SONORA VALLEY, Mexico – The problems began ominously with the Yaqui pueblo peoples who accepted pesticide practices in the 1950s so-called Green Revolution.
The intensive industrial agricultural pesticide approach was born in the Yaqui homeland in the northwestern Mexican state of Sonora’s Yaqui Valley.
The decision whether to accept pesticides divided the poverty-stricken Yaqui community.
The valley Yaqui agreed to grow wheat treated with pesticides for export and other purposes. The other Yaqui removed themselves to the foothills, avoiding pesticide use or exposure.
Long-term research led by Elizabeth Guillette, Ph.D., of the University of Florida found compelling proof that pesticides acted as endocrine disruptors and produced negative health impacts over the years to the exposed Yaqui indigenous communities.
Endocrine disruptors or EDCs, endocrine disrupting chemicals, include DDT and other pesticides.
Guillette’s latest research finds that some pre-adolescent daughters of mothers exposed to pesticide spraying will never be able to breast-feed their babies. With others there is uncertainty. Although there is breast growth, some daughters lacked development of the mammary tissue needed to produce milk, or developed a minimal amount.
As the girls in the exposed group matured, their breast size became much larger than normal, yet they had less mammary tissue and often none at all, while the unexposed girls were normal.
“A large study using my techniques was done in India showing the exact same results,” Guillette said. She published her research findings in the journal Environmental Health Perspectives.
Other EDCs include Bisphenol A or BPA used in many plastic products and dental sealants, and PCBs. EDCs interfere with the hormones that send signals to the nervous system, reproductive system, kidneys, gut, liver and fat.
Human and experimental animal studies clearly show that exposure to certain EDCs before birth can harm the development of the nervous system, neuroendocrine function and behavior.
Population studies that show the age puberty occurs is becoming younger have raised concerns about the influence of EDCs on the rise in precocious puberty.
There is a growing body of evidence that EDCs lower testosterone levels, reduce sperm count, and cause malformations of male sex organs. Evidence in regions and countries where dramatically fewer boys than girls are being born link the skewed sex birth ratios with unidentified external influences and suggest EDCs are involved.
The study proves pesticide exposures can cross generations and have affected the daughters of mothers exposed to agricultural pesticides, Guillette said. “The results underscore the importance of women protecting themselves from manufactured chemicals beginning at birth because they stay in the body.”
“Some of the most devastating injustices [are] visited on indigenous farming communities around the world,” said the Pesticide Action Network. “High exposure to pesticides suffered by many indigenous peoples is a frequent indicator of these injustices.”
What piqued Guillette’s interest was Dr. Theo Colborn’s research, published in her book “Our Stolen Future," that brought widespread attention to hormonal changes wrought to wildlife and humans by EDCs. An anthropologist referred her to the Sonoma Yaqui Valley, where research was promising with two groups virtually identical except for their exposures to pesticides.
Study results from her first long-term study, published in the journal EHP in 1999 in which she tested Yaqui children aged 4 and 5 indicated key differences between the two populations in fine motor skills such as hand-eye coordination, balance, short-term memory, simple problem solving and even the ability to draw a human figure.
“The future of our society depends on today’s children,” Guillette said. “Preventative action to protect them from contamination must occur now, including individual, national and global levels.”