Upwind Report

Glyphosate use in Napa County, California

Reported farm glyphosate use in Napa County, California was 50 pounds per square mile of county land in 2019, higher than 50% of US counties.

Map of Napa County, California and nearby counties, coloring each county's cropland by estimated farm glyphosate use per square mile of county land in 2019 reported use. Darker colors mean more use.

2019 numbers

Per square mile of county land50lbTop 50% in the US
US
1,501st of 3,060
California
18th of 56
Per square mile of cropland434lb

Ranks are by use per square mile of county land, on the 2019 high estimate, among US counties with a value. Counties with the same value share a rank.

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A picture of Napa County against the US county median, with the source, to post or send.

Since 2000

Up from 41 in 2000 to 50 in 2019. Pounds per square mile of county land, high estimate.

Every year's numbers
Glyphosate per square mile of county land by year, in pounds
YearLowHigh
20004141
20013434
20025757
20035757
20045454
20055454
20064949
20075555
20083333
20095858
20104545
20115757
20125757
20136767
20145858
20157272
20166363
20175757
20185252
20195050
See Napa County on the map

About these numbers

The main number is the county's estimated farm glyphosate use for the year divided by all of its land, water left out. A county with a little farmland can use a lot per square mile of cropland and still have far less in total than a county with more farmland, so the whole-county number is the one the map colors, ranks and compares.

These are county estimates, not records. They don't show which fields were sprayed or how much any one field got.

California's numbers are the state's own reported use, which USGS uses in place of an estimate, so the low and high numbers are the same.

Per square mile of cropland is the same total spread evenly over the county's cropland only, so it's higher than the whole-county number wherever only part of Napa County, California is farmland.

Numbers are in pounds per square mile. The source gives kilograms per square kilometer, and 1 kg per km² is about 5.7 pounds per square mile.

Source: Hengl & Brungard from USGS county estimates, 2000–2019 (CC BY 4.0). Land area: US Census Bureau, 2020.

This page shows estimated farm use only. It says nothing about health and is not medical advice.