Front Matter

8 Introduction to Autism Spectrum Disorders

Dr Seneff. The use of RoundupTM has been increasing steadily and stealthily

since the 1990s [29–32]. Figure 1.4 depicts the correlation between the use of

glyphosate and the rise in ASD [29–32].

Glyphosate is one of the most widely used herbicides, derived from glycine,

an amino acid. It was introduced to agriculture in the 1970s. Glyphosate tar­

gets and blocks a plant metabolic pathway known as the Shikimate pathway

that is not found in animals but occurs in certain plants and bacteria. The

Shikimate pathway is required for the synthesis of aromatic amino acids in

plants [29–33]. After four decades of commercial use, and multiple regulatory

approvals including toxicology evaluations, literature reviews, and numerous

human health risk assessments, the clear and consistent conclusions are that

glyphosate is of low toxicological concern, and no concerns exist with respect

to glyphosate use and the risk of cancer in humans. Mainly because of these

reports and its inexpensiveness, its use has skyrocketed 6,504% from 1991 to

2010, according to data from the United States Department of Agriculture’s

(USDA’s) National Agricultural Statistics Service [30]. Glyphosate is the most

widely used herbicide in the world, mainly because it is believed to be nontoxic

to humans and it is inexpensive. Most importantly, glyphosate is perceived to

be harmless because its mechanism of action is to disrupt, in plants only,

the biochemical pathway known as the Shikimate pathway [(32]. Interestingly,

300

Glyphosate use

Correlation of Autism prevalence with glyphosate applied to crops

Autism prevalence

250

200

Glyphosate applied to corn and soy crops (1,000 tons)

Number of children diagnosed with autism

150

100

50

1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

35000

30000

25000

20000

15000

10000

5000

0

2004 2005 2006 2007 2008 2009 2010

0

Figure 1.4 Bar graph showing the number of children diagnosed with ASD versus the

amount of glyphosate used on corn and soy crops in the USA from 1995 to 2010. Of note,

this correlation does not prove causation and the correlation may be simply an unusual

event. Source: Adapted from Ref. [9].