Spatial cluster mapping and environmental modeling in pediatric inflammatory bowel disease

Table 2 Data used in environmental exposure modeling

Variable	Description	Data source and database
Income	Mean of 2005 (adjusted to 2015 dollars) and 2015 census average family income for Local Health Areas	Statistics Canada, BC Community Health Atlas
Ethnicity	Census percent of the population of South Asian, Indigenous, Chinese, Jewish, and Non-Jewish European ethnic origin	Statistics Canada, University of Toronto Computing in the Humanities and Social Sciences Data Centre
Family size	Census average family size	Statistics Canada, University of Toronto Computing in the Humanities and Social Sciences Data Centre
Rurality	Percent of residents in each Local Health Area who lived outside a census metropolitan area or census agglomeration	Statistics Canada
NDVI greenness	Green vegetation cover calculated from land satellite imagery of surface reflection. Maximum and average growing season (May – August) NDVI within 250 m from postal code location. Multiplied by 100 so changes could be assessed as percentages	United States Geological Survey, Canadian Urban Environmental Health Research Consortium
UV vitamin D	Long-term stable monthly mean daily vitamin D dose from solar UV radiation adjusted for postal code elevation (J/m-2) which was averaged for winter (December through February) and summer (June through August)	Environment Canada and Cancer Care Ontario, Canadian Urban Environmental Health Research Consortium
NO2 air pollution	Annual average NO2 concentration in parts per billion	Canadian Urban Environmental Health Research Consortium
O3 air pollution	Average of O3 taken from the highest rolling 8-hour daily average concentration (parts per billion)	Environment and Climate Change Canada, Canadian Urban Environmental Health Research Consortium
PM2.5 air pollution	Annual average surface PM2.5 (μg/m3) concentration	Atmospheric Composition Analysis Group, Canadian Urban Environmental Health Research Consortium
Metam pesticide	2015 metam pesticide applied to fruits and vegetables (kg/ha/yr)	Global Pesticide Grids, Version 1.01, based on the United States Geological Survey’s Pesticide National Synthesis Project and the Food and Agriculture Organization Corporate Statistical Database pesticide databases
Petroleum oil pesticide	2015 petroleum oil employed for grapes and orchards (kg/ha/yr)	Global Pesticide Grids, Version 1.01, based on the United States Geological Survey’s Pesticide National Synthesis Project and the Food and Agriculture Organization Corporate Statistical Database pesticide databases
Glyphosate pesticide	2015 total glyphosate employed in major crops (wheat, corn, alfalfa, and others) in (kg/ha/yr)	Global Pesticide Grids, Version 1.01, based on the United States Geological Survey’s Pesticide National Synthesis Project and the Food and Agriculture Organization Corporate Statistical Database pesticide databases
Population age 0-16.9	Yearly estimates of population age 0-16.9 for Local Health Areas averaged for 2001–2016	Statistics Canada, BC Stats

BC: British Columbia; NDVI: Normalized difference vegetation index; NO₂: Nitrogen dioxide; O₃: Ozone; PM_2.5: Fine particulate matter; UV: Ultraviolet.