing measures of food accessibility, and beginning discussions to develop measures of gentrification.

Connect with Dr. Fuller on Twitter, Facebook, or check out Walkabilly.ca and beaplab.com.

April 1 | 2019

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Temperature-related changes in airborne allergenic pollen abundance and seasonality across the northern hemisphere: a retrospective data analysis.

Ziska LH, Makra L, Harry SK, Bruffaerts N, Hendrickx M, Coates F, Saarto A, Thibaudon M, Oliver G, Damialis A, Charalampopoulos A, Vokou D, Heiđmarsson S, Guđjohnsen E, Bonini M, Oh JW, Sullivan K, Ford L, Brooks GD, Myszkowska D, Severova E, Gehrig R, Ramón GD, Beggs PJ, Knowlton K, Crimmins AR.

Lancet Planet Health. 2019 Mar;3 (3):e124-e131. https://doi.org/10.1016/S2542-5196(19)30015-4

 

Abstract

BACKGROUND:

Ongoing climate change might, through rising temperatures, alter allergenic pollen biology across the northern hemisphere. We aimed to analyse trends in pollen seasonality and pollen load and to establish whether there are specific climate-related links to any observed changes.

METHODS:

For this retrospective data analysis, we did an extensive search for global datasets with 20 years or more of airborne pollen data that consistently recorded pollen season indices (eg, duration and intensity). 17 locations across three continents with long-term (approximately 26 years on average) quantitative records of seasonal concentrations of multiple pollen (aeroallergen) taxa met the selection criteria. These datasets were analysed in the context of recent annual changes in maximum temperature (Tmax) and minimum temperature (Tmin) associated with anthropogenic climate change. Seasonal regressions (slopes) of variation in pollen load and pollen season duration over time were compared to Tmax, cumulative degree day Tmax, Tmin, cumulative degree day Tmin, and frost-free days among all 17 locations to ascertain significant correlations.

FINDINGS:

12 (71%) of the 17 locations showed significant increases in seasonal cumulative pollen or annual pollen load. Similarly, 11 (65%) of the 17 locations showed a significant increase in pollen season duration over time, increasing, on average, 0·9 days per year. Across the northern hemisphere locations analysed, annual cumulative increases in Tmax over time were significantly associated with percentage increases in seasonal pollen load (r=0·52, p=0·034) as were annual cumulative increases in Tmin (r=0·61, p=0·010). Similar results were observed for pollen season duration, but only for cumulative degree days (higher than the freezing point [0°C or 32°F]) for Tmax (r=0·53, p=0·030) and Tmin (r=0·48, p=0·05). Additionally, temporal increases in frost-free days per year were significantly correlated with increases in both pollen load (r=0·62, p=0·008) and pollen season duration (r=0·68, p=0·003) when averaged for all 17 locations.

INTERPRETATION:

Our findings reveal that the ongoing increase in temperature extremes (Tmin and Tmax) might already be contributing to extended seasonal duration and increased pollen load for multiple aeroallergenic pollen taxa in diverse locations across the northern hemisphere. This study, done across multiple continents, highlights an important link between ongoing global warming and public health-one that could be exacerbated as temperatures continue to increase.