EJSCREEN Integration

The U.S. Environmental Protection Agency’s (EPA) EJSCREEN “is an environmental justice mapping and screening tool that provides EPA with a nationally consistent dataset and approach for combining environmental and demographic indicators.”

Adding these organophosphate pesticide (OP) maps to EJSCREEN Mapping Tool: The ArcGIS OP maps described above may be added to the EJSCREEN to view the relationship between organophosphate use and multiple environmental factors and demographics. Go to: https://ejscreen.epa.gov/mapper/

• On the top navigation bar, select: “Add Maps” > “Search For Maps” > “Search Geoplatform”
• A “Search Geoplatform” window will appear. In the search bar, type in “Estimated Use of Organophosphate across Harvested Cropland, by County, in 2017” or “Estimated Use of Organophosphate across Harvested Cropland, by States, in 2017,” then click the “Search” button.
• “Under the list of Map Services/Web Maps found”, look for the maps with “Web Map by hchin_Earthjustice.”
• Click the “Add” link to view the stylized map layers at the county level or state level, respectively.
• The layers will appear on the right under “Select Map Contents”
• Check or uncheck the boxes to display the layer(s)
• Click the plus (+) or minus (-) boxes to expand or hide the legend(s)
• Click on the right arrow boxes to set the transparency for the layer(s)
• Click on the X boxes to remove the layer(s)
• Under the same “Add Maps” dropdown found on the top navigation bar:
• “EJSCEEN Maps” provide layers for environmental indicators, demographic indicators, and environmental justice indexes.
• “More Demographics” provides additional demographic data from the 2000 Census, 2010 Census, and 2014–2018 American Community Survey.
• “Additional Layers” provides other publicly available data, such as schools, Superfund sites, and more.

Map Methodology

Maps by Hetty Chin / Earthjustice
Source data from U.S. Geological Survey and U.S. Department of Agriculture

Volume of Estimated Organophosphate Use

County Level

Data for the estimated 2017 agricultural organophosphate (OP) use at the county-level are found on the U.S. Geological Survey (USGS) website under the Pesticide National Synthesis Project. The data include estimates from both the EPest-low and EPest-high methods, provided in kilograms (kgs). Use for 14 OP compounds (acephate, bensulide, chlorethoxyfos, chlorethoxyfos, chlorpyrifos, diazinon, dicrotophos, dimethoate, ethoprophos, malathion, naled, phorate, phosmet, terbufos, tribufos) are combined to give the aggregate volume of OP used in each county. The volume is converted to pounds (lbs.) by multiplying the kilograms by 2.2046226218. The volume of OP use is represented with proportional circles. Under the EPest-low method, the lowest volume is 0 lb., and the highest is 403,343 lbs. Under the EPest-high method, the lowest volume is 0 lbs., and the highest is 403,343 lbs.

ArcGIS: Estimated Use of Organophosphate across Harvested Cropland, by County, in 2017

• Styles: The scale for the volume is set from 0 lbs. to 400,000 lbs., with the size range adjusted automatically from 4 pixels (px) in diameter to 50 px in diameter, proportional to the volume scale.
• Pop-ups: The title gives the county, state, and the aggregate lbs. of OP used in that county. Distribution across the types of OPs is depicted in a pie chart with slices proportional to the fraction that each compound contributes to the aggregate total for that county. Hovering over each slice gives the volume of each compound in kgs.

CartoDB: EPest-low Volume of Organophosphates Use in the U.S. (by county in 2017) and EPest-high Volume of Organophosphates Use in the U.S. (by county in 2017)

• Style: Circular markers for the centroid of each county are set to a radius based on the volume of OP used in that region. The max diameter is set to 50 px which corresponds to the largest volume of OP found (403,343 lbs). The remaining markers are porportion to these max values and calculated with the equation: symbol size = (50 px) * (square root of county volume / square root of 403,343).
• Pop-up:
• Hover – The county, state, and the aggregate lbs. of OP used in that county are shown.
• Click – The header gives the county, state, and the aggregate lbs. of OP used in that county. The volume of each OP compound is listed. The names of each compound links to more information about that OP.

State Level

Estimated OP use at the state-level is calculated by taking the sum of the volumes found in the counties within each state. The volume of OP use is represented with proportional circles. Under the EPest-low method, the lowest volume is 1,229 lbs., and the highest is 2,268,220 lbs. Under the EPest-high method, the lowest volume is 1,249 lbs., and the highest is 2,837,470 lbs.

ArcGIS: Estimated Use of Organophosphate across Harvested Cropland, by States, in 2017

• Style: The scale for the volume is set from 1,229 lbs. to 3,000,000 lbs., with the size range adjusted automatically from 16 px in diameter to 80 px in diameter, proportional to the volume scale.
• Pop-up: The title gives the state, and the aggregate lbs. of OP used in that state. Distribution across the types of OPs is depicted in a pie chart with slices proportional to the fraction that each compound contributes to the aggregate total for that state. Hovering over each slice gives the volume of each compound in kgs.

CartoDB: EPest-low Volume of Organophosphate Use in the U.S. (by state in 2017) and EPest-high Volume of Organophosphate Use in the U.S. (by state in 2017)

• Style: Circular markers for the centroid of each state are set to a radius based on the volume of OP used in that region. The max diameter is set to 50 px which corresponds to the largest volume of OP found (2,837,470 lbs). The remaining markers are porportion to these max values and calculated with the equation: symbol size = (50 px) * (square root of state volume / square root of 2,837,470).

Concentration of OP use Allocated Across Harvested Cropland

As reported by the USGS, “Harvested-crop acreage data by county from the U.S. Department of Agriculture Census of Agriculture are used to calculate the median pesticide-by-crop use rates for each crop in each Crop Reporting Districts (CRD). These rates are applied to the harvested acreage of each crop in a county to obtain pesticide-use estimates at a county level.”

Concentrations indicated in the maps reflect the USGS estimates allocated to total harvested acreage for all crops reported in the county and total harvested acreage for all crops reported in the state, which includes harvested acreage for crops that did not have OPs applied to them. For this reason, unless all harvested crops reported in the county or state were applied with OPs, the concentrations found on the maps are dilute in comparison to the true concentration. To calculate true concentration, one would need to obtain harvested acreage for each crop that is applied with each specific pesticide.

Additionally, some acres of harvested cropland are withheld in the United States Department of Agriculture’s (USDA) National Agricultural Statistics Service (NASS) database. In these instances, the top value of the disclosed range is used to calculate an estimate for the acres. Unless the actual acreage of harvested cropland was in the top value of the disclosed range, our method of choosing the top value gives a larger area of harvested cropland and thus the concentrations found on the map are further dilute.

Harvested cropland is converted to square miles (sq mi) by dividing the acreage by 640.

County Level

Acreage of Harvested Cropland: 2017 data for the acres of harvested cropland reported at the county-level is found in the USDA NASS database.

Some acres of harvested cropland are withheld to avoid disclosing data for individual operations. The 2017 Ag Census Web Maps Data are used to calculate a value for the withheld acreage. The acres of harvested cropland as percent of land in farms acreage: 2017 (y17_M066) is multiplied with acres of land in farms as percent of land area in acres: 2017 (y17_M059) and with the land area in acres of a county equivalent (or agriculture area) (atlas_acre) to give the acres of harvested cropland.

Some values for the acres of harvested cropland as percent of land in farms acreage: 2017 (y17_M066) and some values for the acres of land in farms as percent of land area in acres: 2017 (y17_M059) are withheld to avoid disclosing data for individual farms. For withheld data, a class range field is provided. The top value of the range is used to calculate the acres of harvested cropland. For acres of harvested cropland as percent of land in farms acreage: 2017 (y17_M066), the class ranges are provided as:

• Less than 10
• 10-19
• 20-39
• 40-59
• 60-79
• 80 or more

Nine percent is chosen for values that fall in the Less than 10 category and 100% is chosen for values that fall in the 80 or more category. For acres of land in farms as percent of land area in acres: 2017 (y17_M059), the class ranges are provided as:

• Less than 10
• 10-29
• 30-49
• 50-69
• 70-89
• 90 or more

Nine percent is chosen for values that fall in the Less than 10 category and 100% is chosen for values that fall in the 90 or more category.

Log: The values of the concentration are not normally distributed. A log transformation is used to normalize the concentration. Under the EPest-low method, the highest value is 5 and the lowest value is -3.2. Under the EPest-high method, the highest value is 5 and the lowest value is -1.8. The log of the concentration is used to create choropleth layers.

Agricultural areas: To provide a visual depiction of where the harvested croplands may be in the United States, the National Land Cover Database (NLCD) 2016 is used. The Pasture/Hay (81) and Cultivated Crops (82) categories are dissolved into one agricultural layer. The ratios of organophosphate use to area of harvested cropland are clipped to the agricultural perimeters found within each administrative region.

ArcGIS: Estimated Use of Organophosphate across Harvested Cropland, by County, in 2017

• Style: The choropleth layer is set to a graduated color ramp that goes from a light beige to represent the lower concentrations to a dark purple to represent the higher concentrations. The color ramp is set to range from -3.2 to 5 for the log of the concentrations. There is no official significance assigned to where the colors fall on the graduated ramp, but these colors may serve to highlight areas for further review.
• Pop-up: The title gives the county, state, and the lbs. per sq mi of harvested cropland for the OP used in that county. Total volume of OP use in that county is listed in lbs. Harvested cropland found within that county is listed in sq mi. Distribution across the types of OPs is depicted in a pie chart with slices proportional to the fraction that each compound contributes to the aggregate total for that county. Hovering over each slice gives the volume of each compound in kgs.

CartoDB: EPest-low Concentration of Organophosphates Use in the U.S. (by county in 2017) and EPest-high Concentration of Organophosphates Use in the U.S. (by county in 2017)

• Style: The choropleth layer is set to graduated colors divided into 12 intervals with the lowest interval set to a light yellow, and the highest interval set to a dark purple:
• ≤ -2.52
• > -2.52, ≤ -1.83
• > -1.83, ≤ -1.15
• > -1.15, ≤ -0.47
• > 0.47, ≤ 0.22
• > 0.22, ≤ 0.90
• > 0.90, ≤ 1.58
• > 1.58, ≤ 2.27
• > 2.27, ≤ 2.95
• > 2.95, ≤ 3.63
• > 3.63, ≤ 4.32
• > 4.32, ≤ 5
• Pop-up:
• Hover – The county, state, and the lbs. per sq mi of harvested cropland for OP used in that county are shown.
• Click – The header gives the county, state, and lbs. per sq mi of harvested cropland for OP used in that county. The volume of each OP compound is listed. The names of each compound links to more information about that OP. Total volume of OP use in that county is listed in lbs. Harvested cropland found within that county is listed in sq mi.

State Level

Acreage of Harvested Cropland: 2017 data for the acres of harvested cropland reported at the state-level and land area in acres of a state equivalent (atlas_acres) are found in the USDA NASS database.

Outliers: We use the medcouple concept to identify the outliers in the state concentrations. Under the EPest-low method, the two highest concentrations are outliers (Georgia’s 246.55 lbs. per sq mi of harvested cropland and Arizona’s 228.24 lbs. per sq mi of harvested cropland). The third highest concentration is 207.89 lbs. per sq mi of harvested cropland, and the lowest concentration is 0.52 lbs. per sq mi of harvested cropland. Under the EPest-high method, the lowest concentration (Vermont’s 7.29 lbs. per sq mi of harvested cropland) and the highest concentration (Arizona’s 555.28 lbs. per sq mi of harvested cropland) are outliers. The second highest concentration is 268.71 lbs. per sq mi of harvested cropland and the second lowest concentration is 12.28 lbs. per sq mi of harvested cropland.

ArcGIS: Estimated Use of Organophosphate across Harvested Cropland, by States, in 2017

• Style: The choropleth layer is set to a graduated color ramp that goes from a light beige to represent the lower concentrations to a dark purple to represent the higher concentrations. With the outliers taken out of consideration, the color ramp is set to range from zero to 269 lbs. per sq mile of harvested cropland. There is no official significance assigned to where the colors fall on the graduated ramp, but these colors may serve to highlight areas for further review.
• Pop-up: The title gives the state and the lbs. per sq mi of harvested cropland for the OP used in that state. Total volume of OP use in that state is listed in lbs. Harvested cropland found within that state is listed in sq mi. Distribution across the types of OPs is depicted in a pie chart with slices proportional to the fraction that each compound contributes to the aggregate total for that state. Hovering over each slice gives the volume of each compound in kgs.

CartoDB: EPest-low Concentration of Organophosphate Use in the U.S. (by state in 2017) and EPest-high Concentration of Organophosphate Use in the U.S. (by state in 2017)

• Style: The choropleth layer is set to graduated colors divided into 11 intervals with the lowest interval set to light yellow, and the highest interval set to a dark purple:
  • > 0, ≤ 25
  • >25, ≤ 50
  • >50, ≤ 75
  • >75, ≤ 100
  • >100, ≤ 125
  • >125, ≤ 150
  • >150, ≤ 175
  • >175, ≤ 200
  • >200, ≤ 225
  • >225, ≤ 250
  • >250
• Pop-up:
• Hover – The state and the lbs. per sq mi of harvested cropland for OP used in that state are shown.
• Click – The header gives the state and lbs. per sq mi of harvested cropland for OP used in that state. The lbs. of each OP compound are listed. The names of each compound links to more information about that OP. Total volume of OP use in that state is listed in lbs. Harvested cropland found within that state is listed in sq mi.