Dr. Myrto Ashe, MD, MPH presents scientific evidence that pesticides affect the health of our children. She explains the mechanism of how pesticides disrupt the health of children.

1. MYRTO ASHE, MD, MPH
HOW AND WHY
PESTICIDES AFFECT
OUR HEALTH

2. Linking
diseases and
pesticides
There are many associations:
• Pesticide applicators and cancer
• Children of pesticide applicators and cancer
• Pest strips, pet shampoos and cancer
• Asthma
• Obesity and diabetes
• Birth defects
• Autism, ADHD, and Parkinson’s disease

3. Childhood Cancer
• The rate has been rising about 1% per year since the 1990s
• What part of this is pesticides?
9000
9200
9400
9600
9800
10000
10200
10400
10600
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012
Number of children diagnosed with cancer every year

4. Childhood Disabilities
• From “The Future of Children” by Neal Halfon and others: most
of this increase involves neurological/behavior abnormalities
0
1
2
3
4
5
6
7
8
9
1990 1995 2000 2005 2010
% children with activity limitations due to
disability

5. Asthma, child and adult

6. THE CHOICES
•Harmless
•Harmful and worth it
•Harmful and not worth it

8. “What we knew (for sure)”:
1940s TOXICOLOGY
•Fetus protected by placental barrier
•The more poison you use, the higher
the death rate
•“The dose makes the poison”
•Biochemical elimination of toxins

9. The Placental Barrier
• This was the main source of reassurance
• But it’s not that helpful:
• Research examined the umbilical cord blood of 10 babies born
in 2004
• Found 287 chemicals
• Each baby had about 200
• 180 carcinogens
• 208 known to cause birth defects
• 217 toxic to the brain

10. Non-monotonic effects

11. Why it “just ain’t so”:
2014 TOXICOLOGY
•The placental barrier not as strong as we thought
•Some chemicals have worse effects at small doses
than at larger doses
•Chemicals in combination have effects that are
multiplicative, not additive

12. Just as our understanding of
toxicology has changed
in the last 70 years,
so has our understanding
of health and illness

13. 2014 MEDICINE
•Beneficial bacteria
•Immune system/inflammation
•Gene expression

14. 2014 MEDICINE
•Beneficial bacteria outnumber human
cells 10 to 1
• Gut biome involved in
detoxification, immunity, nutrition
• Chronic immune system activation causes disease
• Genes are expressed at times, suppressed at other
times, in response to the environment

17. 2014 MEDICINE
•Beneficial bacteria outnumber human 10:1 cells
•The gut biome is involved in
detoxification, immunity, nutrition
•Chronic immune system activation causes disease
•Genes are expressed at times, suppressed at
other times, in response to the environment

18. Beneficial Bacteria
Help us Detoxify
ProcNatlAcadSci U S A. May 29, 2012; 109(22):
8364–8365.
Symbiontsprovide pesticide
detoxification
John H. Werren1

19. Beneficial bacteria train and control
the immune system
NATURE | NEWS
Babies’ weak immune systems let good
bacteria in
Resistance to infections is suppressed
To prevent inflammation from
bacterial colonization.
Sara Reardon
6 November 2013

20. 2014 MEDICINE
• Beneficial bacteria outnumber human 10:1 cells
• Gut biome involved in
detoxification, immunity, nutrition
•Chronic immune system activation
results in disease
• Genes are expressed at times, suppressed at other
times, in response to the environment

22. 2014 MEDICINE
• Beneficial bacteria outnumber human 10:1, or much
more, maybe 1000:1
• Gut biome involved in
detoxification, immunity, nutrition
• Chronic immune system activation causes disease
•Genes are expressed at
times, suppressed at other times, in
response to the environment

23. Toxicology. 2013 May 10;307:35-41.
Epigenetics and pesticides.
• Collotta M1, Bertazzi PA, Bollati V.
• Abstract
•[…] Epigenetics is the study of heritable
changes in gene expression that occur
without a change in the DNA sequence.
[...]
• We review current evidences indicating
that epigenetic modifications may mediate
pesticide effects on human health […]

24. Toxicology. 2013 May 10;307:35-41.
Epigenetics and pesticides.
• Collotta M1, Bertazzi PA, Bollati V.
• Abstract
•[…] Epigenetics is the study of heritable
changes in gene expression that occur
without a change in the DNA sequence.
[...]
• We review current evidences indicating
that epigenetic modifications may mediate
pesticide effects on human health […]

25. SUMMARY
Diseases that affect us depend on
• which genes are expressed
• which bacteria are thriving
•how the genes and bacteria direct our
immune system
A step further
How we think, feel, and act depends on
our environment and what our bacteria
think of our environment…

26. 2014 PHYSIOLOGY
•The brain is full of immune cells
•Immune cells communicate with nerve
cells
•If bacteria control the immune
system, and the immune system has an
impact on nerve cells…

27. • Trends Neurosci. 2013 May;36(5):305-12.
•Gut-brain axis: how the microbiome
influences anxiety and depression.
• Foster JA1, McVey Neufeld KA.
[…] New studies show that bacteria […] in the
gastrointestinal (GI) tract can activate neural
pathways and central nervous system signaling
systems. […]

28. Brain Cells

29. Pesticides pose problems
for developing brains
• Curr Opin Pediatr. 2008 Apr;20(2):191-7.
• Pesticides and child neurodevelopment.
• Rosas LG1, Eskenazi B.
• SUMMARY:
• Given that the literature suggests a link between
organochlorine and in-utero pesticide exposure and impaired
child neurodevelopment, clinicians should educate parents
about prevention of exposure, especially in populations living
in agricultural areas or where household use is common.

30. Environ Health Perspect. Jul 2012; 120(7): 944–951.
Tipping the Balance of Autism Risk:
Potential Mechanisms Linking
Pesticides and Autism
Review
Janie F. Shelton,1 Irva Hertz-Picciotto,1,2 and Isaac N.
Pessah2,3

31. Rise in Autism Rates

32. In autism,
the brain is inflamed
NeuropsychopharmacologyReviews (2013) 38, 241–
242;
Neuroinflammation and Autism:
Toward Mechanisms and Treatments
Christopher J McDougle1,2 and William
A Carlezon Jr2,3
So what causes brain inflammation?

33. Microglia are activated by
body inflammation
Glia. 2013 Jan;61(1):71-90.
Microglia and
neurodegeneration: the role of
systemic inflammation.
Cunningham C.

34. Do pesticides cause body inflammation?
Ecotoxicol Environ Saf. 2009 Oct;72(7):2025-32
Effect of pesticides on cell survival in liver and brain rat
tissues.
Astiz M1, de Alaniz MJ, Marra CA.
Pesticides are the main environmental factor associated with the
etiology of human neurodegenerative disorders such as Parkinson's
disease. Our laboratory has previously demonstrated that the
treatment of rats with low doses of dimethoate, zineb or
glyphosate alone or in combination induces oxidative stress (OS) in
liver and brain[…]

35. Abnormal neurodevelopment
Nerve cell death
Neuroinflammation
Inflammation
Pesticides

36. Neuroinflammation
in other
brain disorders
Journal of Neuroinflammation 2013, 10:43
Neuroinflammationand
psychiatric illness
Souhel Najjar15*, Daniel M Pearlman25, Kenneth Alper4, Amanda
Najjar3 and Orrin Devinsky145

37. Alzheimer’s Disease
J Alzheimers Dis. 2010;21(1):1-14. doi: 10.3233/JAD-2010-
1414.
Neuroinflammation in Alzheimer's
disease: mechanisms, pathologic
consequences, and potential for
therapeutic manipulation.
Hensley K.

38. Parkinson’s Disease
Parkinsonism Relat Disord. 2012 Jan;18 Suppl 1:S210-2. doi:
10.1016/S1353-8020(11)70065-7.
Neuroinflammation in Parkinson's
disease.
Hirsch EC1, Vyas S, Hunot S.

39. Brain Proteins Pile Up
in Parkinson’s Disease
• Alpha synucleinis an
abundant brain protein
• It plays an important role in
the communication between
nerve cells
• In Parkinson’s Disease, it
piles up, causing death of
nerve cells, and eventually
loss of function

40. Pesticides Accelerate the Pile Up
of Alpha Synuclein
Toxicol Sci. 2013 Jun;133(2):289-97
Specific pesticide-dependent increases in α-synuclein levels in
human neuroblastoma (SH-SY5Y) and melanoma (SK-MEL-2)
cell lines.
Chorfa A1,and others
Studied the role of rotenone, paraquat, maneb and glyphosate
“Our data support the hypothesis that pesticides can
trigger some molecular events involved in […]
Parkinson's disease.”

41. Genetics of Parkinson’s Disease
Toxicology. 2013 May 10;307:17-23.
The interplay between environmental and genetic factors in
Parkinson's disease susceptibility: the evidence for pesticides.
Dardiotis E1, and others
Abstract
[…] genetic susceptibility either in metabolism, elimination and
transport of pesticides or in the extent of mitochondrial
dysfunction, oxidative stress and neuronal loss may predispose
individuals to PD if they have been exposed to pesticides
These individuals will be dependent on their beneficial bacteria to
detoxify.

42. Do pesticides affect our beneficial
bacteria?
•Glyphosate interferes with the shikimate
pathway, which does not exist in animals
•Good, since we are animals!! So is it safe?
•But our beneficial bacteria are not animals
•What is the effect on our gut microbiome?

43. Glyphosate Could Alter Gut Microbes
Curr Microbiol. 2013 Apr;66(4):350-8.
The effect of glyphosate on potential pathogens
and beneficial members of poultry microbiota in
vitro.
Shehata AA1, Schrödl W, Aldin AA, Hafez HM, Krüger M.
Abstract
[…] The presented results evidence that the highly pathogenic bacteria as
Salmonella Entritidis, Salmonella Gallinarum, Salmonella
Typhimurium, Clostridium perfringens and Clostridium botulinumare highly
resistant to glyphosate.
However, most of beneficial bacteria as Enterococcus
faecalis, Enterococcus faecium, Bacillus
badius, Bifidobacteriumadolescentis and Lactobacillus spp. were found to
be moderate to highly susceptible.

44. Overgrowth of
Clostridium botulinum
Anaerobe. 2013 Apr;20:74-8.
Glyphosate suppresses the antagonistic effect of Enterococcus
spp. on Clostridium botulinum.
Krüger M1, Shehata AA, Schrödl W, Rodloff A.
Abstract
“During the last 10-15 years, an increase of Clostridium botulinum
associated diseases in cattle has been observed in Germany. The
reason for this development is currently unknown.”

45. In humans: Clostridium difficile
• Pediatr Infect Dis J. 2013
Oct;32(10):1138-40.
• Clostridium difficile
infection in the
hospitalized pediatric
population: increasing
trend in disease incidence.
• Deshpande A1, Pant
C, Anderson MP, Donskey
CJ, Sferra TJ.

46. Understanding this system
•The more beneficial bacteria are impacted
(pesticides, antibiotics, C-sections, etc...)
•The more efficient your genetics need to be to
avoid harm from pesticides
•Over time, more and more people are being
affected by chemicals

47. Conclusions
Pesticides affect
•- gene expression
•- beneficial bacteria
•- inflammation in the central nervous system
•- accumulation of important proteins (alpha
synuclein)
There is a serious lack of information about the
effect of combinations of chemicals

48. THE CHOICES
•Harmless
•Harmful and worth it
•Harmful and not worth it

49. Evaluating the Trade-off
PROS
• Cost
• Time
• Convenience
• Esthetics
• Force of habit
CONS
- disruption of the immune system, resulting in
- any or all of the disease on the rise:
autism, ADHD, celiac disease, Crohn’s, ulcerative
colitis, asthma, birth defects and childhood
cancer, obesity and diabetes.