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Trends in glyphosate herbicide use in the United States and globally

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  • Newcastle University and Benbrook Consulting Services (BCS)

Abstract and Figures

Background: Accurate pesticide use data are essential when studying the environmental and public health impacts of pesticide use. Since the mid-1990s, significant changes have occurred in when and how glyphosate herbicides are applied, and there has been a dramatic increase in the total volume applied. Methods: Data on glyphosate applications were collected from multiple sources and integrated into a dataset spanning agricultural, non-agricultural, and total glyphosate use from 1974-2014 in the United States, and from 1994-2014 globally. Results: Since 1974 in the U.S., over 1.6 billion kilograms of glyphosate active ingredient have been applied, or 19 % of estimated global use of glyphosate (8.6 billion kilograms). Globally, glyphosate use has risen almost 15-fold since so-called "Roundup Ready," genetically engineered glyphosate-tolerant crops were introduced in 1996. Two-thirds of the total volume of glyphosate applied in the U.S. from 1974 to 2014 has been sprayed in just the last 10 years. The corresponding share globally is 72 %. In 2014, farmers sprayed enough glyphosate to apply ~1.0 kg/ha (0.8 pound/acre) on every hectare of U.S.-cultivated cropland and nearly 0.53 kg/ha (0.47 pounds/acre) on all cropland worldwide. Conclusions: Genetically engineered herbicide-tolerant crops now account for about 56 % of global glyphosate use. In the U.S., no pesticide has come remotely close to such intensive and widespread use. This is likely the case globally, but published global pesticide use data are sparse. Glyphosate will likely remain the most widely applied pesticide worldwide for years to come, and interest will grow in quantifying ecological and human health impacts. Accurate, accessible time-series data on glyphosate use will accelerate research progress.
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Benbrook Environ Sci Eur (2016) 28:3
DOI 10.1186/s12302-016-0070-0
RESEARCH
Trends inglyphosate herbicide use
inthe United States andglobally
Charles M. Benbrook*
Abstract
Background: Accurate pesticide use data are essential when studying the environmental and public health impacts
of pesticide use. Since the mid-1990s, significant changes have occurred in when and how glyphosate herbicides are
applied, and there has been a dramatic increase in the total volume applied.
Methods: Data on glyphosate applications were collected from multiple sources and integrated into a dataset
spanning agricultural, non-agricultural, and total glyphosate use from 1974–2014 in the United States, and from
1994–2014 globally.
Results: Since 1974 in the U.S., over 1.6 billion kilograms of glyphosate active ingredient have been applied, or 19 %
of estimated global use of glyphosate (8.6 billion kilograms). Globally, glyphosate use has risen almost 15-fold since
so-called “Roundup Ready,” genetically engineered glyphosate-tolerant crops were introduced in 1996. Two-thirds of
the total volume of glyphosate applied in the U.S. from 1974 to 2014 has been sprayed in just the last 10 years. The
corresponding share globally is 72 %. In 2014, farmers sprayed enough glyphosate to apply ~1.0 kg/ha (0.8 pound/
acre) on every hectare of U.S.-cultivated cropland and nearly 0.53 kg/ha (0.47 pounds/acre) on all cropland worldwide.
Conclusions: Genetically engineered herbicide-tolerant crops now account for about 56 % of global glyphosate use.
In the U.S., no pesticide has come remotely close to such intensive and widespread use. This is likely the case globally,
but published global pesticide use data are sparse. Glyphosate will likely remain the most widely applied pesticide
worldwide for years to come, and interest will grow in quantifying ecological and human health impacts. Accurate,
accessible time-series data on glyphosate use will accelerate research progress.
Keywords: Glyphosate, Herbicide use, Genetic engineering, Herbicide-tolerant crops, Roundup, Pesticide use
© 2016 Benbrook. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License
(http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium,
provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license,
and indicate if changes were made.
Background
A Swiss chemist working for a pharmaceutical com-
pany, Dr. Henri Martin, discovered glyphosate
[N-(phosphonomethyl) glycine] in 1950 [1]. Because no
pharmaceutical applications were identified, the mol-
ecule was sold to a series of other companies and samples
were tested for a number of possible end uses. A Mon-
santo chemist, Dr. John Franz, identified the herbicidal
activity of glyphosate in 1970, and a formulated end-use
product called Roundup was first sold commercially by
Monsanto in 1974 [2].
For two decades, the number and diversity of agri-
cultural and non-farm uses grew steadily, but the
volume sold was limited because glyphosate could only
be sprayed where land managers wanted to kill all vegeta-
tion (e.g., between the rows in orchards and viticulture;
industrial yards; and, train, pipeline, and powerline rights
of way). Some applications were, and still are made after
a crop is harvested, to control late-season weeds that
escaped other control measures. In some regions, des-
iccant applications are made late in the growing season
to speed up harvest operations, especially in small grain
crops.
In 1996, so-called “Roundup Ready” (RR), genetically
engineered (GE) herbicide-tolerant (HT) soybean, maize,
and cotton varieties were approved for planting in the
U.S. is technological breakthrough made it possible
to utilize glyphosate as a broadcast, post-emergence her-
bicide, thereby dramatically extending the time period
Open Access
*Correspondence: charlesbenbrook@gmail.com
Benbrook Consulting Services, 90063 Troy Road, Enterprise, OR 97828,
USA
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Page 2 of 15
Benbrook Environ Sci Eur (2016) 28:3
during which glyphosate-based herbicides could be
applied. Alfalfa and sugar beets engineered to tolerate
glyphosate were first approved and commercially mar-
keted in 2005 and 2008, respectively, but federal lawsuits
citing procedural violations of the National Environmen-
tal Policy Act delayed full commercial sales until 2011 for
RR alfalfa and 2012 for RR sugar beets [3, 4].
To quantify the environmental and human health
impacts stemming from pesticide use, it is essential to
know how much pesticide is being applied in a region
on a given crop, collectively across all crops, and in
other places (e.g., forests, rangeland, along rights-of-way,
industrial yards). Ideally, data are available on the land
area and crops treated; the timing and method of appli-
cations; rates and number of application; the formulation
applied and the total volume applied per hectare. Unfor-
tunately, all these data are rarely available.
Rising use heightens risk concerns. Growing reliance on
the broad-spectrum herbicide glyphosate has triggered
the spread of tolerant and resistant weeds in the U.S.
and globally [510]. To combat weeds less sensitive to
glyphosate, farmers typically increase glyphosate appli-
cation rates and spray more often [1113]. In addition,
next-generation herbicide-tolerant crops are, or will soon
be on the market genetically engineered to withstand the
application of additional herbicides (up to over a dozen),
including herbicides posing greater ecological, crop dam-
age, and human health risks (e.g., 2,4-D and dicamba) [6].
is paper presents trends in glyphosate use in order to
help researchers better understand and quantify the risks
and benefits stemming from uses of glyphosate-based
herbicides. Detailed data on trends in glyphosate use in
the U.S., both in and outside the agricultural sector, are
presented, while the data on global glyphosate use are
less complete and more uncertain. Fortunately, sufficient
data are available to track the impact of GE herbicide-
tolerant (HT) crops on global glyphosate-based herbicide
(GBH) use since 2010 [1417].
In order to better understand the many factors driving
the trajectory of glyphosate’s use and impacts, two time-
line graphics are presented in the “Discussion” section,
Fig.1.
Methods
Use data
roughout this paper, all references to glyphosate or
glyphosate-based herbicides encompass all commercial
end-use formulations. All data on volumes of glyphosate
applied refer to kilograms or pounds of the active ingre-
dient glyphosate, rather than glyphosate plus the adju-
vants and surfactants included in an end-use formulation
to enhance uptake by weeds and facilitate mixing and
spray applications.
Glyphosate is applied in a variety of forms including
isopropylamine salt, ammonium salt, diammonium salt,
dimethylammonium salt, and potassium salt [1]. E.g., in
its corn pesticide use survey in 2014, the National Agri-
cultural Statistics Service (NASS) collected data on four
different forms of glyphosate applied at different rates:
isopropylamine salt, glyphosate, glyphosate ammonium
salt, and glyphosate potassium salt [11]. Total corn hec-
tares treated with glyphosate in the U.S. and kilograms
of active ingredient applied are the sum across the four
forms of glyphosate. “Total glyphosate” rate of appli-
cation is calculated as an average of the four applica-
tion rates reported for the different forms of glyphosate,
weighed by the area treated with each form of glyphosate.
e same process can be used to calculate “total glypho-
sate” average number of applications per hectare.
Four data points are generally collected and/or calcu-
lated when government agencies or private survey com-
panies report pesticide use data on a given crop in a
defined area and time period: (1) the percent of crop hec-
tares treated with a given pesticide; (2) the average rate
of application; (3) the average number of applications per
crop year; and (4) total kilograms of pesticide applied to
the crop. When a data source does not report total kilo-
grams or pounds applied, or one other of the above key
parameters, the missing variable can be calculated based
on:
where Weightp,c is the amount of pesticide p applied to
crop c (kg active ingredient [a.i.]), AreaTreatedp,c is the
area of crop c to which the pesticide p is applied (ha),
TotalAreac is the total area planted with crop c (ha), and
Ratep,c is the “Rate per Crop Year” for pesticide p on crop
c. “Rate per Crop Year” is the product of the average rate
of application multiplied by the number of applications
per crop year, and is a useful metric because certain crops
may be planted in the fall and harvested the next spring
or summer of the following year.
U.S. data sources
e U.S. Department of Agriculture (USDA), through the
National Agricultural Statistics Service (NASS), has col-
lected reasonably comprehensive pesticide use data for
major grain, row crop, fruit, and vegetable crops since
1990 [18]. Periodic USDA surveys are also available to
track pesticide use on major crops back into the 1970s.
Between 1997 and 2007, the U.S. Environmental Pro-
tection Agency (EPA) issued several reports on the vol-
umes of pesticides applied in the agricultural, industrial/
government, and urban/suburban sectors [1923]. EPA
use reports capture a number of lower-volume pesticide
(1)
Weight
p,c=
AreaTreated
p,c
TotalAreac
×TotalAreac×Ratep,
c
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Benbrook Environ Sci Eur (2016) 28:3
60
65
70
75
80
85
0%
20%
40%
60%
80%
100%
120%
Million Acres
Percent Acres Treated
Soybean Acres
Percent Acres Treated with Glyphosate Total Acres Planted
0.00
0.50
1.00
1.50
2.00
2.50
3.00
0.00
0.50
1.00
1.50
2.00
2.50
Number of Herbicides per Acre
Herbicide Use per Acre
Overall Soybean Herbicide Use
Avg Number of Herbicides per Acre Total Herbicide Use per Acre
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Percent of Total
Number of Apps and Rate
Reliance on Glyphosate in Soybean Producon
Glyphosate as Percent of Total Herbicide UseGlyphosate Number of Applicaons
Glyphosate Rate per Crop Year
0
5
10
15
20
25
30
35
40
45
50
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
Bushels per Acre
Yield per Seed (lbs)
Soybean Producon
Bushels per Acre Yield per Seed Planted (lbs)
a
b
c
d
Fig. 1 Trends in U.S. soybean production and glyphosate use
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Page 4 of 15
Benbrook Environ Sci Eur (2016) 28:3
uses not included in USDA surveys and are the only pub-
lic source of data on industrial/government and subur-
ban/urban pesticide use.
Data on glyphosate use on specific crops in the U.S.
are primarily drawn from pesticide use surveys carried
out by the USDA’s NASS. Pesticide applications at the
national and state level have been reported since 1990 by
NASS for most major field crops; fruit crops have been
surveyed in odd years; and vegetables have been covered
in even years [18].
Estimates of overall GBH use by U.S. farmers and
ranchers are available from three sources: the sum
of crop-specific NASS data in any given year; the
EPA periodic reports noted above; and, the pesticide
use data set compiled by the U.S. Geological Survey
(USGS), which in turn draws heavily on private survey
data [2426]. Both the EPA and USGS use data com-
pilations augment NASS data with a variety of other
information sources that cover uses not included in
NASS surveys. In addition, a number of private com-
panies conduct surveys of pesticide use in the U.S. and
around the world, although detailed results are not
publicly accessible.
NASS surveys a limited number of crops in any given
year. In the tables that follow, pesticide use is linearly
interpolated in years lacking survey data but bounded by
reported values. In years before the first, or after the last
NASS survey, annual values are extrapolated (see [27],
Additional file1: Tables for details).
In each year, NASS strives to collect data on states that
collectively account for at least 85% of the area planted
nationally to a given crop. For some crops, 15 or more
states are surveyed to reach this threshold, while in other
crops only two states are required (e.g., lemons in 2011,
two states; corn in 2010, 21 states). Accordingly, when
NASS reports national estimates of total pesticide use on
surveyed acres of a given crop, the data typically under-
estimate total national crop use by~15%, since national
acres planted always exceeds NASS acres surveyed. is
is why in several Additional file1: Tables [27] the pounds
of herbicides applied are reported on both NASS-sur-
veyed acres and total national acre. To estimate use on
all planted hectares/acres, the average rate of application
per crop year on NASS-surveyed acres is applied to the
total planted area [28].
Total volume ofglyphosate applied
NASS use data were downloaded and integrated into the
“Pesticide Use Data System” (PUDS). Additional file1:
Tables S6–S15 [27] report glyphosate use in the U.S. on
grain crops, fruits, vegetables, nuts, and other crops for
1982, 1992, 1995, 1998, 2001, 2004, and every 2 years
thereafter through 2014. ese tables report average rates
of glyphosate application and rate per crop year weighted
by the acres treated with each of the multiple forms of
glyphosate included in NASS surveys. Total pounds of
all forms of glyphosate applied to all crops surveyed by
NASS are shown in Additional file1: Table S17 [27]. Val-
ues in years when NASS did not survey a given crop are
interpolated or extrapolated (see Additional file1: Table
S17 for details).
Little or no government or published survey data
are accessible on the volume of glyphosate applied on
canola and pima cotton, as well as two more recently
approved and planted GE-HT crops (alfalfa, sugar
beets). Estimates of GBH use on these crops were made
for 2012–2014 in Additional file 1: Table S16, based
on NASS data on acres planted, estimates of adoption
of glyphosate-tolerant varieties issued by commodity
groups, academic weed management specialists, or in
trade press articles.
EPA pesticide use summary reports
Pesticide use reports have been released by the EPA for
1987, 1993, and every two years thereafter through 2007
[1923].
ese reports encompass more crops and agricultural
uses than the NASS reports, and also quantify use in
three sectors: “U.S. Agriculture,” “Industrial/Commer-
cial/Government,” and “Home and Garden.” EPA pesti-
cide use reports draw on NASS survey results, a number
of proprietary pesticide use datasets, and pesticide pro-
duction and use data submitted by registrants, or col-
lected during the course of a regulatory review of a given
pesticide.
e EPA has not reported pesticide use data since 2007.
However, NASS coverage of the major uses of glyphosate
is somewhat consistent since 2007, and the U.S. Geologi-
cal Survey (USGS) has also issued detailed reports and
a dataset of pesticide use covering 1992-2011 [25, 29].
Results from NASS, EPA, and USGS are integrated in
Additional file1: Table S18 [27] to produce annual data
from 1974 through 2014 in glyphosate use in agriculture,
non-agricultural applications, and total glyphosate use.
Global glyphosate use data sources and estimates. A
special issue of the journal Pest Management Science in
2000 focused on glyphosate uses, issues, and challenges.
Woodburn [29] summarized global glyphosate use from
1994–1997, and provided valuable information on agri-
cultural and non-agricultural uses. Woodburn’s analysis
drew upon proprietary data sources and surveys.
Several sources of industry data on global glyphosate
production are available for 2011–2014 [3033]. Global
use data in Additional file 1: Table S23 between 1997
and 2011 are interpolated and track the annual rates of
growth in the U.S.
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Benbrook Environ Sci Eur (2016) 28:3
Glyphosate use onherbicide‑tolerant hectares
Global soybean production in 2014 was 315.4 million
metric tons (11.6 million bushels), with the U.S. (108
million metric tons), Brazil (94.5 mill. metric tons), and
Argentina (56 mill. metric tons) accounting for 82% of
the global harvest [34]. e International Service for
the Acquisition of Agri-Biotech Applications (ISAAA)
compiles annual, global data by country, continent, and
worldwide on hectares planted to various GE crop vari-
eties ([1417], [27], Additional file 1: Table S20). Data
from these briefs were combined with estimates of aver-
age glyphosate rates of application ([27], Additional
file1: Table S21), yielding estimates of total glyphosate
use from 1996 to 2014 on GE, herbicide-tolerant cotton,
maize, soybeans, and canola, and globally for all crops
([27], Additional file1: Table S23).
Use in Argentina and Brazil. GE-HT soybeans
accounted for 100 and 93% of the soybean hectares
planted in Argentina and Brazil in 2014 [34]. Sistema
Integrado de Información Agropecuaria (Ministerio de
Agricultura Ganadaria y Pesca) reports data on hec-
tares planted to soybeans in Argentina [35], and the
Instituto Brasileiro de Geografia e Estatística (IBGE)
provides the same data for Brazil [36]. For Argen-
tina and Brazil, Soystats [34] provides percent of area
planted to GE-HT soybeans for 2000–2014. Benbrook
[37] and Meyer and Cederberg [38] provide informa-
tion on glyphosate use rates per crop year, which are
substantially higher than those in the U.S. Ferraro and
Ghersa [39] also document applications to soybeans in
Argentina that can range up to seven per year, substan-
tially more than in the U.S.
Results
Glyphosate use inthe U.S
Farmers and ranchers in the U.S. applied an estimated
0.36 million kg of active ingredient (0.8 million pounds)
in 1974 (Table1). e volume applied increased steadily,
but not dramatically, through 1995, to 12.5 million kg (28
million pounds).
e 12.5 million kg applied in 1995, prior to the GE era,
made glyphosate the seventh most heavily applied pes-
ticide in U.S. agriculture that year, according to the EPA
([27], Additional file1: Table S19). e top-six pesticides
applied by U.S. farmers and ranchers in 1995 included
two herbicides mostly used on corn (#1 atrazine, and #2
metolachlor), three soil fumigants primarily applied on
fruit and vegetable crops (#3-5, metam-sodium, methyl-
bromide, dichloropropene), and one broad-leaf herbicide
relied on in multiple cropping systems (#6, 2,4-D).
As GE-HT crops gained market share in 1996–2000,
agricultural applications of glyphosate in the U.S. rose
rapidly, reaching 36 million kg (79 million pounds) by
2000 (Table1). at year, agricultural uses of glyphosate
accounted for 80% of total national use (in 1974, the agri-
cultural share of total glyphosate use was about 60%). A
decade later in 2010, agriculture’s share had risen to 90%.
From 1974–2014, a total of 1.37 billion kg of glyphosate
(3.0 billion pounds) was applied in the U.S. agricultural
sector (Table1).
Glyphosate use in the agricultural sector rose 300-fold
from 1974 to 2014 (0.36–113.4 million kg; 0.8–250 mil-
lion pounds). Non-agricultural uses rose less dramati-
cally, by 43-fold in the same time period, because there
were far fewer new, non-agricultural uses registered.
Glyphosate has been on the market as a herbicide for
42years. In the first 31 of these years (1974–2004), U.S.,
farmers applied only~27% of the total volume (weight)
of glyphosate applied since 1974. Nearly 67 % of total
agricultural glyphosate use in the U.S. since 1974 has
occurred in just the last 10years (Table2).
Use bycrop inthe U.S
Table 3 provides an overview of trends since 1990 in
glyphosate applications on 12 major crops in the U.S.
surveyed by NASS, as well as an estimate of use on all
Table 1 Glyphosate active ingredient use inthe United States: 1974–2014
Data in thousands of kilograms or pounds of glyphosate active ingredient. From the National Agriculture Statistical Service pesticide use data and the Environmental
Protection Agency pesticide industry and use reports (1995, 1997, 1999, 2001, 2007). See Additional le1: Table S18 for details
1974 1982 1990 1995 2000 2005 2010 2012 2014
Glyphosate Use (1000 kg) 635 3538 5761 18,144 44,679 81,506 118,298 118,753 125,384
Agricultural 363 2268 3357 12,474 35,720 71,441 106,963 107,192 113,356
Non-agricultural 272 1270 2404 5670 8958 10,065 11,335 11,562 12,029
Glyphosate use (1000 lb) 1400 7800 12,700 40,000 98,500 179,690 260,804 261,807 276,425
Agricultural 800 5000 7400 27,500 78,750 157,500 235,814 236,318 249,906
Non-agricultural 600 2800 5300 12,500 19,750 22,190 24,989 25,489 26,519
Share agricultural (%) 57.1 64.1 58.3 68.8 79.9 87.7 90.4 90.3 90.4
Share non-agricultural (%) 42.9 35.9 41.7 31.3 20.1 12.3 9.6 9.7 9.6
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Page 6 of 15
Benbrook Environ Sci Eur (2016) 28:3
other crops. Soybeans accounted for about one-third
of total agricultural glyphosate use in 1990, a share
that rises to almost one-half by 2014 (Table 3). e
three major GE-HT crops (soybeans, maize, cotton)
accounted for~200 million pounds of glyphosate use
based on NASS data, or 80% of total farm and ranch
use in 2014 (249.9 million pounds; Table3). USGS data
for 2012 place total GBH use on the three GE-HT crops
at 235 million pounds; the difference between NASS
and USGS data arises from higher USGS estimates of
use on corn and cotton.
Detailed glyphosate use data for NASS-surveyed crops
are provided in Additional file1: Tables S11–21 [27] for
1982, 1992, 1995, 1998, 2001, 2004, and every even year
thereafter through 2014. In each table, the following crop
groups are used: grains, fruits, vegetables, nuts, and other
crops. For each crop and year, the data points include
percent of acres treated, rate of application, number of
applications, rate per crop year, pounds applied to sur-
veyed acres and to total national crop acres. Additional
file1: Table S5 provides glyphosate herbicide data at the
state level for winter wheat in Kansas from 1993–2012.
Global glyphosate use
Worldwide glyphosate use was modest in the 1970s com-
pared to the most heavily applied herbicides then on the
market (e.g. atrazine, metolachlor). e volume applied
grew relatively slowly until the GE era ([27], Additional
file 1: Table S24). By 1994, global agricultural use had
reached 43 million kg of active ingredient (95 million
pounds). Another 13 million kg were applied outside
agriculture, for a total of 56.3 million kg (124 million
pounds).
Global agricultural use of glyphosate mushroomed
following adoption of GE-HT crops in 1996. e total
volume applied by farmers rose 14.6-fold, from 51
million kg (113 million pounds) in 1995 to 747 mil-
lion kg (1.65 billion pounds) in 2014 (Table4). In this
same time period, agricultural use of glyphosate in the
U.S. rose 9.1-fold. Global non-agricultural uses have
increased fivefold since the introduction of GE crops,
from 16 million kg in 1995 to 79 million kg (35–175
million pounds; Table4).
Total worldwide glyphosate use (agricultural plus non-
agricultural) rose more than 12-fold from about 67 mil-
lion kg in 1995 to 826 million kg in 2014 (0.15–1.8 billion
pounds; Table4). Over the last decade, 6.1 billion kgs of
glyphosate have been applied, 71.6% of total use world-
wide from 1974–2014 (Table5).
Table 2 Share of total glyphosate active ingredient use
bydecade inthe U.S
Estimated from National Agriculture Statistical Service (NASS), USGS, and EPA
data. See Additional le1: Table S18 for details
Total use
(million kg) Increase
fromprevious
period
Share of
total use
1974–2014 (%)
1974 0.6 NA 0.0
1975–1984 26 25 1.6
1985–1994 77.1 51 4.8
1995–2004 433 356 26.9
2005–2014 1070 637 66.6
Total 1607
Table 3 Glyphosate active ingredient applied tomajor crop inthe U.S., 1990–2014
Data are pounds of active ingredient applied
National Agriculture Statistical Service. See Additional le1: Table S17 for details
1990 1995 2000 2005 2010 2014
Soybeans 2,663,000 7,628,350 43,870,826 72,043,130 107,697,606 122,473,987
Corn 880,066 2,620,860 4,779,306 25,587,085 69,494,324 68,949,452
Cotton, upland 192,429 1,013,052 10,145,096 16,308,461 17,815,794 17,421,787
Wheat, winter 331,758 239,051 1,702,193 5,045,592 13,922,880 12,353,488
Alfalfa 381,525 402,666 422,334 469,539 479,184 8,853,600
Wheat, spring (excl. durum) 90,659 416,744 1,892,420 2,203,603 4,128,957 4,217,788
Sorghum 236,305 751,913 1,540,931 2,652,943 3,924,301 4,178,573
Sugar beets 36,130 59,012 87,439 118,139 2,226,610 2,763,075
Canola 0 0 552,632 647,368 1,284,317 219,392
Oranges 885,201 1,149,594 1,487,882 1,898,798 1,631,050 1,683,156
Wheat, spring durum 75,308 199,483 450,635 444,785 1,190,234 1,201,807
Barley 13,168 45,563 248,554 658,954 996,626 1,064,160
Other crops 1,897,522 2,733,922 3,736,751 4,249,288 4,648,224 4,526,043
Total crops 7,683,070 17,260,209 70,916,999 132,327,684 229,440,109 249,906,307
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Page 7 of 15
Benbrook Environ Sci Eur (2016) 28:3
Use onGE‑HT crops
For over a decade, the vast majority of hectares planted
to maize, soybeans, canola, and cotton have been geneti-
cally engineered (GE) to be herbicide-tolerant (HT) (see
Fig. 2a; [1517]). In 2012, 265 million kgs of glypho-
sate were applied on GE-HT soybeans, or about 73 %
of all glyphosate applied on GE-HT crops, and 41% of
total, global GBH use (Table6). Between 2010 and 2012,
glyphosate use rose moderately in GE-HT cotton pro-
duction (10%) and soybeans (19%), but more sharply in
GE-HT maize (47%) and canola (36%).
e percent of global agricultural glyphosate use
accounted for by GE-HT crops rose from 51% in 2010 to
56% in 2012 (Table6). is percentage cannot be calcu-
lated accurately for earlier years because comprehensive
ISAAA time series data reporting on hectares planted to
GE-HT crops began in 2010 [14].
Discussion
Volume applied inthe U.S
e United States has the world’s most complete, pub-
licly accessible data on glyphosate use. e combination
of NASS, EPA, and USGS glyphosate use data provides
a solid foundation to track trends in agricultural, non-
agricultural, and total glyphosate use from commercial
introduction through 2014. A report issued by the
National Center for Food and Agricultural Policy [40]
provides useful, detailed information on glyphosate use
by state and crop for 1995, drawing on NASS, EPA, and
information from land grant university weed manage-
ment specialists.
Annual agricultural glyphosate use volumes in the
nine EPA pesticide use reports issued between 1997 and
2007 exceed NASS annual totals for the same years by
20–70%, largely because EPA had access to multiple data
sources that made it possible to estimate the volume of
glyphosate applied on all crops, as well as non-crop use
patterns (e.g., pasture and range uses). NASS estimates,
on the other hand, were limited in any given year to the
crops surveyed in a particular year, and NASS never or
rarely surveys pesticide use on crops grown on limited
acreage. e differences are largest in the first two dec-
ades of glyphosate use (through 1995), and reflect the
array of glyphosate uses not covered in NASS, crop-by-
crop pesticide use surveys. But as total agricultural use
rises sharply post-1996 in the wake of the introduction
of GE-HT crops, glyphosate use on the major GE crops
(maize, soybeans, cotton) is fully captured in NASS, EPA,
and USGS data. Differences in agricultural use estimates
between the datasets all but disappear by 2007 (NASS,
184.2 million pounds glyphosate use; EPA mid-range,
182.5; USGS, 183.2; [27], Additional file1: Table S18).
Factors driving use upward
Several factors have driven the increase in glyphosate use
since commercial introduction in 1974. In terms of area
treated, the dominant factor has been the commerciali-
zation of GE-HT crops. Not only has glyphosate been
sprayed on more hectares planted to HT crops, it has also
been applied more intensively—i.e., more applications
per hectare in a given crop year, and higher one-time
rates of application [13, 28].
In the U.S. soybean sector, the average number of
glyphosate applications rose from 1.1 per crop year
in 1996 to 1.52 in 2014, while the one-time rate of
Table 4 Global agricultural andnon-agricultural use ofglyphosate: 1994 through2014
Data in thousands of kilograms or pound of glyphosate active ingredient. See Additional le1: Table S24 Table for details
1994 1995 2000 2005 2010 2012 2014
Glyphosate use (1000 kg) 56,296 67,078 193,485 402,350 652,486 718,600 825,804
Agricultural 42,868 51,078 155,367 339,790 578,124 648,638 746,580
Non-agricultural 13,428 16,000 38,118 62,560 74,362 69,962 79,224
Glyphosate use (1000 lb) 124,112 147,882 426,561 887,030 1,438,485 1,584,242 1,820,585
Agricultural 94,508 112,608 342,525 749,108 1,274,546 1,430,002 1,645,927
Non-agricultural 29,604 35,274 84,036 137,922 163,940 154,240 174,658
Share agricultural (%) 76 76 80 84 89 90 90
Share non-agricultural (%) 24 24 20 16 11 10 10
Table 5 Share oftotal global glyphosate active ingredient
use bydecade
Calculated from data in Additional le1: Table S24
Total use
(million kg) Increase from
previous
period
Share of
total use
1974–2014 (%)
1974 3.2 NA 0.0
1975–1984 130.5 127 1.5
1985–1994 387.3 257 4.5
1995–2004 1909 1522 22.3
2005–2014 6133 4224 71.6
Total 8563
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Page 8 of 15
Benbrook Environ Sci Eur (2016) 28:3
application rose from 0.7 kg/hectare (0.63 pound/acre)
to 1.1kg/hectare (0.98 pound/acre) in the same period
([27], Additional file1: Table S2). Shifts in weed com-
munities favoring species less susceptible to glyphosate,
coupled with the emergence of first, less sensitive, and
eventually glyphosate-resistant weeds drove the incre-
mental rise in the intensity of glyphosate applications on
GE-HT crops [13, 10]. Rising reliance on glyphosate by
soybean producers in the U.S. is graphically portrayed in
Fig.1a, while Fig.1b shows modest change during the GE
era in soybean yield/acre or production per soybean seed
planted. Steady increases in the number of applications
of glyphosate, rate per crop year, and glyphosate’s share
of overall soybean herbicide use are shown in Fig.1c.
Other factors contributed to rising glyphosate use.
ese include steady expansion in the number of crops
0
50
100
150
200
250
300
Pounds Applied (mil.)
Glyphosate Pounds Applied
Total Agriculture UseCorn UseSoybean UseOther Crops
$0
$10
$20
$30
$40
$50
$60
0
50
100
150
200
250
Price per Pound
Pounds Applied (mil.)
Glyphosate Price per Pound
Pounds Applied in Corn and Soybean Producon Average Price of Glyphosate ($/pound)
0
2
4
6
8
10
12
14
16
0
20
40
60
80
100
120
140
Number of Resistant Weeds
Acres (mil.)
Emergence and Spread of Resistant Weeds
Cumulave Number of Glyphosate Resistant Weeds in the U.S.
Projected Acres With One or More Resistant Weeds
a
b
c
Fig. 2 Use and impacts of glyphosate in corn and soybean production
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Page 9 of 15
Benbrook Environ Sci Eur (2016) 28:3
registered for use on glyphosate product labels, the
adoption of no-tillage and conservation tillage systems,
the declining price per pound of active ingredient (see
Fig.2b), new application method and timing options, and
new agricultural use patterns (e.g., as a desiccant to accel-
erate the harvest of small grains, edible beans, and other
crops).
e one-time average rate of glyphosate application
on Kansas wheat has incrementally risen threefold, from
0.33kg/hectare in 1993 to 0.95kg/hectare in 2012 ([27],
Additional file1: Table S5). e trend toward no-till and
conservation tillage systems has increased wheat farmer
reliance on herbicides, including glyphosate. e average
two applications in recent years on winter wheat could
include a pre- or at-plant spray, an application during a
summer fallow period, and/or a late-season application
intended to speed up harvest operations (a so-called
“harvest aid” or “green burndown” use) [41]. e average
rate per crop year—the single most important indicator
of the intensity of glyphosate use—rose even more dra-
matically, from 0.47kg/hectare in 1993 to 2.08kg/hectare
in 2012 (4.4-fold).
Harvest-aid uses of glyphosate have become increas-
ingly common since the mid-2000s in U.S. northern-tier
states on wheat, barley, edible beans, and a few other
crops, as well as in much of northern Europe [4143].
Because such applications occur within days of harvest,
they result in much higher residues in the harvested
foodstuffs [42]. To cover such residues, Monsanto and
other glyphosate registrants have requested, and gener-
ally been granted, substantial increases in glyphosate
tolerance levels in several crops, as well as in the ani-
mal forages derived from such crops. Table7 provides
an overview of key crops on which regulatory authori-
ties have granted large increases in glyphosate tolerances
to accommodate GE-HT crop uses, as well as harvest
aid, green burndown applications. Note the 2,000-fold
increase in the glyphosate tolerance on dry alfalfa hay and
silage from 1993 to 2014, an increase made necessary by
the approval and planting of GE-HT alfalfa. In response
to the large increase in expected residues from such uses,
some European countries now prohibit harvest-aid appli-
cations on food crops (e.g., Germany, since May 2014).
Global use ofglyphosate
Farmers worldwide applied about 51.3 million kgs (113
million pounds) of glyphosate in 1995 ([27], Additional
file1: Table S23). To place this volume of global glyphosate
use in perspective, in just one country (the U.S.) that year,
farmers applied~60 million kgs (132 million pounds) of
two herbicides (atrazine and metolachlor) on mostly one
crop (maize) ([27], Additional file1: Table S19).
But the scope and intensity of glyphosate use world-
wide rapidly changed as GE-HT crops gained market
share. ere were about 1.4 billion hectares of actively
farmed, arable cropland worldwide in 2014 [44]. Across
Table 6 Glyphosate use on herbicide-tolerant (HT) crops
andall crops
Data are millions of kilograms of glyphosate active ingredient
National Agriculture Statistic Service, International Service for the Acquisition
of Agri-biotech Applications, and Meyer and Cederburg (2010). See Additional
le1: Table S23 for details
2010 2011 2012
Cotton 8.6 11.8 9.5
North America 5.64 6.99 6.32
Rest of world 3.00 4.8 3.1
Maize 47.7 65.6 70.2
North America 26.1 28.5 31.0
Rest of World 21.63 37.1 39.2
Soybeans 223.7 239.1 265.1
North America 41.9 42.0 43.6
Rest of world 181.7 197.1 221.5
Canola 13.7 16.5 18.6
North America 0.4 0.3 0.5
Rest of world 13.3 16.2 18.1
Global use on HT crops 293.7 333.0 363.4
Global use on All crops 578.1 616.8 648.6
Percent use on HT crops (%) 51 54 56
Table 7 Changes inselected U.S. EPA glyphosate tolerance
levels (ppm)
2012 and 2015 tolerances—40 CFR Part 180.364, “Glyphosate; tolerances for
residues.” 1993 tolerances—”Glyphosate Reregistration Eligibility Document
(RED),” (7508W), Oce of Pesticide Programs, U.S. EPA, September 1993. 1999
tolerances—EPA Tolerance Reassessment document for Reassessed Group 3
tolerances, August 4, 1999
1993 1999 2012 2015
Soybeans
Grain 20 20 20 40
Hay 15 200 200 100
Forage 15 100 100 100
Maize
Corn grain 0.1 0.1 5 5
Corn stover NT NT 6 100
Sweetcorn 0.2 0.2 3.5 3.5
Oats
Grain 0.1 0.1 0.1 30
Wheat
Grain 0.1 5 5 30
Straw 0.1 85 85 100
Edible beans 0.2 0.2 5 5
Alfalfa
Dry hay 0.2 200 200 400
Silage 0.2 75 75 400
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Page 10 of 15
Benbrook Environ Sci Eur (2016) 28:3
this landmass, there were an estimated 747 million kg of
agricultural applications of glyphosate. Accordingly, if
this volume of glyphosate had been applied evenly, about
0.53kg of glyphosate could have been sprayed on every
hectare of cropland on the planet (0.47 lbs/acre).
Glyphosate was, of course, not applied evenly on every
hectare of cropland. e average rate of glyphosate appli-
cations per hectare per crop year during 2014 fell in the
range of 1.5–2.0kg/hectare [27]. At these rates of appli-
cation, the total volume of glyphosate applied in 2014
was sufficient to treat between 22 and 30 % of globally
cultivated cropland. No pesticide in history has been
sprayed so widely.
Since losing global patent protection around 2000, doz-
ens of companies began manufacturing technical glypho-
sate, and/or formulating glyphosate products. Some
two-dozen Chinese firms now supply 40% of the glypho-
sate used worldwide, and export most of their annual
production [45].
e loss of patent protection and increased generic
manufacturing of glyphosate has placed downward pres-
sure on prices since 2000 [30, 45, 46]. e major manu-
facturer, Monsanto, has typically not competed directly
or solely on price, and instead has been successful in
holding or expanding market share by bundling purchase
of higher-price, Monsanto brand, Roundup herbicides
with the purchase of Monsanto herbicide-tolerant seeds
[4547]. Especially in the U.S., this bundling strategy has
been augmented by various volume incentives and dis-
counts, special financing, rebates for purchase of other
herbicides working through a mode of action other than
glyphosate’s (to delay the spread of resistant weeds), and
other non-price benefits tailored to appeal to large vol-
ume customers [4648].
e diversity of global uses in agriculture and other
sectors has grown over the past 40 years [9], making it
more difficult to compile accurate global data across all
glyphosate uses, especially by sector and specific use. As
a result, global glyphosate use projections can only be
based on industry-wide glyphosate production figures,
as done from 1997–2014 in Table4 and Additional file1:
Table S24 [27].
Impact ofGE‑HT technology
e development and marketing of GE, Roundup Ready
crops fundamentally changed how crop farmers could
apply glyphosate. Before RR technology, farmers could
spray glyphosate prior to crop emergence, for early-sea-
son weed control, or after harvest to clean up late-sea-
son weeds. But with RR crops, glyphosate could also be
sprayed 1–3 times or more after the crop had emerged,
leaving the crop unharmed but controlling all actively
growing weeds. is historically significant technological
advance set the stage for unprecedented and rapid
growth in the area planted to RR crops and sprayed with
glyphosate (from usually less than 10% of cotton, maize,
and soybean acres pre-1996, to 90% or more today) [47,
49, 50].
e interplay of various factors leading to increased
glyphosate use is apparent in Fig. 2a, which shows the
trend in overall glyphosate use on the key GE-HT crops
in the U.S., the correlation between reductions in average
price per pound and use (Fig.2b), and rising use and the
emergence of resistant weeds (Fig.2c).
Use of glyphosate on some GE-HT crops may have
declined, or may soon begin declining in some regions
because (a) adoption of GE-HT soybeans, cotton, and
canola has peaked in most of the countries that have
embraced GE technology [9], and (b) farmer willingness
to pay for repeat applications of glyphosate, or further
increase application rates, typically declines as glypho-
sate-resistant weeds become well established, as they
have in much of the U.S. [13] and in Brazil and Argentina
[10]. On the other hand, GE-HT crops may move into
some regions not previously planting them (e.g., China),
and reductions in the price of generic glyphosate herbi-
cides could lead to more intensive use in some countries.
In the countries that have planted the largest shares of
GE-HT crops (the U.S., Argentina, and Brazil), glypho-
sate use rates per hectare per crop year have risen sharply
since around 2000 [20, Additional file1: Tables S2, S3,
S22]. Worldwide on GE soybean and cotton, average
total herbicide use per crop year per hectare has approxi-
mately doubled from 1996 to 2014, with the increase
in glyphosate volumes applied per hectare accounting
for nearly all of the per hectare increase. Maize herbi-
cide use per hectare has risen modestly, if at all, in large
part because adoption of GE-HT maize hybrids allowed
farmers to reduce reliance on a half-dozen other widely
used maize herbicides applied at relatively high rates
(e.g.,~1kg/hectare per crop year) [11].
Because GE-HT soybeans account for two-thirds of the
total hectares planted to GE-HT crops worldwide, the
doubling of average herbicide use per hectare of HT soy-
beans drives the sizable increase in overall herbicide on
all GE crop hectares. ere is, as well, a clear connection
throughout South America in the adoption of GE-HT
technology and no-tillage systems [17, 38]. No-till farm-
ing in South America lowers machinery and labor costs,
and reduces soil erosion, but at the expense of height-
ened reliance on herbicides for weed control, and other
pesticides to control insects and fungal pathogens.
Despite gaps in publicly accessible data, the dramati-
cally upward trajectories in glyphosate use in the U.S. and
globally are unmistakable. In the pre-GE era (1974–1995)
in the U.S., non-agricultural glyphosate uses accounted
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Page 11 of 15
Benbrook Environ Sci Eur (2016) 28:3
for~34 to 42% of total use. e share of total glypho-
sate use accounted for by the agricultural sector shifted
markedly upward post-1996, starting at 66% in 1996 and
reaching 81% 5years later (2001) and 92% by 2014 ([27],
Additional file1: Table S18).
e total volume of use and the split between agricul-
tural and non-agricultural uses in the pre-GE era period
are subject to greater uncertainty than in the 1996–2014
period. However, pre-1995 glyphosate use is minor com-
pared to the post-GE period, when both data quantity
and quality improved, especially covering applications in
the U.S. and on global GE-HT hectares planted.
Figure3 arrays milestones in the history of glyphosate dis-
covery, commercialization, and regulation, while Fig.4 dis-
plays key events in the history of glyphosate use and impacts.
Rising use triggers new concerns
Driven by the growing diversity of uses and dramatic
increases in volumes applied, levels of glyphosate and
its primary metabolite aminomethylphosphonic acid
(AMPA) have been detected in the air [51], soil [52],
and water [49, 53]. With few exceptions though, con-
temporary levels of glyphosate in the air, water, and food
result in typical human exposure estimates that remain
well below the “levels of concern” or “Acceptable Daily
Intakes” established by regulatory bodies around the
world.
Still, a growing body of literature points to possible,
adverse environmental, ecological, and human health
consequences following exposure to glyphosate and/or
AMPA, both alone [54] and in combination with inges-
tion of GE proteins (e.g., EPSPS, Bt endotoxins) [55].
Environmental studies encompass possible glyphosate
impacts on soil microbial communities and earthworms
[5658], monarch butterflies [59], crustaceans [60], and
honeybees [61].
Studies assessing possible risks to vertebrates and
humans include evidence of rising residue levels in
soybeans [62, 63], cancer risk [64], and risk of a vari-
ety of other potential adverse impacts on develop-
ment, the liver or kidney, or metabolic processes [54,
55, 6580].
Relative toxicity andimpacts
For years, glyphosate has been regarded as among the
least chronically toxic herbicides for mammals, and
indeed only three EPA-registered synthetic pesticides
in current agricultural use have a higher chronic Refer-
ence Dose (the imidazolinone herbicides imazamox,
imazethapyr, and imazapyr).
For human exposures, the U.S. EPA has set glyphosate’s
daily chronic Reference Dose (cRfD) at 1.75 milligrams
per kilogram of bodyweight (mg/kg bodyweight/day).
e EU-set cRfD for glyphosate was recently raised from
0.3 to 0.5mg/kg/day, 3.5-fold lower than EPA’s. A team of
scientists has compiled evidence supporting the need for
a fivefold reduction in the EU cRfD to 0.1mg/kg/day [81],
a level 17-times lower than EPA’s.
Glyphosate is a moderate dose herbicide with relatively
low acute and chronic mammalian toxicity, to the extent
mammalian risk is accurately reflected in required EPA
toxicology studies. After an exhaustive review, however,
glyphosate was classified in 2015 as a “probable human
carcinogen” by the International Agency for Research on
Cancer [64], based on increased prevalence of rare liver
and kidney tumors in chronic animal feeding studies,
epidemiological studies reporting positive associations
with non-Hodgkin lymphoma, and strong mechanistic
evidence of genotoxicity and ability to trigger oxidative
stress [64].
e body of toxicological studies supporting glypho-
sate’s current EPA and EU cRfD, and hence all contempo-
rary uses of this herbicide, dates back to the early 1970s
through mid-1980s [82]. Recent studies suggest that
glyphosate in its pure form, and some formulated glypho-
sate end-use products, may be triggering epigenetic
1970 2014
1970 19751980 1985 19901995200020052010
First glyphosate patent issued
EPA establishes first glyphosate
tolerance in soybeans -- 2 ppm
First commercial sales of RR maize,
soybeans, and coon in U.S.
USDA/NASS
publishes soybean
report reporng
"Glyphosate
Effecveness
Declines"
Monsanto chemist J. Franz
recognizes herbicidal acvity
of glyphosate
First commercial glyphosate
registraons in the U.S.
Glyphosate agricultural use
reaches 2.8 million kilograms,
less than 1/10th the annual
volume applied of atrazine or
alachlor
EPA increases
glyphosate wheat
tolerance from
0.1 ppm to 5 ppm
EPA increases glyphosate soybean
tolerance from 6 ppm to 20 ppm to
accommodate residues in RR soybeans
U.S. EPA increases
glyphosate oilseed
crop group
tolerance from 20
ppm to 40 ppm
2006 -2011
Center for Food Safety ligaon
slows deregulaon of new RR crops
(alfalfa and sugarbeets)
Fig. 3 Milestones in the history of glyphosate discovery, commercialization, and regulation
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 12 of 15
Benbrook Environ Sci Eur (2016) 28:3
changes through endocrine-mediated mechanisms [54,
73, 75, 76, 79, 81, 83].
Evidence from multiple studies suggests that the kid-
ney, and secondarily the liver, is at risk of glyphosate-
triggered, or glyphosate-enhanced chronic degeneration
[55, 71, 72, 84, 85]. Industry metabolism studies in farm
animals, rats and mice, and rabbits were conducted in the
1970s and 1980s, and show that in animal feeding stud-
ies, glyphosate levels in the kidney usually exceed those
in the liver by three- to tenfold, and those in the liver
exceed levels in other tissues by a wide margin [86].
e apparent tendency of glyphosate to concentrate in
the kidneys, coupled with glyphosate’s action as a chelat-
ing agent, has led some scientists to hypothesize that
glyphosate can bind to metals in hard drinking water,
creating metallic-glyphosate complexes that may not
pass normally through kidneys [71, 72]. For this, or other
as yet unrecognized reasons, the risk of chronic kidney
disease may be heightened in human and animal popula-
tions with heavy glyphosate exposure.
e IARC classification and emerging evidence rela-
tive to kidney damage and endocrine effects height-
ens the need for, and will complicate ongoing and
future glyphosate worker and dietary-risk assessments.
Annual residue tests are carried out by the U.K. Food
Standards Agency (FSA). Residues of glyphosate were
found in 10–30% of grain-based samples from 2007–
2013, at generally rising levels [87]. Glyphosate and
AMPA residues are present at relatively high, and rising
levels (over 1ppm) in a high percentage of the soybeans
grown in the U.S., Canada, Brazil, Argentina, Paraguay,
countries which account for 86.6% of the 11.6 billion
bushels of soybeans produced globally in 2014, and
nearly all global trade in soybeans and soybean-based
animal feeds [34, 62].
Conclusions
A high level of confidence can be placed in the trends in
glyphosate use in the U.S. because of consistency across
three independently compiled datasets (USDA-NASS,
EPA, and USGS).
A published paper by a pesticide industry consultant
provides solid data on global glyphosate use in 1994–
1997, both in the agricultural and non-agricultural sec-
tors [29]. Lack of publicly accessible data on global
glyphosate use since the mid-1990s increases the uncer-
tainty in the global estimates reported herein. However,
since the majority of the increase in global glyphosate
use since the late-1990s was driven by the adoption of
GE-HT crops, accessible data from ISAAA and the litera-
ture on GE-HT crops provide a solid basis to project total
glyphosate use on GE-HT cropsover the last ~15 years.
By any measure, glyphosate-tolerant crop technology
has been an enormous commercial success, and at least
initially, simplified weed management in maize, soybean,
and cotton crops both in the U.S. and worldwide [2, 9,
88]. For a few years post-1996, one, or at most two appli-
cations of glyphosate proved highly effective and eco-
nomical on nearly all cropland planted to GE-HT seeds.
As a result, the land area treated with glyphosate rose
rapidly. Over time this triggered the emergence of weed
phenotypes less sensitive or resistant to glyphosate. In
response, farmers increased both the rate of glyphosate
application as well as the number of applications [5, 6,
9, 88, 13]. Many farmers also integrated additional her-
bicides into spray programs [57, 89]. As a direct result,
2015
1996 1998 2000 2002 2004 2006 2008 2010 2012 2014
Confirmed glyphosate resistance in 3 weeds
EPSPS gene amplificaon proposed as
glyphosate resistance mechanism (Gaines
et al. 2009)
Palmer amaranth in
Georgia glyphosate
resistant to 3 herbicide
modes of acon,
including glyphosate
~33 million acres
infested with
glyphosate-resistant
weeds
RR technology in the U.S. increased
herbicide use by 527 million pounds,
1996-2012 (Benbrook 2012)
One or more
glyphosate
resistant
weed on
over 100
million acres
in U.S.
Adverse impacts on
iron and manganese
uptake (Eker et al
2006)
Lolium rigidum --first glyphosate-resistant
weed confirmed in Australia
Glyphosate-resistant Palmer
amaranth confirmed in
Georgia; 10th glyphosate-
resistant weed confirmed
globally
USGS sciensts detect glyphosate
in 60% -100% samples of air and
rain in 3 states (Chang et al 2011)
Glyphosate shown to reduce
water use efficiency in RR
soybean systems (Zobiole et al
2010)
Widespread glyphosate use contributes to
58% decline in milkweed and 81% decline in
Monarch buerflies in the Midwest, 1999-
2010 (Pleasants and Oberhauser 2012)
~61 million
acres
infested with
glyphosate-
resistant
weeds
Adverse impacts on
earthworms, honeybees,
aquac organisms
documented
IARC classifies
glyphosate a
"probable
human
carcinogen"
32
glyphosate-
resistant
weeds
confirmed
globally
Fig. 4 Milestones in glyphosate use and impacts
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 13 of 15
Benbrook Environ Sci Eur (2016) 28:3
average herbicide use per hectare on land planted to
GE-HT varieties has, on average, escalated steadily since
the mid-1990s [8, 11, 88, 13].
e upward trend in glyphosate use has, and will likely
continue to contribute to incremental increases in envi-
ronmental loadings and human exposures to glypho-
sate, its major metabolite aminomethylphosphonic acid
(AMPA), and various surfactants and adjuvants used in
formulating end-use glyphosate-based herbicides.
Given that glyphosate is moderately persistent and
mobile, levels in surface and groundwater will likely rise
in step with use, and this will increase the diversity of
potential routes of animal and human exposure.
Human exposures from around the home and urban
uses of glyphosate also warrant closer attention. Most
end-use, glyphosate products sold for home and urban
use in developed countries contain relatively low con-
centrations of glyphosate, so the risk of experiencing
an acutely toxic exposure is minimal. But in develop-
ing countries, risks stemming from applications of more
concentrated glyphosate products and/or applications of
“home-mixed” products should not be ignored.
e frequency and levels of glyphosate and residues in
a variety of foods are increasing, and more refined die-
tary-risk assessments should be carried out. Reasonably
accurate estimates of glyphosate residues and dietary
exposures in areas lacking residue data can be made
drawing on insights gained from risk assessments con-
ducted in areas with accurate glyphosate use and residue
data.
Abbreviations
AMPA: aminomethylphosphonic acid; Bt: Bacillus thuringiensis; EPA: Environ-
mental Protection Agency; GBH: glyphosate-based herbicide; GE: genetically
engineered; GE-HT: genetically engineered herbicide-tolerant [crop]; GMO:
genetically engineered organism; HT: herbicide tolerant; Kg: kilogram; NASS:
National Agricultural Statistics Service (a USDA agency); RR: Roundup Ready;
USDA: United States Department of Agriculture; USGS: United States Geologi-
cal Service.
Authors’ information
The author (CMB) conducted the research and wrote the paper while serv-
ing as a Research Professor at Washington State University (position ended
5/15/15). CMB ran the “Measure to Manage” program within the Center for
Sustaining Agriculture and Natural Resources, and has worked for years com-
piling data on pesticide use in the U.S. and globally.
Acknowledgements
The author thanks his colleagues at Washington State University’s Measure to
Manage Program for assistance in developing the datasets and carrying out
the analysis. Karie Knoke compiled the glyphosate use dataset and produced
the figures. Nicholas Potter helped develop the tables and refine the analysis.
Reviewers provided helpful suggestions for improvement. Also, thanks to the
U.S. Department of Agriculture’s National Agricultural Statistics Service (NASS)
Additional le
Additional le 1. List of supplemental tables.
for compiling and making available information on pesticide use in the U.S.,
and to the EPA for its helpful periodic reports on pesticide use.
Competing interests
The author is a member of the U.S. Department of Agriculture’s AC21 Agri-
cultural Biotechnology Advisory Committee. From June 2012–May 2015, he
served as a Research Professor at Washington State University. Dr. Benbrook’s
program at WSU received funding from foundations, organic food companies,
and coops. He currently serves as an expert witness in litigation focused on
the labeling of foods containing genetically engineered ingredients.
Received: 11 October 2015 Accepted: 11 January 2016
References
1. Dill GM, Sammons RD, Feng PCC, Kohn F, Kretzmer K, Mehrsheikh
A, Bleeke M, Honegger JL, Farmer D, Wright D, Haupfear EA (2010)
Glyphosate: discovery, development, applications, and properties.
Chapter 1. In: Nandula VK (ed) Glyphosate resistance in crops and weeds:
history, development, and management. Wiley, New York, pp 1–33. ISBN
978-0470410318
2. Duke SO, Powles SB (2008) Glyphosate: a once-in-a-century herbicide.
Pest Manag Sci 64:319–325
3. Monsanto Company. “Genuity Roundup Ready Sugarbeets,”. 2015. http://
www.monsanto.com/newsviews/pages/genuity-roundup-ready-sugar-
beets.aspx. Accessed 9 Aug 2015
4. Monsanto Company. “Lawsuit Involving Roundup Ready Alfalfa,”. 2015.
http://www.monsanto.com/newsviews/pages/roundup-ready-alfalfa-
supreme-court.aspx. Accessed 9 Aug 2015
5. Heap IM (2014) Global perspective of herbicide-resistant weeds. Pest
Manag Sci 70:1306–1315
6. Mortensen DA, Egan JF, Maxwell BD, Ryan MR (2012) Navigating a critical
juncture for sustainable weed management. Bioscience 62:75–84
7. Owen MD, Beckie HJ, Leeson JY, Norsworthy JK, Steckel LE (2014) Inte-
grated pest management and weed management in the United States
and Canada. Pest Manag Sci 71(3):357–376. doi:10.1002/ps.3928
8. Cerdeira AL, Gazziero DLP, Duke SO, Matallo MB (2011) Agricultural
impacts of glyphosate-resistant soybean cultivation in South America. J
Agric Food Chem 59:5799–5807
9. Duke SO (2014) Perspectives on transgenic, herbicide-resistant crops in
the USA almost 20 years after introduction. Pest Manag Sci 71(5):652–657.
doi:10.1002/ps.3863
10. Powles SB (2008) Evolved glyphosate-resistant weeds around the world:
lessons to be learnt. Pest Manag Sci 64:360–365. doi:10.1002/ps.1525
11. United States Department of Agriculture. National Agricultural Statis-
tics Service. Agricultural chemical usage—field crops and potatoes.
http://usda.mannlib.cornell.edu/MannUsda/viewDocumentInfo.
do?documentID=1560. Accessed 17 Dec 2014
12. Blewett TC (2011) Supplemental information for petition for determina-
tion of non regulated status for herbicide tolerant DAS-40278-9 corn—
economic and agronomic impacts of DAS 40278-9 corn on glyphosate
resistant weeds in the US cropping system. United States Environ Prot
Agency
13. National Agricultural Statitistics Service (2014) U.S. soybean industy:
glyphosate effectiveness declines, NASS highlights No. 2014-1. http://
www.nass.usda.gov/Surveys/Guide_to_NASS_Surveys/Ag_Resource_
Management/ARMS_Soybeans_Factsheet/index.asp
14. James C. Global status of Commercialized biotech/GM Crops: 2011. 2011.
ISAAA Briefs 43
15. James C. Global status of Commercialized biotech/GM Crops: 2012.
ISAAA Briefs 44. 2012. doi:10.1017/S0014479706343797
16. James C. Global status of Commercialized biotech/GM Crops: 2013.
ISAAA Briefs. 2013
17. James C. Global status of Commercialized biotech/GM Crops: 2014.
ISAAA Briefs. 2014
18. United States Department of Agriculture. National agricultural statistics
service. Agricultural chemical use program. http://www.nass.usda.gov/
Surveys/Guide_to_NASS_Surveys/Chemical_Use/index.asp
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 14 of 15
Benbrook Environ Sci Eur (2016) 28:3
19. Aspelin AL, Grube AH (1997) Pesticides industry sales and usage: 1994
and 1995 market estimates. Off Pestic Programs, US Environ Prot Agency
20. Aspelin AL, Grube AH (1999) Pesticides industry sales and usage: 1996
and 1997 market estimates. Off Pestic Programs, US Environ Prot Agency
21. Donaldson D, Kiely T, Grube AH (2002) Pesticide industry sales and usage:
1998 and 1999 market estimates. Off Pestic Programs, US Environ Prot
Agency 71
22. Grube AH, Donaldson D, Kiely T, Wu L (2011) Pesticides industry sales and
usage: 2006 and 2007 market estimates. Off Pestic Programs, US Environ
Prot Agency
23. Kiely T, Donaldson D (2004) Pesticide industry sales and usage: 2000 and
2001 market estimates. Off Pestic Programs, US Environ Prot Agency
24. Thelin GP, Stone WW (2013) USGS Scientific Investigation Report
2013–5009: estimation of annual agricultural pesticide use for counties of
the conterminous United States, 1992–2009. U.S. Geol Surv Investig Rep
2013–2019
25. Baker NT, Stone WW (2013) USGS Open-file report 2013–1295: Prelimi-
nary estimates of annual agricultural pesticide use for counties of the
conterminous United States, 2010–2011. US Geol Surv
26. Monsanto Company. Monsanto biotechnology trait acreage: fiscal years
1996–2009, updated: October 7, 2009
27. Benbrook CM (2016) Trends in glyphosate herbicide use in the united
states and globally: Supporting data. Environ Sci Eur. doi:10.1186/
s12302-016-0070-0
28. United States Department of Agriculture (2015) National Agricultural
Statistics Service. Quickstats. http://quickstats.nass.usda.gov/. Accessed
21 Jan 2015
29. Woodburn AT (2000) Glyphosate: production, pricing and use worldwide.
Pest Manag Sci 56:309–312
30. China Chemicals Market (2013) Glyphosate China Monthly Report 4
31. Research and Markets (2012) Outlook for China glyphosate industry
2012–2016
32. Transparency Market Research. Glyphosate market: Global Industr y
Analysis, Share, Size, Growth, Trends and Forecast 2013–2019. 2013
33. Transparency Market Research. Glyphosate Industry Analysis, Share, Size,
Growth, Trends and Forecast 2013–2019. 2014. Major findings reported
by PR Newswire, http://www.prnewswire.com/news-releases/global-
glyphosate-market-is-expected-to-reach-usd-879-billion-by-2019-trans-
parency-market-research-244861481.html
34. American Soybean Association. SoyStats: a reference guide
to important soybean facts and figures. http://soystats.com/
international-adoption-of-biotech-enhanced-seedstock/
35. Ministerio de Agricultura Ganadaria y Pesca. Sistema Integrado de
Información Agropecuaria (SIIA). http://www.siia.gob.ar/sst_pcias/estima/
estima.php. Accessed 22 July 2015
36. Instituto Brasileiro de Geografia e Estatística (IBGE). Tabela 1612—Área
plantada, área colhida, quantidade produzida e valor da produção da
lavoura temporária. http://www.sidra.ibge.gov.br/bda/tabela/listabl.
asp?c=1612&z=t&o=11. Accessed 21 Jan 2015
37. Benbrook CM (2005) Rust, Resistance, Run Down Soils, and Rising Costs—
Problems Facing Soybean Producers in Argentina. Report
38. Meyer DE, Cederberg C (2010) Pesticide use and glyphosate- resistant
weeds—a case study of Brazilian soybean production. Swedish Inst Food
Biotechnol
39. Ferraro DO, Ghersa CM (2013) Fuzzy assessment of herbicide resistance
risk: glyphosate-resistant johnsongrass, Sorghum halepense (L.) Pers., in
Argentina’s croplands. Crop Prot. 51:32–39
40. National Center for Food and Agriculture Policy. National Pesticide Use
Database. 2008. http://www.ncfap.org/database/national.php. Accessed
21 Jan 2015
41. Moechnig M, Deneke D (2009) Har vest aid weed control in small grain.
South Dakota State Univ
42. Glyphosate.eu. Clarification of Pre-harvest uses of glyphosate The advan-
tages, best practices and residue monitoring. Eur. Glyphosate Task Force
43. Seed Potato Growers Association of Manitoba (2010) Prevent herbicide
drift in seed potatoes. Advertisement 0–1
44. Food and Agriculture Organization of the United Nations. FAOSTAT.
http://faostat3.fao.org/. Accessed 1 Jan 2015
45. Hilton CW (2014) Monsanto and the global glyphosate market: case
study. Wiglaf J. http://www.wiglaournal.com/pricing/2012/06/mon-
santo-the-global-glyphosate-market-case-study/. Accessed 17 Dec 2014
46. Dupraz E (2012) Monsanto and the Quasi-Per Se Illegal Rule for Bundled
Discounts. Vt Law Rev 37:203–237
47. Economic Research Sevice, U.S. Department of Agriuclture. “Adoption of
GE Crops in the U.S.,http://www.ers.usda.gov/data-products/adoption-
of-genetically-engineered-crops-in-the-us.aspx. Accessed 3 Aug 2015
48. Callahan GW (2009) Comments regarding agriculture and antitrust
enforcement issues; restraints on competition in sales of off-patent
agrochemicals. Leg Policy Sect. Antitrust Div United States Dep Justice
49. Coupe RH, Kalkhoff SJ, Capel PD, Gregoire C (2012) Fate and transport
of glyphosate and aminomethylphosphonic acid in surface waters of
agricultural basins. Pest Manag Sci 68:16–30
50. Cerdeira AL, Gazziero DLP, Duke SO, Matallo MB, Spadotto CA (2007)
Review of potential environmental impacts of transgenic glyphosate-
resistant soybean in Brazil. J Environ Sci Health B 42:539–549
51. Chang F, Simcik MF, Capel PD (2011) Occurrence and fate of the herbicide
glyphosate and its degradate aminomethylphosphonic acid in the
atmosphere. Environ Toxicol Chem 30(3):548–555
52. Borggaard OK, Gimsing AL (2008) Fate of glyphosate in soil and the pos-
sibility of leaching to ground and surface waters: a review. Pest Manag Sci
64:441–456. doi:10.1002/ps.1512
53. Battaglin WA, Meyer MT, Kuivila KM, Dietze JE (2014) Glyphosate and
its degradation product AMPA occur frequently and widely in U.S. soils,
surface water, groundwater, and precipitation. J Am Water Resour Assoc
50:275–290. doi:10.1111/jawr.12159
54. Myers JP, Antoniou MN, Blumberg B, Carroll L, Colborn T, Everett LG,
Hansen M, Landrigan PJ, Lanphear BP, Mesnage R, Vandenberg LN,
vom Saal FS, Welshons W V, Benbrook CM (2016) Concerns over use of
glyphosate-based herbicides and risks associated with exposures: a
consensus statement. Environmental Health. In press
55. Séralini G-E, Clair E, Mesnage R, Defarge N, Malatesta M et al (2014)
Republished study: long-term toxicity of a Roundup herbicide and a
Roundup-tolerant genetically modified maize. Environ Sci Eur 26:14
doi:10.1186/s12302-014-0014-5
56. Gaupp-Berghausen M, Hofer M, Rewald B, Zaller JG (2015) Glyphosate-
based herbicides reduce the activity and reproduction of earthworms
and lead to increased soil nutrient concentrations. Sci Rep 5:12886.
doi:10.1038/srep12886
57. Kremer RJ (2014) Environmental implications of herbicide resistance: soil
biology and ecology. Weed Sci 62:415–426
58. Eker S, Ozturk L, Yazici A, Erenoglu B, Romheld V, Cakmak I (2006) Foliar-
applied glyphosate substantially reduced uptake nd transport of iron and
manganese in sunflower (Helianthus annuus L.) plants. J Ag Food Chem
54(26):10019–10025
59. Pleasants JM, Oberhauser KS (2012) Milkweed loss in agricultural fields
because of herbicide use: effect on the monarch butterfly population.
Insect Conserv Divers 6:135–144. doi:10.1111/j.1752-4598.2012.00196.x
60. Cuhra M, Traavik T, Dndo M, Primicerio R, Holderbaum DF, Bohn T (2015)
Glyphosate-Residues in Roundup-Ready Soybean Impair Daphnia magna
Life-Cycle. J Agri Chem Environ 4(1):24–36. doi:10.4236/jacen.2015.41003
61. Balbuena MS, Tison L, Hahn M-L, Greggers U, Menzel R, Farina WM (2015)
Effects of sublethal doses of glyphosate on honeybee navigation. J Exp
Biol. doi:10.1242/dev.117291
62. Cuhra M (2015) Review of GMO safety assessment studies: glyphosate
residues in Roundup Ready crops is an ignored issue. Environ Sci Eur
27:20. doi:10.1186/s12302-015-0052-7
63. Bohn T, Cuha M, Traavik T, Sanden M, Fagan J, Primicerio R (2014) Compo-
sitional differences in soybeans on the market: glyphosate accumulates
in Roundup Ready GM soybeans. Food Chem 153:207–215
64. International Agency for Research on Cancer. IARC Monographs Volume
112: evaluation of five organophosphate insecticides and herbicides.
2015. https://www.iarc.fr/en/media-centre/iarcnews/pdf/MonographVol-
ume112.pdf
65. Agapito-Tenfen S, Vilper te V, Benevenuto R, Rover C, Traavik T, Nodari R
(2014) Effect of stacking insecticidal cry and herbicide tolerance epsps
transgenes on transgenic maize proteome. BMC Plant Biol 14:346.
doi:10.1186/s12870-014-0346-8
66. Ben Ali S-E, Madi ZE, Hochegger R, Quist D, Prewein B, Haslberger AG et al
(2014) Mutation scanning in a single and a stacked genetically modified
(GM) event by real-time PCR and high resolution melting (HRM) analysis.
Int J Mol Sci 15:19898–19923. doi:10.3390/ijms151119898
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 15 of 15
Benbrook Environ Sci Eur (2016) 28:3
67. Brändli D, Reinacher S (2012) Herbicides found in human urine. Ithaka J
1:270–272
68. Bushey DF, Bannon GA, Delaney BF, Graser G, Hefford M, Jiang X et al
(2014) Characteristics and safety assessment of intractable proteins
in genetically modified crops. Regul Toxicol Pharmacol 69:154–170.
doi:10.1016/j.yrtph.2014.03.003
69. Carman JA, Vlieger HR, Robinson GW, Clinch-Jones CA, Haynes JI, Edwards
JW (2013) A long-term toxicology study on pigs fed a combined geneti-
cally modified (GM) soy and GM maize diet. J Org Syst 8:38–54
70. Cattani D, de Liz Oliveira Cavalli VL, Heinz Rieg CE, Domingues JT, Dal-Cim
T, Tasca CI et al (2014) Mechanisms underlying the neurotoxicity induced
by glyphosate-based herbicide in immature rat hippocampus: involve-
ment of glutamate excitotoxicity. Toxicology 320:34–45. doi:10.1016/j.
tox.2014.03.001
71. Jayasumana C, Gunatilake S, Senanayake P (2014) Glyphosate, hard water
and nephrotoxic metals: are they the culprits behind the epidemic of
chronic kidney disease of unknown etiology in Sri Lanka? Int J Environ
Res Public Health 11:2125–2147. doi:10.3390/ijerph110202125
72. Jayasumana C, Paranagama P, Agampodi S, Wijewardane C, Gunatilake S,
Siribaddana S (2015) Drinking well water and occupational exposure to
Herbicides is associated with chronic kidney disease, in Padavi-Sripura. Sri
Lanka Environ Health 14:6. doi:10.1186/1476-069X-14-6
73. Hokanson R, Fudge R, Chowdhary R, Busbee D (2007) Alteration of
estrogen-regulated gene expression in human cells induced by the
agricultural and horticultural herbicide glyphosate. Hum Exp Toxicol
26:747–752
74. Ma J, Bu Y, Li X (2014) Immunological and histopathological responses of
the kidney of common carp (Cyprinus carpio L.) sublethally exposed to
glyphosate. Environ Toxicol Pharmacol 39:1–8
75. Paganelli A, Gnazzo V, Acosta H, López SL, Carrasco AE (2010) Glyphosate-
based herbicides produce teratogenic effects on vertebrates by impair-
ing retinoic acid signaling. Chem Res Toxicol 23:1586–1595
76. Romano MA, Romano RM, Santos LD, Wisniewski P, Campos DA, de Souza
PB et al (2012) Glyphosate impairs male offspring reproductive develop-
ment by disrupting gonadotropin expression. Arch Toxicol 86:663–673
77. Schinasi L, Leon ME (2014) Non-Hodgkin lymphoma and occupa-
tional exposure to agricultural pesticide chemical groups and active
ingredients: a systematic review and meta-analysis. Int J Environ Res
Public Health 11:4449–4527
78. Spisák S, Solymosi N, Ittzés P, Bodor A, Kondor D, Vattay G et al (2013)
Complete genes may pass from food to human blood. PLoS One
8:e69805. doi:10.1371/journal.pone.0069805
79. Thongprakaisang S, Thiantanawat A, Rangkadilok N, Suriyo T, Satayavi-
vad J (2013) Glyphosate induces human breast cancer cells growth via
estrogen receptors. Food Chem Toxicol 59:129–136
80. Zdziarski IM, Edwards JW, Carman JA, Haynes JI (2014) GM crops and the
rat digestive tract: a critical review. Environ Int 73:423–433. doi:10.1016/j.
envint.2014.08.018
81. Antoniou M, Habib MEM, Howard C V, Jennings RC, Leifert C, Nodari RO,
et al (2012) Teratogenic effects of glyphosate-based herbicides: diver-
gence of regulatory decisions from scientific evidence doi:10.4172/2161-
0525.S4-006
82. Office of Prevention, Pesticides and TC (1993) Registration eligibility
document: glyphosate, EPA 738-R-93-014
83. Gasnier C, Dumont C, Benachour N, Clair E, Chagnon M-C, Séralini G-E
(2009) Glyphosate-based herbicides are toxic and endocrine disruptors in
human cell lines. Toxicology 262:184–191
84. Meyer H, Hilbeck A (2013) Rat feeding studies with genetically modified
maize—a comparative evaluation of applied methods and risk assess-
ment standards. Environ Sci Eur 25:33. doi:10.1186/2190-4715-25-33
85. Monsanto Company. MRID No. 0081674, 00105995. 1981
86. Germany and Slovakia (2013) Renewal assessment report: glyphosate
residue data. Eur Comm
87. Food Standards Agency, United Kingdom. Expert Committee on Pesticide
Residues in Food. Monitoring Report on Pesticide Residues in Food, mul-
tiple quarters. http://www.food.gov.uk/business-industry/farmingfood/
pesticides
88. Benbrook CM (2012) Impacts of genetically engineered crops on
pesticide use in the U.S.—the first 16 years. Environ Sci Eur 24:24.
doi:10.1186/2190-4715-24-24
89. Christoffoleti PJ, Galli AJB, Carvalho SJP, Moreira MS, Nicolai M, Foloni
LL et al (2008) Glyphosate sustainability in South American cropping
systems. Pest Manag Sci 64:422–427
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... of glyphosate-tolerant crops [2]. Today, over 113 million kilograms of glyphosate are utilized agriculturally each year across the United States [2]. ...
... of glyphosate-tolerant crops [2]. Today, over 113 million kilograms of glyphosate are utilized agriculturally each year across the United States [2]. Glyphosate kills weeds and unwanted plants by inhibiting a key enzyme in the shikimate pathway, enolpyruvylshikimate-3-phosphate synthase (EPSPS), preventing aromatic amino acid biosynthesis vital to plants [3]. ...
Article
Full-text available
Background Herbicides are environmental contaminants that have gained much attention due to the potential hazards they pose to human health. Glyphosate, the active ingredient in many commercial herbicides, is the most heavily applied herbicide worldwide. The recent rise in glyphosate application to corn and soy crops correlates positively with increased death rates due to Alzheimer’s disease and other neurodegenerative disorders. Glyphosate has been shown to cross the blood–brain barrier in in vitro models, but has yet to be verified in vivo. Additionally, reports have shown that glyphosate exposure increases pro-inflammatory cytokines in blood plasma, particularly TNFα. Methods Here, we examined whether glyphosate infiltrates the brain and elevates TNFα levels in 4-month-old C57BL/6J mice. Mice received either 125, 250, or 500 mg/kg/day of glyphosate, or a vehicle via oral gavage for 14 days. Urine, plasma, and brain samples were collected on the final day of dosing for analysis via UPLC–MS and ELISAs. Primary cortical neurons were derived from amyloidogenic APP/PS1 pups to evaluate in vitro changes in Aβ 40-42 burden and cytotoxicity. RNA sequencing was performed on C57BL/6J brain samples to determine changes in the transcriptome. Results Our analysis revealed that glyphosate infiltrated the brain in a dose-dependent manner and upregulated TNFα in both plasma and brain tissue post-exposure. Notably, glyphosate measures correlated positively with TNFα levels. Glyphosate exposure in APP/PS1 primary cortical neurons increases levels of soluble Aβ 40-42 and cytotoxicity. RNAseq revealed over 200 differentially expressed genes in a dose-dependent manner and cell-type-specific deconvolution analysis showed enrichment of key biological processes in oligodendrocytes including myelination, axon ensheathment, glial cell development, and oligodendrocyte development. Conclusions Collectively, these results show for the first time that glyphosate infiltrates the brain, elevates both the expression of TNFα and soluble Aβ, and disrupts the transcriptome in a dose-dependent manner, suggesting that exposure to this herbicide may have detrimental outcomes regarding the health of the general population.
... Among the different pesticides used, the herbicide Glyphosate (GLYP), N-(phosphonomethyl) glycine, has been applied extensively over the last 40 years, assuming minimal side effects. However, concerns about the direct and indirect potential health effects of large-scale GLYP usage have recently increased worldwide [5][6][7][8]. ...
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The broad-spectrum herbicide glyphosate (common trade name "Roundup") was first sold to farmers in 1974. Since the late 1970s, the volume of glyphosate-based herbicides (GBHs) applied has increased approximately 100-fold. Further increases in the volume applied are likely due to more and higher rates of application in response to the widespread emergence of glyphosate-resistant weeds and new, pre-harvest, dessicant use patterns. GBHs were developed to replace or reduce reliance on herbicides causing well-documented problems associated with drift and crop damage, slipping efficacy, and human health risks. Initial industry toxicity testing suggested that GBHs posed relatively low risks to non-target species, including mammals, leading regulatory authorities worldwide to set high acceptable exposure limits. To accommodate changes in GBH use patterns associated with genetically engineered, herbicide-tolerant crops, regulators have dramatically increased tolerance levels in maize, oilseed (soybeans and canola), and alfalfa crops and related livestock feeds. Animal and epidemiology studies published in the last decade, however, point to the need for a fresh look at glyphosate toxicity. Furthermore, the World Health Organization's International Agency for Research on Cancer recently concluded that glyphosate is "probably carcinogenic to humans." In response to changing GBH use patterns and advances in scientific understanding of their potential hazards, we have produced a Statement of Concern drawing on emerging science relevant to the safety of GBHs. Our Statement of Concern considers current published literature describing GBH uses, mechanisms of action, toxicity in laboratory animals, and epidemiological studies. It also examines the derivation of current human safety standards. We conclude that: (1) GBHs are the most heavily applied herbicide in the world and usage continues to rise; (2) Worldwide, GBHs often contaminate drinking water sources, precipitation, and air, especially in agricultural regions; (3) The half-life of glyphosate in water and soil is longer than previously recognized; (4) Glyphosate and its metabolites are widely present in the global soybean supply; (5) Human exposures to GBHs are rising; (6) Glyphosate is now authoritatively classified as a probable human carcinogen; (7) Regulatory estimates of tolerable daily intakes for glyphosate in the United States and European Union are based on outdated science. We offer a series of recommendations related to the need for new investments in epidemiological studies, biomonitoring, and toxicology studies that draw on the principles of endocrinology to determine whether the effects of GBHs are due to endocrine disrupting activities. We suggest that common commercial formulations of GBHs should be prioritized for inclusion in government-led toxicology testing programs such as the U.S. National Toxicology Program, as well as for biomonitoring as conducted by the U.S. Centers for Disease Control and Prevention.
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